Tuesday, February 24, 2009

Outsmarting the Smart Grid

by William Tucker, February 18, 2009

The latest delusion about energy is the “smart grid.” This bright new technological miracle will once again help us overcome the realities of physics and allow us to live in a world run on wind and sunshine.

... Ever eager to show they are “green” and hip it is, General Electric is now running an ad that shows how “the smart grid” will help us forget the difficult choice of whether to power our economy with coal or nuclear.

... The first premise is that, by conveying real-time pricing the smart grid will encourage people to redistribute their consumption of electricity to off-peak hours of the day. This will “level loads” and solve the perennial problem of utilities in meeting demand that occurs a few hours of the day or a few days of the year.

The second premise is that the smart grid will help integrate wind and solar energy - the two balky “renewables” that have the disadvantage of not being dispatchable when we want them. With the smart grid, wind and solar generation will always be available somewhere and so can be conveyed to where it’s needed.

Notice these are different things. The true “smart grid” will be a digitalized distribution system that conveys real-time information. Incorporating remote wind and solar, on the other hand, will require an upgraded grid, something entirely different. Our present 345-kilovolt, AC transmission wires can’t do it without unacceptable line losses. We will need to rebuild to 765 kV DC system – something that could take decades and easily cost several trillion dollars.

One has very little to do with the other. However they are often described as the same thing. Thomas Friedman effortlessly conflates them in Hot, Flat and Crowded when he writes:
[The smart grid] has made large-scale renewable energy practical for the first time ever. Why? Because the flatter your utility’s load profile gets, the more it is able to go out and buy or generate renewable energy and sell it to you and your neighbors instead of energy powered by coal or gas.
This is not true. A flattened utility profile has nothing to do with incorporating wind and solar. In fact it is just the opposite. The one great virtue of solar energy is that it peaks exactly when it is needed – in mid-afternoon and on hot summer days. If we level loads, we will be taking away solar electricity’s greatest advantage.

Let’s go back and examine these issues one at a time. First, start with the premise that the smart grid will enable us to redistribute energy consumption throughout the day. It’s fitting that the girl [in the GE ad] is standing in front of a clothes dryer, because that and washing dishes are the only examples anyone has ever been able to come up with about how residential users are going to “redistribute” their energy consumption.

What else can they do? Are they going to wait until after midnight to watch prime-time television? Are they going to heat up dinner at 4 a.m.? Are they going to turn on lights at sunrise instead of sunset? And how about air conditioning, that most voracious consumer of electricity? One suggestion floated by the Electric Power Research Institute (EPRI) in “The Green Grid,” a study published last June, is that people might “pre-cool” their homes by running the air conditioning in the morning in anticipation of hot afternoons. This may indeed level peak loads. But it will also consume more energy, since some of the pre-cooling will obviously dissipate.

There’s one more thing about drying your clothes at 10 p.m. Have you ever noticed what happens if you leave wet clothes sitting in the washer too long? They start smelling a little moldy, don’t they? Maybe this thing about drying your clothes just after you've washed them isn't such a bad idea after all.

Getting people to redistribute their energy consumption sounds suspiciously like those perennial suggestions for relieving rush-hour traffic by staggering work hours. It may look good on paper, but most people still like to get up in the morning, eat breakfast, work 9-to-5, come home, have dinner, watch some TV and go to bed. And so rush hour traffic – and patterns of electrical consumption – will probably remain much the same.

Although GE carefully avoids saying it, the underlying presumption of the smart grid is that it will somehow help us conserve significant amounts of energy. In that light, the EPRI study – although full of the usual enthusiasm - is also a very sobering document.

First, the study examined all the possible smart-grid savings - from shaving residential voltage to 114 V from 120 V to not having to send meter readers out to homes every month. Even then, its most optimistic prediction was that by 2030 we could reduce electrical consumption by 7 to 11 percent below what is now being projected. That’s not an absolute reduction in consumption but only a slowing of its anticipated rise. Second, as the study concludes, “shift[ing] load from on-peak to off-peak periods may not necessarily save energy.” It will only save money. And when you make electricity cheaper, people may consume more of it. Nor will any of this necessarily reduce carbon emissions. In fact, it may just as likely increase them.

Utilities don’t like peak loads because they have to meet them by building generators that may be used only two or three weeks of the year. These are almost inevitably gas turbines – essentially jet engines bolted to the ground. Because they don’t boil water, turbines can be started up and adjusted almost instantly, enabling them to follow loads. Steam generators, on the other hand, may take the better part of an hour to get to full speed. But turbines run on natural gas, the most expensive fuel. In addition, they sit idle most of the year, a costly way to employ capital.

So if we shift more uses to off-peak hours, we may save the utilities lots of money. But we won’t be saving energy. At best, we’ll be using the same amount. If some kind of electrical storage is employed – another often mentioned component of the “smart grid” – then we will be consuming more energy, since power is always lost in the transitions. And if leveling loads means shifting consumption from relatively clean natural gas turbines to base-load coal plants, there will be an increase in carbon emissions. [emphasis added]

Finally, as we said before, the great virtue of large-scale solar installations will be that they coincide with hours of peak demand. If we ever get to that point, we won’t want to flatten loads. We will want to keep them the way they are.

Wind, of course, is an entirely different animal. Although completely unpredictable, the wind does tend to blow stronger at night and in the fall and spring, exactly when it’s not needed. A strong, steady wind in North Dakota might allow Illinois to cut some coal consumption but it won’t obviate the need for fossil fuels because the wind will always need backup. “The Green Grid” concludes that wind will work best in tandem with - wouldn't you know it - natural gas turbines. They can be adjusted instantly to compensate for the wind's vagaries.

So the prospect that a smart grid is somehow going to save huge amounts of energy and pave the way for a solar future is an illusion. At best it will make electricity a bit cheaper and perhaps shave 5 to 10 percent off the anticipated growth in consumption. But the smartest of smart grids can’t distribute power that isn’t already there. ...