Solar Futures

(via)

… coal-fired power plant is currently under construction in West Virginia. It is the 695-megawatt Longview plant in Monongalia County. Ground was broken in early 2007 for the $1.83 billion dollar plant – the first coal-fired plant built in West Virginia since 1993.

so it costs $2.6 million per megawatt of capacity to build a coal fired power plant.

(via)

… Nanosolar had teamed up with Beck Energy to build the 10-megawatt power plant, which would cost around €30 million ($42.75 million).

and it costs twice as much, $4.3 million per megawatt of capacity to build a solar powered power plant… only this plant needs no fuel except the sun for the next 10-30 years.

 
Ugh, there are way too many variables for me to actually say the solar plant is the way to go. The primary questions being:
 

  • How much does it cost to fuel the coal plant per megawatt-hr
  • What is the solar panel replacement regimen? Do panels need replacing after 5 years? 50?
  • Are the numbers I’m looking at correct? A 10 megawatt solar plant obviously can’t produce at night so we’re not comparing apples to apples…

Ok, lets take a stab at it…. coal costs about $70 per short ton. Coal plants actually produce about 2.5 mWh/ton of coal (How much coal is required to run a 100-watt light bulb 24 hours a day for a year?)

To power the plant for 1 hour and generate 695 megawatts, you need (695/2.5) 278 tons of coal (wow, that’s a lot of truckloads of coal). That coal costs $19,460. To power the plant at full power for 10 years, you’d have to buy $1,704,696,000 in coal. (I’m not counting any other operating expenses but assuming fuel is the largest expense)

So with the solar plant, you’d spend twice as much to build the plant, an extra $1.83 billion and you’d recoup $1.7 billion in fuel costs over 10 years.

Oop, I’ve assumed that the solar plant is capable of running at full power 24 hours a day. Unless the plant is in orbit, it only gets good sun 8 hours/day… 1/3 of the day, tripling the payback period from 10 years to 30. In general amorphous solar panels have a life of 10+ years while crystalline solar panels have a 30+ year life. My first guess is that since Nanosolar’s panels are flexible and “printed” instead of grown crystals that they will have a similar lifespan to amorphous panels. But I certainly could be wrong, after all, they’ve got the word “nano” in the company’s name. And, more importantly, they put a 25 year warranty on the panels, hmm!

If the solar plant has a useful life of 30 years without major repairs (total panel or inverter replacement), it would seem that the costs of a solar plant are conceivably comparable to a coal fired plant. And that’s what we’ve all been hoping for. And then there’s that whole carbon-neutral, no-sulphur-dioxide, renewable thing…

Very exciting.

Leave a Comment

Do not write "http://" in your comment, it will be blocked. It may take a few days for me to manually approve your first comment.

You can edit your comment after submitting it.