Wind Turbines - Effective, affordable and efficient

by Claus Jacobsen, Director, Evance

The three key ingredients for a successful wind turbine installation are space, wind and demand for power. The vast majority of farms offer all three, making a wind turbine a very serious option for farmers wanting to reduce their power bills and carbon footprint.

A small wind turbine, or a pair of turbines, can be of value to all sizes of farms, providing power to light a poultry shed for a small holder, lighting cattle sheds for dairy farmers or powering a grain dryer for arable farms.

The UK boasts more than a dozen manufacturers of wind turbines offering a wide range of different turbines, sizes, power outputs and designs. There are three main types of wind turbines – micro, small and big.

Micro-wind turbines typically have a diameter of less than two metres and are mounted directly to the side or the top of a building, often in towns and cities. There is considerable debate about how efficient these turbines actually are.

Big wind describes the utility sized wind turbines that are built on the coastal, hilly and mountainous regions across Europe. The multi-million investment required for these turbines make them unaffordable for even the biggest farms.

Small wind

Small wind turbines are most suited for use by farmers which are either connected to mains electricity supply (On-grid) or alternatively using diesel generators or batteries (Off-grid). Typically with rotor diameters of between two and twenty metres small wind turbines are set on free standing towers 9 to 30 metres high, and have rated capacities of 3.5kW – 100kW.

Installation

The key piece of information for any farmer considering installing a wind turbine is the average wind speed for the turbine’s chosen location. The Carbon Trust operates an online service - the Wind Yield Estimation Tool - which allows UK farmers to estimate their annual mean wind speed, the annual power yield and carbon savings of a small wind turbine.

Having ascertained that the average wind speed is viable and identified the sort of savings that could be made, there is a structured process that needs to be followed to ensure that the right turbine and tower are selected. The turbine needs to be properly sited and planning permission gained, along with a suitable grid connection. This may sound like a tricky process to negotiate but an experienced turbine distributor such as Hallmark Tractors that understands the needs of framers will be able to provide practical support and guidance at every step of the way.

ROI

When calculating whether a wind turbine will be economically viable three issues need to be taken into consideration. Firstly, what is the actual energy output that the turbine will deliver? Traditionally many of the energy claims of manufacturers were more hopeful than accurate. But British and international standards, including IEC and the BWEA Small Wind Systems Performance Standard, now provide reliable benchmarks for energy output.

It is also possible to install power predictor at the proposed turbine site. A minimum of 30 days data is analysed and seasonally adjusted to provide information on the amount of power that the turbine will produce and so the potential cost savings.

Plus, all turbines now need to meet the criteria set down by the Micro generation Certification Scheme (MCS) which has been designed to provide reassurance to customers that both products and installers meet robust quality and performance criteria.

Secondly, there is of course the cost of equipment and installation. With an operational life of 20 years and a typical installation costing £25,000 a small wind turbine can make a significant contribution to reducing the costs of a farm’s power.

Thirdly, farmers should review which grants are available to support the purchase of the turbine. Grants are available via the EU’s Agricultural Fund for Rural Development, which totals €345 million. Administered by the UK’s regional development agencies, the grants available are up to 50% of the installation cost depending on grant area. Turbine owners can also earn around 10p per kWh produced (whether consumed by the owner or not) under the Renewable Obligation Certificate scheme until April this year.

After April 2010 a new programme of feed-in tariffs will transform small wind turbine economics by paying owners for each unit of electricity generated. One kilowatt hour of wind energy will receive between 4.5 pence to 34.5 pence. These payments will be in addition to the financial benefits of displacing grid electricity and selling excess energy back to the grid. All systems installed from now will qualify.

It has never been a better time to investigate adding a wind turbine to your farm’s assets, both as an economic investment, and to reduce your long term carbon footprint.