Charging the Volt: GM’s Got It Covered


General Motors is prepping for the year-end release of the Chevrolet Volt by supporting the rollout of charging infrastructure. The company selected automotive supplier SPX Service Solutions as its partner for residential EV charging equipment (known as EVSE). The charger is priced at $490, or less than half of what most competitors will offer.

Installation will cost approximately $1,500. SPX is a well-connected supplier to most automotive OEMs, which may have influenced GM’s selection of the company instead of one of the established EVSE companies such as AeroVironment, Ecotality, or Coulomb Technologies.

GM is also setting up a charging infrastructure throughout its home state of Michigan through partnerships with DTE Energy. Approximately 4,400 Volt buyers will receive free charging equipment thanks to grants from the U.S.Department of Energy.

GM also has sky-high aspirations to include solar power in the mix of its EV charging. The automaker will install Solar Tree combination solar arrays and charging equipment at its Warren Technical Center and Milford Proving Ground. The Solar Trees are 27 x 36 feet photovoltaic arrays that can cover up to 6 parking spots, according to Desmond Wheatley, the president and COO of Envision Solar, the manufacturer.

The Solar Trees have a tracking mechanism that increases the capture of solar energy by angling the panels according to the movements of the sun. The company also offers a transportable unit that covers one vehicle. Wheatley says that not only can the panels provide enough energy per day (8-10 kWh) to power a vehicle, but also the shade provided by the array reduces the amount of energy required to cool the vehicle’s batteries before charging can take place.

Envision Solar integrates EV charging equipment from vendors including Coulomb Technologies and Ecotality (but not SPX, which Wheatley says is focused on the residential market) with its Solar Trees. The Solar Tree does not deliver power directly to the vehicles, but sends it to the grid, and the customers will “net out” the difference from the energy consumed by the vehicle.

Envision Solar also has an option which integrates a battery system to store up to 10 kWh of energy for later use. Energy storage enables the Solar Trees to be “islanded” from the grid and provide power to the vehicles in the event of a blackout. Envision Solar uses lead acid batteries from companies including Axion Power.

Using solar power (or at least its net impact) for EV charging is desirable to eco-conscious EV owners, and we’re likely to see many more solar charging systems in the near future. The addition of batteries would enable charging without impacting the grid, something that EVSE company AeroVironment is also developing. This would be of even greater benefit to fast DC charging equipment, which could use cheap off-peak energy to charge vehicles at any time without impacting the grid.

Article by John Gartner, appearing courtesy Matter Network.



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