Except renewables can't actually replace fossil fuels. They need baseload provided by fossil fuels to be viable. They are also defuse energy sources, and so require huge surface area and lots of materials for collectors - not great for a growing world, both in population and per capita energy needs. Oh, they are variable across days, seasons and inter-year periods, but there is no battery technology coming that is able to store even enough power to a moderately sized city for a few minutes, much less the weeks it would need.
>And when we get to that last 5-10%
Try 50%.
False. Renewables could get to 100% of the grid. A key is using hydrogen for the last 10% or so. This is not currently competitive with fossil fuel, but then neither is nuclear.
When you consider that renewable share in % per day in Germany follows a normal distribution then you realize that there are only a few days that actually need to utilize hydrogen or methane to generate power.
For diurnal storage, batteries or other more efficient storage technologies would make more sense, since there would be more charge-discharge cycles over which to amortize the cost of the system.
Also, nuclear is only not competitive due to strangling regulation, not fundamentals.
You repeat an excuse, but nuclear builds have failed, and continue to fail, not because of regulation, but because of the high unforgiving complexity of nuclear power plants. The post mortems at huge cost overruns point to management failures, not new regulations sprung out of nowhere.
Where is this 10% coming from? Solar doesn't work at all between sundown and sunrise. Similarly wind also doesn't align with energy demand either.
Hydrogen isn't the answer either. It is incredibly inefficient to produce via electrolysis, meaning you would have to massively over-provison your collectors.
>This is not currently competitive with fossil fuel, but then neither is nuclear.
Why are you focusing on price? Renewables don't work. They could be free and you'd still be building natural gas plants. This why no nation is actually powered by renewables. When an article claims a nation has reached 100% renewable energy it's always geothermal or hydro - which require the right geography.
> Why are you focusing on price? Renewables don't work. They could be free and you'd still be building natural gas plants.
If price is no object, then obviously renewables can be made to work anywhere. After all, one could dump heat into underground thermal stores and use that as artificial geothermal. The thermal time constant for a several hundred meter chunk of bedrock is measured in centuries.
We have fixed price and supply of electricity over the day due to historical reasons, but it's not the future. And we can make the change gradually using variable pricing and speeding up the transition with the tools of regulation.
And of course other developments will help counter the price spikes - manufacturing and cooling systems adapting their power usage patterns, hvdc lines, energy storage, houses getting more energy efficient to cool/heat by using insulation and heat/cold recovery in ventilation etc etc. Energy is currently just so incredibly cheap that most obvious improvements are left on the table or progressing at glacial speeds.
Which goes to show: there still is baseload to consider, and there always will be. There is a green electricity ceiling that can only be circumvented with storage.
The amount of supply following the current industrial users are incentivised to do, and the requisite investments, will be much higher once the fixed price system is dismantled from the remaining portion of the market.
> Oh, they are variable across days, seasons and inter-year periods, but there is no battery technology coming that is able to store even enough power to a moderately sized city for a few minutes, much less the weeks it would need.
There is no need for "battery technology". This strawman keeps getting repeated just like crappy quadrocopters being used as killer weapons. It's because docile consumers can't see past their own little bubble and imagine that industrial giants also buy all their stuff at the supermarket.
No, you use an entire mix of different technologies and strategies to solve this problem. I don't want to repeat myself but seasonal differences are usually solved by curtailment. If winter needs more power you build enough plants for winter and then curtail the excess energy in summer. Medium term storage needs are trivially met with power to gas (both hydrogen and methane), short term storage needs can be solved via batteries, compressed air or thermal storage. All of these technologies have been available for a long time. The reality is that renewables can easily reach 80% generation without any storage investments at all so practically no country on earth has bothered to invest into additional storage, not because technologies are missing. It's just not a practical concern for the next 20 years.
Like what? What's the mix?
And why is nobody doing it?
>It's just not a practical concern for the next 20 years.
Because they use coal, natural gas, nuclear, hydro or geothermal ... You know power sources that can actually power a modern economy.
>Medium term storage needs are trivially met with power to gas (both hydrogen and methane), short term storage needs can be solved via batteries, compressed air or thermal storage.
You keep using words like 'trivial' when no nation is actually building this kind of infrastructure. No nation even has plans to build this infrastructure.
>All of these technologies have been available for a long
Yes. Therefore it should make you question why they aren't being used. Perhaps they aren't because they don't work at grid-scale?
If you scale that up by several orders of magnitude, you may just provide enough to power a small city for a few hours.
