Local authority

Microgeneration technologies, or generation of power locally, could provide a significant contribution to the UK’s energy supply, says Philip Sellwood.

The UK’s energy mix has never been more in the spotlight. The decline in oil reserves, combined with rising energy demands, are causing concern over how the nation is to fuel its future.

Local energy generation (or microgeneration) — technology installed in the home or in local communities to allow them to generate their own energy — has been recognised as an important and growing part of this mix. It could provide a substantial proportion of the UK’s energy requirements. Mini wind turbines, photovoltaic cells and other small-scale technologies, such as heat pumps, can make a significant contribution to fuel diversity and security of supply while delivering significant carbon reductions.

The Energy Saving Trust undertook a detailed review of technologies, the current market and the possible role and impact of local energy generation in the UK’s energy mix in a report, Potential for Microgeneration Study and Analysis. Commissioned by the Department of Trade and Industry to inform the government’s low-carbon building programme and microgeneration strategy due this spring, this study examined routes for the creation of a sustainable and competitive environment for these technologies, and anticipated time scales for return on investment.

The report concluded that microgeneration technologies could deliver a significant contribution to UK energy needs — ultimately rising to 30–40 per cent of total electricity requirements by 2050. In addition, by 2050 they could help reduce carbon dioxide emissions by 15 per cent per year, with some technologies being cost-effective well before 2020.

However, to bring these technologies into the mainstream, certain barriers must be addressed and, while outlining those, the report also looked at potential solutions. For example, capital grant schemes could help industry overcome the significant cost of technology while additional government interventions might help in other areas, such as planning. A fair price for the sale of local electricity surpluses is also critical.

The report investigated a number of technologies. For instance, combined heat and power generation from Stirling engines could be used to capture the waste heat generated from the production of electricity. Over eight million homes could be reached by 2050, supplying 40 per cent of domestic heating requirements and six per cent of UK electricity supplies. After cost-effectiveness is achieved, it could take another 10–15 years before a significant proportion of domestic energy is generated by this technology.

Fuel cells that combine hydrogen and oxygen to form electricity, heat and water could be the dominant microgen electricity generator, once commercialisation is achieved. In 2050, with appropriate support, small fuel cells could supply nine per cent of UK electricity requirements while reducing domestic sector CO2 emissions by three per cent.

Small wind turbines also show enormous promise. Using wind to generate power has the potential to supply four per cent of UK electricity requirements and reduce domestic CO2 emissions by six per cent by 2050.

The report was less favourable about solar photovoltaic systems, which use cells to convert daylight into electricity. It concluded that, although promising, they are likely to remain expensive for some time, with cost-effectiveness not predicted until 2030. But overall this technology has the potential to supply almost four per cent of UK electricity demands, and reduce domestic sector CO2 emissions by up to three per cent by 2050.

Biomass heating and heat pumps could also be commercial when compared with electrical heating. With appropriate support these technologies combined could reduce domestic sector CO2 emissions by three per cent by 2050.

Using heat from the sun alongside a conventional water heater is currently the largest microgeneration industry, concluded the study — but it will need substantial grant support to maintain uptake and growth.

All in all, the report painted a promising picture for the future needs of the UK and predicted that, over the next 10–40 years, a large proportion of homes or communities could be generating their own energy — saving tonnes of CO2 emissions and helping to reduce the impact of climate change. It also suggested that microgeneration has a key role to play in the future security of supply and is a realistic option for cutting CO2 emissions from energy generation. However, consumer awareness and adoption will be critical to the uptake of these technologies.

Philip Sellwood is chief executive of the Energy Saving Trust