What Particular spatial, environmental and public constraints are presented for the UK wind projects’ development and success? Can they be managed?

In the UK, wind energy is one of the most promising renewable resources. Great Britain has the best wind resources in Europe and one of the best resources around the world.  Wind energy is currently the UK’s major renewable energy supplier (2.2 % of total electricity supply). According to the Committee for Climate Change [1], the UK is able to produce 31 % of its total electricity supply through offshore and onshore wind power.

However there are several issues that impede the UK to make the most out of its wind resources. First of all there is the issue of geographical mismatch. The main energy resources are cited in the North while the major energy consumption is in the south of the UK.

Another issue is transmission. Considering the fact that the energy production and demand will increase and that wind energy will play a key role along with the fact that the current grid of the country is incapable to satisfy the UK’s demand without any reinforcement, especially in the North, it is understandable that transmission is a rather significant issue.

However the scope of this blog is to identify what environmental and spatial constraints and externalities barrier the development and exploitation of the UK’s wind energy resources. Moreover it tries to identify and analyze the correlation between public attitude and wind projects’ success and development, in order to conclude on whether the above mentioned impediments could be managed.

Spatial, Topographical and Public Considerations and Constraints

The UK has a Technical potential of onshore energy around 300 TWh/yr however the practicable potential is only 8 TWh/yr, where technical potential stands for the assessment of the amount of useful energy that could be extracted from UK’s wind energy resources while practicable potential stands for the “accessible” potential. In Table 1 the data for the offshore wind potential is also shown.

Table 1 On shore and off shore UK potential [2]

This vast difference between technical and practicable potential is obviously due to several constraints that barrier the development of several wind projects. These constraints have mainly to do with the environmental impact of wind turbines, spatial and topographical issues and finally with the public attitude towards wind projects. 

Environmental Considerations

Planning of a wind energy project should always take into account the environmental impact of wind turbines. The main impacts on the environment are noise, electromagnetic interference and visual impact.

Noise: Wind turbines produce two kinds of noise: Mechanical noise that is caused from the gear box and the generator of the turbine and aerodynamic noise that is caused by the coactions of wind with the blades of the turbine. In Denmark, the maximum acceptable wind turbine noise level in open country side is 45 db (A) and 40db (A) in residential areas. In the UK there is no specific noise limit for wind turbines. The higher acceptable noise level in the UK is 68 db (A)-referring to buildings near roads. Figure 2 shows the noise levels related to distance.

Figure 1 Noise levels and distance from turbine [3]

Electromagnetic Interference: The wind turbine can severely affect the signal of radio, television or microwave if it is cited between the transmitter and the receiver, since it may reflect some of the radiation causing interference between the original wave and the reflected one.

Visual Impact: Visual impact of the turbines has to do with the local community’s attitude towards wind farms and with several other design factors. However flickering, which is caused by interference between sunlight and the blades of the turbine can be really disturbing for residents that have visual contact with the turbines [3]. 

Spatial and Topographical issues

Before the set out of the planning of wind projects several topographical and spatial issues have to be taken into account. One major constraint that could seriously affect the planning of a wind farm is the shape and the hostility of the terrain at the building site. In particular, uneven and hostile terrains can severely affect the three-dimensional wind flow and increase the mechanical fatigue of the blades; therefore they can affect the Wind Turbines’ (WT) energy efficiency and life time [4]. In Figure 7 we can see how several terrains affect the wind flow.

Figure 2 Wind Profile on several terrains

Other studies [5] are more specific on the constraint factors that affect the planning of wind farms. They categorize the constraints as topographic, wind speed and direction, land use/cover, population, access, resources, hydrology, ecology and historical/cultural resource. Table 2 accumulates these criteria and constraints.

Table 2 Criteria and constraint that affect wind energy projects planning

A recent case study for Wales [6], categorizes on a more general and clear way the constraint factors. According to this there are three major categories of constraint factors. These are namely, the absolute constraints which are general rules and facts that block the creation of a wind farm, the localized constraints which are factors that impede wind farm projects, but they have to do with local conditions, facts and rules, and finally there are electricity distribution issues and additional criteria for the area selection, which criteria that cannot be fitted to any of the above categories. These constraints factors are summarized on Table 3.

Table 3 Constraining factors for wind energy development projects

 Figure 2 displays the National parks’ area (Absolute or Ecology constraints) across the UK.

Figure 3 Land Use Restrictions [7]

Public issues and Management

A quite important factor that has to be taken into account before we start planning a wind farm is the local population on the building site. Most people do not like the idea that wind farms are about to be built near the area of their residence. There are several case studies that indicate how public attitude affects wind projects.

Quite Recently a study [8] has been conducted in the UK in order to find whether there was correlation between the decisions concerning wind farm planning made by the local authorities and the attitude of local officers, parish councils and landscape protection groups. The study concluded that the opinion of the local population and their understanding on wind farm projects significantly affected the final decisions of the local authorities.

A reasonable question rising is how did Denmark manage to become the leading Nation in Wind Energy development while the UK has better wind resources. Is it because the Danish happen to like the way wind turbines look? In fact Denmark has started to develop very early its Wind Industry. The Danish government in the early 1970s promoted very actively the development of renewable energy and strongly encouraged investors to invest on wind energy, in order to be less depended on oil. However Denmark also faced severe public constraints, which have been overcome when the government encouraged small investors- through taxation, subsidies etc.- to enter wind market, and allowed ordinary people to get involved [9]. Another study [10] on the Danish case indicates that people’s participation has played a very significant role on Denmark’s Wind Industry development.

If we take a look in the case of the UK we would see that it is different from the Danish case. According to a UK case study [11], concerning England and Wales, the local community did not have the opportunity to seriously participate or get involved with the wind projects at their residential area. In addition to that, a study on Wind energy planning in England, Denmark and Wales [12] concludes that wind projects in which public gets highly involved are more likely to be accepted and successful. 


  1. Committee on Climate Change. (2008) Building a low carbon technology-The UK’s contribution to tackling climate change. http://www.theccc.org.uk/pdfs/key%20messages%20-%2012%20page%20version.pdf
  2. Gross, R. (2004) Technologies and innovation for system change in the UK: status, prospects, and system requirements of some leading renewable energy options, Energy PolicyNo. 17, November, pp. 1905-1919, Elsevier/ScienceDirect/http://dx.doi.org/10.1016/j.enpol.2004.03.017
  3. Boyle, G., (1996) Renewable Energy: Power for a Sustainable Future, Oxford: Oxford University Press and The Open University
  4. Botta, G., Cavaliere, M., Viani, S., and Pospí, S. (1998) Effects of hostile terrains on wind turbine performances and loads: The Acqua Spruzza experience, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 74-76, pp.419-431, http://dx.doi.org/10.1016/S0167-6105(98)00038-5
  5. Baband, S., and Parry, T., (2001) Developing and applying a GIS-assisted approach to locating wind farms in the UK, Renewable Energy, Vol. 24, September, pp.59-71, Pergamon/ScienceDirect/  http://dx.doi.org/10.1016/S0960-1481(00)00169-5
  6. Cowell, R., (2009) Wind power, landscape and strategic, spatial planning—The construction of ‘acceptable locations’ in Wales, Land Use Policy,  http://dx.doi.org/10.1016/j.landusepol.2009.01.006
  7. Dartmoor National Park Authority. (2009) Maps.  http://www.dartmoor-npa.gov.uk/text/vi-map-nationalparks-citiesmotorways.gif
  8. Toke, D., (2005) D. Toke, Explaining wind power planning outcomes: some findings from a study in England and Wales, Energy Policy [Electronic], Vol. 33, No. 12, August, pp. 1527-1539, Elsevier/ScienceDirect/http://dx.doi.org/10.1016/j.enpol.2004.01.009
  9. Krohn, S., (2002) The Wind Turbine Market in Denmark,


10.  Christensen, P., and Lund, H., (1998) Conflicting views of sustainability: The case of wind power and nature conservation in Denmark, European Environment

11.  Devine-Wright, P., McAlpine, G., et al., (2001). Wind turbines in the landscape: an evaluation of local community involvement and other considerations in UK wind farm development. In: 32nd Annual Conference of the Environmental Design Research Association, Edinburgh, Scotland

12.  Loring, J., M., (2006) Wind energy planning in England, Wales and Denmark: Factors influencing project success, Energy Policy Vol. 35, No. 4, April, pp. 2648-2660, Available: Elsevier/ ScienceDirect/ http://dx.doi.org/10.1016/j.enpol.2006.10.008

Posted in Renewables | Comments Off on What Particular spatial, environmental and public constraints are presented for the UK wind projects’ development and success? Can they be managed?

Server room temperature myth busting – energy savings, disk failure and temperature

Saving energy in server rooms is often the last area tackled in large office environments. This may be due to a lack of understanding about what can be done to save energy and also due to barriers created by out of date information relating to server temperature requirements. On this point, a particular incident comes to mind. Whilst conducting an energy assessment of a large office, in response to a recent server drive failure, I saw the IT manager of the civic centre turn down the server room cooling from 18 degrees C to 16 degrees C. From witnessing actions like this and from several discussions on server room temperature, what seems standard in many IT departments is a paranoia amongst IT professionals to over cool servers in fear of disk failure. I suspect this IT manager might not have made his decision to turn down the thermostat so quickly should he have read some of the studies mentioned here.

In this post, I am going to look at some surprising studies and recent change in thought around server temperature, drive failure rates, and energy savings.

In 2008, the American society of Heating, Refrigeration, and Air-conditioning Engineers (ASHRAE) changed their recommended server room temperature and humidity range. The table of changes has been taken from ‘2008 ASHRAE Environmental Guidelines for Datacom Equipment’ [1] and is displayed below:

The changes in recommended temperature and humidity ranges have been driven by a demand to reduce energy consumption in server room cooling. ASHRAE’s changes mean that free cooling delivered to some server rooms through the use of an economiser can achieve greater energy savings by operating more often instead of energy hungry chillers. Free cooling limits the dependence on electricity driven chilling which according to a recent paper [2], contributes 33% of typical data centre electricity consumption.

But a lot of servers don’t have free cooling, so are there savings in these cases?

A study published by Dell dated 2009 titled ‘Energy impact of increased server inlet temperature’ [3] addresses this question through controlled testing of a variety of server configurations, loads, and cooling arrangements. The study highlights that there are three types of inbuilt server fan arrangements.

1. Fixed speed inbuilt cooling fans that aren’t dependent on inlet temperature.
2. Stepped speed inbuilt cooling fans that step based on server inlet temperature thresholds.
3. Variable inbuilt cooling fans that vary their speed smoothly as inlet temperature increases.

This variability in inbuilt server fan speed means additional power is drawn as inlet temperature increases for the second and third fan types listed above. This means that there is a trade-off between the reduction in chiller cooling loads and the increased requirement for inbuilt server fan cooling. The findings of the study show that depending on the server mix, cooling arrangement and load conditions, there is a sweet spot whereby minimum energy consumption is experienced. This spot lies around the 24 to 27 degree C inlet temperature. A diagram of one of the tests is displayed below:

So raising server inlet temperature to between 24 and 27 degrees C can result in energy savings, but is it safe?

Yes, a lot of evidence suggests that it is. Looking to Google’s 2007 publication ‘Failure Trends in Large Disk Drive Populations’ [4] we are presented with a study of the largest disk drive population at the date of publication. The study highlights that ‘Contrary to previously reported results, we found very little correlation between failure rates and either elevated temperature or activity levels’. In fact the study showed that there is a clear trend showing that lower temperatures correlate with higher failure rates, and that only at very high temperatures is there a slight reversal of this trend.

The following two graphs show key results of the study. The first shows the average failure rate (AFR) as a function of temperature (depicted as dots with error bars). The second graph shows the AFR as a function of temperature and drive age.

These graphs suggest that the IT manager’s decision of turning the set-point down from 18 to 16 degrees C, may result in an increase in disk drive failure. It would be interesting to have measured the inlet temperature of the drive that failed.

In this post I have tried to present a clear argument for evaluating server temperatures. I would suggest thoroughly profiling the temperatures in a server room before deciding to increase temperature set points. My recommendation would be to conduct temperature logging at several server air inlets. Do not rely on the room thermostat to tell you what is going on at the inlet of a server. It could be that whilst an air conditioning unit is set to 18 degrees C, it is incapable of actually reaching this set-point and therefore the air conditioning thermostat is a poor mechanism of measurement of actual server room temperature. In addition to this, a server room could exhibit hot spots due to poor air mixing. This could result in some servers being supplied air at inlet temperatures greatly exceeding what is recommended in this post. It would also be interesting to conduct power logging to verify the savings before and after the alterations. More case studies are needed to debunk the myths about server room temperature.

Please feel free to comment below.

[1] 2008 ASHRAE Environmental Guidelines for Datacom Equipment (Expanding the Recommended Environmental Envelope) – http://tc99.ashraetcs.org/documents/ASHRAE_Extended_Environmental_Envelope_Final_Aug_1_2008.pdf
[2] Improving Data Center PUE Through Airflow Management – http://www.coolsimsoftware.com/LinkClick.aspx?fileticket=KE7C0jwcFYA%3D&tabid=65
[3] Energy impact of increased server inlet temperature – http://i.dell.com/sites/content/business/solutions/whitepapers/en/Documents/dci-energy-impact-of-increased-inlet-temp.pdf
[4] Failure Trends in Large Disk Drive Populations – http://static.googleusercontent.com/external_content/untrusted_dlcp/labs.google.com/en//papers/disk_failures.pdf

Posted in Energy efficiency | Comments Off on Server room temperature myth busting – energy savings, disk failure and temperature

Variable Speed Drives: Is it a viable energy saving solution for commercial and industrial users?


Variable Speed Drive (VSD), also known as inverters or Variable Frequency Drives, is the term that describes the equipment used to regulate the rotational speed and hence torque of an electric motor. Basically VSDs are electronic devices that can be attached to a motor to fluctuate its speed through a control mechanism, such as temperature or pressure.

The concept is not new. Initially VSDs were developed for achieving better process control in the industrial sector and recently they have further developed as a successful solution for smaller industries and building systems due to their potential to save significant amounts of energy. It is possible to couple them with any motor exhibiting a variable load, but the most usual applications are pumps and fans that operate in industrial processes or as part of heating, ventilation and air-conditioning systems (HVAC).

Millions of motors are used by commercial and industrial users around the world, which, according to ABB Group, account for more than 65% of industrial electricity demand. During the design phase of a mechanical project, the exact motor loads is often unknown, this in turn leads to motor selection being oversized to safely meet the maximum system requirements. This leads to energy wastage as the motor operates outside its optimum zone. In order to prevent this and to achieve more control over operations and processes, many commercial and industrial users turn to airflow control vanes, two speed drives and other solutions. These solutions however are inefficient compared to VSDs from an energy saving perspective. In the following lines we shall describe, how VSDs can save energy and money for commercial and industrial users.

VSDs operation and energy saving principles

A VSD can reduce energy consumption of a motor by as much as 60%. This is due to the fact that they control the speed of the motor by altering the frequency and therefore the power supplied to it. Even a small reduction in the rotational speed can give significant savings in the energy consumed by the motor.

The next step is to understand in simple terms how altering the rotational speed of a motor can save energy. In order to do so we take a closer look to the so called affinity laws which are used in hydraulics to express relationships between the variables involved in the operation and performance of rotary machines such as pumps and fans. The following formulas apply to both axial and rotary flows, and are used to express the relationship between head, volumetric flow rate, shaft speed, and power. If we consider that the diameter of the impeller stays the same we have the following:


  • Q is the volumetric flow rate (e.g. CFM, GPM or L/s),
  • N is the shaft rotational speed (e.g. rpm),
  • H is the pressure or head developed by the fan/pump (e.g. ft or m), and
  • P is the shaft power (e.g. W).

Now let’s come back to the declaration that only a small reduction in the rotational speed can significantly reduce the energy consumed by the motor. Let’s assume that the rotational speed, N1, of an industrial pump is reduced by 20%. This should mean that:

If we combine relationships (3) and (4) we get the following expression:

Consequently, a 20% reduction of the rotational speed leads to a 49% power requirement reduction. The explanation for the aforementioned relationships and therefore the energy savings achieved by VSDs lies in the pressure difference across the impeller. When less pressure is produced, less acceleration of air or fluid across the impeller is required. It is the simultaneous reduction of acceleration and pressure that multiplies the savings.

At this point we should clarify to the readers that a VSD does not constrain the rotational speed of a motor to a certain level in order to achieve energy savings. This should mean that the power input would be insufficient at several times. The main advantage of a VSD is that it can alter the rotational speed of a motor so that the power input can match the duty required and this way diminish energy wastage. In the graph below we can see in a simplified way how a system changes its operation after the deployment of a VSD.

In the case where the system operates without the use of a VSD, the power input remains constant regardless of changes in the load output over time, because the controlling device is a throttle or damper. When a VSD is used we the input power is tailored to suit the output duty. The throttle or damper is eliminated with savings in maintenance.

As we have already mentioned VSDs are not the only way to control an operation, therefore the reader may wonder why an industrial or commercial user should prefer this solution over others. The following graph shows how much more energy is saved by VSDs compared to that saved by traditional flow control methods that do not vary rotational speed.

Figure 1 Energy saved by VSD compared to traditional flow control methods

Building system saving example

In the following table we give an example for the energy and cost savings that could be achieved by using a typical VSD for a fan operating in the HVAC system of a hospital. We assumed that the fan is working for 15 hours a day and 7 days a week. The cost of electricity is considered to be £0.075 per kWh. Finally, we assumed that the savings achieved were around 25% which is similar to the savings observed by the HVAC system of Charing Cross hospital after the installation of VSDs.

From the above table it becomes evident that for large buildings where motors operate frequently the payback period could be really short.

Common applications and Summary

VSDs can provide significant energy savings in applications for Industrial users, HVAC systems and Leisure and Commercial buildings. Listed below are some typical applications for each sector:

Typical applications for Industrial users

  • Primary and secondary air fans
  • Boiler feed, chilled water, river water pumps

Typical HVAC applications

  • Variable air volume – air conditioning systems
  • Supply  fans
  • Exhaust air systems, such as dust extraction, paint shop exhaust, and fume cupboards
  • Heating and chilled water pumping, duty/ standby pump sets
  • Refrigeration systems
  • Some modern compressors and chillers

Typical applications for leisure and commercial buildings

  • Swimming pool pumps and ventilation
  • Sports halls, gymnasiums and dance studios
  • Fountains
  • Ice rinks

To wrap up, VSDs are one of the most cost efficient solutions that can reduce energy consumption, carbon emissions and electricity bills. Insulating a building gives a thirty year return of investment, while a VSD usually pays back an investment in less than two years. At this point it should be clarified that the good operation of a VSD is highly depended on the controls and sensors used, however this should be the issue of a future blog.

[1] ABB Drives and Motors Catalogue 2011,  ABB standard drives for fans and pumps

[2] The calculation has been made using the online GE motors calculator, http://www.gemotors.com.br/calculator/index.asp#f

Posted in Energy efficiency | Comments Off on Variable Speed Drives: Is it a viable energy saving solution for commercial and industrial users?

The UK Housing Context

Why retrofit technology is important to the UK

The UK government is committed, via the Climate Change Act and the Carbon Budgets, to a 34% greenhouse gas emissions reduction target by 2020, and 80% by 2050, based on 1990 levels (as well as a 4th Carbon Budget target, soon-to-be-announced by Chris Huhne [update: announced 17/05/2011 as 50% reduction target by 2025]). How should we set about achieving these targets? Where should we focus our energy and attention?

This blogpost will obviously not attempt to answer these questions fully, rather, it will take an example – heating in the domestic sector – in order to explain why more effort should be undertaken on reducing the energy consumption of existing buildings than that of new ones. We will therefore first look at some energy consumption statistics, then compare a few studies, in the hope of convincing you that retrofit technologies are far more important than efficient new build, when it comes to meeting carbon emissions reduction targets.

While much popular attention is devoted to the reduction of emissions in electricity production – whether through wind turbines, solar panels, nuclear power stations or carbon capture and storage – this overlooks two very important aspects of the energy landscape: heat, and energy efficiency.

Energy efficiency represents the most viable means of reducing carbon emissions, because of the lower greenhouse gas abatement costs involved; studies by both the International Energy Agency and McKinsey, have shown this. Heat, meanwhile, is the single largest use of energy in developed (OECD) countries, claiming 37% of total energy consumption, as shown on the pie chart above.

Just over half of this heat is used in buildings: commercial & public buildings or residential dwellings, with the residential sector using nearly twice as much heat as the commercial & public sector. Clearly, most of this heat is used as low grade (less than 100°C) space or water heating.

The pie chart below shows the latest available final energy consumption data for the UK, per sector. The domestic sector, which represents just under a third of total UK energy consumption, uses 84% of its energy to provide heat, of which the vast majority is for space or hot water heating. It is this UK domestic sector, which predominantly uses energy for heat purposes, which we will use as an example to explain why the retrofit market is so important.

There are currently some 26 million dwellings in the UK, using an average of between 18,000 and 20,000kWh per year for heating, depending on the severity of the winter [1], [2], [3]. Of these 26 million, the vast majority are expected to still be standing in 2050. A review of 5 different residential sector energy models [4] suggests that between 85% and 97% of the dwellings already built in 2006 will remain in 2050. What’s more, by considering the amount of new build that is expected to occur between 2006 and 2050, these studies predict that between 66% and 74% of the 2050 housing stock has already been built by 2006.

What this means in terms of the age of houses currently built is depicted in the graph below. This shows, for England, the proportion of houses that were constructed in a specific period (blue line), and a cumulative curve showing the total percentage of homes built during or before a specific period (red line). Using this curve as representative of the whole UK, we can see how 84% of UK dwellings were built before 1985, of which 24% were built in the 20 year period between 1965 and 1984, and the remaining 60% are at least a half-century old (give or take). Similarly, it shows how some 40% of UK dwellings were built before the end of the Second World War and that there has been limited recent construction; only 15% of dwellings were built in the last 25 years.

In short, this all serves to highlight an important cultural aspect in the UK housing market: despite significant construction in the first 40 post-war years,  older properties seem to be valued above newer properties, explaining the combined phenomena of high proportion of retained pre-war properties in the housing stock and a lack of recent construction.

In energy terms, however, this is not positive; older properties are typically very poor in terms of energy efficiency, and therefore require more energy (especially for heating). For example, they are more likely to have uninsulated cavity or solid walls and single glazing (never mind draughts and leaking roofs!). This leads to the following obvious fact: these properties are shown to be too difficult and expensive to retrofit to new build standards. New build will be required to be “zero carbon” from 2016 onwards; this will ensure that emissions associated with the 1/3rd of 2050 dwellings that don’t already exist are minimised – certainly very important, though ‘all’ it achieves is to avoid emissions growth, as most existing buildings will remain!

One study [6] calculates that there is a global potential to cost-effectively reduce emissions in the residential and commercial sectors by approximately 29% of the projected baseline emissions by 2020. Moreover, for only a few percent of the total cost of residential buildings, thermal envelope (the part of the building shell responsible for insulation) improvements can reduce heating requirements by a factor of two to four [6]. Nevertheless, two building energy models calculate that even in 2050, existing houses will have a combined space and water heating demand that is more than twice as large as that for new houses [4], with space heating energy use only reducing by 40% [5].

So, this all indicates that while retrofit insulation measures are important and feasible up to a certain point, it is uneconomical or technically challenging to bring existing dwellings’ thermal performance to a standard similar to that of new build.

Given that even these insulated existing dwellings will still have a greater heat demand than new build, the economic, energy and carbon performance of any potential future heating device is of relatively greater importance to the existing housing stock. And because there will be many more old, inefficient dwellings than new ones, even by 2050, the opposite is true as well: the existing housing stock should be of greater importance to future heating technologies. So, heating systems such as heat pumps, biomass boilers or combined heat and power systems have to be specifically designed for the technical challenge that retrofit properties pose. (The same applies to retrofit insulation methods, but this is already done to a far greater extent).

Hopefully, I have managed to convince you of the importance of retrofit to reducing emissions in the UK residential sector. Similar arguments apply, in a broader sense (i.e. including electrical demand, such as lighting), to the commercial sector, where one study suggests only 30% of currently existing buildings will be demolished by 2050. While retrofit is often considered cost-effective low-hanging fruit, its hassle factor is high (i.e. it is often only cost-effective once you know what your specific retrofit solution should be and, even then, the installation work can be difficult and very disruptive to the resident). There are few one-size-fits-all solutions in the retrofit space. Large-scale deployment will therefore require business models that can get around or deal with this issue, as well as residents who are open to the idea and understand that they stand to gain in both comfort and financial terms!

Let us hope that the Renewable Heat Incentive and the Green Deal will enable this.

[1] H. Singh, A. Muetze, and P.C. Eames. Factors influencing the uptake of heat pump technology by the UK domestic sector. Renewable Energy, April 2010.

[2] A.D. Hawkes and M.A. Leach. On policy instruments for support of micro combined heat and power. Energy Policy, August 2008.

[3] D.P. Jenkins, R. Tucker, and R. Rawlings. Modelling the carbon-saving performance of domestic ground-source heat pumps. Energy and Buildings, June 2009.

[4] Ramachandran  Kannan  and  Neil  Strachan. Modelling the UK residential energy sector under long-term decarbonisation scenarios:  Comparison between energy systems and sectoral modelling approaches. Applied Energy, April 2009.

[5] Brenda Boardman and University of Oxford. 40% house. Environmental Change Institute University of Oxford, Oxford, 2005.

[6] Bert Metz and Intergovernmental Panel on Climate Change. Intergovernmental Panel on Climate Change. Climate change 2007: mitigation of climate change: contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge; New York, 2007.

Posted in Energy efficiency, Greenhouse gas targets | Tagged , , , , , , , | Comments Off on The UK Housing Context

Voltage Optimisation

Voltage Optimisation (VO) is a method of reducing electricity bills in commercial premises. It is not a new concept but recent improvements to the technology have seen better systems in the market place.

What is Voltage Optimisation?

The way VO works is simple. In 1995 the UK’s electricity supply was set at a nominal 230V (plus 10% or minus 6%). Therefore the National grid supply can vary from 216V to 253V but averages at around 240V. On the other hand most electrical equipment is designed to work most efficiently at about 220V. Supplying more than 220V to most electrical equipment wastes energy and can shorten its operation life.

VO equipment is installed between the main electricity feed and the building’s power supply and acts as an interface to reduce the voltage of electricity fed to machinery and equipment, for example from 242 V to around 220 V. Essentially VO systems match the power supply to power demand resulting in reduced electricity bills and carbon emission savings. Theoretically energy bills can be reduced by as much as 25% but evidence suggests that most systems achieve savings between 12 and 18 %.

 Which system?

The VO market has grown in recent years offering different systems that work in slightly different ways.  Basic VO systems step down supply by a pre-fixed amount and deliver savings of around 8%. These work well until mains voltage drops. The VO will continue to lower voltage, though potentially to unusable levels or a worst case scenario of cutting the power supply.

More up to date systems use logic controlled intelligence which monitors the incoming power supply and removes the risk of power shut down. These systems can deliver up to 15% or more of savings. Some VO systems also incorporate an automatic bypass allowing it to switch to bypass mode should it detect a mains supply issue. These units can also be serviced without cutting the power supply to the building. Most VO installations will require an annual service.

 Fixed output voltage stabilisation is a further enhancement that allows output to be fixed, typically at 220V, giving greater savings. One other thing to bear in mind is that the mains supply to the building may reduce over time if new facilities are added to the existing supply, so incoming voltage could drop naturally and having a fixed ratio system in place could cause problems.

Does it work on everything?

The energy savings expected can vary from 0 to 18%. The savings depends on the types of loads being supplied via the VO unit. In general VO achieves more substantial savings on inductive loads and less on resistive loads. The following chart gives an indication of which loads are best suited to VO.

Should you invest in VO?

Reasonable savings can be achieved and VO is a good method of reducing electricity bills and extending the life of equipment and machinery. The cost of the system will depend on the electricity load of the building. When considering investing it is important to understand how each of the systems work and to research what’s on offer, asking pertinent questions and requesting proof of fuel bill savings. The aim is to find a system that provides a good level of saving but also improves the quality and reliability of the supply.

Please leave feedback about your experience with VO technology.

Posted in Energy efficiency | Comments Off on Voltage Optimisation

Should urban and rural local authorities have the same CO2 reduction target?

Following on from my Blog entry ‘Setting carbon reduction targets – What does 34% mean for housing, workplaces and transport’, this blog adds to the discussion around the suitability of different Local Authorities to uniform target setting, I’ll be asking the question: Should Local Authorities with different types of carbon emission reducing potentials, aim for the same reduction target?

The idea for this blog came about from modelling carbon scenarios for local authorities in the UK. We have found increasingly that modelling the LCTP onto rural authorities based on a scaling factor derived from local and national resource potential has resulted in less action needing to be taken in rural authorities than from the same process applied to urban authorities. The results of several gap analyses we have undertaken has shown that on the whole, rural authorities exceed the national targets whilst more urban authorities fall short of the same target.

The following table shows what I see as the Urban, Rural, and Shared Strengths for implementation of National Policy.

District Heating Potential – The DECC methodology for District Heating potential uses a figure of 3000kW of heating per square kilometre to determine if an area has district heating potential. This criteria means that urban environments have much more application for this technology.

Combined Heat and Power (CHP) – This is largely linked to district heating potential but its application is also suitable for single buildings such as hospitals or leisure centres. CHP can be gas or biomass fuelled. Currently there is less suitability for biomass in urban environments because of fuel storage and air quality issues.

Wind Resource – If modelling onshore renewables locally, rather than including them in the decarbonisation of the national grid, there is much more resource for wind in more rural authorities.

Virgin Biomass Resource – Non waste product biomass such as straw or short rotation Coppice is more abundant in rural authorities.
Ground Source Heat Pumps – Due to space constraints in cities, the potential for ground source heat pumps are greater in less dense rural areas.

Biomass Boilers – In part due to space constraints, part due to increased suitability for off gas network properties, a more dispersed effect on air quality and location closer to the source; Biomass boilers have more potential in rural authorities.

Solar Photovoltaic – The DECC methodology for estimating solar photovoltaic potential shows higher suitability rates for houses compared with flats.

Solar Thermal – Similar to Solar Photovoltaics, there is more suitability for domestic hot water and solar thermal air heating with housing rather than flats and terraces.

Waste Stream Biomass – The potential for this is more linked to a per capita basis, but perhaps there is still more potential in rural areas due to exported sewage processing and factory waste like abattoirs. I am uncertain on this point. I have listed this under shared strength for the moment.

Decarbonisation of the National Grid – Assuming that Electricity usage is evenly distributed per capita between rural and urban centres, the savings from decarbonisation of the grid should be even across the board.

Access to funding and larger governance – Economies of scale are beneficial in running projects and programs. We often see smaller rural authorities tackling large portfolios with limited resources whereas city authorities have the luxury of breaking roles into multiple specific roles. This means that larger governance is more able to access funding because they have the capacity to do so. It is also the case that some EU funding is looking for large projects which smaller rural authorities would need to team up to access.

I think target setting is complicated and affected by many factors.

It seems to me that it would make sense for more governance in the places where more carbon saving resource exists. This would mean more money per capita spent in rural settings where our modelling shows that the LCTP arguably more potent.
Should Local Authorities with different types of carbon emission reducing potentials, aim for the same reduction target? I would say ‘’yes’’. Local Authorities should first undergo an analysis of what the national Climate Change Act targets mean in their area by sector. This in turn should align through the LCTP with local resource potentials.

I invite responses to anything that I have written here – feel free to leave a comment in the section below.

Posted in Greenhouse gas targets | Comments Off on Should urban and rural local authorities have the same CO2 reduction target?

Choosing the best strategy for energy and carbon reduction in medium and large organisations

Energy Audits, Energy Service Companies (ESCo), Partnered Energy Efficiency Programs (PEEP)

The intention of this blog is to start some discussion on the best way for medium to large business and government to reduce their built environment carbon emissions. Each method discussed involves the analysis of buildings, project management, and funding. The inspiration for this blog came about as a result of a perceived increase in the number of Energy Services Companies (ESCO) offering free energy audits with guaranteed Energy Performance Contracts (EPC).

The energy/carbon saving options and how they relate to analysis, management and funding are summarised in the graphic below. (click diagram to enlarge)

I have developed the following decision tree to help guide an organisation to make an informed decision about what energy reduction strategy is best suited to the organisation in question. Once the decision meets a red box, exit the diagram for the description detailed in the corresponding section. (click diagram to enlarge)

A. Energy Services Company (ESCo) audit with guaranteed Energy Performance Contract (EPC), combined with a behaviour change program. This is a good solution for an organisation that does not have a lot of time left in their premises, whether rented or owned, but wants to reduce their carbon footprint and operational costs. Some companies offer free audits with free implementation through a pay as you save mechanism.

B. Independent energy audit with outsourced project management (no pay as you save or EPCs). This option gives a good degree of control to the environmental officer whilst relies much less on in house project management/organisation skills and energy efficiency knowledge. The independent audit does not hide behavioural change options that might be discarded under an ESCo type arrangement. Outsourced project management gives access to skilled contractors and correct specification of energy efficiency works. This option prefers not to pursue pay as you save schemes or EPCs because you feel the disadvantages out-way the advantages for your organisation.

C. Independent energy audit with outsourced project management (a decision about pay as you save schemes and EPCs can be made after the audit findings have been given). This option gives a good degree of control to the environmental/facilities officer whilst relying much less on in house project management/organisation skills and energy efficiency knowledge. The independent audit does not hide behavioural change options that might be discarded under an ESCo type EPC arrangement. Outsourced project management gives access to skilled contractors and correct specification of energy efficiency works. As part of the outsourced project management, pay as you save schemes can be investigated to reduce capital expenditure where appropriate.

D. Independent energy audits with in-house project management (no pay as you save or EPCs). This option is suited to organisations that have a strong green facilities management or environmental management arm. The independent energy audits give a good degree of control to the management in making recommendations that are in the best interest of the client organisation. With the project management fees absorbed by the organisation, there may be more budget for a more advanced energy audit, or more budget available for capital energy efficiency works. This option prefers not to pursue pay as you save schemes or EPCs because you feel the disadvantages out-way the advantages for your organisation.

E. Independent energy audits with in-house project management (a decision about pay as you save schemes and EPCs can be made after the audit findings have been given). This option is suited to organisations that have a strong green facilities management or environmental management arm. The independent energy audits give a good degree of control to the management in making recommendations that are in the best interest of the client organisation. With the project management fees absorbed by the organisation, there may be more budget for a more advanced energy audit, or more budget available for capital energy efficiency works. As part of the outsourced project management, pay as you save schemes can be investigated to reduce capital expenditure where appropriate.

F. Independent energy audit with outsourced project management. This option gives a good degree of control to the environmental officer whilst relies much less on in house project management/organisation skills and energy efficiency knowledge. The independent audit does not hide behavioural change options that might be discarded under an ESCo type arrangement. Outsourced project management gives access to skilled contractors and correct specification of energy efficiency works. In this option it is not recommended that pay as you save schemes are pursued. The significant budget and commitment to staying at the premises means that it is better for the organisation to invest its own capital to fully appreciate the cost savings. This gives the environmental and facilities management the most flexibility over the site and does not necessarily prioritise expensive control solutions over behavioural ones.

G. Independent energy audits with in-house project management. This option is suited to organisations that have a strong green facilities management or environmental management arm. The independent energy audits give a good degree of control to the management in making recommendations that are in the best interest of the client organisation. With the project management fees absorbed by the organisation, there may be more budget for a more advanced energy audit, or more budget available for capital energy efficiency works. The significant budget and commitment to staying at the premises means that it is better for the organisation to invest its own capital to fully appreciate the cost savings. This gives the environmental and facilities management the most flexibility over the site and does not necessarily prioritise expensive control solutions over behavioural alternatives.

H. Partnered energy efficiency program (PEEP). PEEPs build a close working relationship between the client organisation and the energy efficiency consultancy. In some cases this can involve embedding an energy efficiency engineer into a large business, but usually government authority, to provide on-going energy efficiency services. The roles of partnership are primarily focussed on conducting energy audits, and project managing prioritised measures. In addition to this the consultancy might provide logging services for mechanical and electrical equipment for before and after retrofit verification, proving technologies through trial installations, as well as providing access to expert advice through the experience and knowledge of the engineering company. PEEPs require a high degree of trust, good engineers, a focus on achieving fast robust results and a high degree of flexibility and responsiveness to change. The partnership can have milestones and performance reviews set to measure progress.

Posted in Energy auditing | Comments Off on Choosing the best strategy for energy and carbon reduction in medium and large organisations

Setting carbon reduction targets – What does 34% mean for housing, workplaces and transport?

The Low Carbon Transition Plan (LCTP) is the central government plan for meeting and exceeding the carbon budget targets outlined in the Climate Change Act. Although it was published before the election the policies within it have largely been retained by the Coalition Government. The plan breaks down the anticipated savings by sector and year from 2008 through to 2022. So what are the targets by sector? This blog highlight some issues that should be considered when setting targets.

Carbon Descent is developing a service to assist Local Authorities in analysing what their targets mean on a sector by sector basis. Should this be of interest, we would be interested in hearing from you.

The following chart from the LCTP shows the 3rd budget period (2018 – 2022). Each budget period consists of five years of cumulative emissions. Note that the vertical axis is interrupted between 0 – 2,400MtCO₂e.

The chart shows that to meet the 2020 target (Carbon budget 2018-2022) the accumulative 5 years of emissions need to reduce from 2964MtCO₂e down to 2544MtCO₂e. The 2964 figure represents the first carbon level for years 2008 – 2012. The savings required from the first budget period in order to meet the third budget are displayed as the second column ‘savings required’ (420MtCO₂e). The plan has built in contingency so that the UK does not just meet the 34% target, it exceeds it. This is depicted in the third column ‘savings from plan’ (459MtCO₂e). The final column gives the remaining emissions of meeting but not exceeding the target.

The plan states that UK emissions for the year 1990 were 777.4MtCO₂e. If we take 5 years of 777.4 we get the value 3,887MtCO₂e. The Carbon Budget 2018 – 2022 of 2544MtCO₂e then represents 65.4% of this baseline. Put another way, 2544MtCO₂e is a 34.6% reduction on a 1990 baseline not 34% as quoted throughout the plan. Furthermore, an additional 39MtCO₂e from column 3 in the above chart gives a remaining carbon budget 2018 – 2022 of 2505MtCO₂e. This equates to 64.4% of the baseline, or put another way, represents a 35.6% saving from 1990.

What does the overall UK reduction target mean by sector?

I have put together the following table informed by the LCTP to show the budgeted emissions by sector.

In the year 2008, the total net UK carbon account is 603.4 which represents a 22% saving and is in agreement with the first budget level (2008 – 2012).

What targets should local authorities aim for? Is it 34%? Well, following the above rationale, I have outlined some considerations for deciding.

The first consideration is that the LCTP is not aiming to bring about 34% savings but rather 35.6% in order to allow for a margin of error in their assumptions/calculations/estimates. This is not a big issue though, it simply adds some contingency for meeting a 34% target.

The second thing to consider is that when using the NI186 dataset as a baseline, this omits the land use and land use change (LULUC), EUETS emissions from heavy industry that are not accounted for under domestic and non domestic point source electricity emissions, Diesel Rail, and Motorways.

• In the case of LULUC, the LCTP has only budgeted to reduce this sector by some 0.6%.
• In the case of Power and Heavy Industry, larger than average savings are achieved in this sector. The NI186 accounts for 70% of EUETS emissions in 2008 through domestic, commercial and industrial electricity use. 30% is excluded from the NI186 dataset from column c ‘Large Industrial Installations’. This 30% mainly represents heavy industry that does not supply electricity to the domestic, commercial and industrial sectors.
• For Diesel Rail and Motorways, these are covered in the LCTP under transport. The NI186 accounts for 76.5% of these emissions in 2008.

Taking the above three points into account, the target could shift from 35.6% up to 41.1% on 1990 levels.

The last consideration is that because the LCTP gives savings across the whole of the UK, this might not mean that these savings are equally distributed between every LA. What should each LAs target be? This is a more complicated question that we would be happy to provide some consultancy on.

Carbon Descent is developing a service to give local government better insight into county, unitary, district, and regional carbon reduction targets. If you are interested in having your authority’s target broken down into sector based targets, or if you would like to know what your authority’s allotment of the national targets are, we would be interested in working with you.

Posted in Greenhouse gas targets | Comments Off on Setting carbon reduction targets – What does 34% mean for housing, workplaces and transport?

Global Cycle Solutions interview, Tanzania

Interview with Jodie Wu, President and CEO, and Daniel Mokrauer-Madden, Logistics Manager
27 December 2010

Interviewers: Linton Hartfield and Felicity Hartfield

Jodie and Daniel outside their office in Arusha

LH: What is Global Cycle Solutions?

JW: GCS is a social enterprise and what we are doing is developing bicycle add-ons that you can put on any bicycle, to turn the bicycle into an income generating device or something which helps ease lives. In Kiswahili we say kurahisisha kazi.
(Jodie points to the A4 print out on the wall)

JW: The mission statement of GCS, ‘To improve village life through affordable quality technology that helps village life’, essentially.

LH: Can you tell us who is involved, a bit about your background and how you have come to this point?

JW: OK, So it has a very evolving history, I guess it starts when I studied Mechanical Engineering at MIT and I went through the whole “I want to be an engineer” and I took my internships at big corporations, and I was like “I don’t want to be an engineer anymore” (laughs). After that I took a course called DLAB, which Daniel was involved in as well. It’s run by an inspirational lecturer at MIT called Amy Smith who has 4 years of experience working in Peace Corps in Botswana.

DM: The D in DLAB stands for 3 things – development, design, and dissemination.

JW: That was my inspiration in the sense that this was the first class that I had taken where I could actually apply my engineering skills in a different context, working with community partners. At the time there were about 25 students who all went to different countries, and I chose to go to Tanzania. I wanted to do something that was very tangible and hands on, so I chose to introduce the maize sheller which is modelled off a device that was used in Guatemala by another NGO called MayaPedal. I brought it into Tanzania hoping it would fit right in but found that it was unsuitable here in the sense of, It was great for shelling maize but the problem was you only use it 2 or 3 weeks per year if you use it at your own farm, it is really heavy, and what makes it expensive is not the technology itself, but everything supporting the technology, like a seat that adjusts, and the flywheel on the back and cutting up a bicycle if you wanted it to be pedal powered. People in Tanzania couldn’t use this device, so why don’t we just put this device on a bicycle, don’t even cut up a bicycle, don’t worry about all the other infrastructure, so they use it during the season and just take it off the bike and use the bike for the rest of the year. The whole concept was a year round device where harvesting technologies would be added right on. That is where the idea came from and I then took it through the next phases of design and dissemination and I put together a team. And then we won some competitions and cash prizes plus were offered some private investment and I really thought this could work. We began here in August 2009 and we are all here indefinitely until we get it off the ground.

LH: This might be a good opportunity to talk about the products.

JW: So we have three products: the maize sheller and the mobile phone charger which both work off a bicycle, and by popular demand another mobile charger which charges from a motorcycle or off other batteries.

The maize sheller which fits onto the back wheel of a bicycle

The phone charger. Locals without access to a power find ways to charge their phones like paying shop keepers or barbers. A typical charge is 300 Tsh for 20 mins. The average daily wage is 3000 Tsh.

LH: What were people doing before using the maize sheller?

JW: There are three main processes. One is doing it by hand, so taking each kernel off by hand.

DM: It’s a really tiring process, if you are at it for 8 hours a day your thumbs get incredibly sore. Like repeatedly texting but for an entire day.

JW: It’s a very time consuming process. The second process is putting the maize into a bag and beating the bag for several hours, and that is the most common practice in Tanzania. It actually damages the bags as you can imagine all the cobs trying to come out and creating holes in the bag. It also damages the maize – the maize is a yellow shell filled with white powder, when you beat it the white powder comes out and that is also a big attraction to maize weevils and other animals.

FH: And you said there is a third process?

JW: And the third type, which is used mainly in Kenya, is using a table made of wooden slats upon which the maize is laid and then beaten. It’s a faster process and the maize is less damaged because once it is shelled it falls between the slats. And also no bags are damaged in the process.

LH: How many people in Tanzania are beating maize in sacks?

JW: It is approximately 70%, and this corresponds with about 70% of farmers who are still using hand hoes, they don’t have tractors. There is also another automated shelling process that is powered by tractors called a power take off. Even so, there are still farms with tractors that can’t afford the 1 million Tanzanian Shillings (approx. $1000 US) for this unit, and it also is not worth hiring the tractor for smaller crops of say 20 sacks of maize.

LH: How many sacks can you beat per day?

DM: It depends on how many people come to your farm, but some people have said they can beat up to 8 sacks per day, and some people pull their children out of school during harvest time to complete this process.

LH: So you have met the market half way, your product lies in between the large scale tractor process and the sack beating method?

JW: Right, exactly. What we were trying to create with the bicycle was a product that families could use. The idea was, just like the tractor, it could travel to different farms for use, so it could service a community. With the bicycle attachment you can shell 15 sacks of maize per day without damaging the maize. For the entrepreneur, he can make enough money to purchase a bicycle and the maize sheller in one month. For the farmer, the unit is not too expensive to purchase themselves. It is a win, win, win situation: a win for the retailer, a win for the entrepreneur, and a win for the farmer.

FH: How have you raised the profile of the company and the products?

DM: We have done some radio promotion through a local radio station. One of our biggest advertisement pushes has been through fairs and exhibitions. We have gone out and set up booths at major agriculture fairs which they have about 4 or 5 of per year in different major cities around Tanzania. We sell our products through TFA, which is a chain store agriculture distributer ‘Tanganyika Farmers Association’ and they have stores in a lot of major cities. This helps us with access to people all across the country.
One of the major pushes though has been through developing partnerships with community organisations that have strong links with the communities, NGOs that are trying to work with a development technology portfolio, some micro finance institutions. One of the lessons we have learnt with partnerships is that you are going to have about 9 failures with every 1 success. It really is about being persistent and determined.

JW: Our sales manager is working from Dar es Salaam with major sponsors, and we have reps working in the field with communities and community groups like credit cooperatives and community banks. So overall there are two approaches – one bottom up and the other top down. And we hope that what we are doing will meet somewhere in the middle.
FH: What areas of Tanzania are using the maize sheller? Where do you see the GCS products spreading to?

JW: We have the three products across Tanzania. The maize sheller is used predominantly in the highlands where maize production is high, and it’s a main staple of East Africa.
We have offices here in Arusha, in Dar es Salaam, Moshi, and Dodoma. We’ love to spread across East Africa and other areas of the world. We’re growing slowly and have learnt a lot since being here, and have expanded from one product – maize sheller – to three. We realised we couldn’t rely on the sheller alone considering that last year Tanzania had the worst drought for 30 years. The chargers and sheller have very different markets and are in different stages of development so adapting to that has been a challenge.

FH: What are the plans for the future?

JW: We are currently working on a rice thresher and a maize grinder, to complete the whole maize life cycle. And we’ve just started a new initiative which stems from the belief that all our products should be made with locals, we call it co-creation. We are trying to build innovation in local communities with community capacity building and workshops for people to develop their own ideas.

DM: Co-creation is about locals teaming up with staff from GCS to assess the needs of their community and come up with a solution together. It really is about local people developing the products they want, ones that fit their constraints. We’re hoping to launch our pilot program in January and from there we are going to see what we can do.

JW: GCS is in the first stage of a start-up: piloting a product, and proving that we can be profitable. And then the next phase will be about scaling, and expansion. But of course we want to get it right in Tanzania before we expand properly into other countries.

For more information, go to Global Bicycle Solutions

Posted in Interviews | Comments Off on Global Cycle Solutions interview, Tanzania

What emissions have UK Local Authorities been measuring against? NI186

The Climate Change Act 2008 establishes a long-term framework to tackle climate change. The act aims to encourage the transition to a low-carbon economy in the UK through unilateral legally binding emissions reduction targets. This means a reduction of at least 34% in greenhouse gas emissions by 2020 and at least 80 percent by 2050. A fourth budget period has recently been proposed which would see reductions of 60% by 2030.

In this blog, I have tried to represent the broad interplay between UK and international emissions as well as the various national CO₂ datasets in the diagram below:

National Indicator 186 Context

I am now going to explain the diagram and each component.

The dotted box on the right contains all the emissions that are covered by the Climate Change Acts 34% target for the third budget period. The figure shows that international shipping, international aviation, and embedded emissions (in the way of imports) are not covered under the 34% target. This figure shows NI186 as a sub set of the LACO₂ data set. Below the LACO₂ data set is the corresponding LACO₂ equivalents. The figure highlights the issue of embodied energy/CO₂ of imports and exports, the need for international cooperation in tackling emissions such as International shipping and Aviation, and Local Authorities responsibilities in the broader context. The diagram is not to scale.

NI186 – This dataset is a subset of the LACO₂ emissions which covers CO₂ emissions only. This set of emissions has been reduced to exclude emissions from sources which it is felt that LAs have minimal influence over. The omitted locally produced emissions are motorways, diesel rail, emissions covered under European Union Emissions Trading Scheme (EUETS) besides point source electricity, and Land Use and Land Use Change (LULUC). Until recently, Local Authorities were required to report annually against the NI186 indicator. Even though this requirement is no longer the case, the indicator is used widely to underpin local carbon abatement strategies, participating Covenant of Mayors obligations, and the Friends of the Earth ‘Get Serious’ campaign. It also generally forms the basis for VantagePoint carbon scenario modelling – though we have used other baselines.

LACO₂ – This data set covers all the emissions in the NI186 plus motorways, diesel rail, EUETS, and LULUC. It is a CO₂ only data set so does not contain any of the other six green house gasses (CO₂ equivalents) such as methane and nitrous oxide. Approximately 70% of the EUETS emissions are covered in the NI186 emissions under domestic, commercial and industrial point source electricity usage. The remaining 30% is included in LACO₂ and refers to other large emitters participating under the EUETS.

Equivalents – This is the part of the local emissions which are not included in the above two datasets. There are a few reasons for this. Firstly the CO₂ component makes up a large majority of the emissions reported under the above two indicators, secondly, in general when CO₂ emissions are reduced through energy efficiency, energy conservation, or renewable energy generation, the equivalents are reduced, and finally, these emissions require more effort to measure than CO₂ alone.

Aviation – The UK national atmospheric emissions inventory shows that emissions from domestic and international aviation assigned to the UK (on the basis of bunker fuel sales) accounted for some 5.5% of UK CO₂ emissions in 2008. 90% of these emissions will now be covered under the EU ETS as of 2012.

Domestic Aviation – So far the EUETS has set a reduction commitment of 5% from 2013 onwards for both domestic and international aviation. This may be revisited as part of the general review for the Aviation ETS Directive in 2014. It is unclear whether the 20% EUETS reduction by 2020 will apply to aviation given the previous point. The Low Carbon Transition Plan (LCTP) states ‘the Government announced a target to reduce UK aviation carbon dioxide emissions to below 2005 levels by 2050, despite forecast growth in passenger demand’. This target is the only one of its kind anywhere in the world, and implies that aviation will be paying a lot for emissions to be abated elsewhere in the EUETS.

International Aviation – International aviation is not covered under the Carbon Budgets. Under the Kyoto Protocol, the International Civil Aviation Organization (ICAO) has been given the responsibility to tackle greenhouse gas emissions from aviation. In October 2010 an historic agreement was reached between the 190 contracting states (including UK) to cap international aviation emissions at 2020 levels. Along with this 2020 cap, it has been agreed that an improvement to fuel efficiency of 2% per year will be achieved. Europe has further committed both domestic and international aviation to the EUETS scheme. Under this scheme the cap to be applied to the aviation sector within the EUETS in 2012 will be 97% of average annual aviation CO₂ emissions in 2004, 2005 and 2006, and from 2013 onwards the cap is set at 95% of average emissions over these years.

International Shipping – According to the LCTP, flights and journeys by sea that begin in the UK but end in a foreign country (and vice versa) are classed as ‘international aviation’ and ‘international shipping’ and are not counted in our carbon budgets and emissions reductions targets for the time being, due to the lack of a globally agreed methodology to allocate responsibility for these journeys to individual countries.

Imports versus Exports – The embodied carbon in imports to the UK should arguably be added to UK’s official carbon footprint. Britain’s footprint is 11 tons CO₂e per year per person. DEFRA reports that the embodied carbon in imports is approximately 6.2 tons CO₂e per year per person. Another estimate, by the science journal Nature, reported that in 2001 imported embodied emissions in the UK accounted for approximately 37% of UK emissions while the embodied CO₂e of exports was approximately 22%. This gap has definitely increased over the past 9 years through increased trade with China.

Posted in Greenhouse gas targets | Leave a comment