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Why would France need to keep building reactors? They're not building more of them because reactors last close to a century.

> That requires predictable energy prices, in a market where solar prices dropped over 80% in a decade. There are three different major energy sources all running half the cost of nuclear right now

And how many of those sources emit no carbon, and deliver power all around the clock? Geothermal and Hydroelectric can, but those are geographically limited.

Solar thermal is zero carbon and 100% uptime, but it's still expensive. Costs are dropping rapidly, though. And as stated earlier, solar + storage or wind + storage also meet your requirements, and are technically viable. It's just a question of cost. Cost of PV solar has dropped so much in the past decade that it could become the winner, even factoring in storage costs. Wind has far less storage costs, because the "What if the wind stops blowing?" theory that sounds so clever isn't really held up by decades of actual data.

Solar thermal is 2-2.5 times the cost of nuclear: https://www.energy.gov/sites/prod/files/2015/08/f25/LCOE.pdf

We could wait for solar thermal to get cheaper than nuclear (and assume that the cost of nuclear also remains static). Or we could just build nuclear power. The latter has the advantage of having consistent generation regardless of weather and time of year, and consuming a fraction of the amount of land.

Wind power has consistent output over long periods of time. But we still need to make the power grid resilient to fluctuations, which would require immense amounts of energy storage. To put it in perspective how infeasible energy storage is, take a look at California's latest energy projects. The current largest storage plant has 183MWh of capacity, and a planned one has a predicted 300Mwh of capacity[1]. By comparison, the Diablo Canyon plant generats 2,2000MWh of energy every hour [2]. These two energy storage plants can only store 5 minutes and 9 minutes worth of power generated by the Diablo Canyon plant respectively.

1. https://www.weforum.org/agenda/2018/11/california-will-repla...

2. https://en.wikipedia.org/wiki/Diablo_Canyon_Power_Plant

Is cost a factor, or is cost not a factor? Pick one. You asked if there was clean, consistent renewable, I gave you solar thermal, and acknowledged it's still cost-prohibitive. But I also expect its cost to plummet as experiments turn to production and lessons are learned.

First of all solar thermal is still intermittent and subject to weather and seasonal fluctuations. It has a built in thermal battery so it's consistent on a 24 hour basis, but it's still a variable source of energy.

Cost is a factor but not the only factor. Intermittency is a factor. Geographic limitation is a factor. Land consumption is a factor.

Cheap intermittent energy is an okay supplement, but cannot reliably deliver when it is needed. Hydroelectric and geothermal are great, non-intermittent clean energy but are impossible to build without the right geography. Fossil fuels are cheap, and deliver power anywhere but emit carbon. Nuclear power isn't as cheap as fossil fuels or intermittent sources. But it's the cheapest non-intermittent source that isn't geographically dependent.

If our goal is to fully replace fossil fuels, then nuclear is the best option (besides building geothermal and hydro where we can). Sure, solar thermal can deliver clean energy without the need for additional energy storage. But we could build twice as much capacity with nuclear and use a fraction of the land, and avoid having to build larger plants in the north and south, and avoid seasonal output fluctuations.

Ignoring clouds, the daily average insolation for the Earth is approximately 6 kWh/m2. [1] So you get about 0.25 KWe averaged daily per m2. Solar has serious land use issues. It is estimated that 1% of the UK would need to be given over to solar to deliver the current power needs. [2]

Noor II CSP delivers 0.66 TWh and is 6.8km2 (200 MW - peak?)

Ringhals Nuclear Power Plant delivers 23 TWh annually (3955 MWe)

A solar plant using the tech of Noor II and the power delivered of Ringhals would be 237km2 - twice the size of Paris.

[1] https://en.wikipedia.org/wiki/Solar_irradiance

[2] https://www.solarpowerportal.co.uk/news/if_solar_covered_one...

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