Tuesday, July 31, 2018

When It Comes To Renewables, We Never Seem To Get The Full Story -- July 31, 2018

I often use the "formula" that 1 MW of electricity will "supply" 1,000 US homes. Apparently I am "way wrong."

From Boiseweekly:
In another life, I was a business reporter, and one of my beats was energy. When writing those stories, I almost always used the handy formula 1 MW = 1,000 homes. I probably would have continued using it if not for a startling number from Idaho Power: If all of the solar projects currently planned in Idaho come to fruition, nearly 2,000 new MWs of energy would begin flowing onto the grid in 2016. According to my math, that would be enough to supply 2 million homes, or 400,000 more homes than there are people in the state of Idaho. It would keep the lights on in almost every U.S. Census-designated housing unit in Cook County, Illinois (which includes the Chicago Metro Area). It could supply Seattle residents six times over.

That couldn't be right.

Then we learned not all MWs are created equal. According to the Solar Energy Industries Association, the number of homes powered by a MW of solar energy depends on average sunshine, electricity consumption, temperature and wind. Nationally, that's 164 homes per MW—a far cry from the ratio of 1 MW:1,000. Website commodities-now.com has a more precise—and circuitous—way of finding how many homes are supplied by a MW, with a formula that includes regional yearly average usage, the type of power plant and how efficient it is. The spread ranges from 400-900 homes per MW hour, with coal at 60 percent capacity or more, and solar at less than 25 percent. So 1 MW of solar could equate to 164 homes; 400-900 homes; or 1,000 homes.
The author completely failed to mention the concept of dispatchable energy. 

The above discussion has to do with rotating turbines or sunshine-fueled solar panels. If the wind stops and/or it's the middle of the night, .... well, you get the idea ...

A completely different discussion has to do with battery storage of renewable energy. When someone says they have a battery that can store 2 MW of electricity, one can assume 1 MW will support 1,000 US homes. The next question is "for how long?"

I was not able to find the answer in this article. Of course, in this case, the battery-stored-electricity is not to meet entire demand but to simply provide a bit of extra "oomph" during high-peak, high-cost periods. Proponents of this project suggest consumers will save money.

The next question, then, of course, how much would be saved by the average consumer. Can't find that answer in the article.

Something tells me gullible council members of South South City, Nebraska, were sold a "white elephant," as they say. 

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