(The Center Square) – Can the power grid – critical to charging electric vehicles at scale – cope with the pace of state and federal decarbonization goals?
The government’s “ambitious” deadlines for transitioning to electric vehicles, or EVs, concern experts who say these policies are optimistic and not necessarily aligned with technological capabilities. At the same time, all involved acknowledge the nation’s electric grid faces a supply chain crisis.
Robert Charette, a longtime systems engineer, contributing editor for IEEE Spectrum, and author of “The EV Transition Explained,” said the viability of a speedy switch is a “nuanced perhaps.”
It depends, he says, on many factors including the speed of grid-component modernization; volume of EV sales; types and timing of EV charging; regulator and political decisions; and critically, economics.
Charette poses the city of Palo Alto, California as an example, because it is a “microcosm of issues involved.”
Palo Alto has the highest adoption rate of EVs in the country – one in five households owns an EV, accounting for over 30% of new car sales. The city also provides incentives to achieve their goal of an 80% reduction of greenhouse gases below 1990 levels by 2030.
However, Charette says there are a few potholes that need to be filled to meet that objective, and the city is not unique in that policies are running up against engineering reality.
Palo Alto’s Assistant Director of Utilities Tomm Marshall was not optimistic about meeting the goal of electrifying all its single-family homes by 2030 when speaking at Utility Advisory Commission meetings last year.
He warned the city’s power grid was showing signs of strain and some transformers were already starting to fail, adding the planned upgrades would take seven years and could cost up to $306 million.
Peak loading is the primary concern. The system was designed to handle daytime peak electric loads decades ago. Off-peak loading allows the system to cool down, assuring equipment longevity.
Typically, power consumption reduces at night, allowing transformers to cool down, but with more people charging EVs at home in the evening, their 30- to 40-year life expectancy could be reduced to just three years.
In his book, Charette quotes authorities who caution that once EV ownership ramps up, residential charging can keep the system’s electric equipment operating at peak load, especially during heat waves.
Solutions involve investing in larger transformers and smart metering systems, as well as obtaining regulatory permission to change rate structures and by encouraging daytime off-peak charging.
Upgrade timing, Charette said, will depend on the availability of engineers, linespeople, and management staff which are currently in short supply. And, as the industry becomes digitized, the labor force will require different skill sets.
“Similar mismatches between climate-policy desires and an energy infrastructure incapable of supporting those policies will play out across not only the United States but elsewhere in one form or another over the next two decades as conversion to EVs and electric appliances moves to scale,” Charette said.
Lehigh Valley engineer Jim Daley, a member of the IEEE Standards Association – with decades-long experience working with criteria addressing the interconnection of renewable and other distributed energy to the electric grid – told The Center Square that grid operators must maintain voltage and frequency within a certain range to maintain safety and reliability.
“When you go outside of those bands, unacceptable things happen,” he said.
Renewable energy sources threaten this balance because their power output is intermittent and unpredictable. The inertia of grid generation can accommodate reasonable variations in renewable energy supply, Daley said.
However, longer disruptions will have significant impact on the grid to meet the demand for electricity.
For example, Daley said, because California relies heavily on renewable energy, the state importins between one-fifth and one-third of its electricity from neighboring states.
When systems are stressed, utility companies do what is called load shedding – meaning they rotate power outages until demand decreases to meet available capacity.
California made the news last summer when it asked residents to avoid charging their EVs just days after announcing a plan banning the sale of gas-powered vehicles by 2035. At times, grid operators have been forced to implement rolling blackouts to avoid a system-wide collapse.
Daley provided numbers shedding light on the scope of what is involved.
There are over 5.5 million miles of distribution lines serving 81 million U.S. residences. Assuming each 25 kVA transformer feeds four residences, that would equate, in the worst case, to approximately 20 million potentially overloaded transformers because of EV charging.
Replacing those transformers will be costly – and that’s even if parts can be found. Supplies for distribution transformers are low and prices have skyrocketed from a range of $3,000 or $4,000 to upwards of $20,000.
While the Biden administration calls for EVs to account for half of all new car sales by 2030, the U.S. Department of Energy acknowledges the electric grid is facing a supply chain shortage.
The department says more than 70% of transmission and power transformers are 25-plus years old, and labor and material shortages make manufacturing more components difficult. Increased electric demand will also require a 60% expansion of these systems by 2030, and three times that by 2050.
Another area of concern is the use of smart devices, which improves grid reliability and resilience, but increases its vulnerability to cyberattacks.
The U.S. Government Accountability Office determined the DOE did not possess a good understanding of the scale of potential impacts facing the grid’s distribution systems and recommended they be addressed in coordination with the Department of Homeland Security and state and industry partners.
Indications from industry experts signal policymakers are treating the situation as a “field of dreams” – assuming the technology will be in place to meet their deadlines.
The key point, according to Charette, is that few have done the detailed engineering to really understand the scope of the issues involved, especially addressing them in the time frames and scale required.
“It really is a Red Queen sentence first, trial later approach,” he said.
