More solar power in Nevada might be just gliding the lily

NV Energy a couple of weeks ago provided the Public Utilities Commission with a report on its compliance in 2017 with the legislatively mandated renewable portfolio standard (RPS).

Under the law, the electric company was required to obtain 20 percent of its power from renewables in 2017 and 6 percent of that had to come from solar generation. By 2025 the requirement will be 25 percent renewables with 6 percent of that from solar sources.

Both subsidiaries of NV Energy met the 2017 requirement. Nevada Power in the southern part of the state generated 23.1 percent of its power from renewables and 44.5 percent of that from solar, meaning about 10 percent of the total power came from solar. Up north, Sierra Pacific generated 25.5 percent from renewables with 31 percent of that from solar, or almost 8 percent of total from solar.

Still more solar projects are on the drawing board.

According to the Institute for Energy Research, there is a solar value cliff after which adding solar photovoltaic capacity has zero value. IER says that cliff is 6 percent of all power production.

“Peak solar generation occurs early in the afternoon, while peak electricity demand typically occurs during early evening,” IER says. “This mismatch presents a scenario called the ‘duck curve,’ in which operators are forced to rapidly scale up other generation sources as solar generation ceases in order to seamlessly meet peak demand.”

When solar photovoltaic exceeds 6 percent of production, the capacity value of additional photovoltaic falls to zero. (Solar thermal power like that produced at Crescent Dunes near Tonopah and Ivanpah power plant in California near Primm have a different generation curve.)

The laws of man seldom take into account the laws of physics and economics.

 

6 comments on “More solar power in Nevada might be just gliding the lily

  1. Steve says:

    Storage (batteries) have always been and continue to be the weak link in the PV panel production equation.

  2. Rincon says:

    The storage may or may not be as expensive as you imagine. The curve presented is oversimplified because it neglects the effects of air conditioner use. The curves of summer and winter would appear quite a bit different, which could simplify or complicate things. Air conditioners tend to run more when the sunlight intensity is high, which fits nicely into usage patterns. If only a few hours of energy need to be stored, as the graph suggests, then the cost may not be prohibitive. I suspect the railroad cars loaded with rocks might be cheaper than batteries with way more capacity for the occasional cloudy days. https://www.scientificamerican.com/article/energy-storage-hits-the-rails-out-west/

    In addition, the electric company in Illinois takes $40 off your bill if you allow them to disable your AC for 2 hours. Cheapskates like me just crank up the AC in the morning to cool the house and coast through the two hours in the evening with a one to two degree rise in temperature. This of course, flattens out the curve for the generators.

    It’s hardly a no brainer either way. The details matter greatly.

  3. Steve says:

    occasional cloudy days

    as opposed to those really sunny nights!

    OH…did you see that? The ctl c and ctl v I used!

    you think you funny.

  4. Rincon says:

    Electricity demand is lower later in the night.

  5. Steve says:

    Solar delivery is ZERO at night….you get what you pay for and zero is worth every penny!

  6. Rincon says:

    So while baseline plants operate 24 hours a day, solar produces in the daytime when demand is highest. It seems workable, but I would like to hear more engineers weigh in on this issue. 99% of the commentary is from people like you and me that only have a superficial knowledge of the intricacies.

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