Monday, November 5, 2012
I saw this up on Facebook a bit ago. The math didn't sit well with me after a lil' bit 'o pre-coffee sluggish brain cypherin'.
So y'all who know me know what I had to do. Break out the spreadsheet and get to Google'in. Here's what I came up with in response/commentary:
Solar power to nuclear power is not an apples-to-apples comparison.
Posts like this are good – necessary to get the information out there to fuel the global paradigm shift to sustainable energy sources. We need more and more of this in the U.S. where the shift has barely begun. We are way behind other countries who are not under the grips of the petrochemicalmilitaryindustrialcomplex/lobby. Way behind.
But these posts/memes are not good when they mis-inform, even if unintentionally. Inaccurate information/math doesn’t help the sustainable energy cause. Don’t even get me started on the topic of intentional/willful disinformation. But I don’t think that’s what we’re seeing here.
Let’s do the 8th Grade math (don’t get me started on the American educational system – let’s say it’s 8th grade math everywhere else in the world – in the U.S. it’s college level math)…grin…
Taking Germany’s nine (9) nuclear power plants at a combined rated capacity of 12,696MW, extrapolating that to twenty (20) plants, yields a capacity of 28,213MW. That converts to 28.21GigaWatts. With an average capacity factor of 70% for nuclear power, we arrive at 173,000GWh (Gigawatt-Hours).
For a total rated capacity of 22GW “Solar”, using a capacity factor of 15% (which is being really generous with the German sunshine – Arizona is 19% - John Wind is correct at about 9% capacity factor) – the simple math gives us 28,908GWh.
20 Nuclear Plants = 173,000GWh
22GW of Solar = 28,908GWh
In this example, the solar values equal 17% of the nuclear values.
So, every 6.58GW of installed solar replaces the output of one (1) average nuclear power plant.
The reason for this is that nukes run almost 100% of the time (downtime for maintenance, repairs, changing fuel rods, decreased demand, etc.) and solar only “runs” when the sun is shining.
To replace twenty (20) nuclear power plants, it would take 131.66GW of installed solar capacity.
Germany’s goal is to have 66GW of installed solar capacity by 2030, which is admirable. It is the right thing to do. But it is not enough.
Germany is currently purchasing electricity from nuclear plants located just outside of their borders, and increasing their coal-fired electricity output to replace the electricity from the eight (8) nuclear plants they shut down in 2011 after the Fukushima disaster.
Adding electricity generating capacity from solar, wind and other renewable sources is the right thing to do.
But it is not everything. It is not the end of the game. It does not get us to where we need to be, energy-wise, nor lifestyle-wise.
The one thing that everyone is not figuring into all of this – is that we ALL need to begin changing our lifestyles to BEGIN USING LESS ENERGY. Using less energy tomorrow than we are today. And even less next year than this year. And less, and less and less.
There is a myth prevailing that we can get all of our energy needs from solar, wind, and other renewables. We can, but not at our current rates of energy consumption. The entire planet will have to drastically reduce its energy needs. And “drastically” is an understatement.
And, indeed, Louis Cruz, Jr. is correct. The photo is of the PS10 Concentrating Solar Facility in Andalucia, Spain.
P.S. None of this analysis deals with the fact that solar only supplies power to the grid during the sunshiney daylight hours – unless we start talking battery storage for every PV array – then the math and economics and environmental benefits get much more complicated.
On a very related subject, check out a prior post of mine...