So far there is no real life example of what you are suggesting. The only countries that has gone green include either nuclear or hydro in their mix.
Storage + Intermittent is not enough to power a modern grid.
Also yes you do need to always meet demand to ensure the frequency is stable, otherwise you'll have massive problems.
Give it a few years; solar and batteries are getting better and cheaper, and the kind of grid interconnections needed for power sharing to even out the intermittency of renewables aren't going to be built in a day. It's an ongoing project.
On the battery front, a major patent on lithium iron phosphate expired just a couple weeks ago. I don't know what the long term consequences of that will be, but if it means being able to buy LFP batteries at $100/kwh or less outside of China, that could change the economics of utility-scale battery storage quite a bit.
In the long run I hope to see high capacity transcontinental HVDC lines linking continents so we can buy solar power from the other side of the Earth when it's night where we are, and sell our surplus when the sun is shining -- no batteries needed. That's hard and expensive. (Supposedly China is working on a deal with Chile where China can buy solar power that gets sent across a proposed trans-Pacific power line. I think that's the kind of megaproject that every industrialized country should be thinking about.)
Due to the gas issue with Russia Germany is planning to re-commission 15 coal plants, that's 10GW of capacity. 20 years ago, Germany had roughly... 10GW of nuclear, now decommissioned.
But again, let's repeat all together "lets overbuild renewable capacity, non-proved large scaled battery storage, a lot of smart-grid and some hydrogen storage".
The biggest world hydrogen tank, the one used by the NASA, can power-up an average natural-gas station for roughly half a day. But hydrogen is the future for sure!
Technosolusionism is actually one of the biggest problem we have. You want to solve this CO2 issue, first reduce your consumption by at least 80% to reach Paris Agreement.
But don't worry, if we're not doing it by will, the laws of physics and thermodynamic will do it by force ;)
Reducing total energy consumption by 80% isn't going to happen short of a nuclear war or equivalent event. Even with fairly extreme energy conservation efforts, the total amount of electricity used is likely to go up as people switch to using electric vehicles for transportation. I think we need a lot more renewables and probably more nuclear too. Whatever it takes to not be burning coal and gas. (And there might be an argument in some cases for building gas plants to replace coal plants. But I'd rather than money and effort were spent on something better.)
I don't see a realistic path forward for hydrogen, except maybe as fuel for aircraft. Batteries are good enough for most things, and a lot more efficient.
Well, the last twenty years or so a conservative German government did what it could to slow down the buildout of renewable energy. It's not very surprising that progress lagged behind optimistic assumptions.
> In the long run I hope to see high capacity transcontinental HVDC lines linking continents so we can buy solar power from the other side of the Earth when it's night where we are, and sell our surplus when the sun is shining -- no batteries needed. That's hard and expensive.
There are a bunch of projects in this space. I love going down this rabbit hole.
The EU supergrid is already being built out, and doesn't require linking far flung continents since it links Norwegian hydro and North Sea wind power, among other sources. A mix of geographically distributed hydro, wind, solar, batteries and perhaps geothermal will negate the need for relying on solar + HVDC stretched around the globe along with the geopolitical risks.
I live in Oregon; we have a lot of dams on the Columbia that can be used for intermittent power. I don't know if they have a capability to pump water upstream at Bonneville or any of the others when they have surplus power, but that seems like it'd be a useful thing to add if its feasible.
In this note you speculate optimistically in several places - "give it a few years", "I don't know what the long-term consequences of that will be", "I hope". Right now, we have what we have. The demonstrated paths to emissions reduction include nuclear and gas. We have a weird situation with electric vehicles in some regions where brown coal is being used to power electric vehicles, making for worse emissions at higher cost than oil - that's where speculation-based policy goes.
It's interesting that we are now at the stage were people demand real life examples of economies having completely transitioned to renewables. The are no real-life examples for economies being 100% nuclear and nuclear power plants have been build for 70 years (receiving large subsidies the whole time), so why are you demanding from a technology 20years old what the much older tech has not achieved? It's not like electricity grids can be changed overnight.
The core difference is that Nuclear Power Plants are dispatchable sources - they fit existing models, they do not require drastic changes in the grid to ensure stability like intermittent sources do.
> Storage + Intermittent is not enough to power a modern grid.
As a previous comment pointed out, one solution is to just over-construct renewables. You can look through a graph of output of wind+solar for a large area and find the minimum output compared to its rated capacity. The output from wind+solar is never zero, and the minimums are usually short. Last time I looked at the numbers for UK, if I remember correctly, it looked like they had to have 2-3 times the rated capacity to produce enough for the vast majority of days with minimum production.
It's more accurate to say that nobody has demonstrated that storage + intermittent can power a large scale modern grid (there are plenty of examples for micro grids and islands). Whether it actually can or not is unknown.
And part of the reason is that nobody has really needed to demonstrate it yet. There have so far been other workarounds that have been acceptable. UK and Germany doesn't have their own hydro-power, but has built grid connections to tap into Norway's for instance.
> Also yes you do need to always meet demand to ensure the frequency is stable, otherwise you'll have massive problems.
The other side of this, that is increasingly being taken more seriously, is to have more adaptive loads. There are for instance large parking garages built for EV car ride sharing or rental services that are V2G capable. The cars have quite a lot of flexibility in when they do their charging, and they can even feed energy back into the grid. There have been studies of anything from varying the temperature of freezers and hot water tanks across the country, to varying production rate or temperatures is metal production.
To me, if we're serious about solving climate change, this is essentially a problem that solves itself: we absolutely need to make a MASSIVE amount of green hydrogen.. for trucks, ships, planes, e-fuels, fertilizers, steel, etc. That's a HUGE amount of load that can easily be load-balanced to follow the production from renewables. You can even feed some of the stored hydrogen back into the grid in rare cases with extremely low production, probably using existing gas peaker plants.
I'm not against nuclear btw, but feels like the most enthusiastic nuclear proponents often have a very myopic view of the problem. That is, they assume in 20-30 years, everything will look exactly the same as before, except all electricity is nuclear+some renewable. Assuming we don't solve the energy storage and load balancing problem is equivalent to assuming we don't solve the climate crisis, because CO2 emissions are about so much more than just electricity production.
> one solution is to just over-construct renewables
How is that a solution? No amount of solar/wind farms will make sun shine in Europe at night, or shine sufficiently in winter (when energy needs are the greatest).
> No amount of solar/wind farms will make sun shine in Europe at night
Wind farms don't need to make the sun shine at night, they just need to make the wind blow at night. So far they have managed to achieve that quite well.
More seriously, the amount of solar/wind farms you need is just enough to charge (home/car/grid) batteries during the day with the amount of energy that you will lack during the night. Fortunately energy requirements at night are lower than during the day, and the wind keeps blowing, so you might not even need batteries at all most nights, and could get away with just a 2x factor of wind farm over-construction.
> shine sufficiently in winter (when energy needs are the greatest)
Yes, this is the real problem. In the winter there are is greater demand and less supply; windless days become much more significant; and batteries can't store summer energy to be used in winter. For this, you do need more like 5x over-construction, perhaps combined with things like biofuels or atmospheric carbon capture using the excess energy during the summer.
Not a country, and quite optimal conditions but South Australia tells what the future will bring globally as renewables and storage continue to scale. Switch hydro from continuous to more of a peaker style of operation and we are very close.
> Sometimes the sun does shine and the wind does blow. That’s most of the time in South Australia, apparently. The average share of wind and solar during October was 72%. For 29 out of 31 days, 100% of the power used in South Australia (SA) was renewable. The sky didn’t fall, the grid didn’t collapse, and the apocalypse is not nigh.
