https://www.energy-charts.de/power.htm?source=all-sources&we...
Look at the beginning of the week on 18.December and Wind+Solar are only 5% to electricity production. Over 50% now. 5% then.
What is the end game here? Duplicate the whole infrastructure and have backup coal/gas/nuclear plants for half the time? That is why Germanys electricity prices are so high.
France: 17 cent per kwh vs Germany: 29 cent per kwh
Getting off fossil fuels. Specifically, it's something called the "European Grid Vision" [1]
The short version is advances in long range power distribution using DC transmission lines mean we can transmit power further with less loss than traditional high voltage AC lines. ABB has done wonders in rolling out HVDC technology [2].
But what does this have to do with the variable duty problem you ask? Alternative energies are hard to grid precisely because they are so variable as you observed. But with efficient transmission you could, for instance, collect solar in North Africa to provide power to the continent as well as pump up water into dammed fjords in Scandinavia which can be drained at night to through hydro-electric supplies. Wind in Germany or Tarifa can supplement dams one week, which can be drained the next. And of course there is always geo-thermal and nuclear.
So yes, today one needs the backup coal/gas/nuclear plants but not by 2040 in the updated roll-out schedule.
The endgame for Germany is wind + Russian gas, see Nordstream2.
You can't really compare that. The 17 cent are not real prices in a competitive market. In France electricity production is mostly monopolistic & state owned - some kind of deregulation start last year. ;-) EDF is state owned. Increasing the electricity price to cover real costs is not an option, the population will vote against it. Guess who pays for keeping the old reactor fleet alive? Costs for maintenance are rising to an estimated 45 billion Euros in 2025. Guess who pays for the super-expensive new reactors like the EPR? Without government money the company which builds it would have been imploded long ago.
Germany OTOH makes electricity expensive: there are taxes, investments in renewable energy, investments in decentralized grid, research, etc.. This also keeps consumption low and creates incentives to invest in new and efficient infrastructure and electricity consuming devices.
Although they consume 70% of Germany's grid energy, they are exempt from (or receive rebates for) much of the green energy taxes/levies.
- distribute regenerative sources geographically to have a better average production; there's always wind somewhere in Europe
- increase storage capacity through various means; e.g. pumped storage, chemical batteries
- make electricity consumption match production through various means; e.g. have (industrial) cooling and heating work in excess if there is an excess of "free" energy, charge electrical car batteries
- reduce electrical capacity requirements through gains in efficiency; e.g. improve home insulation
It's also not just a matter of production capacities: we're throwing away huge amounts of regenerative energy because we don't have the technology to a) adjust other production sources fast enough, b) store excess production and c) we don't have the infrastructure to transport it.
I know it is due to historic energy markets and old metering technology, but the fact that a kWh costs the same no matter the time of day is a situation that cannot continue.
And once you have intermittent excess energy that is essentially free some opportunities to use it might spring up, e.g. run various electrochemical processes for free and store the products or smelt aluminium or something like that.
End game? Trying to produce as much wind and solar as possible.
Those numbers are only getting better and better with every year.
Public education about grid engineering and its challenges would be a good thing.
[1] http://pubs.acs.org/doi/abs/10.1021/es401820p
[2] http://journals.plos.org/plosone/article?id=10.1371/journal....
There is some research going into putting concrete spheres into the ocean and pumping water in and out of them. The principle is the same but it doesn't need hundreds of hectares of forest to be cleared.
That's why you see energy being exported to hydro-rich Norway on windy winter days. It allows water to be retained in Norway's storage lakes for later use.
[1] http://pubs.acs.org/doi/abs/10.1021/es401820p
[2] http://journals.plos.org/plosone/article?id=10.1371/journal....
There are also problems with N2O emissions on the reservoirs, specially near the agricultural regions. And this is all without even talking about reducing biodiversity and destroying spawning areas for the fish by filling those with mud. So yes, efficiency is not always friendly.
[1] https://partofthething.com/thoughts/a-medium-length-primer-o...
France cannot react to a fluctuating power demand like Germany can and Germany simply takes over the French excess power. You cannot power down a (French) nuclear plant as quick as you can spin up a (German) gas turbine. So Germany operates on a stable power source of less than they actually need and import from France but if more power is needed, Germany quickly spins up their gas turbines for the time it takes to power up the coal plants. France' power plants normally run at full power and if the demand falls off, they are in a bit of trouble and rely on Germany to help them out. Be it by taking over electricity (most of the time) or delivering electricity (sometimes).
If Germany didn't take the excess electricity, France would have to burn it off.
http://www.businessinsider.com/french-heat-wave-one-tumultou...
> France imports UK electricity as summer heatwave puts a third of its nukes out of action
https://thinkprogress.org/france-imports-uk-electricity-as-s...
> Germany powers France in cold despite nuclear u-turn
https://www.reuters.com/article/europe-power-supply/germany-...
> France was heavily dependent on power imports from Germany during the first cold spell of this winter, despite the fact that most of the country’s nuclear reactors are back online