The Answer to Climate Change Is Renewable Energy, Not Nuclear Power

[PamW]

25. It has to do with the stability of the grid

FogerRox,

Basically, the National Academy of Sciences is saying is that the intermittent "non-dispatchable" ( no "throttle" ) nature of non-hydro renewables creates instability on the grid. The unreliable nature of the renewables can be compensated for by having enough "dispatchable" ( with "throttle" ) generators. ( It's like "covering" for an unreliable co-worker. ) According to the NAS, as long as the capacity of the dispatchable generators out numbers the capacity of the renewables by roughly 4:1; then the grid will remain stable. ( At the margin, it may take the "extra effort" of multiple co-workers to compensate for a single unreliable worker. )

The problem then is to get enough storage. However, that is going to be a very tall order. Imagine how much energy storage capacity one would have to have to store a single day's output of a 1,000 Mw(e) power plant, or 1 Gw(w) ( gigawatt ) power plant. The answer to that is simple; the amount of energy produced by a 1 Gw(e) power plant in a single day is 1 Gw-Day. ( The product of a unit of power and a unit of time is always a unit of energy. )

How much energy is 1 Gw-Day? You can get Wolfram Alpha to do the conversion for you:

http://www.wolframalpha.com/input/?i=convert+1+gigawatt-day+to+kilotons

and you find that 1 Gw-day is 20.6 kilotons or about the energy of the atomic bomb that vaporized Nagasaki.

So for EACH large electric power plant you want to supplant, and we have thousands; you need the ability to store an atom bomb's worth of energy.

At present, there's really only one technology that comes anywhere near to having that type of capacity; and that is pumped-storage hydro.

Unfortunately, that's limited by the number of sites; and the opposition from people who want to tear down dams rather than putting up more.

So we can't just "wave our hands" and say "problem solved" when it really isn't.

As for HVDC; that doesn't do anything for the non-dispatchable / unreliable nature of renewables. In fact, there's a downside because one of the methods for sensing the load so that you can match it ( which is the real problem ); is the frequency drift in an AC system when the load isn't matched. With DC; you've given that up.

The bottom line is that we aren't going to have the storage technologies or capacity on the type of time-scale we need to avert the global-warming catastrophe; which is why the top climate scientists say we need to go with nuclear power:

http://www.cnn.com/2013/11/03/world/nuclear-energy-climate-change-scientists/index.html

http://www.cnn.com/2013/11/03/world/nuclear-energy-climate-change-scientists-letter/index.html

Renewables like wind and solar and biomass will certainly play roles in a future energy economy, but those energy sources cannot scale up fast enough to deliver cheap and reliable power at the scale the global economy requires. While it may be theoretically possible to stabilize the climate without nuclear power, in the real world there is no credible path to climate stabilization that does not include a substantial role for nuclear power

It's not just me that has come to this conclusion; it's the VAST MAJORITY of scientists; including climate scientists like James Hansen.

The good thing about science is that it is true, whether or not you believe in it.
--Neil deGrasse Tyson

PamW