Grid connected systems
In grid connected systems the output of the turbine is directly connected to the existing main electricity supply via an OFGEM approved inverter and meter. The energy produced by the turbine can be used on-site when demand is sufficient, or exported to the grid and sold to your utility company. It is also possible to claim Renewable Obligation Certificates (ROCs) for each unit of electricity generated, which have a significant value. This is particularly relevant if you are a business consumer of electricity, as on-site electricity can qualify you for exemption from the Climate Change Levy.
The grid connected wind turbines electrical configuration is again very dependant on the on-site conditions, and your individual circumstances.

Grid connections
When a wind turbine is connected to the mains supply, the connections must be of a high technical standard and comply with the Engineering Recommendation G83/1 and domestic installation must be carried out by a Part P approved electrical contractor. Depending upon the size of the wind turbine an import export meter may need to be installed, along with an approved ROC meter.

Turbine sizes
Small scale wind turbines vary in size with a range of models available, from less than 100 watts (W) up to 50 kilowatts (kW) smaller systems less than 100w are often used to charge 12 volt (V) or 24V batteries, for standalone systems. Turbines ranging from 0.6kW to 50kW can be used to provide electricity generation for individual houses and businesses.

Siting a Small Wind Turbine
The first stage of any wind energy project is the available resource base. Feasibility assessment determines the average wind speed available on the site and accordingly the amount of energy that can be generated. The amount of electricity produced by a wind turbine over a year depends critically on the annual mean wind speed at the site, higher wind speeds produce more energy.
The ideal site would be an exposed hill top or rise which is clear of obstructions such as trees or buildings which may produce turbulence. Ideally, the turbine site should not be more than a few hundred metres from the property, or the cost of the cable connection can rise prohibitively.

In general, small scale wind turbines start to generate electricity in wind speed of approximately 2.5 to 4 meters per second (m/s) with typical rated optimum wind speed is 10-12m/s. for instance a 6kW turbine at a wind speed of 5 m/s will generate an average of 11,000 units of electricity per year.

To obtain the average wind speed at your site, please email your post code to info@revolutionpower.co.uk where the average wind speed will be calculated at three different heights and emailed back to you or alternatively call 01325 320910

Planning
Small scale wind energy installations require planning permission and local consultation with the relevant stakeholders, such as neighbours. Deciding factors include environmental considerations, access to the site, noise and visual effect. Overall national planning policies support the development of small scale wind energy.

Planning Policy Statement 22 (PPS22) sets out a clear national policy framework on renewable energy for planning authorities in England to ensure that the Government’s renewable energy targets are met.
Under PPS22 regional and local Planning Authorities should recognise the full range of renewable energy sources, their differing characteristics, location requirements and the potential for exploiting them subject to the appropriate environmental safeguards.

Small scale developments can also be permitted within areas such as National parks, Areas of Outstanding Natural Beauty and Heritage Coasts provided that there is no serious environmental detriment to the area concerned.
PPS22 introduces a new policy area for small systems by encouraging Local Planning Authorities to require new developments to supply a percentage of their energy needs from renewable energy sources. This will be applicable to business and community developments.

Cost of Small Scale Wind Energy
After the initial outlay of the turbine itself and the time obtaining planning permission, grid connection and power purchase agreement with a local electricity company – running costs are comparatively low and the fuel, the wind itself, is free. Wind energy technology is robust, requiring little in the way of maintenance; in fact most installations only require an annual check up. Turbines typically have a working life of 20 – 25 years.

Renewable Obligation
In addition to the low maintenance costs, wind energy also has the benefit of counting towards the Renewables Obligation targets, introduced in April 2002.
This is a legal requirement placed on electricity companies to source an increasing proportion of their supply from renewable resources up to 10% by 2010 and increasing to 15% in 2015. Small generators can sell an ROC certificate for each unit of electricity generated for a price close to the value of a unit of electricity – IN ADDITION TO EITHER ALSO USING THE ELECTRICITY THEMSELVES OR SELLING IT TO THE UTILITY COMPANY. In effect, electricity from a small wind project has double the value of “normal” non-renewable electricity.