The analysis shows why utility companies need to seriously consider future energy systems.

How electric cars destroy the Texas power grid

An analysis shows that only charging 60,000 next-generation electric vehicles at the same time may one day threaten the Texas grid. 

Analysts from GTM’s parent company said that based on a 100-kilowatt electric vehicle battery, the charging time is 5 minutes, which may become the standard for electric vehicles in three or four years. The demand for a single charge of 60,000 vehicles will be equivalent to 70 GW. Mackenzie.

Prajit Ghosh, head of power and renewable energy research at Wood Mackenzie Americas, said this is the same as the current peak demand for the entire ERCOT.

Ghosh said that this calculation is part of a Wood Mackenzie report on the impact of electric vehicles and shows the importance of grid operators and other stakeholders staying ahead of the electrification of vehicles.

"Electric cars are a huge disruptive power idea, which is mainstream," he said. "When you filter out the micro-issues, you will understand that some forces can [influence] the speed of the development of electric vehicles."

Grid load is one of the problems: 60,000 cars may sound like many cars need to be charged at the same time, but it only accounts for a quarter of 1% of the 24 million cars registered each year by the Texas Motor Vehicle Administration.

At the current charging rate, this level of electric vehicles will not weaken the grid. "If you charge a 100 kWh battery in 1 hour, then its instantaneous demand is 100 kW," Ghosh explained.

As electric vehicle manufacturers move toward the goal of faster and faster charging, the challenge comes. "If you assume that a 100-kilowatt battery is fully charged in 5 minutes, this means that the instantaneous demand is 1.2 megawatts," Ghosh said.

"This means that with more and more electric vehicles on the system, we must consider how to manage this charging. You can have a lithium-ion battery that can be charged in a few minutes. But the physical principle of charging will not change. This is A basic truth."

Failure to properly consider these effects may lead to a situation where, for example, electric vehicles increase the demand for fossil fuels by increasing the peak power requirements of the grid rather than reducing them.

Wood Mackenzie hopes to explore these intricate issues through a series of interdisciplinary reports in 2018.

The "Rise of Electric Vehicles" report released this month is the first in a series of reports that explore the interaction between electric vehicles and the oil, electricity, and metal markets.

Joshua Castaneda, chief analyst of Wood Mackenzie's Electricity and Renewable Energy Research in the Americas, said that for now, electric vehicles are not in danger of paralyzing the power grid.

Most electric vehicle owners charge their cars at night because the grid capacity is usually in excess and may use sufficient solar energy for charging during the day. In addition, utilities may increasingly encourage car owners to charge electric car batteries when there is remaining power.

"If utility companies work with grid operators so that they can manage this load more easily, then the problem is not a problem," Castaneda said.

If grid operators can solve this balance problem to achieve steady growth in electric vehicle sales, then electrified transportation may severely hit the oil industry before decarbonization in the energy industry causes losses.

Most of this will be attributed to the efficiency difference between internal combustion engine vehicles (usually only about 20% to 30% efficiency) and electric vehicles (about 80% or so).

Increased efficiency means that the shift to electric vehicles will result in a drop in oil demand, even if the additional grid electricity required for vehicles comes from fossil fuels. A key factor in the transition will be the rate of decline in battery costs for electric vehicles. 

Ghosh said that carpooling and autonomous driving may drive this shift. "Carpooling is already an effective concept," he said. "If you switch to autonomous driving and carpooling, this is very promising for electric vehicles."

Due to the inconsistent demand for electric vehicles, it is not clear how quickly these changes may take effect. "The answer hasn't come out yet," Ghosh said.