Can more electric cars lead to a more stable energy system?
We are now accustomed to charging stations refuelling our cars with energy, but what if the growing fleet of electric cars could also feed energy back into the grid when needed? So-called vehicle-to-grid technology could be a future solution that both contributes to a more stable electricity system and offers a number of advantages for households.
In Japan, where power outages are relatively common, electric car batteries are often used as a backup power source when the grid goes down temporarily. In this case, the car's battery feeds back the energy it stored when it was last charged.
Value for consumers
In Sweden, we do not have the same problem. In fact, power outages are becoming less frequent. However, even here, more and more households are looking into ways of securing their electricity supply in the event of a temporary outage, particularly in light of recent social developments such as the Coronavirus pandemic and the current unstable security situation in Europe. This can also help other motorists whose cars have run out of power and enable households to balance energy usage during the day when prices are highest.
– But whether it is economically viable for end users remains an open question in Sweden, says Mattias Persson, a researcher in electrical power systems at RISE. Stefan Pettersson, a professor and the head of the electromobility unit at RISE, agrees.
– Something of value must be created before consumers will buy this. You could get paid for the electricity you feed back into the grid, become more self-sufficient in combination with solar cells, or contribute to a green transition, which some people find valuable.
Future network benefits
In a future where this technology is commonplace, electric cars could contribute to increased grid stability. Smart charging ensures that cars are charged when there is plenty of electricity in the grid. At critical energy consumption peaks, it sends energy back to the grid instead.
– The individual car doesn't make much difference here, says Stefan Pettersson, but collectively, many vehicles can create opportunities.
If you collect a large number of rechargeable vehicles, the potential energy they generate can be fed back into the grid. This also presents a potential business opportunity for grid owners.
Due to increased electrification and greater energy needs, it is possible that we in Sweden may find ourselves in a situation where the infrastructure is unable to deliver the desired output at certain times.
– Even if the network is stable, problems can still arise due to highly fluctuating usage. In such cases, this can be a way of stabilising the frequency from a more local perspective, says Stefan Pettersson.
– In Gothenburg, for example, local flexibility markets have been set up to counteract transmission constraints. This means that smaller, more local grids can benefit from this too, as well as the large electricity grid, says Mattias Persson.
It is the laws, not the technology, that get in the way.
Legislative changes are required
When it comes to technology and infrastructure, there are few technical obstacles. According to Stefan Pettersson, charging points need to be designed so that they can also receive energy, but this technology is not difficult to implement.
Instead, a few other elements are required, such as standards, laws and policies. Today's electricity law was not written with mobile consumers, such as electric cars, in mind and it may limit what players in the system can do to find profitability.
– It is the laws, not the technology, that are getting in the way. There are grey areas and white areas in the legislation. On the one hand, existing legislation can hinder the technology, and on the other, the concept of feeding energy back into the grid is not even defined. Is it permitted at all?
Interdisciplinary collaboration is required
RISE has the capacity to be a valuable partner in many areas where questions remain unresolved, whether that involves developing and reviewing standards, or drafting legislation and policies.
– We have test sites for battery wear and IT security, which will be very important issues, says Mattias Persson.
– For a vehicle-to-grid solution to be widely implemented, many different areas of expertise need to collaborate to gain an understanding of the bigger picture. Stefan Pettersson says that these areas of expertise are available at RISE.
This is where electricity, vehicles and telecommunications converge. We can work across disciplines and conduct research into the remaining obstacles. At RISE, our expertise ranges from technology and behaviour to business models, laws and policies. By working together with partners in the field, we can get closer to finding a solution.