Explaining  Negative Electricity Prices 

When my colleagues and I developed the theory of real time electricity prices back in the dark ages (1982), we were amused to see that our equations allowed for the optimal price to be negative. Power companies would pay consumers to use more electricity! At the time, we thought it was a paradoxical case that was unlikely in practice, except possibly in the middle of the night in systems with lots of nuclear units.

Fast forward 30 years, and negative prices are a regular occurrence in real systems, including in Texas and California. And now they are even happing in the middle of the day. But there is still a puzzle: why don’t generators stop generating the moment the price goes negative?

Several blog posts from Berkeley’s great Energy Institute, and my response to one of them, show that real power systems can have a lot of unanticipated phenomena. Take together, these probably explain these apparently strange behaviors.

Source: Is Solar Really the Reason for Negative Electricity Prices? – Energy Institute Blog.   and from Catherine Wolfram, Is the Duck Sinking?
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Photovoltaics in Mission Bay neighborhood = 30% wasted

TL;DR In Southern California should put PV on houses and buildings that are far from the coast, because coastal areas are cloudy much of the summer. But the actual pattern is the opposite. I estimate a 30% magnitude of loss. Even my employer, UCSD, has engaged in this foolishness in order to appear trendy.

The bumpiness of this graph shows the effects of coastal weather in August.

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Can Elon Musk Get SolarCity’s Gigafactory Back On Track?

Elon Musk clearly has a blind spot about manufacturing. Building a giant factory for the first use of a new process does not work, and theoretically it cannot work. Even if it did work, it would be non-competitive. Once a factory is built and machines installed, subsequent new discoveries/knowledge cannot be incorporated, except at the margins.

To reach the 100-megawatt goal, sources indicate that the pilot production line in Fremont would eventually need to yield between 800 to 1,000 high-efficiency Whitney panels per day. But the team was not able to automate the process consistently enough to produce more than dozens of Whitney panels per day, according to people familiar with the matter. Most of the production resulted in “scrap,” they say. “The big problem was simply that they couldn’t scale up the technology to the point where you could run it in a factory,” a source familiar with the development explains.

Source: Can Elon Musk Get SolarCity’s Gigafactory Back On Track?

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Worst graphic of the month?

Distorted pictures. The water droplets are drawn with linear scaling, when they should use area scaling. 672 gallons is about 3X 198 gallons, but the picture looks 11X larger!

Selective facts. Once-through nuclear cooling is about 400 gallons/MWh. Solar thermal normally uses wet cooling, with up to 900 gallons/MWh, or “500 to 800 gal/MWh.” (US DOE) New solar thermal dry cooling tech can reduce this “90%”, but does not work well on hot days. And dry cooling is also possible for nuclear plants.

SO distorted. Both visually and in substance.

There are plenty of arguments pro and con various energy technologies, but blatant distortion does not help make good decisions!

What happens if California’s solar panels start to fail over the next few years?

Solar Industry Anxious Over Defective Panels – NYTimes.com.I had not solar panel quality was becoming such an acute issue “so soon.” Judging by this NYT article, many Chinese-branded PV panels are not reliable.  This article sounds straight out of the book that Barry Naughton pointed me to, Poorly Made in China. The performance degradation  data on well-made panels is pretty encouraging: 0.5% per year is typical, but the key is well made. There are many manufacturing shortcuts and quality problems that will lead to failure of electrical connections after a few thousand temperature cycles, for example. (Think night/day in Colorado!)

testing solar panels

Power inverters, which are straight power semiconductor products, apparently may also be unreliable. https://www.greentechmedia.com/articles/read/3-Reasons-Why-Chinese-Solar-Inverters-Cost-Half-of-American-Inverters

It will be interesting to see what this problem with Chinese panels leads to in trade/market share. California and other states that subsidize PV should only pay for systems that pass good certification – for both performance and safety. For obvious reasons, testing long-lifetime behavior of electronics is very tricky.I wonder if we will   see a repeat of the “solar water heating” fiasco of the 1980s, when lots of houses put pool heaters on their roof that started to leak and ended up getting ripped out. When the economics of a project are based on a 20 year life, and it only lasts 5 years, that is a colossal fail. If it catches on fire, as described in the NYT article, that is another situation entirely!  What is the typical guarantee for homeowners in California?