A reader has asked if it is possible to heat a house with a wind turbine. The simple answer is that it is possible, but it's unlikely to be the best solution.

Heating demand depends on the construction of the home and the weather. A home requiring a 13kW boiler will need a maximum of 13 x 24 kWh of heat a day (ie 312 kWh) - although this maximum would only be reached when the outside temperature stayed below -3C for a 24 hour period.

The home would require around 26,000 kWh of heat a year - less in the south of England, more in north Scotland. A typical heating system to generate heat from a wind turbine would include a thermal store providing hot water for underfloor heating. However, storing heat from the summer to use in winter is not a practical proposition. A 10,000 litre water store will store around 350 kWh of energy. Assuming a 30 degree temperature drop is acceptable, once the stored water falls below 45C it will need additional heating to deliver space heating.

The 10,000 litre tank will store enough heat for a cold day without wind.

A 6 kW turbine located in an open field with no nearby obstructions will need an average wind speed of more than 8 metres per second to generate 26,000 kWh of electricity a year, and wind speeds as high as this are only found in exposed locations such as Dartmoor. So, providing the space heating from a 6 kW turbine is unlikely to be satisfactory as much of this energy would be generated when you do not require heating.

If your home is connected to the national grid you may be better connecting the turbine to the home's electricity system and then the surplus electricity during the summer months can be sold back to the grid to reduce the bills in the winter. You may also want to consider using a heat pump for your heating; this will reduce the electricity required for heating by between 60 to 75% as it extracts heat from the air or ground around your home.

For any wind turbine project to be successful you need to  be sure that you have an appropriate site. This probably means setting up a wind monitor for a period of time and measuring the local wind speed.

There is a national database of wind speeds, which can be used as a first step. You will need to see a wind speed in excess of 5.5 m/sec to make a wind project interesting. This database can be accessed from many places including the Encraft website.

Photo by kthypryn

About the author: Graham Eastwick is a director of Encraft, and manages renewable energy installations for home owners, community organisations and small businesses across the UK.

If you have a question about anything in the above blog, please ask it in the comments section below.