2021-07-28 Concentrated Solar Power, Solar PV

Thread from FB

<< Michael Burns

Concentrated Solar Power (CSP) is a totally different technology, which has a lot of operational advantages over PV, but still many disadvantages compared to other generation types. Functionally, CSP is simply thermal energy storage, so like a battery, when it’s “charged”, it can be included in the short term operational plan, and dispatched like any other source. However, also like a battery, it can’t be figured into long-term capacity planning, because it’s state of charge can’t be guaranteed at any given future time. Therefore, for long-term planning, it still needs spinning reserves to back it up, which adds significantly to the cost, and sort of defeats the purpose.

CSP is limited mostly by siting options. You can build them in the desert, but that’s about it. Also, since it’s using a steam cycle, you need an abundant source of water for condensing the outlet steam back into water. Ironically, the regulatory changes pushed by the Obama administration EPA related to water usage for thermal power generation actually made it even more difficult to find viable sites for CSP…

The theme of this entire discussion is… this shit’s not as simple as policy makers would like you to believe. Anything can be done with sufficient resources (time & money), but it’s super important that we keep energy affordable for both individuals and businesses. It’s absolutely possible to shift to 100% renewable energy sources, but to do so while maintaining our current level of reliability would/will be ridiculously expensive, and I don’t think that’s the approach we should be taking. >>

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I’ll discuss several changes that individually may not solve the problem but together they may be able to.

Q1.) It’s necessary to have this generation source that is dispatchable, by that meaning that it’s available 24 hours, 7 days. The solar plus storage at this time doesn’t have more than about 4 to 6 hours storage. This can be addressed in more than 1 way.

A1a.) Redox flow batteries can have multiple storage tanks to store the electrolyte so as long as there is ‘charged’ electrolyte the battery can discharge to the grid. Discharge time is limited by the stored electrolyte.

A1b.) The excess solar power generated is used to generate green hydrogen, which is stored underground, in the same salt caverns that are now being used to store natural gas. The hydrogen will be used to power the existing gas turbines that are now being used. GE is developing a gas turbine that will run on hydrogen. Early on, hydrogen will be added to natural gas to lower its CO2.

The hydrogen will be stored for months so that when daylight is shorter during winter the deficit will be made up by hydrogen.

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Q2.) << It’s absolutely possible to shift to 100% renewable energy sources, but to do so while maintaining our current level of reliability would/will be ridiculously expensive…>>

A2a.) Researchers recommend that wind or solar capacity be 3 to 6 times the load so that there is enough to supply the load and the needs of the storage batteries, redox flow type for long term storage. Also if the renewables are 5 or 6 times, the excess will be used to generate green hydrogen, to be sold to the customers who are now buying gray hydrogen (from fossil fuels). Again the storage will be underground where natural gas is now stored.

The expenses for building the excess renewables capacity will be paid for by the money that *was* being used to buy coal or natural gas for the (now decommissioned) fossil fuel plants.

The researchers have found that the cost of building a new utility scale solar plant is less than the cost of fueling a thermal power plant.

Utilities (PG&E for example) are opening PPA bids for a certain amount of power at a certain location. The solar and wind are underbidding the natural gas turbine plants.

Tesla among others is piloting the VPP virtual power plants. The millions of Tesla EVs are able to join the VPP if they have a bidirectional charger. This will make a very large virtual power plant.

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Q3.) << …it’s super important that we keep energy affordable for both individuals and businesses. >>

A3.) There are *no* ongoing costs for fuel for renewables. Solar has almost no moving parts so maintenance is low. Automated glass cleaners can work all night. But the biggest cost for solar PV is installation and it is lower cost than the ongoing costs of fuel for thermal power.

The excess solar capacity used to generate green hydrogen will earn money when hydrogen is sold to the customers that are now using gray hydrogen — which they will no longer be allowed to use. The absence of ongoing fuel costs earns money for the solar or wind plants.

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New nuclear power plants in the western world have had tremendous cost overruns and delays in construction: costs have skyrocketed to tens of billions of dollars and delays of more than 10 years. Utilities have seen this and are unwilling to enter into contracts for new NPPs knowing that there’s a better than even chance that they will have the same problem. It’s a sad and unfortunate fact that the nuclear power industry has done such a bad job, and ruined the industry; Westinghouse has gone bankrupt and put utilities at risk of further financial ruin.

Other new nuclear technologies have taken decades to get to the points of approval to begin construction. And the public has fought to prevent construction in their areas. This has made utilities even more wary of new nuclear plants.

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