For weeks now, Germany and its European neighbors have had a peak season for wind power. The winter storms Sabine (also known as Ciara or Elsa), Victoria (known as Dennis in UK) and Yulia brought new records - most recently the unprecedented peak value of 46.2 gigawatts (GW). Renewables accounted for 69 percent of net electricity production in the third week of February, with wind accounting for 55 percent. Never before has so much wind power been fed into the German power grid. Are these figures the result of extreme weather conditions, which simply brought us an extraordinary number of storms this winter, or is there a general trend here? And how does the German energy system actually cope with these record values?
Where does wind energy stand?
First of all, let's take a look at the feed-in values of the past few months, for example in Germany: With reliable consistency, wind power has been the number one energy producer since October and has given us a greener electricity mix. Both onshore and offshore wind plants together supplied over 73 terawatt hours (TWh) of electricity in the fast five months. By way of comparison, lignite ranked second by a wide margin at around 38 TWh and nuclear power third at 30 TWh.
Anyone who now thinks that the current winter is an exceptional phenomenon is mistaken. In the winter months of 2018/2019 and 2017/2018, wind likewise played the main role in the energy mix for several months: from the beginning of October 2018 to the end of March 2019, wind fed around 79 TWh into the grid, compared with around 72 TWh in the same period last year.
Record wind feed - and the grid remains stable
In view of these figures, one can say beyond doubt that wind energy is the backbone of the German energy production in winter. And just to be loud and clear so that the critics of the energy transition also get the message: Despite records in feed-in values, not a single blackout occurred. The grid remained stable. This shows how well our energy system is now adapted to fluctuating energy sources - even though the limits of the current expansion status are becoming apparent at one point or another.
210 gigawatt hours of wind curtailed
According to research by German newspaper ZEIT ONLINE, the transmission system operators had to curtail 210 gigawatt hours (GWh) of wind power during the storm front Sabine alone to prevent bottlenecks in the power grid - non-produced electricity with which the annual demand of a small town could be covered. It is not only a pity to miss out on this otherwise fine electricity, but this also generates costs. Because if renewable energy plants (RE plants) are forcibly curtailed as part of the feed-in management, the operators receive compensation for the lost revenue. These costs then end up on the end customer’s bill via a grid usage fee. The same applies, incidentally, to the costs for the forced throttling of coal or gas-fired power plants as part of the redispatch. According to the German Federal Network Agency, compensation payments for feed-in management and redispatch already amount to 0.95 billion euros for the first three quarters of 2019 alone.
Stagnating network expansion, lack of flexibility options
Anyone who now wants to blame the renewables for these costs overlooks the real culprits. In order to exploit the potential of wind power, we need, on the one hand, a better grid infrastructure that transports wind power from the north to the south. But its expansion is stagnating, as is the design of flexibility options on the consumption side that could absorb the surplus electricity locally.
No cheap wind power for electricity storage and converters
For three weekends in a row, an extremely high wind input met with low demand for electricity - resulting in around 20 hours of negative electricity prices on the European short-term exchanges. The 6-hour rule, according to which the market premium for subsidized plants under the Renewable Energies Act is suspended if prices remain negative for more than six hours, took effect in both cases - as it has done several times in recent weeks. Additional electricity consumption could ease this situation - for example by Power-to-X plants or electricity storage facilities that could obtain their electricity at these times. The reason why this is not happening is the levies and taxes that currently make this power purchase model unprofitable. Direct use of the to-be-curtailed renewable electricity for heating applications is also not yet possible for legal reasons. Sector coupling works somehow differently...
Inflexible base of fossil power plants
Finally, let us take a look at the conventional power plant park in Germany. Even though individual coal-fired power plants were shut down during the storms, an inflexible base continues to run stubbornly unimpressed by high wind generation. This is not necessarily due to technical restrictions. Often there is simply a lack of incentives to act flexibly on the markets and thus to produce in a systemically useful way. The fact that fossil power plants do not leave the market may also be due to the fact that they provide must-run capacities for the balancing energy market. Alternatives that are more advantageous are also available in this area, which are not yet used sufficiently: Flexible RE plants and the electricity storage and conversion facilities mentioned above are ideal players for grid stabilization and can provide low-emission control energy.
Tailwind for wind energy
The energy transition has already come quite far in Germany. Now we need a tailwind from the political sector: to get the expansion of wind power going again, to create a suitable grid infrastructure and to make use of the flexibility potential that is still untapped.