Solar is now the cheapest form of energy

[exchemist]

Sharing wind, tidal, & solar energy smooths things out.
That North Sea is quite the powerhouse.

That is certainly true. The more renewables you have of different sorts, the more you can bridge the outages in any one of them. Wind and tides keep going at night.

 

[Heyo]

Solar Is Cheapest Energy: Renewable Energy vs. Fossil Fuels Cost




It's expected that there will be more demand for solar energy in the decades to come.



Cost was always the biggest barrier to solar, as the start-up costs made it too expensive, which is why gas and coal were generally favored.

Interesting news, especially in a time when prices for oil and gas are on a long time low. We'll have to invest in solar in the next years because there isn't any more space to place wind generators.

 

[Revoltingest]

If anyone wants one, I know where to buy a stirling cycle engine
powered generator with an 12' diameter parabolic mirror using
electronic sun tracking. The became obsolete when the cost
of photovoltaic panels dropped.

 

[Vinayaka]

Interesting. However I think with the cost of solar panels coming down, this will prove to be a technological dead end. And it only works where you have pretty intense sunshine.

All part of an integrated system using many kinds of sources. I believe that's the inevitable outcome. There is potential in a lot of ideas that go beyond fossil fuels.

 

[Mindmaster]

Cost was always the biggest barrier to solar, as the start-up costs made it too expensive, which is why gas and coal were generally favored.

I've never th

 

[Heyo]

Because of Carnot cycle limitations, no heat engine can in practice convert more than about 60% of the heat input into mechanical work or electricity.

As opposed to the 20% that photovoltaic brings.

 

[Mindmaster]

Cost was always the biggest barrier to solar, as the start-up costs made it too expensive, which is why gas and coal were generally favored.

I've never actually thought cost was the biggest barrier. (probably true in the 80s-90s) I think the real barriers are:

1) Space. Solar has low power output density for the space required. This is not necessarily a problem in the western half of the USA (what else are you going to do with desert), but is a problem for the eastern half and unworkable. If you got a few acres of land with a southern exposure it's pretty good, but otherwise (most of us) not so much.

2) It takes a lot of toxic chemicals to make solar panels. Those end up in the earth or in the water. They are also largely disposable and unable to be refurbished once their cells have exceeded their useful life. It probably could be done, but not without exceeding the cost of new panels that are probably 2x better anyway. This means a lot of this eco-warrior waste is unrecoverable, and just sitting in the pile.

 

[exchemist]

As opposed to the 20% that photovoltaic brings.

Good point! But I wonder how much of the intercepted light is transferred to the boiler in one of these solar steam plants.

 

[Revoltingest]

I've never actually thought cost was the biggest barrier. (probably true in the 80s-90s) I think the real barriers are:

1) Space. Solar has low power output density for the space required. This is not necessarily a problem in the western half of the USA (what else are you going to do with desert), but is a problem for the eastern half and unworkable. If you got a few acres of land with a southern exposure it's pretty good, but otherwise (most of us) not so much.

2) It takes a lot of toxic chemicals to make solar panels. Those end up in the earth or in the water. They are also largely disposable and unable to be refurbished once their cells have exceeded their useful life. It probably could be done, but not without exceeding the cost of new panels that are probably 2x better anyway. This means a lot of this eco-warrior waste is unrecoverable, and just sitting in the pile.

My solar panels are going on existing buildings.

 

[Heyo]

Good point! But I wonder how much of the intercepted light is transferred to the boiler in one of these solar steam plants.

Depends on the material of the mirrors but even cheap mirrors have a wider range than photo cells. The main problem is in the steam engine. The yield depends on the temperature gradient, i.e. the difference in temperature. In places where you have much sunlight (desert), you usually don't have much water for cooling.

 

[exchemist]

Depends on the material of the mirrors but even cheap mirrors have a wider range than photo cells. The main problem is in the steam engine. The yield depends on the temperature gradient, i.e. the difference in temperature. In places where you have much sunlight (desert), you usually don't have much water for cooling.

Yes. It seems a pity, given that the sun's surface is at 5000K, that one chooses a working fluid that even under supercritical temperatures won't be above 400C or so at the high temperature end of the cycle. But water does have other advantages as a working fluid.

 

[Shaul]

And yet China and the developing world keep building coal powered plants. Perhaps you should tell them.

 

[exchemist]

And yet China and the developing world keep building coal powered plants. Perhaps you should tell them.

Perhaps who should tell them, and why do you think they do not know already?

China is building both coal and solar. My understanding is their main concern is keeping up with electricity demand, since they are at that stage at which people are becoming rich enough for the first time to install a lot of electricity-consuming devices.

There's a graph here showing that, as of last year, solar in China was not yet quite as cheap as coal but very soon would be:
Already Cheaper Than Gas, China’s Renewables to Undercut Coal by 2026

Nobody sensible imagines that countries are going to switch instantly and 100% from one type of generation to another. But the trend is very clear and the effects are obvious.

 

[Tambourine]

Solar energy has always been the cheapest form of energy.
It's just that we externalize the environmental and social costs of other energy forms, and make the wrong people pay for it.

 

[Tambourine]

And yet China and the developing world keep building coal powered plants. Perhaps you should tell them.

The US continues to operate decades-old coal powered plants for entirely political reasons.
Do you consider that a more admirable way of going about it?

 

[Shaul]

Solar energy has always been the cheapest form of energy.
It's just that we externalize the environmental and social costs of other energy forms, and make the wrong people pay for it.

That’s not true. Hydroelectric is cheaper according to the U.S. Department of Energy. Hydro Power Vs. Solar Power Advantages

 

[exchemist]

Solar energy has always been the cheapest form of energy.
It's just that we externalize the environmental and social costs of other energy forms, and make the wrong people pay for it.

I think you may need to unpack that a bit. There are externalised costs for solar too, surely? Also, what sort of solar would have been feasible before the advent of photovoltaics?

 

[Shaul]

The US continues to operate decades-old coal powered plants for entirely political reasons.
Do you consider that a more admirable way of going about it?

The U.S. plants were built before we knew better. The Chinese are doing it now despite knowing better. Plus the U.S. is replacing its coal plants. So, yes, yes indeed, the U.S. approach is far better than China’s. Far better.

 

[Shaul]

Perhaps who should tell them, and why do you think they do not know already?

China is building both coal and solar. My understanding is their main concern is keeping up with electricity demand, since they are at that stage at which people are becoming rich enough for the first time to install a lot of electricity-consuming devices.

There's a graph here showing that, as of last year, solar in China was not yet quite as cheap as coal but very soon would be:
Already Cheaper Than Gas, China’s Renewables to Undercut Coal by 2026

Nobody sensible imagines that countries are going to switch instantly and 100% from one type of generation to another. But the trend is very clear and the effects are obvious.

The facts are that the number of coal plants in the U.S. are going down and the number in China are still increasing.

 

[exchemist]

The U.S. plants were built before we knew better. The Chinese are doing it now despite knowing better. Plus the U.S. is replacing its coal plants. So, yes, yes indeed, the U.S. approach is far better than China’s. Far better.

Here is a quite interesting article that gives what seems to be a plausible explanation: Why would anyone finance another coal power plant in China? - Resilience

What it boils down to is that they have firstly a huge need to ramp up electricity capacity and second, being an unwieldy Communist state of enormous size, have rafts and rafts of perverse incentives accumulated at different levels within officialdom over time, that take ages to reform. The article makes clear they are working on this reform but it is going to take time.

Sometimes, I think, we are in danger in the West of a simplistic "Yellow Peril" mentality by which we assume everything the Chinese do is the obedient execution of some top-down masterplan. In reality they have their own share of unhelpful regulations and competing internal agendas.