Microgeneration

Microgeneration is the the generation of low-carbon heat and power by individuals, small businesses and communities to meet their own needs. Types of generation include, but are not limited to: Photovoltaic cells, wind turbines, small scale hydroelectric plants, solar water heaters, biomass burners. Whilst not strictly a form of microgeneration, ground source heats pumps and air pumps are an effective way to efficiently heat well insulated buildings.

The initial capital costs of a microgeneration project are often off-putting, but there are lots of grants and awards available to help with these. More information on grants and loans can be found here. The government have set up an incentive scheme to help people earn back the costs of installation sooner. The feed-in-tariff is an elevated price which you will be paid for energy supplied to the national grid when you are generating more energy than you are using. Read more here. Also Hot Rocs

A few micro-generation technologies are covered below:

• Solar Electricity
• Solar Heating
• Wind
• Hydroelectric
• Ground Source

Solar Electricity
Photovoltaic solar panels convert sunlight directly into electricity. They produce most power in direct sunlight but still produce some electricity on a cloudy day. For maximum efficiency they are placed on a south facing roof, attached directly to a slanting roof or constructed on an A-frame for a flat roof.

There are a variety of different materials and constructions each with different associated costs and efficiency. Panels are rated according to their peak power output, typically a panel of 1 sq metre will have an output of 140ppw (peak watts). For example a 1.8kW peak power system costs about £11.5k.

Typical installation
1.8kW peak output
10 meter square panel area
£11.5k

Once installed on the roof the panels will need wiring into your existing electrical circuit. An inverter will be needed and the connection is usually made where your electricity meter and circuit breakers are. An installation will take about 3 days, depending on the size.

You should only need planning permission for PV panels if you live in a conservation area, although it is always advisable to check before you go ahead with any construction. Systems will have an expected lifetime of over 30 years and should only need to be checked every 3 to 4 years.

Photos courtesy of mjmonty and Julian-

To find a quote in your area click here

Solar heating
Solar heating panels capture the heat from sunlight and this is used to heat water and contribute to your current central heating or hot water system. There are two types of panel for heating water: glazed flat panels and evacuated solar tubes. In studies evacuated tubes perform best in the UK climate and flat panels closely second.

The total area of panels you will need depends on the size of building you wish to heat. For most of the year (in the UK) solar tubes will heat the water to above 60 degrees centigrade and due to their construction are not as affected by outside temperature as flat panels.

The peak power output is similar to that of an immersion heater. From March to September solar will do most of your water heating, and this extends the lifetime of your boiler which will not need to fire up as often. During the winter months the panels will provide about half your water heating.

Installation takes around 5 hours depending on the size. Unless you already have a twin coiled water tank you will need a new one as part of the installation. Some piping work will need to be done too. Panels can be roof, wall mounted or free standing. Buildings in conservation areas and listed homes will need planning permission. It is best to check with your local planning office before any installation.

Photos courtesy of Julian- and Dominic Alves

Wind turbines
As a small island wind is something we have in good supply. Massive wind farms may not be feasible in our back gardens but there are a wide variety of small turbines which can be fitted on top of roofs or built free standing in larger gardens or fields.
A 6.5m metre high tower with a 2.5kw turbine for example.

Photos courtesy Elizabeth D'Orazione and Mr. T in DC

Hydroelectric turbines
If you are lucky enough to live near a fast flowing river or weir you may be able to harvest power from the water. The energy that the water loses as it descends is used to power a turbine which turns a generator. The output from the generator will depend on the flow rate of the river but this will have a more consistent output. The costs and possible outputs from small scale hydroelectric plants depend vastly on the location and installation so you will need to contact a supplier to get an estimate.

Photos courtesy of Tristram Biggs and Andrew Kuchling

Ground source heat pumps
This works by heat moving from the ground, where temperatures stay fairly constant all year around, into buried tubing containing water and anti-freeze. A heat pump then concentrates this 'low grade heat' into more concentrated heat useful for heating space and water.

The heat pump is mains powered and generates 3 or 4 times as much energy as it consumes to run. For a domestic sized building a typical system would cost between £7k and £12k. Heat pumps can also be used to cool buildings in the summer if a reverse heat pump is fitted.

Outside your building you will need to bury piping, typically 50 metres buried in trenches 1-2 metres deep. In addition the heat pump itself will need to be sited inside, preferably near the boiler. A heat pump unit is about the size of a small fridge. Your current heating system may need modification as this approach runs at lower water temperatures - commonly via underfloor heating, although larger area radiators are also an option. With burying pipes, modifying heating systems and enhancing insulation as recommended, this approach is comparatively disruptive and therefore may be more appropriate to new builds or major refurbishments.

Photos courtesy of Bryn Pinzgauer

http://www.heatpumps.org.uk/

The Microgeneration Certification Scheme
The microgeneration certification scheme (MCS) is the only independant certification scheme to cover all microgeneration products and services. It was set up to provide greater protection for consumers and has support from the Department for Energy and Climate Change.
Visit their website.

Feed-In Tariffs
Feed-In Tariffs (also known as FITs) are a renewable electricity incentive scheme, one in which you are paid for generating your own electricity. The tariffs were introduced and are funded by the Government to help increase the level of renewable generation in the UK. You earn money from all the energy you generate, including if you use it yourself. In addition you are paid for any surplus electiricty you supply to the national grid. Broadly speaking all households, businesses and cummounity organisations such as schools and care homes qualify for FITs. Most forms of renewable electricity generation in all sizes up to 5 megawatts are eligible. Generation tariff depends on the type of generation and the scale but ranges from 10p/kWH to greater than 40p/kWh. Export tariff is set at a base level of 3p/kWh but your supplier may offer you a higher price.
For full information on eligibility, tariffs and how to sign up visit the Feed-In Tariffs website.

HotROCs
HotROCs is the UK's first renewable heat incentive provided by the supplier "Good energy". You are paid 4.5p for every kilowatt hour of heat you produce. This calculation is done based on the location, size, angle and orientation of your system. The scheme is funded through a premuim charged to Good Energy gas customers. Until funding is secured for the government sponsored Renewable Heat Incentive, HotROCs remainds the only such incentive available in the UK.
Full information and how to apply here.

http://www.theengineer.co.uk/in-depth/interviews/steven-harris-of-t...