Power Surge: Will The EV Revolution Overwhelm The Grid?

August 27, 2013

It seems logical to argue that an EV merely shifts pollution from the tailpipe to the stereotypical pollution-belching, coal-fired power plant down the road. Much more than just an embarrassing bit of irony for the mobile environmentally-conscious, this argument raises the specter of EV-induced brown-outs, followed by an even more ironic rush to build more polluting power plants to keep up with the EV's power demand. Now that Telsa Motors' (TSLA) Model S has proven that an EV can achieve mass market appeal, this rather thorny argument needs to be objectively addressed.

Power Generation 101

To accurately assess the potential impact a substantial increase in EV charging would have on the power grid, we must begin with the understanding that power generation is a real-time business. Utilities do not possess a means of storing mass quantities of electricity that were produced at a time when demand was low so that they can be dispensed when demand is high. This means that a utility must maintain enough power generation capacity to meet peak demand year-round, 24 hours a day, all the while knowing that it may only need all of that power for a fraction of that time (say mid-afternoon on the hottest days of the summer when every residential and commercial air conditioning system is running full-tilt). Though every region is different, the typical utility runs its plants with the cheapest operating costs (coal and nuclear) non-stop to cover a carefully calculated "base load." As demand ramps up beyond this base load, marginal generation is brought online.

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