The power outside

For those not in the know: the G-Wiz is a tiny electric car from the turn of the century. It was built in India but found its biggest market in London. Although it was lambasted by Top Gear and others in the UK’s motoring press, commuters from outlying suburbs overlooked its low speed, limited range and poor crash protection because of its exemption from the Congestion Charge and suitability for micro-car parking… well, for a few years, at least.

The G-Wiz also did all of us a great service. Its manufacturers, presumably techies from outside the motor industry, published its power ratings in kilowatts. According to Wikipedia, the motors of the original version cruised at 4.8kW, delivered 13.1kW during an all-out 40mph sprint, and were powered over the vehicle’s laughable 50-mile range by 1600Ah of lead-acid batteries.

The important point here isn’t that those figures are extraordinarily low (your domestic boiler probably peaks at 35kW). It’s that REVA, makers of the G-Wiz, chose to publish its vital statistics in a format which made its engineering commensurate with that of domestic technologies like steam irons and washing machines.

Petrolheads

This practice has since become standard across the EV market, so we know that, for example, sedate UK maker Vauxhall rates the maximum power of their latest Corsa-e electric hatchback at 100kW. Petrolheads in the motor industry, however, continue to favour old-fashioned brake horsepower figures.

While deriving SI ratings from BHP isn’t exactly rocket science — 1kW = 1.3BHP — this persistent habit of using measurements that don’t align with the rest of the economy hinders clear thought.

Might you, for instance, feel differently about driving your Land-Rover Discovery 3.0 ‘Metropolitan Edition’ through the streets of a country suffering increasing fuel poverty if you knew that its 276kW engine was burning enough power to heat 10 houses?

To publish kilowatt and kWh-based figures is to emphasize the universal applicability of electric power. And, once you’ve understood that your car’s battery is easily capable of running your house, it’s natural to wonder about the practicalities of doing so.

Although the industry has been slower on the uptake than you might expect, EV makers around the world have begun addressing this very issue. US software house AutoGrid recently partnered with ride hailing app Zūm to ensure that the electric school buses it’s rolling out in California can double as a ‘virtual power plant’. In Germany, Porsche engineers have hooked up five Taycans to the grid via computer-controlled inverters for use in fast-response ‘load balancing’ operations.

In future, car makers may come to regard the close integration of their vehicles with house energy systems as a potential selling point. After all, why pay for two massive storage batteries when one is enough?