Microgeneration: An Overview
How Families and Businesses Can Generate Their Own Power
Microgeneration is the production of low or zero carbon heat or power by individual households, businesses or communities.
In recent years it has become easier and cheaper for households to generate the domestic energy they use themselves. Although start-up costs can seem high, the increased efficiency of today’s microgeneration technology, plus the range of grants now available to help households switch to microgeneration, means that the costs can usually be recouped within a few years.
Microgeneration technologies offer a number of advantages over grid electricity and fossil fuels:
- Individuals using these technologies will save money on gas and electricity bills, and in some countries such as the United Kingdom, Germany and the USA it is possible to make money by selling surplus electricity back to the national grid.
- Individuals will be able to lower their own carbon output, thus reducing their contribution to global warming.
- The reduced demand for grid electricity reduces the need for investment in large, new power stations. Reduced demand also reduces the need for additional upgrades to the grid.
- Combined Heat and Power systems (CHP) allow the waste heat by-product of microgeneration to be used for heating purposes. This increases efficiency and offsets total energy costs.
- Up to 8% of electrical power is lost during transmission. This is not an issue with electricity produced by microgeneration.
The most commonly used and widely available microgeneration technologies are small scale wind turbines, solar photovoltaic (PV) electricity, ground source heat pumps, solar energy for heating and water and MicroCHP (combined heat and power) installations:
Micro wind turbines
Small turbines with a blade span of 2m – 5m can be fixed to the roof of a building or a mast nearby. The efficiency of a micro turbine depends on the location and the surrounding environment.
Photovoltaic (PV) electricity
Solar PV cells convert energy from the sun into elecricity. PV cells contain one or two layers of semiconducting material, usually silicon. The cells are grouped into arrays – large flat panels which can be fixed to the roof of a building. The electricity produced is then transformed from DC (direct current) to AC (alternating current) using an inverter installed within the building.
Ground source heat pumps
These use a vertical or horizontal loop buried in the ground which transfers heat from the ground into a building. It can then be used to provide space heating or to heat domestic hot water.
Solar water heating panels
These are used to heat water using energy from the sun. They are composed of solar panels or collectors fitted to the roof – these can be either flat plate systems or evacuated tube systems.
Combined Heat and Power
This is a highly efficient method of generating electricity because the heat produced during the generation of power – using a gas turbine, engine or steam turbine – can be recovered and used to provide hot water for space heating.
