If you fancy a wind turbine and have carried out any research, you will have come across average wind speeds. If you haven’t then google average wind speed calculator. You will be asked to enter either your OS grid reference or your postcode. You are then returned the average wind speed for your location. In my case, and for this example, the average wind speed at 10 metres above ground level is 6.4m/s. Unfortunately though, it would appear that average wind speed is the starting point of a great deal of misunderstanding that is being readily used by the renewable energy installers.
Wind Power takes a bit of thinking about. A wind turbine doesn’t produce a steady amount of power. On our website, 'reality Green' we have an more detailed version of this article that looks at the power supplied by a 5kW Evance R9000 wind turbine. We needed to know how average wind speed compared to what was really happening so we monitored the wind for a period of 6 months over winter when the wind is usually at its strongest. With figures based on the average wind speed the wind power was more than adequate to generate the amount of power we were looking for and it is this figure that is often given out by installation companies. Forget the environment, their calculations demonstrate that you could have a payback in 7 or 8 years, and over the 20 years of the life of feed in tariffs (FITs) you will make a large chunk of money. This sounds like one serious earner. But then we monitored the wind and found out that in reality, we would only generate 5110kWh in a year.
So how did we do it? Wind speed readings were registered every 5 minutes so the amount of actual wind power on any particular day was easy to work out. What the figures showed was quite shocking. Rather than the 11,000kWh of generated power in a year suggested by our average wind speed figure, we only would have achieved 5,110kWh in a full year. That’s less than half. The location (which you can see on our website - reality Green) is an elevated, open site with great exposure to the prevailing winds but even with these plus points, the figure for actual power that would have been generated was less than half. I can only work on the figures I have and intend to obtain data from other sites to see if this is repeated up an down the country. If it is repeated, then I do feel with such a wide difference between the figures being suggested by installation companies and what is actually achievable, then there could be a serious case for mis-selling.
From an environmental standpoint, generating 5,110 kWh falls short of the 6500kWh target I have to cover all my electrical power requirement. I was hoping the figure would be more than I require to allow for the charging of an electric vehicle in the future. I could go for a larger wind turbine but the finances get rather out of hand. After all, on the returns being offered you would not cover repayments if you borrowed the money. Photovoltaics may be possible to make up the shortfall. The challenge to achieve sustainable living will have to continue.
Wind Power takes a bit of thinking about. A wind turbine doesn’t produce a steady amount of power. On our website, 'reality Green' we have an more detailed version of this article that looks at the power supplied by a 5kW Evance R9000 wind turbine. We needed to know how average wind speed compared to what was really happening so we monitored the wind for a period of 6 months over winter when the wind is usually at its strongest. With figures based on the average wind speed the wind power was more than adequate to generate the amount of power we were looking for and it is this figure that is often given out by installation companies. Forget the environment, their calculations demonstrate that you could have a payback in 7 or 8 years, and over the 20 years of the life of feed in tariffs (FITs) you will make a large chunk of money. This sounds like one serious earner. But then we monitored the wind and found out that in reality, we would only generate 5110kWh in a year.
So how did we do it? Wind speed readings were registered every 5 minutes so the amount of actual wind power on any particular day was easy to work out. What the figures showed was quite shocking. Rather than the 11,000kWh of generated power in a year suggested by our average wind speed figure, we only would have achieved 5,110kWh in a full year. That’s less than half. The location (which you can see on our website - reality Green) is an elevated, open site with great exposure to the prevailing winds but even with these plus points, the figure for actual power that would have been generated was less than half. I can only work on the figures I have and intend to obtain data from other sites to see if this is repeated up an down the country. If it is repeated, then I do feel with such a wide difference between the figures being suggested by installation companies and what is actually achievable, then there could be a serious case for mis-selling.
From an environmental standpoint, generating 5,110 kWh falls short of the 6500kWh target I have to cover all my electrical power requirement. I was hoping the figure would be more than I require to allow for the charging of an electric vehicle in the future. I could go for a larger wind turbine but the finances get rather out of hand. After all, on the returns being offered you would not cover repayments if you borrowed the money. Photovoltaics may be possible to make up the shortfall. The challenge to achieve sustainable living will have to continue.
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