Now that we know we can generate mass amounts of renewable energy, we must
learn how to efficiently store it
By Denis Hayes
By Denis Hayes
In the run-up to a solar eclipse on March 20 of this year, European tabloids had a Y2K-style field day. In the middle of a bright, sunny day, European solar panels together produce about as much electricity as 90 large nuclear power plants.
Germany, with the largest solar commitment, obtains as much as 50 percent of its electricity from the sun during the sunniest hours. The eclipse was scheduled to arrive in the middle of the day and panic was setting in.
Eclipses occur
over very broad regions, so grid operators can't count on a sunny Spain to
compensate for a cloudy Poland. Moreover, the decrease in sunlight (and the
subsequent slingshot back to full sun) during an eclipse occur rapidly; grid
operators have no experience managing such abrupt, sweeping shifts. Some
predicted the eclipse would produce a catastrophe.
As with Y2K, there was no catastrophe. Europe experienced only a partial eclipse; much of Germany was fairly cloudy; and grid operators had had ample time to work out detailed contingency plans. But, as with Y2K, there had been legitimate reason for concern, and the experience offered a valuable lesson -- if we are smart enough to absorb it. We need better ways to store renewable energy.
Renewable energy
technologies are becoming increasingly competitive for a major share of the
world's energy. In 2014, almost half of all new global investment in
electricity generation was in renewables. China, at $83 billion, was the
largest investor. Even excluding huge dams, the world generated 9.1 percent of
all electricity from renewables last year -- mostly solar and wind.
Solar and wind
energy involve no greenhouse gases, no mountain top mining, no fracking, no
radioactive isotopes, no oil spills... But sometimes the wind doesn't blow. And
sometimes the sun doesn't shine.
In the early
years, the intermittent nature of renewable energy was thought to be of little
concern. We could use renewable electricity when available and switch back to
conventional fuels when needed.
But as renewable sources become a cornerstone of our energy mix, we will need to find ways to store power for those times when renewables are unavailable.
But as renewable sources become a cornerstone of our energy mix, we will need to find ways to store power for those times when renewables are unavailable.
Sunlight is, by
far, the most abundant energy source on earth. But how do you store surplus
electricity to use when you need it? Possibilities include batteries,
ultracapacitors, and flywheels, all of which have important uses. One of the
most attractive options is to use the sun's energy to make hydrogen; store the
hydrogen until it's needed; then put it into a fuel cell to make electricity.
At the time of
the first Earth Day in 1970, these technologies faced formidable challenges.
Solar modules were ultra-expensive devices produced by a cottage industry whose
only significant customer was NASA. Hydrogen was tricky to store and expensive
to transport. Fuel cells required expensive catalysts like platinum.
Those did not
appear to be monumental challenges for a species that had split atoms and gone
to the moon. But gasoline was cheap and the oil industry was politically
potent. Technical challenges are overcome only with ample funding, creative
minds, and dogged perseverance. America's embarrassingly modest, start-and-stop
federal support has been more of a tease than a sincere effort to build an
industry.
The latest tease
relates to hydrogen fuel cell vehicles. For no good reason, the federal tax
credit for fuel cell vehicles ended last December while the incentives for
battery powered cars continue to be in effect until each manufacturer has sold
200,000 such vehicles. Helping manufacturers achieve economies of mass
production makes vastly more sense than cutting off incentives on some utterly
arbitrary date.
Hyundai slowly
began leasing Tucson fuel cell vehicles last year, and Toyota -- the company
that launched the hybrid vehicle revolution in 2000 with its Prius -- plans to
begin selling the Mirai fuel cell vehicle in America later this year. This is
worst possible moment to remove the incentives for such vehicles!
Elon Musk, a
very bright guy and the CEO of Tesla, disagrees, calling hydrogen fuel cell
electric vehicles "mind-bogglingly stupid." But the arguments he uses
against them mostly echo the same arguments that had been used against battery
electric vehicles until Musk himself upended the paradigm.
Of course, he might well be right -- the multiple energy conversions, high cost of infrastructure, etc. -- might prove to be the kiss of death. But this depends upon a long string of assumptions about the future. It is not self-evident to people who don't own Tesla stock that electric cars should receive rich subsidies while fuel cell vehicles receive none.
Of course, he might well be right -- the multiple energy conversions, high cost of infrastructure, etc. -- might prove to be the kiss of death. But this depends upon a long string of assumptions about the future. It is not self-evident to people who don't own Tesla stock that electric cars should receive rich subsidies while fuel cell vehicles receive none.
Ultimately,
though, this is a bigger issue than which alternative vehicle will prove to be
the long-term winner. One way or another, we need to have a way to store very
large amount of sunlight for times when the sun isnt shining. And hydrogen --
for fundamental reasons -- has to be considered among the most attractive
contenders.
Hayes, the
organizer of the first Earth Day in 1970 and director of solar energy research
under President Jimmy Carter, is president of the Bullitt Foundation and board
chair of Earth Day Network.