I don't disagree with Bilby's opinion that having to sell solar-produced electrical power to other states is ridiculous, but it isn't, in my opinion, a fault of the solar industry itself.
The number of days that California dumped its unused solar electricity would have been even higher if the state hadn’t ordered some solar plants to reduce production — even as natural gas power plants, which contribute to greenhouse gas emissions, continued generating electricity
Other types of energy, apart from solar, could also become more flexible. Many natural gas power plants have signed contracts with utilities that limit how often they can be turned off or ramped up and down.
“We need to make sure we can schedule the power plants to be available when needed,” Denholm says. “Those contracts have to change so the output from the power plants can vary.”
https://ww2.kqed.org/science/2016/04/04/what-will-california-do-with-too-much-solar/
This article does a decent job of looking at the positives and difficulties of solar, as well as possible options. It also includes this graph:
View attachment 11718
It does a good job of showing the issue. My question is about that light blue section in the middle labeled "imports" - what kind of imports, from where? I can understand that it may be difficult to power up/down natural gas or nuclear to counter-cycle with solar, but why can't the use of "imports" be reduced?
Last month, power company AES flipped the switch on a bank of 400,000 lithium-ion batteries it installed in Escondido, California, for Sempra Energy. Sempra’s San Diego utility plans to use the batteries, made by Samsung SDI, to smooth out power flows on its grid.
Tesla is supplying batteries to a Los Angeles-area network that would serve Edison International, which would be the world’s largest of its kind when finished in 2020, according to the developer, Advanced Microgrid Solutions. The network would spread across more than 100 office buildings and industrial properties.
When the Edison utility needs more electricity on its system, the batteries would be able to deliver 360 megawatt-hours of extra power to the buildings and the grid, enough to power 20,000 homes for a day, on short notice. At other times, the batteries would help firms hosting the arrays to cut their utility bills, said Susan Kennedy, chief executive of Advanced Microgrid Solutions, which is developing the project.
“It will show how you can use communication and control technology to make a bunch of distributed energy assets act like one big one,” said JB Straubel, Tesla’s chief technical officer.
http://www.theaustralian.com.au/bus...s/news-story/79478ee0f10372b7d7f22f54c48d9385
The above article included an estimated cost of the batteries vs the natural gas, which shows the batteries are currently about double. However, does that take into consideration the cost of paying other states to take excess solar power and/or turning off the solar power fields?
Stored power from lithium-ion batteries can do the work of a natural-gas peaker plant at an average cost of between $US285 and $US581 a megawatt-hour, according to a December report by Lazard Ltd. In contrast, electricity from a new gas peaker plant costs between $US155 and $US227 a megawatt-hour, according to Lazard.
Another article about the battery trials:
https://www.nytimes.com/2017/01/14/...california-big-batteries-as-power-plants.html
“We are looking at a tipping point for wind and solar,” Denholm says. “Wind and solar in many places in the country is actually the cheapest option. And that’s the first time in history where that’s been the case.”
The Australian article is behind a paywall, so I can't read it. Where does it get that incredibly low figure from?
The Mira Loma battery farm cost around $100,000,000, or $1,250,000 per MWh. I simply don't believe that suitable grid-scale batteries can cost as little as $600/MWh - if they did, we wouldn't be having this conversation. Elon Musk recently offered to build a battery farm in South Australia, and quoted $US250/kWh for a 100 megawatt hour system (
source) - that's $250,000 per MWh, one fifth of the cost of Mira Loma, and seems cheap at the price. I suspect that the Lazard figure you quote is per kWh, not per MWh, which would be an easy mistake to make, but would lead to a thousand-fold underestimate of the costs.
It's also worth noting that these systems have a power rating of 4 times the storage rating - an 80MW plant with 20MWh of storage can supply 20MW of power for 4 hours, or 80MW for an hour - and if you want it to cover all of the time the sun doesn't shine, then with a Solar capacity factor of 28 (lets be generous, pretend clouds don't happen, and say 33.3, to make the math easy), you will get 1.25MW of power out of it overnight. For a hundred million bucks, you would want to get a lot more than 1.25MW of power to be even vaguely competitive. (and of course, you still have to pay for the 2.5MW of solar panels to charge it up during the eight hours per day that the sun is shining on them).
This whole idea is one of those 'sounds great until you think about it' things - remember solar roadways?
The purpose of the electricity infrastructure is to guarantee that power will be there whenever the citizens flick a switch, and to do so at the lowest cost in terms of a) risk to human life; b) risk to the environment; and c) dollars. Solar power as it is currently implemented raises c), while also raising b) due to the need for gas power overnight, and particularly in the evening peak. Battery storage increases a) and b), and MASSIVELY increases c).
Nuclear power reduces a), b) and c), (relative to the status quo of burning coal and gas, with a small contribution from wind and solar). The only options that are cheaper than nuclear power are massively polluting, so they lower c) while pushing a) and b) through the roof. There are no options that are safer than nuclear power, and no clean options that are cheaper.
