Database of wind turbines and solar farms, and renewable energy generation in Cornwall
The first windfarm in the country was opened at Delabole in north Cornwall in the early 1990s. Since then, many other wind turbines have been installed, either as individual turbines of varying size, or in collections generally described as windfarms.
In recent years, since about 2010, we have seen solar farms constructed in Cornwall. As the price of solar penels has fallen dramatically over the years, there has been a boom in solar farms in the county.
Capacity and capacity factor
The wind turbines and solar panels generate very low carbon electricity. Generation from wind and solar is clearly not continuous because of the variability of wind and the fact that solar panels will only generate in day-time and with generation greater on sunny days in the middle of the day than on cloudy days, or early in the day, or late in the day when the sun is lower in the sky.
When describing the scale of a renewable project, it is usually stated as installed capacity expressed either in kilowatts (KW) or megawatts (MW). These figures are the instantaneous, maximum power generation (similar to how a car manufacturer may quote the top speed of a particular model of car). In order to calculate the expected energy generated from an installation over a period of time, e.g. a year, it is necessary to know the capacity factor of the installation. A typical capacity factor for a wind turbine is 30% which means that the average power generated over a period of time is 30% of the maximum rate. The energy generated in a year is derived from the formula:
Capacity (in megawatts) x 24 hours x 365 days x capacity factor = energy per year in Megawatt hours
For solar, the capacity factor is 12%. This means that a turbine of 1 MW capacity will, on average, generate two-and-half times as much energy each year as a 1 MW solar farm.
In total, as at end of February 2015, there are approximately 417 wind turbines in Cornwall. I have put these turbines into categories as follows (my categories, not necessarily an industry standard) and calculated the number of turbines in each category.
Turbines on wind farms (2 or more large turbines) varying in size between 280 KW and 2.5 MW. 13 wind farms, 85 turbines in total.
Individual large turbines over 500 KW capacity: 3 turbines
Industrial scale turbines typically 500 KW capacity, e.g. turbines such as the one at Melbur blockworks on the road from Grampound Road to Fraddon: 25 of this size of turbine
Large farm turbines, in the range of 150 to 400 KW: 14 of this size
Typical farm turbines, of 50-100 KW capacity, e.g. on Grampound Hill, on Grogarth Farm Tregony, or on Treworgans Farm Ladock: 111 of this size
Small farm turbines of 20-40 KW capacity: 82 of these
Micro turbines, of less than 20 KW capacity: 120 of these
Solar farms typically cover an area from 5-20 hectares and with a capacity of 2-10 MW (a few are larger than this range). As at end of February 2015, there were 51 operational solar farms with another 12 under construction.
Total renewable generation
It has been suggested that, as a result of the expansion in renewable installations in Cornwall over the last few years, Cornwall is now a net exporter of electricity. The situation is that, in the middle of sunny summer days, with all solar farms producing power at, or close to, their maximum capacities, the generation is in excess of the demand for electricity at that time and, as a result, some power will flow back up the grid out of Cornwall. However, over the day as a whole, and over the year as a whole, the predominant flow is from the National Grid into Cornwall. Over a year as a whole, Cornwall's wind turbines and solar farms can generate approximately 21% of Cornwall's electricity demand. When the latest solar farms under construction come online, that percentage will rise to about 25%. So we are still a very long way from being self sufficient in electricity generation.
The tables below show the information on all wind turbines and all solar farms in Cornwall including the calculation of total renewable generation.