[Arnt]

That link says two years, actually. 2016 dropped from 2015, 2017 and 2018 increased, nothing is specified for 2019. Are you saying there was another increase in 2019?

I assume that coal plants become unprofitable once they need considerable maintenance because they're not being built any more, which I assume means that no investors consider them a worthwhile investment. Further, because the price of solar and wind power is dropping. If the price curves continue as in the past decade, then in a few years, building a new solar plant becomes cheaper than operating an existing power plant in the first parts of the world. At that point, what coal plant owner will spend money on signfificant maintenance?

[Iwan-Zotow]

> Are you saying there was another increase in 2019?

Data not yet out, but yes, I believe so. There is a prediction it would rise till 2022 though not yet reaching the peak of 2013.

https://www.greencarcongress.com/2019/03/20190306-coal.html

> I assume that coal plants become unprofitable once they need considerable maintenance because they're not being built any more

mmm... not sure this is true about coal plants not being build. China and India I believe still building them.

> Further, because the price of solar and wind power is dropping.

well, while they are dropping, coal production is gorwing three years in a row (and potentially another three years in making).

> hen in a few years, building a new solar plant becomes cheaper

and what people supposed to do by night?

You recognize, that even if you saturate your grid by solar electricity from, say, 11 to 5, there are still 18 hours left...

[njb311]

Renewable energy storage is a solved problem, with a number of techniques already in use. It is a recognised part of the scaling-up of renewables generation by the grid operators, along with the knowledge that grids themselves need to be updated. But the idea that somehow energy experts are slapping their foreheads thinking 'OMG how did we miss this' is slightly insulting.

[Iwan-Zotow]

> Renewable energy storage is a solved problem, with a number of techniques already in use.

mmm... could you name a most significant one?

> But the idea that somehow energy experts are slapping their foreheads thinking 'OMG how did we miss this' is slightly insulting.

well, let me remind you how this conversation started - coal production is GROWING. Not because someone is just evil, but this is what customers demand - reliable supply of cheap electricity

[Arnt]

Where I come from, the hydroelectric plants are run partly according to the price. There are rules, the rivers can't be dry, but as far as permitted, the operators let the water flow when the price is high. Much of the weather forecasting is paid for by that; the power generating companies model electricity demand for the coming hours and days.

Where I live right now, the farmers are building things like this: https://upload.wikimedia.org/wikipedia/commons/thumb/f/fa/20... The green things are more or less balloons, because it pays to store the gas until peak time and burn most of it then.

[Iwan-Zotow]

> Where I come from, the hydroelectric plants are run partly according to the price. There are rules, the rivers can't be dry, but as far as permitted, the operators let the water flow when the price is high. Much of the weather forecasting is paid for by that; the power generating companies model electricity demand for the coming hours and days.

yeah, the only problem is how to apply this model to, say, south of US - California, Arizona, New Mexico, Nevada etc. Not a lot of hydro around

> The green things are more or less balloons, because it pays to store the gas until peak time and burn most of it then.

not sure how it is applicable to electric storage