Could the UK survive completely on Solar Power? I was recently discussing this with Pete Hague after reading some of the recent blog posts on Do The Math. There is certainly enough solar energy hitting the land every 4.5 hours to power the world for a year, but is there enough hitting our dull and cloudy land to keep us in energy? And is it feasibly harness-able?
First we need to know how much sun we get. Below is a plot of the average isolation values (in units of kWh/m^2/day) over a 10 year period for London (Blue), Dublin (Red) and Edinburgh (Green) taken from here.
The below table shows the maximum, minimum and average values. I have also adjusted the values to take into account the efficiency of solar panels. I have used a value of 20%, taken from here, this value can of course improve over time but it is currently the best we have.
|Insolation||Adjusted for 20% PV Efficiency|
The current energy usage of the UK is about 3 trillion kWh/year or 8.2E9 kWh/day. So all we have to do is divide the amount we need by the amount we can get to see what kind of area we’d need to cover in solar panels. So our table is now
|Insolation||Adjusted for 20% PV Efficiency||Required Area (m^2)|
As a comparison, to put these areas into perspective, the combined area of Scotland and Wales comes out at about 10E10 square meters. Now I’m not suggesting we have to cover them both in solar panels, I’m just pointing out how potentially useful it would be. Obviously if we did just cover Scotland and Wales in solar panels we’d end up with a surplus as there wouldn’t be much left there that required energy anymore.
From this brief analysis it is obvious that we cannot hope power the country on solar alone. Even if we assume 100% efficient solar cells and constant 4.74 kWh/m^2/day of solar radiation we are left with 1.7E9 square meters. Even if we found the room we might not have the money or resources for something on this scale (although it would probably do a lot of good for the job market). Solar is one of the most abundant and easily obtainable forms of renewable energy but if we ever wanted to make the country self sufficient when it came to energy it looks like solar is not really a feasible option in large quantities. It would need some help.