Frequently Asked Questions

How much do I get for exporting my electricity to the grid?

At Earthmill we group our fleet of turbines together to receive a preferential rate of export. This can make thousands of pounds worth of difference to our customers in the long run. The energy that our fleet produces is sold to Opus Energy. The rate is currently 4.9 pence for every kWh exported back to the grid.

Should I choose wind or solar?

Certain sites are not suitable for wind power, in which case solar is a great alternative. However, if your land has suitable conditions for wind then a turbine does tend to produce higher returns.

What is pre-accreditation and can I pre-accredit my turbine?

You can no longer pre-accredit a wind turbine to secure a current FiT rate prior to installation as of September 2015.

What is the Feed-in Tariff?

FiTs, or the ‘Feed in Tariff’ is a financial reward issued by the Government for generating clean, renewable energy.  For every kwh of energy your turbine produces (whether you use it yourself or sell it back to the national grid) you will receive payment.  You can find out more about current rates on our wind Feed in Tariff page

Is there a warranty for the turbine?

Yes. Manufacturers’ warranties cover the controls and wind turbine for 5 years. Additional warranties are available to cover years 6-10, please contact us for further details.

How much maintenance is required?

Depending on the type of turbine either a 6 monthly service or a service after 5000 hrs of operation is required. The service and maintenance schedule isn’t dissimilar to the MOT and Service your car requires.

How much space is required for a turbine?

Once installed turbines take up very little ground space ranging from 6m x6m to 12m x 12m. During construction a wider area is needed for the various delivery vehicles and cranes.

How long does it take to complete a wind turbine project?

The first stage is to obtain planning permission and apply for a new grid connection. It typically takes between 6 and 12 months to navigate the planning process although in some instances this can be achieved in a faster time frame. Once grid connection and planning permission are secured, we can pre-accredit your project securing the best rate of FiT available for 12 months. This allows time to order your product, grid upgrade works to be completed by your local DNO and for us to install your turbine. 

A typical project takes 12-18 months to complete however this varies on a case by case basis. 

What happens to the electricity I don’t use?

Any electricity that you do not use is sent back to the grid, a meter measures how many kWh are exported and you are paid for this.

What if lightning strikes?

Nothing too exciting! The turbine blades and tower are lightening protected as are the electrical circuits. In the event of a lightning strike the turbine will shut down for safety reasons and will require an engineer visit to re-start it and check the systems. 

When is it too windy?

Wind turbines are designed to operate in windy areas and can withstand high speed gusts whilst maintaining normal operation. When the wind speed is exceptionally high for an extended period of time, they will shut down to prevent any damage occurring. 

The wind speed at which a turbine will (shut down) at varies between models, the cut-out wind speed can be found for each model within the turbine specifications. All the turbines that we supply will automatically restart once the wind speed reduces to a safe operating level. 

How noisy are they?

In the UK, wind turbine noise is generally regulated by ETSU–R–97. These planning guidelines state that a wind turbine should not register to be louder than 45 decibels from any nearby dwellings. There are therefore recommended ‘acoustic set-back’ distances for each turbine that Earthmill supply in order to achieve this. Our turbines require between 180m and 500m (model dependent) from nearby dwellings to adhere to the guidelines. However these distances can be reduced in areas where there is background noise present such as roads or machinery.

Is my site windy enough for a turbine?

We have access to a number of complex wind speed databases that will give an indication of the wind speed at your site. You can use our site assessment tool to request a desktop assessment of your site, which is conducted by one of our in-house specialists.  Site assessments are complimentary and don’t obligate you to take your enquiry further.

Do I need planning permission?

Yes, planning consent is required for structures over 4m high. We have an experienced team of in-house planning consultants who understand the complex guidelines and policies that need to be adhered to in order to ensure a successful application.

What is the life span of a turbine?

A turbine will last for 25 years plus as long as it has been correctly sited and well maintained. Its life span is increased if regularly serviced and maintained.