Electrical plants can be generally grouped into 2 categories, base load generation, and peak load generation. Base load plants are mostly nuclear, coal and hydro. A base load plant usually puts out a huge amount of power 24/7. Because they are large plants they can't just startup and shutdown in an instant but are kept up and running all the time to provide the base load of power that we need around the clock. During the day and peak usage times smaller peak load plants are brought online to add in the additional power required to run your office and AC during the day. They are generally gas turbine in the US though there are probably still some oil fired plants out there. I expect to increasingly see solar and to a lesser extent wind become part of the peak load system but they do not significantly enter into the equation at all yet.

Base load plants are the most efficient and the least expensive to operate, but are the most expensive to build as they tend to be huge construction projects. I think that small base load plants might start around 600 mega watts and go up to 5 or 6 GIGAwatts of power output. They are generally located near or just outside of the cities or areas that they service due to the high cost and low efficiency of having to bring power long distances over really big wires. Peaking plants are smaller and very inexpensive and quick to build. A small gas turbine can be thrown up in a couple of years without the huge investment of a bigger plant. But operating it is hugely expensive. Gas cost per megawatt is hugely more than coal which is hugely more than nuclear which is hugely more than hydro. Coal only competes with itself. The main use for coal in the US is for electrical generation, the price fluctuations of coal affect only the price of electricity really. Gas on the other hand is used for much more than just electrical generation. It's the most common solution for home heating. If you have to run your peaking plant a lot you use a LOT of gas which then raises the price of gas which raises not only my electric bill, but my heating bill too. The impact of using peaking plants more than absolutely necessary is much more felt by the consumer than the electric utility who just pass on those higher costs.

Transmission lines are expensive and inefficient. We are capable of moving huge amounts of electric power from one place to another over long distances, but it's very expensive and power is lost to resistance in the lines and inductive losses and ground losses. They are also very expensive to build and require continual maintenance like any other infrastructure. It will always be cheaper and more efficient to generate your power as close to where you use it as possible. This is why we truck in miles of train cars full of coal to coal plants, rather than build the coal plants near the coal mines and build power lines. It's more efficient and cheaper to maintain the entire railroad industry to move the coal than to build transmission lines from where it comes from! Building transmission lines is not insignificant to the environment either. A huge amount of steal is required for the towers and it must be maintained, painted, the areas under them must be cleared and mowed, the ground treated with herbicides to keep plants from growing up the towers. They already cut huge corridors across the country. Any solution that can minimize the creation of new transmission corridors is to be preferred over one that requires the movement of power from remote areas. Assuming there is a choice of course.

We don't store any electricity. Every time you turn on a light a generator somewhere turns a little harder. It is generated as you use it. As you turn on more and more lights the load on that generator goes up and up until it tops out. The load is generally shared among many plants and they know enough about usage patterns to keep the available load above the rising demand. This is actually not just up to the electric companies, but in many places they are required by law to provide a certain amount of overhead. A gas plant that is idling waiting for you to turn on your AC is burning gas just sitting there doing nothing until you start using the current. They don’t turn on a dime and so sit and wait in this ready state waiting for you to get to work and startup your computer. There is no battery technology to store giga watts of power. There are some very small demonstration plants, and some companies starting to work on huge lithium battery arrays, but their cost estimates so far are so high as to elicit laughter rather than contracts from electric companies. I'm sure this will get better and it already has, but the idea of running the world purely on solar for instance will not happen because you cannot build a world spanning transmission line to bring power from places in the world where the sun is shining to the dark side, nor can you store thousands of gigawatts of power in batteries. (a potential option is putting the panels in space and beaming down the power as microwaves to antennas on the ground, more on this in another article perhaps, suffice it to say that this is not a solution that can be put together in the short term of the next 10 years, probably not the next 50)

Understanding why solar and wind cannot replace the current system of base load and peak generation is important. One would think that solar would make a perfect peak load generator. During the day is when we use the most power and during the day is when the sun is shining. Even just as clouds move across the sky though the amount of power delivered would fluctuate from almost nothing to the full capacity, whatever fraction of the needed power that might be. That may be great for your particular electric bill, but as far as base and peak load it wont make any difference to the plants that the electric company has to maintain and the peak turbines in hot standby. If the sun goes behind a cloud a turbine somewhere has to be spinning ready to pick up the slack. Hot standby uses less gas than actually generating, so less gas will be used, but the electric company cannot simply reduce it's plant size and planning just because you may or may not use slightly less power that day. They are required by law to be ready to supply the peak without browning out.

It is much better for the environment to find something to replace those peaking plants and base load generation plants rather than to pick away with solar/wind in small doses which cannot significantly impact the plants that are still required to be built, maintained and run in hot standby mode by the electric company.

Reducing usage through increased efficiency is also a terrific goal, but any solution that reduces the quality of life that people expect will not be tolerated even as the seas rise to greet us. Simply changing out all my bulbs with CF bulbs (which I have done personally) is great, but the savings through that and more and better HVAC systems and improved insulation and whatnot will only slow our growth, they will not reduce the demand. They cannot because they just aren't a big enough part of the whole. The solution must improve the availability of power and be able to scale as the population and usage of power scales up. People simply will not live with less air conditioning, and I don’t think that real solutions will require it. If you give people only the choice of doing without, or continuing to emit carbon, they will choose the carbon. And I don’t believe that they do have to do without.

My own personal reading of all this information has brought me to the conclusion that nuclear power is the safe and quickest route to solving all these problems. There are a lot of myths and really old and just incorrect information and fear about nuclear power. As I've looked into this I've found that just about everything I thought I knew about nuclear power was wrong. I'll write further notes about the specifics.

You’ll notice that I haven’t included a bunch of foot notes in this little paper. With the state of the internet the way it is, just linking to an article that repeats what you repeated is no promise of it’s accuracy. The information in this article is as I currently understand it to be true. If you have information to add or corrections to make, please drop me an email. If you question a fact or figure or conclusion, go and read up and discover something new and come back and tell me. Just suggesting that nuclear power is evil or some such thing is not helpful however and I may choose to publish your email with derision.

November 7th, 2008 by James Sentman

(the picture at the head of the article is of the fountain in Forsyth Park, Savannah GA)