Microgeneration is a broad term for ways that energy can be produced on a small scale for homes. It usually refers to generation from renewable resources such as solar power, wind, or water. The different types are explained below.
Biomass energy is usually from the form of wood or specifically grown energy crops. These crops are then burnt in boilers to provide heating and hot water. While this may not sound environmentally friendly, burning these types of fuels only releases the carbon dioxide that was collected during their life time. If the wood or energy crops are then replanted this is where the environmental benefits are made.
- Solar Water Heating Solar panels that provide water heating are generally considered to be more appropriate for home use than photovoltaic solar panels. They can be fitted to roofs on existing buildings and can provide up to 100% of hot water used during summer months.
- Photovoltaic (PV) These solar panels provide electricity; they usually require a southerly orientation and work best if not overshadowed. Due to the climate in the UK it is unlikely that PV solar panels will provide all the electricity for a home, but they can make a contribution. Initial outlay tends to be high, but grants are available.
Wind turbines are essentially windmills with improved blades for electricity generation. Small scale turbines are available for home use. Turbines can supplement the existing power supply but on their own are usually unable to provide 100% of power for a home. During peak output some energy companies will buy back power to put into the national grid. It is important to ensure that turbines are efficient and will generate enough power to make a contribution for your usage, and to outweigh the carbon dioxide produced by manufacture.
Ground Source Heating Pumps
Work on a similar principle to a fridge or air conditioning. A ground loop contains a coolant pumped around a loop dug in the ground. A heat pump then takes heat away from the coolant as it moves around the loop and distributes it to a heating system. They require space for the ground loop which may be a restriction for some homes.
Micro hydro systems are turbines that are powered by water, depending on the catchment area of the river or stream power may be able to be generated all year. The amount of power generated depends on the rate of flow and the head (the distance the water falls). Hydro systems will require an abstraction licence from the Environmental Agency (external link) (this is allowed before water can be removed from streams, rivers, or groundwater).
Hydrogen fuel cells
While not strictly microgeneration, hydrogen fuel cells could provide an alternative to many applications where hydrocarbon fuels (such as petrol and diesel) are used such as powering cars, other potential uses would be replacing batteries, and possibly powering homes.
The government is currently reviewing planning permission for microgeneration for houses. Please email email@example.com for further information.