There is pressure on the power grid—and it's not just between 5-9 PM when dinner is in the oven. In 6 years, half of all cars in Denmark are expected to run on electricity as part of Denmark's effort to reduce CO2 emissions. That's 1.5 million electric and hybrid cars that will strain the power grid.
Along with the technology company IBM and the platform provider Spirii, which develops solutions for electric vehicle charging, a team of researchers at DTU has collected data from 1400 electric vehicles in Denmark to investigate how electric vehicle batteries can contribute while charging.
"We have found that each electric vehicle owner can save 6-10% on their bill by, to some extent, making the consumption of their chargers flexible while charging their cars. This is relevant when the power grid is exposed to extreme imbalances - it doesn't happen so often, but it does happen. In return, system operators can provide a more stable power supply even with increased integration of the more unpredictable wind and solar energy sources," says DTU Associate Professor Jalal Kazempour.
As part of the 'Investment Model for Power Flexibility Services' project, this research team affiliated to DTU and IBM examined the business potential of leveraging access to electric vehicle batteries to increase the share of renewable energy in the power supply.
"Each electric vehicle owner can save money by contributing to maintaining a stable power supply and at the same time increasing the share of green energy in our electricity consumption because it is a key service for system operators," he explains.
Existing technical solution
The technological solution already exists, enabling electric car chargers to provide a grid service called frequency containment reserve for disturbances (FCR-D). When the power grid faces an extreme operational situation under a significant imbalance between power supply and demand, electric car chargers providing FCR-D services will automatically be activated to adjust their consumption. They will increase or decrease their consumption depending on the grid's need, helping the grid to restore the balance immediately.
The Nordic system operators have so far offset the imbalance by purchasing FCR-D services from, for example, conventional power plants that generate energy using gas or other fossil fuels. However, this contributes to increasing CO2 emissions, which Denmark has committed to reducing by 70% by 2030 compared to 1990. More flexible resources will be needed to balance the power grid.
Denmark only covers about 50% of its annual electricity consumption through wind and solar energy. That figure is challenged by sustainable energy sources behaving stochastically according to the wind or sunshine. And an investment in a massive capacity of batteries to store renewable energy is very expensive.
The electric car chargers are already part of the infrastructure that can help reduce the need for FCR-D services from fossil fuels and increase the share of renewable energy. Furthermore, adjusting consumption during an electric car's charging does not emit more CO2.
