Micro-generation is the production of heat and power by individuals or communities – typically by renewable energy – enabling them to meet their own requirements at, or approaching, zero-carbon cost.
As an approach, it has much to recommend it, both in terms of its energy efficiency – generation takes place at or very near to where the power is needed – and as a very effective direct means of reducing the household carbon footprint.
There are a number of micro-generation technologies to choose from – and, perhaps best of all, they can qualify for government grants towards their installation cost.
- Air source heat pumps – these absorb heat from the air outdoors to heat buildings and warm domestic water, and can even work when outside temperatures are as low as minus 15 degrees C. Three to four units of heat are produced for every one unit of electricity needed to drive the pump.
- Bio-energy – this form of renewable energy is generated from biomass – recent organic material – and unlike fossil fuels, the carbon it releases is offset by the CO2 it absorbs during its growth, hence the reason it is considered carbon neutral. Although there are many forms of suitable biomass, wood chips, pellets or logs tend to be the most usual for most small scale household or community schemes.
- Ground source heat pumps – these work by transferring heat from the ground; ground source heat pumps can be used to warm homes and buildings and pre-heat domestic hot water. Like air source pumps, they provide three to four units of heat for every one unit of electricity used by the pump.
- Solar photo-voltaic – often known as “PV” – generates electricity using energy from the sun. Although it can be expensive to install, compared with some other renewable energy technologies, a properly installed PV system requires very little maintenance work.
- Solar thermal hot water – this uses solar renewable energy directly, the sun’s heat warming a series of solar panels which then heat up domestic water. With water heating accounting for around a quarter of typical domestic energy usage, installing a solar hot water system can cut your bills and your carbon footprint.
- Small scale hydro-electric – these turn the energy of moving water into electricity, using a turbine which is turned by the flow of water – and even a fairly small stream can generate a useful amount of power. Any hydro-electric system below 100kW qualifies as “micro”; most domestic systems are only a few hundred watts, while commercial versions would be rated at 25kW or more.
- Wind turbines the wind turns a generator unit, which produces electricity. The UK has around 40 per cent of Europe’s total wind energy, making this a source of renewable energy that has great potential for British homes and communities.
Other types of micro-generation include forms of combined heat and power (CHP) and fuel cells.
Grants for Micro-Generation
All of these renewable energy micro-generation systems are currently eligible for government grants, under the UK’s Low Carbon Buildings Programme, administered by the Department of Business Enterprise and Regulatory Reform (BERR) – the successor to the DTI.
Applications are welcome from both individuals and organisations and, dependent on the technology in question, if your project fulfils certain conditions – and you use a certified installer and an authorised product – up to 30 per cent of the installation costs can be covered.
Although the types of micro-generation all have their own particular characteristics which affect how appropriate they are for individual projects, the one thing they all share is that, unlike conventional alternatives, they offer a way of generating power where it is needed. Known as “distributed generation” or “embedded power”, the transmission losses are as small as it’s possible to be – which, from an energy efficiency point of view, is about as good as it gets.