An objecter ( A smart grid consultant) to the Ashcombe Solar Farm has calculated that the 71 acre array will only generate power for 324 homes. The applicant 'Solstice' has stated it will power 2,100 homes. It is a big difference. Are there any power experts out there who can do the Maths if so, how many homes do you make it?
According to my research, a home requires a solar panel measuring 285 square feet. There are 43560 square feet per acre. So 43,560 divided by 285 equals 152 homes that can be powered by an acre. Multiply that by 71 acres equals 10,851 homes. Obviously that's straight mathematics that doesn't allow for space between the panels, however there you go.
I might change my name to Carol Vorderman.
2100 homes sounds closer conservative estimate. Calculation depends on so many things - direction the panels are facing, angle at which they are pitched, weather, type of panel, transmission efficiency etc. We have solar PV which is a major saving but doesn't provide all our electricity - don't forget you can't generate at night. I estimate that our panels occupy about 180 sq ft and over the year provide about one third of our electricity requirements ( we do not have gas or oil). So, following JCs calculations above, we would need 540 sq ft to cover whole year which equates to about 80 homes per acre. So 71 fully occupied acres would equate to 5680 homes. If only 50% of acreage is used ( allowing for space between arrays to prevent overlapping and servicing) then this would result in power for 2840 homes. This would reduce further because of transmission efficiency - from the arrays into the grid and subsequently across the grid.
As Neilh rightly states they do not generate at night, which is when the majority of electricity is used. In addition during dull or rainy days the power generated is considerable less so to me the only place solar should be installed is on the roof of a building. Not on a green field site.
The more homes the site is capable of supporting, the smoother the planning request will be, even if it's pure fiction. Does the planning dept have a chart/body who verifies these claims? Governments have been doing stat's manipulation for decades to their advantage.
One hopes that Teignbridge Planners are well informed by independant consultants. As Planning Applicants and their agents often try to pull the wool over their eyes, and in turn the eyes of third parties. Often 'pure fiction' is by deliberate omission. But does this figure have to be accurate? I would have thought so, from what I understand the solar power industry is subsidized by the tax payer. The industry should be accountable. The Smart Grid Consultant does not live in Ashcombe so his interest may only be to reveal what he believes to be closer to the truth. Here is his Maths ....
Nowhere does the applicant justify their quantitative figures. Performing a more "in depth" analysis than the applicant, they state that the proposed solar farm will produce "a peak output of approximately 7.5 MW." The latest government statistics[4] for 2013 reveal an average "capacity factor" of 10.3% for solar PV in the UK. The capacity factor is the total amount of energy generated during a period of time divided by the amount of energy that would have been produced operating continuously at full capacity. Some simple arithmetic reveals that the Sawmills solar array would thus be expected to deliver 10.3% of 7.5 MW of electrical power on average. Given that there are 365 x 24 = 8760 hours in one year, the solar farm should deliver 0.103 x 7.5 x 8760= 6767 MWh of electrical energy over the course of an average year like 2013. The Government's "United Kingdom housing energy fact file"[5] reveals an average annual energy use per home of 18.6 MWh. The energy potentially generated by the solar farm would thus power 6767 / 18.6 = 324 “average homes”, not the “2,100 homes” that the applicant claims.
Agreed - the Planners need independent expert advice because the the figures can be 'manipulated' or interpreted in so many ways. For example, just based on personal experience .....
1. our peak output is 4kw. Pro-rataed over 71 acres that would equate to about 37Mw, not the 7.5 quoted, (assuming 50% spare space needed on the site). That would imply about 1600+ homes (i.e. 324x37/7.5)
2. "average annual energy use per home is 18.6 MWh". I assume this is just electrical energy - seems high. Our usage is about 10Mwh. It would be interesting to compare what other people here use per annum.
3. We generate about 3Mwh. So, based on my figures in original post this means that around 1100sq ft would equate to power for 6 homes (180sq ft x6). So each acre would support 40 homes and 71 acres would equate to about 2800 homes. Then apply 50% "space reduction" gives 1400 homes. But if avearge usage is actually 10Mwh instead of 18.6Mwh then the number of homes goes back up to 2500+ (1400x18.6/10).
In any event the 324 homes quoted seems very low based on personal experience
Apparently one mistake solar panel planners make is to have most of them facing south. Although intuitively this makes sense, they have found in Germany that it is better to have a mix of east, south and west facing panels to avoid a midday spike in the supply.
Please 