Researchers from Skoltech have developed a computational model (a set of rules and formulas for calculation) that allows industrial enterprises to compare different ways of reducing electricity costs. It is based on the use of solar panels on factory grounds and employees' electric vehicle batteries. The work was published in the journal Applied Energy.
Solar and wind generation account for a growing share of global energy, but they require a lot of land, and existing power lines do not always cope with the additional load. One way out is to generate electricity near the point of consumption. Factories are well suited to this: they have large roofs and grounds, and energy demand is high enough to use it on site.
Electric vehicles parked at the office stand idle for hours. If they are connected to bidirectional charging stations (such devices allow electricity to flow both into the battery and back), the cars can give part of their energy to the factory. This technology is called vehicle-to-grid. However, unlike stationary batteries, electric vehicles arrive and leave with their owners. By the end of the day, the battery must retain a charge for trips, and the driver may refuse to participate altogether.
The model proposed by the team links drivers' willingness to participate, charging prices, compensation for energy supplied and battery charge levels. In other words, incentives determine how much flexibility the factory gets: not every connected car is automatically considered available.
In a 10-year test scenario, the researchers compared six options: grid only, solar panels only, vehicle-to-grid only, solar with managed charging, and combinations of solar and bidirectional charging under fixed and behavioral assumptions about driver participation. The calculations were carried out for Moscow conditions, where industrial consumers pay for electricity at hourly prices and separately for capacity linked to peak hours.
The results showed that solar panels reduce electricity purchases, while coordinating the charging and discharging of cars creates additional value. Managed charging brings benefits even without energy being supplied from batteries, and bidirectional mode provides even more flexibility. Accounting for real driver willingness led to more cautious financial estimates than assuming that all technically available cars participate. In terms of investment efficiency, the vehicle-to-grid-only solution pays back faster than the option paired with solar panels, although the latter promises greater returns in the long term.
"Employees' electric vehicles allow the same battery to be used both for personal trips and for the factory's energy flexibility. We take into account drivers' willingness to participate in coordinating solar generation, charging and discharging. This helps businesses compare operating schemes and assess whether the additional flexibility justifies the investment," the press service quoted lead author Ahmed Eltwam, a PhD student in Skoltech's Engineering Systems program, as saying.
The authors emphasize that the conclusions are based on modeling with estimated market and operational data. Assumptions about driver participation are taken from previously published studies rather than from a survey at a specific enterprise. Although the calculations were performed for Moscow, the model can be adapted to local prices, payment rules, demand, weather and vehicle availability. The financial results remain tied to the analyzed conditions. Validation and calibration of the model on real data on electric vehicle charging at work is a priority for future research.