Just cut it out

Ten nuclear plants that currently provide up to 15% of the UK's electricity supply are due to close by 2020. The question is: do we have to replace these power stations with new nuclear plants? It's not an easy one to answer.

When it was first introduced, nuclear power was hailed as the energy source of the future. But a series of nuclear accidents in the 1970s and 1980s, and hard lessons learnt about the risks of disposing of the waste, raised concerns over the safety of generating plants. The technology has since fallen out of favour with the public.

Now, with global warming high on the agenda, the argument that nuclear power plants generate far less carbon dioxide than fossil fuel ones has given the industry a new selling point - and induced the UK government to look seriously at this technology again.

But surely we are missing the point by simply asking how we can supply this energy. I think we should be asking the question: do we actually need any more electrical energy and can we actually get by on less?

According to figures from the DTI, in 2003 the UK had an installed electricity generation capacity of approximately 80 Gigawatts, of which 77% was generated using conventional thermal technology; 15% was from nuclear; 5% came from hydropower (including pumped storage); and 3% from renewable sources.

For comparison, China is adding 80 Gigawatts of generating power to its existing generating capacity every year - in other words, the equivalent of the UK's total current generation capacity every year.

A large part of the energy generated is used in buildings. In general, more than 50% of the UK's greenhouse gas emissions come directly or indirectly from buildings. All of which means building services engineers can have a major impact on future energy demand.

Technology such as thermal storage means services engineers hold the key to nuclear-free energy supply

The real issue of energy capacity lies with peak energy demand. Because the grid must be continually balanced - ie, electricity supply must precisely equal demand, power stations have to continually change their output using response generators. These often run at reduced capacity, which is inefficient, expensive and produces vast amounts of unnecessary carbon dioxide emissions.

So, to make the grid run more efficiently, surely all services engineers have to do is reduce peak energy demand. Just shifting part of the electrical load to night-time consumption would achieve the Carbon 60 target in the summer months. In winter we could satisfy Carbon 70 by the same means. This would ensure we use existing generating capacity more efficiently, enabling suppliers to provide lower-cost energy, and negate the need for more nuclear power stations.

It should be straightforward. When we produce a design for a building, we have to submit a load profile showing the peak and average demand. We could then utilise technology, such as thermal storage, to reduce the peak to a figure closer to the average. Then the energy supply to a building could be based on the average load and not the peak load.

The construction cost of 1 kW of nuclear-generating capacity is approximately £900-£1200. If a scheme were to receive a grant of half of this figure, say £500, for every peak kilowatt saved, we could invest this money in energy-saving technologies.

If we utilise technologies to reduce our peak demand, what would be the overall impact on UK energy requirements? Research by the University of Strathclyde shows that if engineers used current energy storage technologies, together with an energy-modelling tool under development at the university, we would have sufficient generating capacity.

Building services engineers must provide clear leadership. Between now and 2012 we should try to rewrite the peak energy requirements for the UK to a figure that matches the average energy requirement. If we succeed, when the government reviews energy needs in six years it might decide it no longer needs a new generation of nuclear power stations.