> Apparently , wind+solar don't work at night (...)
This line of argument is either disingenuous or ignorant.
https://m.dw.com/en/new-energy-storage-facilities-in-high-de...
This line of argument is either disingenuous or ignorant.
https://m.dw.com/en/new-energy-storage-facilities-in-high-de...
https://www.energy.gov/sites/default/files/2019/07/f65/Stora...
Depending on how reliable you need your energy you'll need various energy storage mixes. Judging by the uk, wind can spend an entire month producing at 15% of it's normal output and can spend days at 3%. So you need a LOT of storage if you want to be sure the lights stay on. In the high hundreds of billions of Euros (and considerable ongoing costs given they need the equivalent of replacement eveey 10-20 years) in the case of Germany.
(And yes, we are going to need a lot of storage. On amounts close to 1/3 of our daily generation capacity. We also need some long-term and transportable solutions. And yes, there are currently no options on the market, for very obvious reasons. All of those can be done.)
By "nearly no" do you mean "tens, possibly hundreds of billions"? Batteries alone have had tens of billions in investment in the last few years.
> On amounts close to 1/3 of our daily generation capacity.
What kind of mix and overproduction are you thinking of that gets you ratios that low without brownouts? I suspect that if you want to live off wind and solar you'll need a week of capacity to get no brownouts when it's still and gray for a week unless you get nameplate capacity 10x your average needs.
Wind + solar isn't a reliable energy source, period. You need a base load, whether that comes from hydroelectric, nuclear or, unfortunately, fossil fuels. Wind and solar are great at topping off things and should be deployed as much as possible for individuals to reduce the demand on the overall network, but they will never be a credible energy source, no matter how much people say "but batteries are just around the corner!". They are no, they are a waste of valuable metals and they are horribly polluting to produce.
The situation completely changed now the highly variable loads are cheaper now than the former base supplies. So you would always use your money to overbuild on the variable supplies not build constant supplies. The thing is solar and wind don't compete with gas, they compete with coal solar. However with the way solar and wind costs are going, we will likely reach a point where it makes more sense to overbuild so much to even cover the load peaks instead of using gas peakers.
Everyone has had the experience of walking around on a windless night. You can have many such nights in a row.
Energy storage is not a short or medium term solution. Pumped hydro is already maxxed out pretty much everywhere it's possible as not all dams are suitable -- in fact most aren't. Battery storage for large grids currently covers minutes of use, a few hours may be attainable. But wind can be absent for days or weeks, and there's such a thing as winter when you're as far from the equator as Germany.
Ignorant. Right.
The Australian National University recently disagreed: https://www.anu.edu.au/news/all-news/anu-finds-530000-potent... . But even very large amounts of pumped hydro storage are probably not the cost optimum -- according to https://www.sciencedirect.com/science/article/pii/S001429211... , the optimum lies in the direction of significant overgeneration, which reduces storage requirements massively (even while allowing opportunistic consumers of electricity such as for example hydrogen production).
> But wind can be absent for days or weeks, and there's such a thing as winter when you're as far from the equator as Germany.
Interestingly enough for Germany, the period less likely to suffer from prolonged lack of wind is winter. So the more likely periods of decreased wind happen in summer, where they're interrupted daily by significant solar generation. At the very least in German conditions, these two events (lack of wind and lack of sun) are not only not independent, but they're actually anticorrelated. That also helps deal with the whole situation.
This is a worldwide assessment. Look at Northern Europe, and notice the complete lack of dots on the map.
> Interestingly enough for Germany, the period less likely to suffer from prolonged lack of wind is winter
Want you bet your freezing bottom on it? "Less likely" does not cut it for a vital commodity. Famine, drowning and thirst also occur when a commodity that's otherwise readily available on average isn't. They're considered somewhat unpleasant.
I'm not quite sure what you're trying to say here. Northern Europe generally doesn't need the kind of sites that this study was looking for (a pair of locations vertically separated and horizontally close with a river close to the lower location); they already have "once-through" hydro plants on rivers with reservoirs high in the mountains.
> Want you bet your freezing bottom on it? "Less likely" does not cut it for a vital commodity.
I don't have to "bet my freezing bottom" on it. The "less likely" part means lower expected value of energy needs not satisfied by a combination of solar and wind power. This lower expected value translates into lower expenditure of backup supplies such as synthetic gas being expended for that purpose, and therefore the lower average annual cost of using such supplies. That makes this approach viable.
Either disingenuous or ignorant, yes.
> Energy storage is not a short or medium term solution.
The primary role of energy storage systems in renewable energy sources is to balance supply and demand. Your assertion makes no sense because it ignores even the most fundamental aspects of the problem domain.
> Pumped hydro is already maxxed out pretty much everywhere it's possible as not all dams are suitable -- in fact most aren't. Battery storage for large grids currently covers minutes of use, a few hours may be attainable. But wind can be absent for days or weeks, and there's such a thing as winter when you're as far from the equator as Germany.
Irrelevant. You're trying to put up a strawman based on a fictitious scenario where energy production comes from a single source: wind. It's the tired old meme from two decades ago.
Meanwhile, back in the real world not only are power grids distributed at a continental level but there also multiple sources of power feeding into that grid, including imported energy generated from renewable sources.
There is nothing close to the grid capacity to make this statement true.
Germany lacks base load capacity and imports energy from coal and natural gas burning neighbors when their renewables go offline. To offset this, Germany is building more base load capacity in the form of gas driven plants. This isn't a secret, it's not disingenuous to point it out.
The better option, from the point of view of carbon neutrality, is to make up that availability gap with nuclear. The Germans are unwilling to do this, and likely they hope that eventually they can import energy from neighbors that are willing to make up this gap with nuclear plants the Germans themselves were unwilling to build.
Today, and in the future if hydrogen hits unforeseen snags, nuclear remains the proven option.