Why the US is still trying to make mirror-magnified solar energy work

8 comments

1. **From the article:**

   The US is continuing its decades-long effort to commercialize a technology that converts sunlight into heat, funding a series of new projects using that energy to brew beer, produce low-carbon fuels, or keep grids running.

   On July 25, the Department of Energy will announce it is putting $33 million into nine pilot or demonstration projects based on concentrating solar thermal power, MIT Technology Review can report exclusively. The technology uses large arrays of mirrors to concentrate sunlight onto a receiver, where it’s used to heat up molten salt, ceramic particles, or other materials that can store that energy for extended periods. 

   The DOE has been funding efforts to get concentrated solar energy off the ground [~since at least the 1970s~](https://www.sandia.gov/labnews/2018/08/16/solar-40/). The idea was initially driven in part by the quest to develop more renewable, domestic sources of energy during the oil crisis of that era. 

   But early commercial efforts to produce clean electricity based on this technology [~have been bedeviled~](https://www.technologyreview.com/2016/03/18/8794/one-of-the-worlds-largest-solar-facilities-is-in-trouble/) by high costs, low output, and other challenges. 

2. >The focus of the concentrating solar field has also **shifted away from using the technology to produce electricity**—a job that its solar photovoltaic cousin now does incredibly effectively, cheaply, and on a massive scale—and toward using it to provide the heat **needed for various industrial processes** or as a form of very long-duration energy storage for grids.

   For electricity it needs a steam turbine and those things suck in this scenario, using the ‘heat’ as such to replace ‘fossil’, like in greenhouses or kitchen cookers, is pretty efficient.

3. Government keeps throwing money at CSP but no major private investor does. It has promise but in the USA there is just a bad taste in the investment world for it.

   Overall it’s hard to justify hot moving liquids vs just non moving plates of glass to an electric heater. PV has just become so stupid cheap.

4. Thermal solar is costly vs PV. You still have a full steam cycle power plant to operate vs PV that feeds to an inverter then onto the grid.

5. >But she says the department continues to invest in the development of the technology because it remains one of the most promising ways to address three big areas where the world still needs better solutions to cut climate-warming emissions: long-duration grid storage, industrial heat, and steady forms of carbon-free electricity.

   I kind of like CSP, I think the future is probably to pair it with traditional solar PV pannels parks and use a single transmission infrastructure alternating between them. Solar PV transmitting with normal sun day/night cycle and the concentrated solar heating all day long and dispatching after sun down.

   China has too much of a lead in PVs but concentrated solar is still anyones game, and thermal storage can be much cheaper at scale.

6. That ship has sailed, sadly. They are beautiful.

7. It’s all about which is cheaper. I think solar panels are cheaper so I think they will win.

8. Power continues at night as well.