Electrical Vehicle Charging Station with Solar Component designed for existing retail petroleum sites
The electric vehicle charging station (EVCS) is designed to be placed at existing retail petroleum fueling sites along major highways; it includes level 2 and 3 chargers. The approach is to design a charging station which is economically attractive to existing petroleum retailers. The microprocessor (MP) controlled EVCS has a load center for aggregating a charging load from a renewable energy source, from an electrical energy storage source, and energy directly from the transmission grid when storage is depleted. The objectives are to provide: a method to maximize the use of an alternate energy source in the aggregated charging load, to use an energy storage system to augment the aggregated charging load when the alternate source is insufficient and to prevent local grid brown-out; and to provide an EVCS which can be used retrofit and has high probability of return on investment for retail petroleum station owners. The energy storage system is recharged off-peak when rates are cheapest and household usage lowest. To achieve the foregoing objectives, the EVCS uses a solar panel array to produce electricity, where the solar panels are mounted on the flat surfaces of canopies at the fueling sites since sufficient ground is not usually available. The MP uses algorithms (patent pending) to prioritize the electrical content of the aggregated charging load from the load center to the charging meter in the order of renewable, stored, and direct grid, which is used only when storage is depleted. The MP further causes the storage system to be recharged from the transmission grid during off-peak. Any solar production when no EVs are being charged is put in grid for credit.
In the US there are presently about 800,000 EVs, which are charged primarily at home overnight with level 1 chargers, and at workplaces (or city sites) during the day with level 2 chargers. Many studies predict there will be 8 million EVs in the US by 2025. A recent analysis by the Department of Energy found that approximately 400 corridor EVCSs would be required to provide convenient access to EV drivers across the US interstate system. A level 2-3 charging infrastructure needs to be quickly developed so drivers will gain confidence for longer trips with faster charging. There are presently thousands of privately owned retail petroleum sites along major highways which would make ideal EVCSs since these sites are already developed and operating. This project is developing a 50-100 kWh charging station, which is designed to be economically attractive to these owners/operators. In many locations up to 50% of the electrical energy will come from solar panels (free fuel) which are mounted on top of existing canopies since ground surface is limited. The solar energy is augmented with electrical energy from on-site storage storage batteries to aggregate the charging load. The storage system is recharged from the grid off-peak when rates are cheapest and local household usage lowest. This has the additional advantage of preventing local brown-outs, which would occur if 50-100 kWh were quickly removed from grid on-peak during high local household usage.
The project uses solar energy, has a net decrease in the carbon footprint, and preserves integrity of the grid by preventing local brown-outs. Many existing sixteen fueling position petroleum retail sites have 220 by 20 feet canopies for weather protection. This is 4400 square feet of flat surface for mounting about 250 solar panels. Premium panels produce about 300 kWh; in five hours of direct sun these panels would produce about 375 kWh daily. The initial work in proof of concept includes; determining weight of various premium solar panels with aluminum mounts; and designing software architecture of MP algorithms. Three of the team members have many years experience in petroleum equipment design and manufacture, the forth member has many years experience in grid design with a major utility.
