| Solar is much cheaper and wind was already cheap, however the question, for both carbon and cost, is what is the price of the renewable intermittents with storage and backup. Batteries and storage in general have not had the step changes in cost and performance that solar has. Backup tends to be fossil plants. Ultimately energy density is a zero sum game for the environment and cost. In more detail: On storage:
Rough calculations show, if there were just enough Powerwalls to backup US peak demand for one hour it would require 10x the global annual mining production of lithium. And that's just one hour. And that doesn't include the electricity production. On panel material required for production:
It's generally estimated that US power, with good transmission, would require enough solar panels to cover the entire state of Massachusetts. Most non solar advocates think it's this square footage that's important. But of course this can largely be put on built land or in deserts so that is a relatively moot point. In fact, I want to get solar panels on my roof. However the real concern is what does this look like in terms of material mining? In immense panel production factories? (which isn't the greenest mfg process ever, likely one of the reasons it is largely done in China) On mining and transporting material required:
Mining is almost entirely powered by fossils, it has to be. And so is most transport. And so is recycling of metals. So the energy density of an energy source really is a zero sum game. If it takes a millionth the material for one source versus the other, that adds up. On maintenance
Then in maintenance, solar farms are truly "farms"- they require a lot of water to wash away dust to operate optimally. A states' worth of water is significant. On lifetime/end of life
First of all the lifetime of a panel is very optimistically 30 years/for a nuclear plant 60-80 years, and for the UPower fuel in particular can be used and recycled repeatedly for about 70+ years. afterlife/recycling
Then in recycling at end of life, and this is why I got so excited about nuclear as a somewhat hippie child growing up around oil companies in Oklahoma, solar is going to require a lot of energy (and fossil fuels or nuclear) to recycle, while nuclear can produce energy in recycling its fuel. The main import, to me, is: what is the energy density of this energy, and if emitting, how much pollution? Coal is far more energy dense than wind, which is why humans evolved from windmills and wood to coal. But it's so polluting which is why we are all working towards better sources, and the greater energy density (nuclear on order of 2M x any other source) that's roughly 2M less trucks transporting, 2M less mining to do, 2M less recycling, etc. Thats more on the environment than pure cost like you are saying but the costs add up if the full life cycle is taken into account on both sides. |