What about land cost for solar? At what point does that become a significant part of energy cost? Solar is less diffuse than wind but more diffuse than any fuel-based energy technology.
If it’s not significant now, surely at some point on our way to becoming a Kardashev Type 1 civilization it becomes a problem?
Solar panels are more economically productive than any unused land, forestry, or agriculture, and even some land uses in built up areas, such as car parking. What this means is that deploying solar upgrades utility.
There is a question whether there is enough land. The short answer is yes, easily, it’s not even close. Something like 4-5% of Earth’s land surface with solar can provide enough energy for 10 billion people to live at current US levels of energy consumption, and more than 35% of Earth’s land surface is essentially uninhabited deserts, mountains, swamps, forests, etc.
The longer answer is that we can provide the food needs of our civilization with about 20% of Earth’s land surface area under more-or-less intense cultivation, our civilization consumes roughly 100x more energy in the form of electricity, oil and gas, than food, and solar energy is about 1000x more productive, per unit area, than plants.
Strictly speaking, Kardashev Level 1 would require the entire surface, land and water, of Earth to be paved with solar. This is not particularly desirable nor necessary, in my opinion!
Strictly speaking, Kardashev level 1 requires control over a whole planet’s energy budget such that we are capable of using it. It says nothing about what we do with it. “Choose to not use it and leave some spaces wild, when we could easily choose otherwise” seems like a perfectly valid way to meet that criterion (that we don’t yet meet).
Right now land costs are on the order of $1k-$2k/acre/yr (1 acre ~ 4000m2, but I find it a convenient metric because an average acre receives an average of just over 4MW of sunlight if you spread it across the full 8760 hours in a year, which gives an average of ~1MW output at current efficiencies if you had 100% panel coverage). and with current efficiencies in typical regions that’s something like 2000-8000 MWh/yr depending on local weather and panel layout, so <$1/MWh. If we move towards tandem or other multijunction cells (which seems plausible in the 2030s) that power density could double. In addition there are some slower trends that should start to support things like agrivoltaics (dual use of land without decreasing crop yields) and comparably cheap or cheaper non-silicon semitransparent panels (which can actually be used in greenhouses or over crops, selectively absorbing wavelengths plants can’t use while providing shade to reduce water consumption).
In other words, there are lots of options to address this. World electricity consumption would have to increase by at least 3 orders of magnitude before land use even started to become a consideration.
I do think the OP is overestimating the rate at which energy storage and synthetic fuel costs will fall, and that that is a bigger consideration than land use. I also think resistance to early retirement of existing assets will slow down the later stages of the move away from fossil fuels, both in electricity generation and in transportation fuels. But I doubt that shifts the overall timeline by more than 5-10 yrs.
What about land cost for solar? At what point does that become a significant part of energy cost? Solar is less diffuse than wind but more diffuse than any fuel-based energy technology.
If it’s not significant now, surely at some point on our way to becoming a Kardashev Type 1 civilization it becomes a problem?
Solar panels are more economically productive than any unused land, forestry, or agriculture, and even some land uses in built up areas, such as car parking. What this means is that deploying solar upgrades utility.
There is a question whether there is enough land. The short answer is yes, easily, it’s not even close. Something like 4-5% of Earth’s land surface with solar can provide enough energy for 10 billion people to live at current US levels of energy consumption, and more than 35% of Earth’s land surface is essentially uninhabited deserts, mountains, swamps, forests, etc.
The longer answer is that we can provide the food needs of our civilization with about 20% of Earth’s land surface area under more-or-less intense cultivation, our civilization consumes roughly 100x more energy in the form of electricity, oil and gas, than food, and solar energy is about 1000x more productive, per unit area, than plants.
Strictly speaking, Kardashev Level 1 would require the entire surface, land and water, of Earth to be paved with solar. This is not particularly desirable nor necessary, in my opinion!
Surely, long before we pave over the earth, we will have expanded into space for energy, farming and minerals, and probably living as well.
Strictly speaking, Kardashev level 1 requires control over a whole planet’s energy budget such that we are capable of using it. It says nothing about what we do with it. “Choose to not use it and leave some spaces wild, when we could easily choose otherwise” seems like a perfectly valid way to meet that criterion (that we don’t yet meet).
Right now land costs are on the order of $1k-$2k/acre/yr (1 acre ~ 4000m2, but I find it a convenient metric because an average acre receives an average of just over 4MW of sunlight if you spread it across the full 8760 hours in a year, which gives an average of ~1MW output at current efficiencies if you had 100% panel coverage). and with current efficiencies in typical regions that’s something like 2000-8000 MWh/yr depending on local weather and panel layout, so <$1/MWh. If we move towards tandem or other multijunction cells (which seems plausible in the 2030s) that power density could double. In addition there are some slower trends that should start to support things like agrivoltaics (dual use of land without decreasing crop yields) and comparably cheap or cheaper non-silicon semitransparent panels (which can actually be used in greenhouses or over crops, selectively absorbing wavelengths plants can’t use while providing shade to reduce water consumption).
In other words, there are lots of options to address this. World electricity consumption would have to increase by at least 3 orders of magnitude before land use even started to become a consideration.
I do think the OP is overestimating the rate at which energy storage and synthetic fuel costs will fall, and that that is a bigger consideration than land use. I also think resistance to early retirement of existing assets will slow down the later stages of the move away from fossil fuels, both in electricity generation and in transportation fuels. But I doubt that shifts the overall timeline by more than 5-10 yrs.