Duck Curve Skeptic

SYV

I am very skeptical of the duck curve we all see. They all seem to be from the Winter months. How about a duck curve from the Summer months when offices, big warehouse stores, factories , etc. are using air conditioning and fully staffed. Also, I do not know how solar energy, at less than 14% of the California energy feed in could throw the curve off as far as the curve shows.

BB.

What is a "duck curve" (just have not heard the term before in any technical or hunting usage)?

My engineering rule of thumb... When GT solar was less than 10% of the grid capacity/energy usage, it could pretty much be "ignored" when running the power grid, and subsidies could be "buried" (utility charges everyone slightly higher rates to subsidies the retail and solar power industry)...

Over 10%, you are talking about levels that cause utility engineers and MBA's to pull out their hair--And you run real risks of catastrophic and cascading grid failures (see Australia).

A good place to start for California public power figures (~85% of the total grid infrastructure in the state) is this website (lots of data, clean "daily use graphs", etc.):

http://www.caiso.com/TodaysOutlook/Pages/default.aspx

It is really interesting to see it today... When the USA has pretty much shut down much of the private industry.

Most of the time, power usage goes up during work hours, and may even peak as people get home and turn on A/C, cook, clean, lights.

Today's chart, a 8 am, usage went from ~18,000 MWatts to ~8,000 MWatts for net power usage (I guess as solar/wind/co-generation systems "kicked in"?).

If you are trying to manage your generation sources--Big stuff like Nuke, coal, etc.... (cheap power) vs peaker power (natural gas turbines) vs the "unmanged power" that is "expensive (subsidised solar & wind)... These massive changes in usage cost you a lot (it can take 24 hours to ramp up and down a "base load" type power plant). So you end up "spinning standby" of your "cheap power" and pay for the unmanaged "expensive power"... Wonder why Californians pay something like $0.20 to $0.40 per kWH, and in the middle of the country, less than $0.12 per kWH?

-Bill

SYV

In case you are interested, here is a link to a Duck Curve video. https://www.youtube.com/watch?v=KwA44fr7apw&feature=youtu.be

The curve was justification for PG&E to move the peak rates to evening times when solar isn't being produced. This greatly impacted the ROI of solar installations. If you go back to your link http://www.caiso.com/TodaysOutlook/Pages/default.aspx and look at the bottom chart that shows renewable input to the total demand. Pick a Summer day before Covid-19, for example on July 10, 2019 you get renewables contributing 43% of the feed. Solar actually accounts for only about 14% of the total feed, so how can this be. I realize renewables include geothermal, wind, hydro but they do not peak at around noon so it must be mostly solar. It just seems the data must be skewed to allow rate increases. California solar installer have developed a deep distrust of PG&E.

BB.

Everything goes through the California Public Utility Commision... When you hang your business on Political/Lobbying/Subsidies, anyone that can convince a few government officials to take a 90 Degree turn, it can ruin "your day".

What happens next?:

https://www.latimes.com/business/la-fi-hy-musk-subsidies-20150531-story.html

MAY 30, 2015

Los Angeles entrepreneur Elon Musk has built a multibillion-dollar fortune running companies that make electric cars, sell solar panels and launch rockets into space.

And he’s built those companies with the help of billions in government subsidies.

Tesla Motors Inc., SolarCity Corp. and Space Exploration Technologies Corp., known as SpaceX, together have benefited from an estimated $4.9 billion in government support, according to data compiled by The Times. The figure underscores a common theme running through his emerging empire: a public-private financing model underpinning long-shot start-ups.

“He definitely goes where there is government money,” said Dan Dolev, an analyst at Jefferies Equity Research. “That’s a great strategy, but the government will cut you off one day.”

-Bill

Ampster

SYV said:

........ Solar actually accounts for only about 14% of the total feed, so how can this be. I realize renewables include geothermal, wind, hydro but they do not peak at around noon so it must be mostly solar. It just seems the data must be skewed to allow rate increases. California solar installer have developed a deep distrust of PG&E.

I don't think they have a way to measure residential solar as far as how CAISO collects the data. It just shows up as reduced consumption, which is the belly of the duck curve. The CAISO is a state entity and has no reason to skew the data. Generally rate increases benefit solar owners. I agree changing time windows does not. The CEC pushed the utilities toward TOU rates in the hopes that would reduce consumption during the neck of the curve. The utilities were making a lot of money off the tiered rates. 
Long term this is a death spiral for the utilities as more solar and batteries create load departure as more people self consume. That is what is happening in Hawaii. 

BB.

In the "olden days" (5+ decades ago), our local utility would put ads on their trucks for washing machines and dryers... Because they were generally used during off peak times. During sane times, the utilities tried to create a load/customer profile that would give them them, as much as possible, a steady state load profile... Those that could be powered by the "cheapest" energy sources (coal, nuclear, etc.).

All of the conservation, green energy (solar, wind, non-large scale hydro, etc.) made for these dramatic peaks and valleys--Which to a degree were based on weather, seasons, and pricing--Such as when wind subsidies were (still are?) so high, that the wind farms would not shut down their turbines when there was too much wind power (overloading feeder lines, more power than a region could consume)--To the point when utilities would pay $$$/kWH to not generate power, they still would, because the subsidies "were setup up to make them money no matter the needs/instructions from the utilities".

We have had a few posters over the years that have had notices from their utilities that their power prices were going negative for a short period of time--To help the utility balance the loads vs the sources.

It all sounds really nice... But many of these problems were created because of government/lobbies/and people that, apparently, have no idea how "cause and effect" work.

-Bill