By Joe Fisher, CEO
Batteries will eventually play a leading role in our nation’s energy independence on two (and as will be shown related) fronts: Electric Vehicles (EVs) and the Smart Grid. The “eventually” part of this prediction depends on first overcoming a few challenges, however. The main challenge with EVs is the battery’s weight. For the Smart Grid, the main challenge is cost. That’s not to say battery cost is not important for EVs; it’s just that on the scale of a car, the cost is already at acceptable levels.
That an all-electric fleet of vehicles would greatly reduce (and may even eliminate) our dependence on foreign oil is rather obvious. Getting there will take some time, of course, and will be driven mostly by the price of gasoline. If the price remains around $3/gallon (adjusted for inflation), it will take the rest of the century; if prices rise to over $5/gallon, most cars could be all-electric within two decades.
Achieving that worthy goal will also be possible only with a better battery, and that means a much lighter batter. Propelling a vehicle that weighs less demands proportionally less power. But way too much of the total weight in today’s EVs comes from the batteries themselves! This is not unlike rockets, where the weight of the propellant needed to reach orbit constitutes 80-90% of the total weight. Without a lighter battery, EVs will be relegated to local commuting. And that’s not good enough. What is truly needed, therefore, is a lightweight battery that can go up to a few hundred miles on a single charge, or one that can be fully recharged in mere minutes—or both.
Although not as heavy as lead-acid batteries, the various lithium battery chemistries in use today are not exactly lightweights. Next-generation battery systems currently in development are showing great promise for increasing energy density by as much as three times, resulting in a battery weighing one-third (or less) of today’s best EV battery. And these batteries could be available in as few as three years. When that happens, the auto industry will finally be poised to begin eliminating gas-guzzling vehicles.
In the Smart Grid today, the battery’s role today is limited mostly to “smoothing” the production of solar and wind power as renewable sources of energy. Periodic cloud cover and regular variations in wind velocity make solar and wind quite intermittent, which complicates their integration into the electrical grid on a large-scale basis. Batteries can minimize these peaks and valleys, making solar and wind more dependable, if not dispatchable in “virtual power plants” that aggregate multiple, distributed sources.
But can batteries really compete effectively with traditional large-scale energy storage technologies, such as pumped hydro and compressed air, which are used in peaking power plants? Not today. And some of the current and exotic chemistries proposed, like sodium-sulfur and vanadium redox, may never be cost competitive.
But imagine tens of millions of EVs plugged into the Smart Grid. Such an enormous amount of storage could enable, quite literally, a nationwide vehicle-to-grid (V2G) virtual power plant. Much work needs to be done, of course, to ensure that all these batteries can give back some power when needed by the grid while still maintaining their “all gassed up and ready to go” charge for the commute to and from work. As for cost? That’s also good news, because utilities will incur little or no capital expenditures to make this possibility a reality.
How will the V2G virtual power plant help achieve energy independence? In meeting the ever-increasing demand for electricity, it will make renewable sources of energy more viable and minimize the need for utilities to build more gas-fired power plants, leaving our nation’s reserves of natural gas for other uses. (Note that building new coal-fired power plants will become increasingly problematic with the need to reduce our carbon footprint.) And if that next-generation battery is able to eliminate a future dependence on foreign sources of lithium, then the U.S. may well be able to achieve full energy independence.
