Range anxiety, the fear of being stranded without a charge, is one of the best-known issues holding back drivers from making the switch to electric vehicles. For EV owners in the United States, a lack of public charging is only the beginning of their frustrations. A 2024 survey from nonprofit Plug In America found that 68% of EV drivers have visited a malfunctioning or broken EV charger within the previous 12 months. A recent Consumer Reports survey found that 21% of all US chargers inspected had an issue of some sort.
Most of the issues EV owners experience with public chargers stem from their lack of profitability. This discourages operators from fixing issues efficiently, discouraging utilization and leading to bigger financial losses. Lack of profitability can be attributed to several factors, including high upfront capital expenditure, or land and equipment acquisition costs. The single biggest profitability killer for EV chargers are utility demand charges, which are fees paid by businesses based on power usage.
Demand charges support transmission and distribution network upgrades. Grids need to be built out to be able to meet peak demand, no matter how rarely that might occur, which adds costs. Demand charges also discourage excessive and fluctuating electricity usage and help ensure grid stability. Energy charges (per kilowatt-hour) cover the cost of the volume of electricity consumed, whereas demand charges (per kilowatt) cover the cost of moment-to-moment delivery of power.
Demand is assessed in 15-minute intervals throughout each billing month. Customers are usually charged for the highest 15-minute demand interval that occurs throughout the month. As a result, even a short EV charging session at the wrong time can lead to a doubling or tripling of electricity costs for the month, significantly affecting profitability for EV charger operators. Low utilization compounds the problem, spreading high demand costs for power across less energy sold, making the electric bill significantly more expensive for the operator.
Solar integration
Solar power combined with energy storage can significantly diminish this risk. While the majority of installed EV chargers still rely solely on grid electricity, there is growing demand for integrated chargers. Solar provides an additional energy source to the grid, and software can then prioritize different energy sources throughout the day, making use of the grid when prices are low or at nighttime, switching over to stored power during peak demand times. This approach can dramatically reduce costs.
Chargers with solar and battery storage are clustered together in groups of six to 10, each cluster amounting to the total grid capacity needed to charge a single car. A software system is programmed to prioritize each potential source of energy (grid, solar, and storage) and adjust as needed throughout the day. Our company’s data show that this kind of system can cut grid draw to just a few off-peak hours overnight, use solar and storage exclusively to charge vehicles during the day, and even return excess power to the grid in the process.
This not only avoids demand charges, but ensures that the chargers are a net benefit to the grid, rather than a draw.
Adding solar to EV charging systems also gives operators flexibility to choose between Level 2 and Level 3 charging systems. By increasing the efficiency of Level 2 chargers, developers can forgo upgrades to much more expensive Level 3 charging options. A commercial Level 2 charger typically costs around $3,000, whereas a Level 3 charger can cost $50,000 or more and requires a very expensive 480 V, three-phase electrical circuit.
Unlocking the advantages of integrating solar and storage with EV charging requires software that can integrate distributed energy into the grid and ensure chargers are not restricted by grid limitations. This can help avoid crippling demand charges. EV chargers with integrated solar are still relatively rare today, but they are the most logical solution to solving the profitability conundrum for charging operators.
About the author
Tom McCalmont is CEO and co-founder of Paired Power, specializing in resilient solar microgrid charging solutions for EVs and EV fleets. He has more than 25 years of solar, storage, and EV charging experience. Prior to Paired Power, he co-founded McCalmont Engineering, which has designed more than 15 GW of solar projects in 40 US states and currently designs over 10% of the country’s total PV project capacity per year. Prior to that, he was CEO and co-founder of Regrid Power, one of California’s earliest and most successful solar installation companies.
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