Flexibility for the power system - Virtual power plant for renewable energies

We are convinced that a secure power supply is possible that consists of 100% renewable energies. Next Kraftwerke has already been operating a virtual power plant for 14 years, which now coordinates and controls a huge team of decentralised renewable energy plants. In this way, we prove every day that a digital, decentralised and green energy system works. And we continue to follow this path: we are increasing our pool of electricity generators, consumers and storage facilities and ensuring that these plants interact intelligently. In this way, we manage to profitably trade our customers' generated and consumed energy on the markets and contribute to the stability of the electricity system.

Next Kraftwerke draws on a wealth of experience in aggregating, controlling and marketing RE plants. We were among the first to supply balancing energy from interconnected plants to a transmission system operator. We recognised the opportunities of renewable energies for the balancing energy market at an early stage and did pioneering work. We specialise in providing flexibility for the power system.

The most important core elements of the virtual power plant are the central control system and the remote control unit Next Box. The Next Box connects the decentralised plants with our control system via a bidirectional, secure mobile radio connection. The Next Box controls the plants and also exchanges data. Among other things, the control system receives information about the utilisation of the networked plants and their feed-in power.

For example, we use machine learning for solar forecasting. PV is one of the volatile electricity producers, and the amount of electricity can vary greatly depending on the weather. In PV forecasting, we process weather data, system schedules, consumption and feed-in data to be able to make a precise forecast of the electricity feed-in. In machine learning, the computer learns to recognise patterns in data and predict developments. The patterns help to identify deviations and adjust forecasts. The closer we are to reality with our forecasts and the shorter term we are able to draw correct conclusions from the data, the better we can estimate prices and deliver market-driven bids.

I would like to illustrate this with a simple look at two figures in Germany: In 1990, there were about 800 generation plants in Germany, i.e. larger power plants, through whose control the power system was operated safely. In 2022, there were 2.6 million plants in the photovoltaic sector alone, and the security of the electricity system is based on the complex interaction of these and many other plants. This is because the total number has risen sharply with the expansion of RE plants. Several million data points are processed in our virtual power plant. For example, the live data of plants are retrieved every second. Without the rapid generation, evaluation and transmission of this and other data, our business would not be possible. An intelligent, meaningful and reliable linking of data is enormously important for the control of the plants and for our trading business - whether on the balancing energy market or the spot market.

The projects - including the project with Honda - have all been completed successfully. They have shown that it is technically possible to provide primary and secondary control power from a fleet of vehicles and thus contribute to the stability of the power grid. In other words, the technology works: Every single vehicle in the Honda e-car fleet was able to implement the charging and discharging command. The individual charging state preferences of the e-drivers were also taken into account.

In this respect, smart unidirectional charging is still in its infancy. A car that charges based on electricity price signals is the absolute exception. At the moment, it's a case of plugging in and charging, regardless of whether electricity is currently in short supply.

First of all, the possibility must be created that quarter-hourly chargeable measurement data is available at the charging points, which are often located in private households - keyword smart meter. The grid usage fees must also be addressed. The electricity that is drawn and fed back must not be burdened by taxes, levies and surcharges - especially if this is done to stabilise the grid. In addition, the availability of bidirectional wallboxes is currently still limited and there is a lack of vehicles that are capable of implementing bidirectional charging at all. A certain number of vehicles is needed to set up an economic business model. I would also like to see, that we create opportunities for flexibility service providers such as Next Kraftwerke to remove flexible assets such as e-cars, but also heat pumps, for example, from the electricity supplier contract with submeters, so that their flexibility can be marketed independently. Then the flexibility could even be used almost anywhere, independent of the wallbox or charging station, and everything could be controlled via the car itself.

Quite simply: if we have a lot of wind and sun, the battery charges. If PV or wind power plants supply less electricity - e.g. due to weather conditions - e-vehicles feed back into the grid. If all cars were electric today, we would have a decentralised electricity storage of about 2,000 to 3,000 GWh. And cars are parked more than 95% of the time. Even during rush hour, more than 80% of cars are parked at the side of the road. In principle, therefore, they would be available - with restrictions, of course - as electricity storage.

However, electric cars cannot compensate for seasonal fluctuations in renewable energies. For that, we need other storage facilities and flexibilities. Also, the additional electricity drawn by electric cars will cause costs in the electricity grid. But: electric cars will play an important role as short-term electricity storage. And with the increasing electrification of all areas of life, the importance of virtual power plants will continue to grow.

is CEO of Next Kraftwerke Benelux. In 2014, he founded the Next Kraftwerke Belgium branch together with Jan de Decker. He specialises in grid and market integration of renewables and other distributed generation. Until 2014, he was Senior Renewable Energy Expert at 3E, advising public and private clients on renewable energy, among other things. Before that, he headed the "Wind Energy and Grid Integration of Renewable Energies" team at the German Energy Agency in Berlin. Paul Kreutzkamp holds a degree in physics.