78 Miles of solar

AES, which has a coal (454MW) and solar plant (4MW) plant in Guayama, is recommending the installation of 10,000MW of solar in Puerto Rico. They are advocating this as the primary source of PR's electrical supply. The use of batteries is included to even out availability but they do not address what happens when we have 2-3 cloudy days in a row (That never happens in PR, does it?).

That is 10,000MW nominal which translates to about 2,500 effective MW.

For a sens of scale, here is what the existing coal/solar plant looks like. 

So I was thinking about how much space 10,000MW would occupy. Looking around I find that the AES and Humacao solar sites each occupy 6-7 acres per nominal megawatt. Panels will continue getting more efficient so let's say 5 acres per MW. 10,000MW will require 50,000 acres. That is about 78 square miles or 202 square kilometers.

That is a lot of land that can't be used for much else. Nothing will grow under the panels so we lose the carbon eating potential of plants, even if just weeds. Some of it can be built on roofs or over parking lots but even so we still lose a lot of land. Not just land but relatively flat land. You know, like you would use for agriculture. Flat land that we have precious little of

To picture just how much 80 square miles is, I put an 80sqm block on top of a map of PR. The yellow block is to scale and is 40 miles long by 2 miles wide. Of course, the panels will be distributed in smaller areas but the total cumulative area will be the same.

Two other problems with making us dependent on solar:

1) Resiliency - Puerto Rico experiences regular hurricanes and has since forever. There is no reason we should not expect another Maria in the future. Hurricanes and solar panels do not mix. Just take a look at the Humacao solar farm which was completely destroyed.

2) Cost - Solar is not cheap. At present AES sells coal powered electricity to PREPA for 9-12 cents/kwh. EcoElectrica sells LNG powered juice to PREPA for about the same price. 

PREPA pays 18c/kwh for solar and has locked into contracts for 20 years at this price. 

Detailed data on how much PREPA purchases and how much it pays from these and other plants is available at their site https://aeepr.com/Documentos/Ley57/Tablas%20Compra%20de%20Energ%C3%ADa.pdf

Puerto Rico must have cheap, reliable, clean energy. Solar is not the way to get there. 

I will be happy to have AES or anyone else invest their own money in solar energy on the same basis as any other form of energy. No tax or regulatory sweeteners. Especially no sweetheart power purchase agreements. PREPA needs to buy solar on the same basis as they buy coal, gas, oil or other energy. They need to pay time based avoided cost. PREPA needs to purchase a mix of energy buying whatever is cheapest at any given minute.