Every year, billions of kilowatt hours of clean energy must be regulated to ensure the stability of the power grid. As part of a cooperation project with a distribution network operator, sonnen has now commissioned a virtual power plant made of networked sonnenbatteries in northeast Germany, which intelligently stores excess wind energy instead of throwing it away. The whole thing is managed via blockchain. The remuneration for a service provided is paid in a crypto currency.
sonnen has put another virtual power plant (VPP) into operation in northeastern Germany, thus supporting the regional power grid with new technology. If too much wind energy flows into the grid, the sonnenBatteries in that region will store the excess energy. The home storage systems are primarily used in private households for their own clean solar power supply. In addition, the sonnenBatteries are networked with each other to form a virtual power plant, a distributed large-scale storage system. If more wind energy is produced than is needed for consumption, sonnen’s VPP can act as a flexible element to absorb the wind power from the grid.
The network operator intervenes the flow of energy in a targeted manner in order to avoid overloading the power grid. This occurs when there is more energy available than the grid can transport – similar to a traffic jam on the motorway. As a rule, the wind turbines are then regulated to avoid the bottleneck. The VPP from sonnen now offers a technology that intelligently prevents this regulation and stores the surplus instead.
In 2018, around 5.4 terawatt hours (5,400,000,000 kilowatt hours) of energy from renewable sources were lost in Germany alone, due to shutting down renewable production plants. This corresponds roughly to the annual per capita consumption of all inhabitants of Berlin or, measured against the average emissions of the electricity mix in Germany, 2.6 million tonnes of CO2 that could have been saved with this clean electricity.
The currently free storage capacity is marketed on the digital exchange “EW Origin” of the Energy Web Foundation (EWF). If, for example, a storm predicts a surplus of wind power and thus a possible bottleneck in the power grid, the grid operator reports this demand via the platform. Origin’s software registers this request and automatically matches it with the available storage capacity in sonnen’s virtual power plant.
If the grid operator accepts this offer from sonnen, the VPP software automatically calculates the times at which the excess wind power will be captured. sonnen’s smart algorithm not only takes into account the current charge level of the individual sonnenBatteries, but also the most even use of the participating storage units in the VPP.
“With a flexibility market for renewable energies and the automatic exchange of supply and demand, we are realising the next step towards a smart grid that can deal much more flexibly with fluctuations from renewable energy,” says Jean-Baptiste Cornefert, Managing Director of sonnen eServices. “Virtual power plants such as those from sonnen are the technical building block for this power grid that has been missing up to now and can help to ensure that less green energy is lost.”
“Matching renewable supply with available demand is at the core of EW Origin”, explained Micha Roon, CTO for Energy Web Foundation. “sonnen’s project is a vision of the future: using a blockchain-based approach to reduce curtailment from large-scale wind energy by leveraging the available capacity of distributed batteries. When we at EWF talk about accelerating a low-carbon, customer-centric electricity system, this brings that to life.”
The individual transactions between sonnen and the network operator are written to a blockchain via a so-called “Smart Contract”. Smart Contracts are digital contracts that automatically deposit the agreed terms between two parties. They offer a maximum of security and transparency for all parties involved. The blockchain automatically pays sonnen for successful transactions via the crypto currency “DAI”.
The virtual power plant in the north-east of Germany is already the third grid service that sonnen’s VPP can provide in Germany. In 2018, sonnen received prequalification for the primary control power market from the transmission system operator TenneT. In addition, sonnen had successfully implemented the Germany-wide redispatch in a project with TenneT. In addition to Germany, sonnen is also active worldwide in the USA, Australia, Italy and Great Britain with virtual power plants for various applications.