Obviously electricity storage is critical to moving away from fossil fuels and thus to slowing and eventually reversing global warming. Even though the cost of solar and wind power are falling fast, the sun doesn't shine at night, and is lower in the sky with a shorter day in winter than in summer, and the wind is variable. So we need to be able to store power when it's made to use later when it's needed.
Well, the good news is that battery costs are plummeting. For example, over 15 years, the cost of a laptop battery has fallen from $2000 to $250, a compound rate of decline of 13% per annum. If that trend continues, then they will halve again over the next five years. But will it continue? The pessimists say no (they always say no)
The likelihood, actually, is that new battery technologies will accelerate that decline, if only because as solar power becomes widespread and the need for storage builds, so will it become immensely profitable to find solutions to the storage problem.
Here are two:.
- A new lithium-ion battery that is -- wait for it -- 2000 times as powerful and recharges 1000 times faster than existing lithium-ion batteries. (The lower chart in this article requires a bit of explaining. As far as I can make out, the coloured blobs represent different iterations/models of the new battery; the stars with 'A123' and 'Sony CR1620' represent existing batteries, as I assume do the squares with 'MB1', 'MB2' and 'MB3' next to them)
- A completely new storage technique using silicon and graphene, with a similar technique to the new lithium-ion battery above, namely giving the surface of the storage material (in this case silicon) a nanosurface which multiplies its effective surface area 100s of times. Once again, orders of magnitude (i.e, 10 or 100 times) faster recharge and energy density.
Still experimental. But would you bet that something like either or both of them won't be in production within 5 years?
Meanwhile, Tesla is constructing a giga factory which will cut the costs of EV (electric vehicle) batteries (existing technology) by 30 to 50%. Elon Musk (first PayPal, now Tesla, soon the world?) is confident every garage will have an EV within 6 years. Prolly one of his. One clever idea: using EV's to provide peak energy to buildings, for example. All the EV's would be plugged in to the building's grid , recharging when power demand is low, but releasing power to the building when demand peaks.
When I got my first laptop, paid for by my work, it cost $12,000 (in 1992 money! -- double that to get an estimate in today's money). These days you can buy a much more powerful one with quadruple the electricity storage for $400 or $500. Then, I was the only commuter on the train using a laptop. Quite literally, the only one. For several years. Now everybody has them -- or their equivalent: smartphones and tablets. Some ppl have all three.
Coal is in trouble. For now, oil is OK, but very soon (3 years?) electric cars and lorries will start to seriously compete with petrol and diesel vehicles. Gas is still OK for now, because it emits half the CO2 of coal for the same power output. But how much longer will it last, as PV cell and battery costs plummet and their efficiency improves?
As it becomes more and more compelling and urgent to cut greenhouse gas emissions, so the cost of doing so is precipitously declining.
I wouldn't buy a coal share for any money.