Energy Efficiency Measures

Mike Weatherley Excerpts

Wednesday 17th November 2010 Westminster Hall

[Graham Stringer (Blackley and Broughton) (Lab)]

It is a pleasure, Mr Sheridan, to serve under your chairmanship.

Decarbonisation policies and renewable energy policies, both nationally and internationally, may not be in crisis but they are at a turning point. The Chicago climate exchange ended carbon trading, and a year ago the Copenhagen summit was not a success. Wind farms are increasingly criticised as an environmental blight as well as extremely expensive, and it has been noted that energy companies make three times as much money from wind farms as they do from coal and oil. The debate takes place in that context.

I am rather impressed by the potential contribution that heat pumps could make to our future energy needs. However, we must have complete assurance that the installed technology will actually deliver what it says on the tin. I fear that in 30 or 40 years, many of our energy policies, including wind farms, will be seen in the same way as we now look back on deck-access housing accommodation from the 1960s and 1970s—a good idea at the time, but no more than that. Heat pumps are a big investment for both householder and taxpayer, and both deserve to be assured that they will be worth the money.

Heat pumps extract heat from the ground or the air, and redirect it for space heating and hot water. The efficiency of heat pumps is measured by their coefficient of performance, which I shall refer to as COP. It is the ratio of heat produced per unit of electricity consumed in generating that heat. A COP value of 3 means 3 kWh of heat output per kWh of electricity used to run the pump. Higher COP values represent relatively more efficient heat delivery.

COP values vary by season; the colder the ground or the air, the more work the pump has to do to raise the temperature to acceptable levels for domestic heating, and the more energy is consumed. Poor design and installation also affect the COP. In well-insulated buildings with low temperature under-floor heating of about 40° C, ground-source heat pumps can be beneficial. Conversely, in poorly insulated buildings, where the pump is required to heat high-temperature radiators and hot water to about 60° C, their performance is less impressive.

The 2009 European directive on renewable energy excludes low-performing heat pumps from making a contribution to renewable energy targets. It states that

“Only heat pumps with an output that significantly exceeds the primary energy needed to drive it should be taken into account.”

From other data, we can deduce that that the EU implicitly requires heat pumps to achieve a COP of 2.875 before their energy contributes to the renewable energy target. The logic behind the EU requirement for a minimum efficiency level is that replacing a fossil-fuel heating system with a poorly performing heat pump may result in increased CO₂ emissions. That is because the emissions costs in the extra electricity requirement of a heat pump need to be balanced against the emissions of burning a fossil fuel.

The most recent study of heat-pump performance, “Getting warmer: a field trial of heat pumps”, was published by the Energy Saving Trust on 8 September. The study reveals that the performance of heat pumps installed in the UK is surprisingly poor. It showed that only one of the 22 properties that had ground-source heat pumps achieved the implicit minimum EU directive COP, and that only nine of the 47 sites with air-source heat pumps achieved that standard. Something similar occurred during the Joseph Rowntree Foundation study in Elm Tree mews in York; a communal ground-source heat pump was installed that had a nominal design COP efficiency of between 3.2 and 3.5, but despite a number of interventions throughout the year’s monitoring, the delivered COP efficiency was 2.15. As a result, it failed the renewable test.

The risks are clear. There is the potential for consumer dissatisfaction with technology that fails to deliver on value for money after expensive and possibly disruptive installation; in some cases, it will raise carbon emissions rather than lower them; problems may arise from the EU failing to count the majority of heat pumps in the UK as a contribution to our renewables target; and there is the possibility of failing to qualify or to remain qualified for renewable heat incentive payments.

[Mike Weatherley (Hove) (Con)]

I wonder whether there are any source problems, such as in my constituency of Hove, with chalk-based land. Would that present an additional problem?

[Graham Stringer]

I understand from my A-level physics—it was a long time ago—that the real problem is the difference in temperature between the ground and the building being heated.

In response to a parliamentary question, the Minister of State, Department of Energy and Climate Change, the hon. Member for Bexhill and Battle (Gregory Barker), confirmed that

“Heat pumps that do not meet the required average seasonal performance factor, as defined in Annex VII of the use of energy from renewables sources Directive 2009/28/EC, will not count as renewable.”—[Official Report, 21 October 2010; Vol. 516, c. 865W.]

In order for heat pumps to have the correct COP, each installation needs to be inspected and monitored to ensure compliance. How will the Minister monitor that, if it does not do what it says on the tin? I would be grateful if he answered that question today.

The Energy Saving Trust report was bad news for heat pumps, but disappointing COP values are only part of the picture. The threshold for being considered renewable takes no account of the carbon footprint generated by manufacture and the emission of the heat pump’s fluorocarbon refrigerant. Fluorocarbons used as refrigerants can be highly polluting if they leak, because their global warming potential can be thousands of times that of CO₂. The refrigerant R404A, for instance, has a global warming potential 3,800 times that of carbon dioxide. In a written answer, the same Minister said:

“we would expect heat pump manufacturers to avoid using this particular gas wherever possible.”—[Official Report, 19 October 2010; Vol. 516, c. 649W.]

Unfortunately, I understand that 15% of heat pumps use that refrigerant.

A further study undertaken by Atlantic Consulting, “Fluorocarbons’ Contribution to Air-Source Heat-Pump Carbon Footprints”, showed that the contribution of fluorocarbons to the carbon footprint of heat pumps was considerable. Production and disposal of heat pumps made a negligible contribution; however, in power generation, fluorocarbons added 20% to the footprint. The annual operating leak rate was estimated at 6% of rated charge, in accordance with the current estimate of the Refrigeration, Air Conditioning and Heat Pumps Technical Options Committee of the United Nations Environment Programme. Another academic study from 1999 found leak rates as high as 8%. Those rates are significant; they are not negligible, as was claimed in a written answer of 19 October 2010, which was based on information supplied by the industry.

Further, could the Minister obtain independent confirmation of whether the leak rates are negligible or significant, as a lot could ride on that for the future of the industry? There are no current mandated standards on leak rates for heat pumps, but the problems do not end there, because much damage is done when the refrigerants are vented into air at the end of the installation’s life, as all too often happens. I also see from a recent parliamentary answer, on 19 October 2010 at column 647, that no information is held on quantities of HFCs and HCFCs recovered and recycled in the UK. So we simply do not know how much of these dangerously polluting gases, which are controlled under the Kyoto convention, are emitted into the atmosphere at the end of the life of the installation. If emissions are not measured, they cannot be managed.

UNEP’s RTOC, which I mentioned earlier, has adopted a working assumption that end-of-life emissions of refrigerants are on average over 50%. That is not “negligible”. Atlantic Consulting’s findings are supported by a similar, peer-reviewed study published by the university of Delft in the Netherlands, which found that,

“Even though heat pumps are generally considered to be sustainable heating systems because they extract heat from renewable sources rather than by burning non-renewable fossil fuels this research shows that a heat pump is actually not more environmentally friendly than a gas-fired boiler.”

A press release from Atlantic accompanying its report argued that the RHI should be re-targeted, pointing out that,

“Under the proposed RHI, homes and offices in the UK would be subsidised to displace or replace gas- or LPG-fired heating with heat pumps, even though this would, at best, cause a very minor reduction in carbon emissions, and in many cases an increase.”

Currently, the Government are considering the detail of how the RHI will operate. The potential contribution of heat pumps to our renewables target is significant, but some way has to be found of assessing and certifying each installation, so that it makes a genuine and positive, rather than negative contribution. Ideally, minimum fluorocarbon leak rate standards should be mandated for heat pumps, so that these powerful global warmers do not undermine their contribution further.

The key point is that the nominal or certified design of coefficient of performance of a heat pump can differ radically from the efficiency after installation; so radically, in fact, that it can detract from rather than add to our battle against climate change. The Department of Energy and Climate Change is to subsidise heat pumps with taxpayers’ money at 5.5p per kWh for 20 years. That is an enormous amount of money committed for a long period, and we must be absolutely certain that taxpayers’ money subsidises only that which is renewable after installation and that which is good, rather than inefficient, not renewable and bad.