Unlike many other products, customers buy electricity when they need it, not when it’s cheap. It doesn’t really matter whether a wind farm in the German North Sea can produce a lot of electricity cheaply during a windy day when that electricity is needed three days later in Munich.
This complete lack of matching supply and demand is what drives electricity prices with a large share of renewables in the market so high.
In Germany, lots of electricity is produced from renewables at times when it’s not needed. This causes market prices to be negative at times and Germany is paying neighboring countries money to buy that excess electricity.
At the same time, producers of renewables have guaranteed sales by German law, i.e. their electricity is always bought by the market whether it’s needed or not.
It’s this gap between supply and demand that customers are paying for which drives German electricity prices.
Currently, we’re paying 31 Euro cents in Germany per kWh while French customers whose grid has a large share of nuclear pay just 17 Euro cents per kWh on average.
At the same time, the average CO2 emissions in Germany per kWh are at 400 grams in Germany while they’re only at 50 grams in France. That’s because whenever solar and wind aren’t delivering any electricity we’re starting up coal and gas plants.
I wish proponents renewables were honest enough to not withhold these problems.
I mean, absolutely no one argues that it’s not that expensive to build a wind or solar farm. What makes wind ans solar expensive is keeping the necessary backup plants in standby for when they’re not delivering and paying for getting rid of excess electricity from renewables when they’re not needed.
The intermittency and low energy density are inherent physical properties of solar and wind farms which is why 100% renewables is newer feasible (unless for countries like Norway who have the possibility to build lots of hydro plants).