Storage innovations

As we know, the problem with renewables has been that of storage. But that problem is being tackled. Improving battery technology is an imperative. As it stands, but a 1,300 metric ton battery larger than a football field that can generate 40 million watts of power, currently deployed in Fairbanks, Alaska to protect against blackouts, could only, in 2003-4, provide enough electricity for about 12,000 residents for seven minutes. It would take hundreds of units the size of the Fairbanks unit to store electricity from solar and wind to equal the power generated by one coal plant. Other types of batteries have been developed, but some have low “round-trip efficiency”—they lose energy as it is stored and comes out of storage. Lithium ion batteries have high “round-trip efficiency” but are very expensive, and a lithium metal-air battery, when it absorbs moisture from the air in addition to the oxygen it needs, can explode. According to NewScientist, a promising type of power plant cools excess energy and stores it in the form of liquid air, or cryogen. The Highview 300-kilowatt pilot plant supplies energy to the UK National Grid. The process warms the cryogen when electricity is needed; it recovers only about 50 percent of the electricity fed into it, but cryogen plants can be located anywhere, costing far less to operate per kilowatt than batteries. Excess energy from wind power can also be stored in the home, raising the temperature of an energy customer’s water heater or storing the heat in ceramic bricks in a nearby space heater. These devices, run by microchips and remote-controlled by the power administration, then act as a battery, giving back power when needed. Such a pilot program in the US Pacific Northwest saw energy customers having to pay to participate. But research is peeling away the many hurdles. Once we have an efficient way of storing power, nothing should hold the sun and wind from powering the planet.