There is a widespread perception among those not conversant
with the details of electric power systems that we could someday soon get all
our electric energy from “green” sources like solar power, wind power and hydroelectric
power. That is naïve. It’s one of those popular ideas that sound plausible to
people who don’t really understand the technology. Let me explain why.
Power engineers talk about “base load” and “peak load”. The
base load is the steady amount of power required 24/7 on the grid to run
factory motors, refrigerators in homes and in stores, electric trains and
subways, furnaces and air conditioning systems, etc, etc. Peak load is the
extra power required occasionally, such as in the evening when everyone turns
on lights, or in very hot weather when everyone turns their air conditioning to
high. Now the problem for wind and solar green power is that it is only
available when the sun shines or the wind blows, so it is not very good for the
base load, which needs to be generated reliably all the time. Hydroelectic
power does better (so long as there is enough water in the reservoir or river),
but we have already exploited just about all the hydroelectric sites in the
country, so this isn’t going to grow much more.
There is a myth that we can just use batteries to store the
extra wind or solar power until it is needed, just like our iPhones do. That sounds
great to people who don’t really understand battery technology and battery
economics. Yes, batteries are getting better and cheaper, but there are physics-based
limits as well as economics limits to what can be achieved, and they fall far,
far short of storing enough power to manage the base load. That’s why it’s hard
to find an all-electric car that can go more than about a hundred miles between
charges, even with a thousand pounds of batteries.
Good base load generating plants are coal fired, oil fired,
gas fired and nuclear ones, and all except the nuclear plant produce greenhouse
gases. So if we really want to go “full green” we are going to have to have
nuclear power plants, lots of them. That
means we will have to get over our hysteria about nuclear power plants. It’s true that there have been bad accidents
with nuclear power plants – Chernobyl and Fukushima come to mind – but we have learned from those design
flaws. And no doubt if we build lots more nuclear power plants there will still
be an occasional accident – humans aren’t perfect. But it’s a matter of
balancing risks. If we don’t build nuclear power plants we will continue to
drive global warming, which in the end may produce a far more serious and
widespread problem than an occasional nuclear power plant accident.
So by all means we ought to expand our solar and wind power
farms as far as possible, but we will still need nuclear power to help sustain
the base load if we really want to go full green. And that will require the
public to get over its irrational fear of nuclear power. After all, even the Sierra Club has come to understand the necessity of nuclear power.
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