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Charge of the Enlightened Brigade

Are electric vehicles really green?

Charge of the Enlightened Brigade
Charge of the Enlightened Brigade

If you have ever visited New York or London, you may have felt the choking sensation of diesel engine fumes as fleets of buses file through crowded city streets during peak hours.

It’s not pleasant during the height of summer when stagnant air stirs with hot exhaust fumes to create a rather rancid city atmosphere that seems to close in around you. So, news that Abu Dhabi has two eco-friendly EcoSmart 1 electric buses that run solely on stored energy from an arsenal of onboard batteries, seems a brilliant idea.

With a range of 160km, total engine torque from zero rpm and a smooth power delivery, the buses have received rave reviews from everyone who has ridden aboard. Without pistons clattering about in the engine bay, the familiar rattle of the diesel engine has been replaced by the faint whir of electric motors and power delivery systems.

It also recoups energy while slowing down, turning the engine into a generator as the driver lifts off the throttle, to power the batteries and extend range. One person claimed the bus was so quiet and smooth that it, “wasn’t like being on a bus at all. There was no noise or vibration at all.”

However, the electric bus may not have as rosy-smelling a future as some may have you believe. While the bus is touted as a zero-emission alternative to stinky, traditional diesel-powered public transport, they can’t deliver an entirely guilt-free ride.

They still rely on fossil fuels in one way or another. The engine may not produce emissions or tap crude oil reserves directly, but the power station feeding the grid that the bus is plugged into during its charging cycle does. And, what’s worse is, it manages to do this while sitting idle, not being used. Can there be any worse claim to fame than harming the environment while not doing anything?

Removing the diesel engine and replacing it with a power station doesn’t mean you’ve made the entire operation more ecologically friendly; you have simply shifted blame elsewhere. Studies in the UK also show that the cost per mile in terms of CO2 produced was actually far higher in electric cars than petrol ones.

It also raises questions over what sort of pressures moves like this may pose on the national grid. In some areas of the Gulf, this would place a considerable burden on existing power facilities.

Sharjah struggles to cope with its demand as it stands (particularly during summer when the annual power outages somehow take everyone by surprise) while other areas are running perilously close to their maximum capacity.

The billions that Saudi is dedicating to energy demand over the next decade and the UAE’s plans for a nuclear power station by 2016 will help, but other regions are still running to catch-up with current demand, let alone any
future increases.

Powering vehicles by renewable sources seems the next logical step to look at, but technology isn’t sufficiently advanced to offer suitable answers.

Photovoltaic cells aren’t ideally suited to the GCC climate, and there seems to be a reluctance to adopt CSP (Concentrated Solar Power) projects which would help increase power capacity. Plus, both rely on the sun being out – which makes them useless at night, when most buses would be charging.

Wind energy remains in its infancy around the Gulf too – and major developments are vital for it to come anywhere near meeting the GCC’s demands.

So, where does that leave us? A complete reliance on fossil fuels isn’t desirable, and a completely guilt-free life isn’t possible by sucking power from the grid.

Maybe a mix of the two, where a small, low-emissions petrol engine is used to generate electricity to power an onboard motor which drives the wheels, offers the best of both worlds. It also means the bus, though still wholly reliant on fossil fuels, won’t end up stranded somewhere with a dead bank of batteries.

Carlin Gerbich is a senior reporter on Construction Week magazine.