The Challenge of Energy: Part 2
By John D. Turner
23 Jun 2010

It’s all very well and good to talk about coal, oil, natural gas, hydro-electric, and nuclear power. But those are all “old-fashioned” power sources, damaging to the Earth, and “unsustainable”. We need, so we are told, a more “progressive”, “renewable”, and “non-polluting” source of energy for our growing energy needs. We need to not only have sufficient energy, we need to feel good about how we generate that energy and how we use it. We need to be “green.”

So let’s take a look at the two most popular of “green” technologies; solar and wind.

Both solar and wind energy, we are told, are “free”. Solar generates “free” electricity from the sun, which shines whether we tap it or not, while windmills generate “free” energy from the wind that blows whether we tap it or not. Sounds good. But how “free” is it anyway? And more importantly, how available is it? When I flip a switch to turn on the lights at night, will I get light?

This is where both solar and wind currently fall miserably short, in my estimation from becoming true solutions to our major power supplies (although there is a possibility in the future for solar which I will discuss later). While energy generated from coal, oil, natural gas, hydro-electric, and nuclear power are available 24x7 (leaving aside down time for repairs, and refueling in the case of nuclear plants), power from solar and wind are intermittent. There is no guarantee of how much you will have available for use at any given time. It’s feast or famine with both.

Solar, for example, only works when the sun is out. This means that for roughly half the day, you get nothing from solar. This depends of course on the time of the year and your latitude. In general, you get more in the summer and less in the winter, with the difference becoming more pronounced the further north you go.

And as if that were not enough, there are other variables such as cloud cover, obstructions (dust on the panels reduces their effectiveness; snow on the panels reduces output to zero), and orientation (they work best when pointed directly at the sun, meaning that a tracking system is optimal – increasing costs). The amount of electricity generated by a given solar cell depends on the amount of solar radiation it receives and the efficiency of the cell. And of course, as the panels’ age, they lose efficiency as well.

Plus, they take up a lot of space. And they are vulnerable to weather effects such as tornados, hurricanes, wind storms and hail storms to a much greater degree than a conventional power plant.

Windmills have similar problems. They only work when the wind is blowing. But, you might say, the wind is always blowing. Well, no it isn’t. What’s more, it has to be not only blowing, but it needs to be blowing within a certain range in order to be useful. Too little, and little or no power is generated. Too much and the mill has to be shut down to avoid damage. And in between those two extremes, the amount of electricity generated depends on how many RPMs the blades are turning. It is not a fixed amount. A given generator may be rated at 5 KwH. That does not mean it produces 5 KwH on a continual basis.

Because the electrical output for both of these technologies is unpredictable, storage technologies are necessary for both. There are a number of ways to do this; the most common approach is to store the excess capacity in batteries so that the power is available during those times when the sun is not out (solar) or the wind is not blowing. Or you have a conventional power plant on standby to produce electricity to cover the shortage.

Because of the need for backup storage and/or backup power generation, I do not see these technologies ever becoming our main power sources. As supplemental power, they work OK; they can be used to reduce our need for conventional power plants. They will not replace them.

And they are not cheap. Despite the claims of “free” energy, the solar panels and windmills are hardly free. In order to generate enough electricity from solar panels to power my home, for example, I would need to lay out roughly $60,000. That does not include the battery storage. And I would still have to be connected to the grid in case there was a long period of reduced solar input (like the past week and a half when we had pretty much continuous cloud cover) and I ran out of stored power. That or have a backup generator of some type using conventional fuel such as propane, natural gas, or diesel.

As for wind, as anyone who has had the opportunity to opt for “green” wind power from their electric company has found, it is more expensive per KwH than electricity from conventional sources. But it’s green. If you want, you can pay more and feel good about yourself.

It’s also a racket. The grid is not a packet-switched network and electricity does not come in TCP/IP packets with little tags on it saying where it was generated, to be sent to the appropriate home via some sort of “electricity router”. Electricity is electricity; the same no matter how it is generated. It is generated, transported, and directed to your home via the grid. The electric company isn’t going to run a special wire to your house to provide you with electricity generated by their “green” windmills. The electricity they produce is going to go into the grid whether or not you or anyone else subscribes to their feel good higher rates. It’s simply a marketing ploy to help pay for their windmills.

There is nothing wrong with that. If you want to help your electric company to pay for windmills that they are going to buy and install anyway, fine! Thank you for your service; you are helping keep my electricity rates lower. But if you believe that by paying the extra cost that you are somehow getting “green” electricity, generated by those same windmills and your neighbors, who are paying less are getting “dirty” energy from conventional fossil fuel or nuclear plants, you are deluding yourself.

Neither are windmills or solar panels as “earth-friendly” as their proponents would like you to believe. It is true that they release no “greenhouse gasses” while in operation, however the same is not true when it comes to their manufacture, transportation, installation and maintenance. Then there are the problems associated with the storage technologies used to provide power when they are unable to operate (at night or when there is no wind, for example) or operating at less than optimal power levels. If the “makeup” power is provided by conventional fossil fuel plants, there are the associated greenhouse gas emissions; if by nuclear power, the associated waste.

If the storage is provided by batteries, then what do you do with the batteries when they reach the end of their useful lifecycle? In the case of decentralized home power generation, this is typically done using standard lead-acid batteries, with the associated disposal problem of millions of lead-acid batteries.

Still, they have their niche. Both are useful in reducing our need for fossil fuel power generation, making us less dependent on foreign sources of oil. This is a big deal because this is a large strategic center of gravity for our country. However, since most of our power is generated from coal, which is mined here at home, this really isn’t that big a factor in our overall petroleum consumption. The biggest problem we have there is fueling vehicles, which, unless electric cars become more useful and available, all the solar and windmills in the world won’t fix. And the battery problem I mentioned above? This becomes an even greater issue with millions of electric cars cruising the highways. Once again, there is no such thing as a free lunch.

I personally like the idea of supplementing power, during daylight hours, with solar panels on the roofs of houses. Every house has a roof; it will be there whether it has solar panels on it or not, so there is no need to build additional structures. It doesn’t have to power the entire house; if it would simply power my air conditioner during the daytime, I would be happy. That way, I don’t need storage batteries. Unfortunately, we have the cost problem again.

I mentioned one way that solar could become a major player, providing the 24x7 baseline power necessary for a modern technological society and sustained growth. That would be to move the power generation off the Earth, where we are limited by the day/night cycle, and put it into space, beaming the power back to Earth where it would be collected in large “rectennas” and transported to the grid from there.

It is an idea that has been around for awhile, first researched way back in the mid 1970’s. The technology to do this is available now; the national will to do so is not. And with the president’s recent evisceration of NASA’s manned space program, the ability to do so, at least by the United States, is currently non-existent as well.

So, how much of our power is currently being generated in the United States by these two methods? Well, as of now, we generate 0.1% of our electrical needs in the US via solar panels. But not to worry! According to articles I have read in the past year or so, solar power generators are becoming more “common.” In fact, so common that by 2025, a mere 15 years from now, we might be able to generate as much as 10% of our electric needs from solar! Of course, that depends on how much our electric power needs also grow. And on massive upgrades to the power grid (which won’t be cheap). And assumes that the cost of solar power continues to drop and/or generous government subsidies continue to be made available. One thing about predicting the future – it isn’t easy; it’s something we get wrong more often than we get it right. Particularly when we are trying to be optimistic.

Wind power? We currently generate about 1.9% of our power (35,000 megawatts) from windmills here in the United States. Just to give you an idea of the number of windmills we are talking about, the largest wind farm in the United States, the Roscoe wind farm, is located here in Texas, with a capacity of 785.1 megawatts. It consists of 627 wind turbines and spans four counties, covering an area the size of Manhattan.

By comparison, Hoover Dam, the 38th largest dam in the world, has a total gross power rating of 2080 megawatts. While it is true that Lake Mead, which sits behind the dam and provides the power, is quite large, it is also true that Lake Mead provides enormous secondary benefits which are not provided by the 627 eyesores comprising the Roscoe wind farm.

After a period of time, maintenance becomes an issue as well. Which is easier to maintain; 627 independent windmills spread over an area the size of Manhattan, or 17 generators located in the vicinity of a 1200 ft dam?

All “renewable” power sources (excluding hydro-electric) taken together, biomass, geothermal, solar, and wind account presently for 3.7% of all electricity generated in the United States. And whereas the percentage growth in solar and wind energy production each year is relatively high, the growth in total percentage of power produced increases quite slowly. Adding 100 windmills to a wind farm of 100 windmills increases the capacity of that wind farm by 100%. However it only leads to a very small increase in total amount of electrical generation capacity provided by wind power across the entire United States.

We have a long way to go before either of these two technologies will meet a significant fraction of our electric needs. And while they may be contributors, they are not reliable enough sources to meet our baseline needs without significant overcapacity being built to compensate for the inherent unreliability.

That being said, while both have a place in the total energy mix of our nation, neither, at least at this time, is a viable replacement for coal, natural gas, or nuclear power. In my humble opinion.