Photo: James Day
Problem Electricity is the ultimate just-in-time commodity, sent off to consumers as soon as it's generated. But solar and wind installations produce power only when the sun is shining or a breeze is blowing. If you could bank that energy when it's abundant and release it later as needed, you'd have a more reliable, more environmentally sound power grid.
Solution Obama's stimulus package includes $2 billion in grants for battery development. For power grids, sodium-sulfur technology is the best bet. It's more efficient and power-dense than zinc-bromide or lead-acid, and in Japan, where NaS batteries are made, enough have been installed to power the equivalent of at least 155,000 homes. Later this year or next, American Electric Power, a major utility serving 11 midwestern states, will install 4 megawatts' worth of NaS cells in Presidio, Texas. That's on top of the 6 megawatts of battery power AEP installed in three other states last year. "We wanted a real thing that really works," says Ali Nourai, AEP's manager of distributed energy resources. "We didn't want to send a technician out every other day to fix some experimental system." Regulatory uncertainties still abound, but utilities across the US plan to bring sodium-sulfur systems online. Soon, more and more cities will come with batteries included.
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<p><
ressed Air</em-peak power forces air into a sealed space (like an abandoned mine or salt dome); when energy is needed, the air is released and burned with natural gas to spin a turbine.</p>
<p><_heels</em_e, heavy wheels get spun up by a generator. When they decelerate, they spit the power back out, providing an uninterruptible backup energy supply.</p>
<p><_ed Hydro</em_er is pushed up an incline to a reservoir. To put electricity back into the grid, the water is allowed to rush back down, driving a set of turbines.</p>
to Fix the Grid, Now: <a href= the People</a> <a = Electricity Everywhere</a> <a =Clean Energy to Distant Cities</a> <a =the Electrons in Real Time</a> <a =ectricity Like Pork Bellies</a> <a =gawatts, Not Megawatts</a> <a =servation Simple (and Easy)</a> <p>rery Could Recharge in Seconds</a></p>
