However, it is now clear that the emerging micro CHP technologies, which were not included in this original target, may help to make up for the disappointing growth currently being experienced in conventional CHP markets. (Micro CHP is relatively insensitive to the high fuel prices and low electricity prices which have had a detrimental effect on larger scale CHP.) Although CHP generally represents a cost-effective carbon dioxide abatement measure, micro CHP is potentially even more cost-effective. Perhaps more importantly, it can readily be implemented in the vast majority of existing homes, for which relatively few substantial energy efficiency measures can be implemented in a realistic commercial manner.

Until recently, however, studies of the potential for micro CHP have focused almost entirely on natural gas-fired applications. A number of commentators have questioned this approach, as it is widely believed that a substantial additional market for liquid fuels may be available. It is against this background, that the UK-based EA Technology established a project to examine the economic and environmental aspects of liquid fuels in micro CHP applications, and to evaluate potential prime mover technologies. The study examined liquid fossil fuels as well as a range of biofuels. Evaluation of the WhisperTech Stirling engine was also carried out, using kerosene, fuel oil and recycled vegetable oil.


Domestic energy consumption represents around one-third of all UK carbon dioxide emissions. Of that total, around 85% is used for space and water heating in a typical existing home. An additional 5% is used for cooking (which may use electricity or fossil fuels) with only 10% for lights and appliances – see Figure 1. Similar proportions apply to other European countries. Thus, although it might appear attractive to produce electricity from ‘zero carbon’ technologies, in the domestic sector this can only address up to an absolute maximum of 15% of the typical domestic energy demand. Of course, different proportions and absolute values apply to new homes where space heating can be virtually eliminated, but at the present rate of construction it will take centuries to replace the existing inefficient housing stock, even assuming this were desirable for other reasons.

FIGURE 1. UK domestic energy consumption by application Water heating

In other words, if we are to effectively address the key environmental challenge of climate change and carbon mitigation, it is logical to focus efforts on tackling the 85% rather than the 15%.

The European Parliament’s decision to adopt the Cogeneration Directive has been welcomed by trade association COGEN Europe. In December, the second reading of the Cogeneration Directive was passed in the Plenary session of the Parliament, with a resounding majority in favour of a set of amendments that also meet the requirements of the Council of Ministers. The Directive has therefore overcome its last major hurdle and is now almost certain to become law.

The last stage, the formal adoption by the Council of Ministers, will take place in the early part of this year and is, in effect, a formality.

Simon Minett, Director of COGEN Europe, said that the Parliament’s agreement of the compromise ‘is great news for the industry and will result in a sound legal basis for cogeneration as a solution to carbon dioxide emission reductions, energy savings and a rational option to meeting the future needs for Europe’s electricity demand. The decision of the Parliament to reach an early agreement with the Council means that the Directive will now be in force soon and we can redouble our efforts to improve the European market for cogeneration’.

The Association had been concerned that, if the Parliament had decided to stick to some of its proposed amendments and not reach a compromise with the Council, the whole Directive could have been lost due a lack of time before the Parliamentary elections next year.

COGEN Europe has long advocated the need for a Directive to provide a framework for the support and development of cogeneration, reduce market and institutional barriers to its development and to re-energize the growth of cogeneration in Europe.

The agreed text takes on board several suggestions from the Association. Although it does not set mandatory targets for EU Member States, it establishes a series of concrete measures in favour of cogeneration and it provides a framework for national policies to increase its use.

Meanwhile, the European Commission has adopted a draft legislative package for the energy sector designed to strengthen competition, promote investment and, crucially, to prevent the reoccurrence of blackouts that hit several countries last year. The new Directive on energy infrastructure, which will see more cross-border electricity services, has been criticized by the supporters of distributed generation and environmental groups. The legislation package includes: