Wind turbines at CAFRE
Two wind turbines have been erected by CAFRE
A 5 kW Iskra turbine was installed at the Horticultural Development Centre on the Greenmount Campus to generate electricity for use in the unit. A 15 kW Proven turbine was installed at Loughry Campus to provide power for the refrigeration units which run 24/7 in the Food Technology Centre. These will enable the two locations to obtain Renewable Obligation Certificates (ROCs), see bottom of article for information on ROCs.
The 5 kW Iskra turbine is mounted on a 12 metre tower and has a blade diameter of 5.4 metres. It is located on a level site close to the glass houses. There are a number of trees and buildings in close proximity and this may reduce the generation efficiency. The turbine is designed to be efficient at lower wind speeds and is responsive to changes in wind speed and direction.
From the available information it was estimated that the turbine would generate 8700 kWh per annum based on an annual average wind speed of 5.4m/s. This equates to a saving in electricity cost of £957 per annum, given an average cost of 11pence per kWh. Adding ROCs gained from renewable generation would add a further saving of £335.The estimated carbon reduction would be 4 tonnes per annum, which is 7 percent of total carbon generated from electricity used by the HDC.
The 15 kW Proven turbine is mounted on a 25 metre tower on an elevated site and is fitted with 9 metre blades. It is anticipated that it will produce an annual output of around 33,000 kWh, giving an annual saving of approximately £5600(including ROC’s). With domestic electricity price rising to 16.75 pence/kWh on 1 October and 3.8pence/kWh for the ROC, the annual value would increase to £6780. If, as is proposed, the turbines become eligible for double ROC’s in April 09, the figure would increase to £8035. Measurement equipment has been installed which will provide accurate information on windspeed and related output of the system throughout the year. As there is a continual power requirement by the refrigeration system all the electricity generated is used on the site.
Renewable Obligation Certificates (ROCs)
Ofgem require suppliers to produce evidence of their compliance of the scheme by producing green certificates referred to as Renewable Obligation Certificates (ROCs) Each ROC represents one Megawatt Hour (MWh, 1,000 units or 1,000 kWh) of renewable electricity generated. ROC's are awarded to renewable generators who are accredited with OFGEM. Therefore if you are a renewable generator and are accredited with OFGEM to receive ROCs for every MWh of electricity you generate, the ROCs can be sold to electricity companies/suppliers providing an annual income. This would be in addition to revenue received on all exported units of electricity, and help reduce payback time. It is important to note that you are eligable to claim ROC's on all the energy you produce, even if you use it yourself!
Ofgem require suppliers to produce evidence of their compliance of the scheme by producing green certificates referred to as Renewable Obligation Certificates (ROCs) Each ROC represents one Megawatt Hour (MWh, 1,000 units or 1,000 kWh) of renewable electricity generated. ROC's are awarded to renewable generators who are accredited with OFGEM. Therefore if you are a renewable generator and are accredited with OFGEM to receive ROCs for every MWh of electricity you generate, the ROCs can be sold to electricity companies/suppliers providing an annual income. This would be in addition to revenue received on all exported units of electricity, and help reduce payback time. It is important to note that you are eligable to claim ROC's on all the energy you produce, even if you use it yourself!
How much is a Renewable Obligation Certificate (ROC) worth?
The government sets the values of ROCs the price increases each year with inflation. At the moment (2006-2007) the “Buy Out” price as its called, stands at £33.24 per megawatt hour (MWh). ROCs are bought and sold in the market place by large generators, traders, brokers and electricity suppliers. Market prices vary on a daily basis. To see recent ROC prices look at the Non-Fossil Purchasing Agency website
The government sets the values of ROCs the price increases each year with inflation. At the moment (2006-2007) the “Buy Out” price as its called, stands at £33.24 per megawatt hour (MWh). ROCs are bought and sold in the market place by large generators, traders, brokers and electricity suppliers. Market prices vary on a daily basis. To see recent ROC prices look at the Non-Fossil Purchasing Agency website
