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But that's already cheaper than building new coal or natural gas plants. The cost per watt of solar plus battery, right now, is the cheapest available form of p

But that's already cheaper than building new coal or natural gas plants. The cost per watt of solar plus battery, right now, is the cheapest available form of power. I don't understand why you don't think that it's going to replace a majority of primary and secondary energy usage on the planet relatively quickly. I'd bet a dollar that, in 50 years time, nearly all energy usage is going to be primitive biofuels or solar-PV-origin.

XorNot 2y ago
The sticker price of any given power source is irrelevant: the question is how much does it return on the investment. If building a solar installation is cheaper per kW then building a gas generator, that literally doesn't matter if the only times the solar installation generates power is when power prices are negative.
- jaggederest 2y ago
  Including batteries. It's a peaking plant in a can. As far as I can tell the all-in non-land costs are cheaper, full stop. I also did the analysis for new nuclear under a relaxed regulatory regime (i.e. substantially cheaper and faster than now) and there's no way it wins. For the price of a gigawatt of nuclear, you can get 5 gigawatts of solar that's online next year, plus half a gigawatt of battery. I could be wrong, I'm just an armchair economist on this stuff, but I just don't see how it makes any economic sense to build anything but solar unless you're located somewhere remote and arctic (i.e. Åland or something)
  - XorNot 2y ago
    But it's the half gigawatt of battery which is the problem - it's nowhere near enough. Roughly batteries scale 1:4 power-to-energy. So 0.5 GW is only about 2 GWh of actual storage. But you need that for almost 18 hours a day since solar tends to have about 6 productive hours a day. So your batteries are covering you for maybe 0.1 GW of constant draw - presuming nothing goes wrong (i.e. a week of regional cloud cover). On top of that the solar plant capacity factor is somewhere between 10% - 30% in most locales, so the sticker plate capacity of 5 GW is going to be under 2.5 GW at best (and that would be a 50% capacity factor). I've never been able to find a way to square an actual "no fossil fuels grid" with the supposed cheapness of solar or wind - it always feels like people are quoting selectively useful $/GW values and then not giving a full accounting of the assumptions behind them - i.e. GW type quotes originate with thermal powerplants which have capacity factors which are essentially "whatever you want if you pay us".
    - ben_w 2y ago
      I'm less optimistic about the current state of affairs than the person you're conversing with, but I think more than you. The LCOE values I've seen place batteries+PV at ~ nuclear… but nuclear is more expensive than almost anything else. I anticipate further reductions in the price of batteries from the learning curve and demand driven by electric cars where they're already cheap enough to replace ICEs, such that the cost of batteries for electricity time-shifting will be OK fairly soon (as in: 5-10 years)but that's a forecast and not a guarantee. There's also the possibility of a global power grid — the maths works out just fine, few hundred billion USD and a year or two of global aluminium production, we have to spend more than that on upgrading the last (hundred) miles even if we never build the global interconnects — but basically only China has both the interest and the capabilities to attempt something like that as part of a future belt-and-road initiative, everyone else will definitely not get past the "talking about it" stage.
      - XorNot 2y ago
        I mean that to me seems like the obvious answer if we're doing solar: don't really do storage, just wrap the generating capacity around the Earth and have it follow the sun. Nation-states would likely still retain strategic reserves of thermal powerplants, but they wouldn't be run, and the budgeting for them would be under national defense and interpreted through that lens (i.e. you can buy it down with strategic alliances and diplomacy).
        svnt 2y ago
        Why wouldn’t the right answer just be don’t grid-tie and switch back to DC for everything. Almost everything gets simpler and cheaper.
        ben_w 2y ago
        Switching everyone to DC is expensive; for one, we'd have to replace all the AC transformers on the existing grids.
    - 2y ago

XorNot 2y ago

The sticker price of any given power source is irrelevant: the question is how much does it return on the investment. If building a solar installation is cheaper per kW then building a gas generator, that literally doesn't matter if the only times the solar installation generates power is when power prices are negative.

jaggederest 2y ago
Including batteries. It's a peaking plant in a can. As far as I can tell the all-in non-land costs are cheaper, full stop. I also did the analysis for new nuclear under a relaxed regulatory regime (i.e. substantially cheaper and faster than now) and there's no way it wins. For the price of a gigawatt of nuclear, you can get 5 gigawatts of solar that's online next year, plus half a gigawatt of battery. I could be wrong, I'm just an armchair economist on this stuff, but I just don't see how it makes any economic sense to build anything but solar unless you're located somewhere remote and arctic (i.e. Åland or something)
- XorNot 2y ago
  But it's the half gigawatt of battery which is the problem - it's nowhere near enough. Roughly batteries scale 1:4 power-to-energy. So 0.5 GW is only about 2 GWh of actual storage. But you need that for almost 18 hours a day since solar tends to have about 6 productive hours a day. So your batteries are covering you for maybe 0.1 GW of constant draw - presuming nothing goes wrong (i.e. a week of regional cloud cover). On top of that the solar plant capacity factor is somewhere between 10% - 30% in most locales, so the sticker plate capacity of 5 GW is going to be under 2.5 GW at best (and that would be a 50% capacity factor). I've never been able to find a way to square an actual "no fossil fuels grid" with the supposed cheapness of solar or wind - it always feels like people are quoting selectively useful $/GW values and then not giving a full accounting of the assumptions behind them - i.e. GW type quotes originate with thermal powerplants which have capacity factors which are essentially "whatever you want if you pay us".
  - ben_w 2y ago
    I'm less optimistic about the current state of affairs than the person you're conversing with, but I think more than you. The LCOE values I've seen place batteries+PV at ~ nuclear… but nuclear is more expensive than almost anything else. I anticipate further reductions in the price of batteries from the learning curve and demand driven by electric cars where they're already cheap enough to replace ICEs, such that the cost of batteries for electricity time-shifting will be OK fairly soon (as in: 5-10 years)but that's a forecast and not a guarantee. There's also the possibility of a global power grid — the maths works out just fine, few hundred billion USD and a year or two of global aluminium production, we have to spend more than that on upgrading the last (hundred) miles even if we never build the global interconnects — but basically only China has both the interest and the capabilities to attempt something like that as part of a future belt-and-road initiative, everyone else will definitely not get past the "talking about it" stage.
    - XorNot 2y ago
      I mean that to me seems like the obvious answer if we're doing solar: don't really do storage, just wrap the generating capacity around the Earth and have it follow the sun. Nation-states would likely still retain strategic reserves of thermal powerplants, but they wouldn't be run, and the budgeting for them would be under national defense and interpreted through that lens (i.e. you can buy it down with strategic alliances and diplomacy).
      - svnt 2y ago
        Why wouldn’t the right answer just be don’t grid-tie and switch back to DC for everything. Almost everything gets simpler and cheaper.
        ben_w 2y ago
        Switching everyone to DC is expensive; for one, we'd have to replace all the AC transformers on the existing grids.
  - 2y ago