Renewable energy in the real world

Renewable energy will solve all our problems! A wind- and solar-based renewable energy system which will free us from all carbon emissions is within our grasp, and all we have to do to attain power Nirvana is reach out for it with trust in our hearts. What’s not to like?

Whenever I hear this I am reminded of Hyman Rickover’s opinions on the development of nuclear reactors back in the 1950’s. Admiral Hyman G. Rickover ran the US Navy’s nuclear reactor development program and was intimately familiar with the real-world problems that this involved. He understood full well the difference between pipedreams and reality, or, as he referred to it, between the academic and the practical. He had this to say in 1953 about the difference between academic and practical reactors:

An academic reactor almost always has the following basic characteristics: (1) It is simple. (2) It is small. (3) It is cheap. (4) It is light. (5) It can be built very quickly. (6) It is very flexible in purpose. (7) Very little development will be required. It will use off-the-shelf components. (8) The reactor is in the study phase. It is not being built now.

On the other hand a practical reactor can be distinguished by the following characteristics: (1) It is being built now. (2) It is behind schedule. (3) It requires an immense amount of development on apparently trivial items. (4) It is very expensive. (5) It takes a long time to build because of its engineering development problems. (6) It is large. (7) It is heavy. (8) It is complicated.

An academic renewable energy system is very similar to the academic nuclear reactors described above. You just have to put up a few wind turbines and solar arrays and presto! the world will be full of bluebirds and unicorns, and electricity will be too cheap to meter. After all, we don’t have to pay for any fuel costs: wind and sunshine are free!

Now let’s take a look at a practical renewable energy system. Wind turbines only work when the wind is blowing at the right speed. Too little wind and there is not enough energy to generate any power. Too much wind and the turbines must be shut down lest they overspeed and burn out. In Ontario this means that the conditions for wind turbines to generate power occur about 25% of the time. Similarly, solar arrays only work when the sun is shining, which means that in Ontario they also generate power about 25% of the time. Consequently, whether we use wind or solar power we will need back-up power for the 75% of the time that wind and solar aren’t available. Usually this comes from gas-fired power stations. When the wind blows at the right speed or the sun shines, we can switch off the back-up power. However, large-scale gas-fired power plants don’t run at their best when they are constantly switched on and off. Far better to let them run 100% of the time, in which case we can dispense with the wind and solar altogether which, when all is said and done, are merely bit players.

Another awkward characteristic of practical wind energy systems is that all those thousands of wind turbines have to be serviced. When you service a gas-fired power station you shut it down for a week or two every year (‘scheduled maintenance’), take the covers off everything, and let your technicians get to work in air-conditioned comfort. Servicing wind turbines means sending a crew to each and every one of those thousands of individual turbines, often in difficult-to-get-to, out of-the-way spots, then climbing up to a cramped nacelle at the top of a tall mast … you get the picture. Servicing a large fleet of wind turbines is very expensive.

Yet another awkward characteristic of practical wind energy systems is that turbines are located where the wind blows strongest, which is not necessarily where the power they produce is wanted. You therefore tend to have lengthy, and hence expensive, grid connections to get the power to where you want it. Gas-fired power stations, on the other hand, can be built fairly close to where the power is wanted. Oh, and because of the intermittency of wind and solar power, the grid system needs to be much more robust, and hence expensive, than if you have steady power as you do with gas-fired power stations.

And then there is the question of robustness of the power generators themselves. Gas-fired power stations don’t really care about the weather, even if there’s a hurricane blowing. Wind turbines and solar arrays however are quite fragile and do care about the weather. Before the recent hurricane season, Puerto Rico had some large solar arrays (with emphasis on the word had). Wind turbines have to be shut down if the wind blows too strongly, otherwise they have a nasty habit of bursting into flames or falling to pieces.

All of which goes to explain why renewable energy is so much more expensive and less reliable than energy from more conventional sources such as gas-fired plants. A gas-fired plant can profitably sell electricity at 6 to 7 cents per kilowatt hour (kWh). Wind power gets 11 to 13 cents per kWh in Ontario, while solar gets about 40 cents per kWh. However, whenever the wind blows or the sun shines, the grid system operator is obliged to take power from wind and solar operators in preference to any other sources. They have to do this, otherwise nobody would ever want to take wind and solar power, because it’s too expensive. Furthermore, wind and solar power are contractually required to be accepted whenever they are produced, regardless of whether the power is needed or not. Since wind is often strongest at night, when power demand is very low, Ontario is often in the position of having to sell wind power to other jurisdictions (usually in the US) at whatever price it can get. Sometimes this is a negative price; we have to pay them to take our power. Meanwhile, the wind turbine owners are still being paid at 11-13 cents/kWh for whatever they produce.

Of course, the aficionados of renewable energy tell us that these are merely minor inconveniences, and in reality we are saving the planet by not generating any carbon dioxide. It seems almost churlish to tell them that, as a result of the increased carbon dioxide levels in the atmosphere, our planet has greened by 14% over the last thirty years, i.e. there is 14% more vegetation cover on our planet than there was thirty years ago.

Whether or not carbon dioxide is harmful (and this is a moot point, in spite of the constant drumbeat of assurances by our political masters that ‘the science is settled’), one thing is certain. Whoever is making sacrifices to save the planet, it isn’t the owners of wind turbines and solar arrays.

 

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