Electricity Policy

Sat06242017

Last updateThu, 16 Mar 2017 7pm

ISSN 2331-1223  Twitter

Facts, opinion, and oversimplification in our ever-evolving electricity grid

We recently had admitted to sometimes exhibiting an excess of zeal for clean energy. So, in a search for balance, we decided to indulge some knowledgeable friends who, if not exactly curmudgeons, may know too much.

Last week we surprised ourselves by taking issue with the many headlines proclaiming 2016 as “the hottest year on record.” It was. But the headlines did not tell the full story. In fact, in 2016 the global temperature rise above the prior 2015 record was less than one-tenth of a degree Celsius higher! In other words, easily well within the margin of error. For those of us concerned about the still-unknown effects of unchecked climate change, it is tempting to dramatize many effects that many predict, the worst of which still lie in the future: e.g., sea rise that will inundate much of south Florida, even Mar-a-Lago. Despite Hurricane Sandy and other oft-cited effects of sea rise and storm surge, relatively little projected damage can readily be seen—because it hasn’t occurred yet. But should we be concerned? Yes.

Likewise, though we are big fans of renewable energy, we have to admit that the many headlines announcing that new wind and solar capacity added to the grid in 2016 far outpaced that of coal, natural gas, and nuclear. While literally true, this blithely ignores the fact that a megawatt of installed solar or wind doesn’t provide nearly the same amount of energy as, say, a megawatt of natural gas generation. We’re not advocating gas generation, but one should compare the energy output of sources or their effective capacity contribution as well as their nameplate capacity.

The above cavils invite a reexamination of what some would call “magical thinking.” Where does that leave us? Well, we’re still in search of the truth, “the whole truth, so help us, God.” The latest oversimplification of the truth falls on the other side of the clean energy ledger.

Several recent articles have noted that using storage in conjunction with solar generation may increase both overall energy consumption and emissions. Why? Because any form of storage, whether pumped hydro, or compressed air, or batteries uses extra energy in charging and discharging the storage, and in the round trip from generation to storage and back again.

Is that a bad thing? Perhaps not. It might depend, for one thing, on the source of the energy that’s being stored. Take wind, for instance. Wind energy often maxes out at night, precisely when system demand is lowest. Wind often has to be curtailed at night. Wouldn’t it be better to put it to economic use, storing excess wind and releasing it at system peak demand to trim high prices and curb use of the most polluting peaker generation?

What about solar? Same thing. Solar maxes out in midday and late afternoon, and will sometimes have to be curtailed—spilled, in effect. This will be increasingly true as more and more solar comes online, either in grid-scale generation or rooftop solar.

Is it a bad thing to store excess wind or solar energy and use it to arbitrage against higher priced energy at peak demand. I would say it’s a good thing, especially if the energy would be virtually costless and pollution-free, as wind and solar typically are.

In the ever more complex energy sphere, things can be reduced to very simple—sometimes too simple—terms, often to dramatic effect, but not always accurately. Steve Jobs said: “Think different.” We say: Look deeper.

—Robert Marritz 

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