Denmark reached 100% wind capacity in 2013, 9 years ago, and is today completely dependent on Norway and Sweden to supply hydro energy when demand exceed supply. Around 50% of the energy Denmark consume is from imports.
Denmark wind and solar farms do sell a lot of energy to other countries when the weather is optimal, but when its not they have to buy that energy from somewhere. EU ruled a while back that the Swedish energy grid must sell energy to Denmark if there is available energy, and so the Swedish grid and the Danish grid is thus tied in a way that removes any distinctions between the two.
Denmark is thus a terrible example of wind replacing fossil fuels, unless they suddenly would forgo imports and live with only having power 50% of the time. They are a great example of how you can invest in renewable energy as long the issue of grid stability can be solved through imports.
There are of course windy days where wind generates more electricity than is consumed, but the 53% figure is for the first half of the year.
The U.K. is up to around 40% of annual electricity consumption from renewables too. (43% of generation which I think excludes the 8% from imports.)
Net Zero is a good target but ultimately it’s getting most of the way there which is important. We need to replace heating, transport and industrial uses so we have to build out as much emissions free generation capacity as we can as quickly as we can. Renewables currently seem like the most cost effective approach.
Denmark sounds like a big success story. You've got half of locally consumed energy being generated locally from wind and solar, and you're also sending renewable energy to other countries which reduces the amount of fossil fuel they have to burn.
They should build even more so they can send even more and have an even bigger impact. And if their neighbors did the same thing and sent excess capacity to each other, then it'd all net off to not needing much storage at all. Maybe 10 percent of supply needs to be met with gas peaker plants when variability gets really bad, prior to storage solutions becoming cost effective.
So this case study of Denmark shows there is little substance to the criticisms of renewables.
With about 50% average effectiveness, overcapacity is fairly simple to calculate. With 100% capacity you get what we have today, ie around 50% from renewables and 50% from imports. At 200% capacity you get 75% from renewables, 25% from imports. at 400% capacity you get 87.5% from renewables, 12.5% from imports. At 800% capacity you get 93.75% from renewables, 6.25% from imports. at 1600% capacity its 96.875% from renewables, 3.125% from imports (assuming that renewables can scale down to that low weather conditions).
Obviously, running at high overcapacity results in significant less profits unless you can sell the overcapacity to other countries. When Denmark hit 100% wind capacity the growth of new wind halted dramatically down to basically the same as consumption growth. There is a limit on how much you can dump, i mean export, to other countries before there is no one willing to buy excess energy during periods of optimal weather conditions.
Firstly, Denmark's renewables are largely wind. But wind and solar are negatively correlated. As they add more solar, the variability will cancel out.
Secondly, variability is heterogeneous across geography. You're not building the second wind turbine in the same location as the first. As you connect countries up, or as you build in locations that don't currently have it, the variability cancels out.
Denmark is tiny. If the EU takes it up as a project, significant amounts of variability cancelling will happen, as you mix offshore wind, onshore wind, and solar, across the continent.
So, > 80% of EU's energy, from wind and solar, without any storage, should be achievable.
> running at high overcapacity results in significant less profits
Still better economics than nuclear. Even if you're at 3x overcapacity, it's still cheaper[1]. Not to mention you can sell most of that overcapacity (even to countries outside the EU) and get the money back, or convert it into green hydrogen and sell that.
Well, Denmark is tiny so if its not windy in one location then its unlikely to be very windy in an other. Same for the sun.
EU has however already taken it up as a project. It is called the European energy grid, which as I describe above forces countries to sell to each other. There is an economical limit to this from transit and transport costs, but in concept the whole union is already a single grid connected from the southern part of Italy to the polar circle in northern Sweden and Finland.
Denmark consumes around 33 Terawatt of electricity. They import 20 Terawatt. They also sell about 14 Terawatt of renewable energy. Sweden (hydro + nuclear), Norway (hydro), and Germany (coal, gas) are the main players that provide those 20 terawatt of electricity to Denmark.
This far up north the sun doesn't cancel out the still periods of wind. Demand for heating during winter far exceeds the few hours of sun that you get.
Green hydrogen, as nice as it is for reducing the emissions from steel industries, still costs about 10x of nuclear if you use that green hydrogen to produce power. There is a big economical reason why no one is doing that at this point in time. Estimates from researchers in the field varies from around 2035 to 2055 before we will have our first commercial green hydrogen power plant in operation. Still green hydrogen would be a nice way to recover costs if Denmark did decide to go for 300% overcapacity, but they would still need to heavily depend on Sweden, Norway and Germany to provide the electricity when demand exceeds supply. Their own grid will not suffice.
Why doesn't solar cancel wind far up north like it does elsewhere? The sun shines longer in the summer, and it's less windy in the summer.
"Well, Denmark is tiny so if its not windy in one location then its unlikely to be very windy in an other. Same for the sun."
That's true to a large extent for Denmark, but untrue to a large extent for the EU or larger countries. That's why I said that the EU can get over 80 percent of its energy just from renewables without storage, for a cost significantly cheaper than nuclear.
Denmark wind and solar farms do sell a lot of energy to other countries when the weather is optimal, but when its not they have to buy that energy from somewhere. EU ruled a while back that the Swedish energy grid must sell energy to Denmark if there is available energy, and so the Swedish grid and the Danish grid is thus tied in a way that removes any distinctions between the two.
Denmark is thus a terrible example of wind replacing fossil fuels, unless they suddenly would forgo imports and live with only having power 50% of the time. They are a great example of how you can invest in renewable energy as long the issue of grid stability can be solved through imports.