The Green Gap

In the Cold War, we feared a Missile Gap was a strategic weakness. Nowadays, we must awaken to the fact that the Green Gap is true strategic weakness: the nations whose economies will thrive in the coming years will not be those with the biggest factories, but those with the most sustainable, efficient, and ecological markets. What we require is a Strategic "Green Reserve" of ecological design to weather the coming changes that both climate and resource scarcity will force on the international economy.

Monday, 27 February 2012

A Little Good News

While I can tend to get a bit pessimistic at times about the global economy (actually... I'm not really pessimistic... probably the best thing the economy can do right now is contract: it means gas will become relatively more expensive and we'll have more market incentive to create clean alternatives), it helps to see some positivity sometimes:
Envia Systems, backed by venture capitalists, General Motors, and the Department of Energy, plans to announce on Monday at the ARPA-E conference that the company has created a lithium ion battery that has an energy density of 400 watt-hours per kilogram, which Envia CEO Atul Kapadia told me in an interview could be the tipping point for bringing electric cars to mainstream car owner.
Kapadia tells me that current lithium ion batteries deliver an energy density of around 100 to 150 watt-hours per kilogram, while Envia’s battery can deliver 2.5 times that energy with about the same weight as the current electric cars that have hit the market. To build a 300-mile range electric car with standard lithium ion batteries, it would cost around $40,000 just for the batteries alone, says Kapadia.
Envia says with an energy density of 400 watt-hours per kilogram, its battery cell costs could be at $125 per kWh.
That's very good in relation to other battery technologies. Just to shed a little gloom on the topic, though, the energy density of gasoline (or petrol) is 47.2 MJ/kg. The Envia Li-ion battery energy density is 1.44 MJ/kg. We're only off by a factor of 32 give or take, but it's better than nothing. Li-air batteries have an energy density of 9 MJ/kg, so there are other technologies out there that might supplant Li-ion, but for now, I'll take what I can get.

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