Effect of EV growth on grid security
For the power and utilities sector, the growth in EVs really matters. In my last blog, The countdown to digital reinvention for utilities, I identified that a first significant “tipping point” is only a few years away, when the cost of residential solar and battery systems will reach cost parity in several regions.
“EVs will create a game-changing “tipping point” in the evolution of the energy system that will require significant investment in new infrastructure.”
Similarly, EVs will create a game-changing second “tipping point” in the evolution of the energy system that will require significant investment in new infrastructure. This will determine the way future power networks are designed and controlled.
As active loads, EVs increase the demand on the network during charging. But it is recognized that the growth in the EV market won’t cause utilities companies concerns regarding total nationwide electricity demand.
Across Europe, for example, our analysis indicates that total power consumption will increase by around 5%, and 4% in Australia by 2050. Instead, the challenges are centered at a local network level where there is a risk of overloading residential transformers.
A single plug-in electric vehicle (PEV) with a 240V, Level 2 charging system consumes about 7kVA. With most residential transformers only built to manage between 10 and 50 kVA, there are concerns that several EVs charging simultaneously could overload the transformer – or even take it offline.
Residential transformers are particularly at risk of overload during peak hours, especially if there are multiple EVs in a neighborhood.
With annual EV sales expected to be in the tens of millions by 2030, the consequences for the local power system are significant. Uncontrolled EV charging (i.e. where there are no controls/incentives in place to modify load scheduling) is likely to coincide with evening peak demand – users will tend to charge their vehicles as soon as they get home from work – which will add to the pre-existing peak load and may take distribution voltages outside the acceptable range.
Creating value from EV flexibility
Leveraging the flexibility of EVs can help manage the impact of charging them on the grid:
- Dynamic pricing: “Time-of-use” rates can be introduced to encourage drivers to charge their vehicles at off-peak times to avoid higher electricity bills. Dynamic pricing forms an essential part of effective demand-response programs and the optimization of the digital grid.
- Design and governance: Properly designed and controlled EVs can offer ancillary services such as supply/demand matching and support the supply network, for example by providing reactive power support.
- “Smart charging”:”, The intelligent charging of electric car batteries, can be used to incentivize drivers to charge EVs during periods when supply from renewable energies is at its highest, thereby reducing the demand for fossil fuel powered plants.
- Workplace charging: A possible solution to managing high volumes of intermittent renewable generation coming online during peak daytime hours, providing much needed stability to the grid.
- “Smart” algorithms: AI enabled algorithms can take into account a huge number of parameters, such as weather and user patterns - managing a high volume of data to help predict charging patterns.
Beyond variable power consumption, there is also a huge untapped potential of vehicle to grid (V2G) connectivity. Millions of EVs amount to millions of batteries that could be integrated into the system, providing more opportunities to manage and optimize the grid. Smart charging can enable EVs to act as decentralized storage resources that can benefit the power system as a whole and minimize, or eventually avoid, grid reinforcements.
“Millions of EVs amount to millions of batteries that could be integrated into the system, providing more opportunities to manage and optimize the grid.”
Recent EY analysis for clients in Europe indicates that the majority of today’s EVs are generally under-utilized during the day, left in car parks. However, as autonomous EVs start to enter the market, utilities could potentially make it attractive for vehicle-owners to authorize their AEVs to automatically travel to certain neighborhoods, and to “plug the gap” when high loads are expected and the vehicles are otherwise not in use.
On the home front, as the adoption of domestic power storage and solar systems expands, consumers will be able to store energy and charge vehicles at times that avoid peak-hour charges. Several utilities are already looking at what possible compensation models may be required to optimize consumer behaviors.