Q&A: Cheap oil and the future of energy

The oil price has plummeted, while shale gas has made the US
increasingly energy self-sufficient. What does this mean for the
world’s shift to renewables, and the role played by fossil fuels in
our energy mix? Will nuclear energy disappear because of
concerns over the safe storage of nuclear waste?
After over four years as the United States Secretary of Energy,
Nobel laureate Steven Chu, Stanford University professor of
physics and molecular and cellular physiology, discusses the
current energy landscape and the outlook for the future.
During your time at the Department of Energy, the deployment of
renewable energy in the US doubled. With fossil fuel prices
falling, is that killing the business case for renewables, and if
so, what does it mean for investment in renewable energy
solutions?
The decline in fossil fuel prices does have some
effect, but remember that 78% of the economies
of the US have State-mandated renewable
portfolio standards. They require that a specified
fraction of electricity must come from renewable
energy. For example in California the goal is 33%
renewable energy by 2020.
Right now renewable electricity is roughly 13% of
total electricity generated in the US. Half is
hydropower and the other half is mostly wind
energy, with some solar, biomass and
geothermal. Renewable energy costs have come
down significantly. Even if natural gas, which is
the cheapest form of electricity generation
today, stays at $4 million BTU (British thermal
units), wind without subsidy is almost as
inexpensive.
Electrical generation in the sunnier parts of the
US is also approaching equality with a new
natural gas power plant. The cost of wind and
solar is anticipated to decline for at least a
decade or two. Perhaps in a decade, renewables
will be competitive with any new form of energy
in many parts of the US.
What do you think is the biggest energy problem today?
It’s a combination of things. As renewable
energy and electrical storage become less
expensive, one has to design the grid system to
take full advantage of lower-cost energy.
As renewable energy becomes an increasingly
larger fraction of the total energy, the cost of
stand-by electricity and storage becomes part of
the cost of renewables. Sometimes, the wind
does not blow and the sun does not shine.
There are countries that have about 25%
intermittent energy integrated over the year. One
of the challenges is how do you go from 25 to
50% and higher. It means you have to balance
loads over wider areas, because the larger the
area you collect energy, the more you can even
things out. But at the 50% level you’ll need
energy storage as well.
Germans call it the “Energiewende”, the switch from fossil fuel
and nuclear to renewables: Is the world really on this path?
Countries are going to take different paths. I
wish that Germany would continue to operate
their nuclear reactors for the duration of their
useable lifetime to allow for a more orderly
progression.
In Germany, about 30% of their electricity comes
from renewables – 10% biofuels and the rest
wind and solar. Virtually all of the wind is in the
northern part of Germany and electricity has to
be transported to heavy industrial areas in the
southern part, and some people don’t want the
transmission lines in their line of sight. Germany
has to figure out how to deal with this issue.
China also is moving – it has now set goals to
cap carbon emissions and coal use, and be 20%
renewable by 2030 or earlier. It is a very good
sign when a developing country like China says
that clean energy is an important goal,
regardless of whether there’s a UN agreement or
not. For them to say, “We’re going to go ahead
and do this” is a very big deal.
What are the most interesting scientific advances right now that
have the potential to transform clean energy?
In the solar photovoltaic field there are new
compound materials called perovskites, which
have increased efficiency in laboratory tests
from 3.8% in 2009 to over 20% by 2014. If we
can use these materials in tandem with silicon,
photovoltaic generation could increase to
produce 50% more energy.
There are also new battery and “super-capacitor”
chemistries and structures. A super capacitor
can accept and deliver much more power per
unit volume than a battery, and a modest-sized
super-capacitor will allow full energy recovery
during the braking of vehicles. I am particularly
excited about nanostructured batteries and
graphene-based super-capacitors. Energy
efficiency technologies are also improving: cars
of equal performance are able to go twice as far
on a gallon of gas as automobiles of 40 years
ago, and a Boeing 787 uses only 30% of the fuel
of a Boing 707 per passenger mile. Efficiency
improvements are part of the transformation.
Electric cars are hailed by some as an important contribution to
our energy problems – do you agree?
Yes. The cost of electric vehicle batteries has
come down to about 40% of what it used to be in
2008. According to the projection of the Tesla
Gigafactory, a lithium ion battery factory, electric
cars’ battery costs will go down another two-fold
from today. Within five years, we may be able to
buy a car that goes 200 miles for $25,000.
The energy density of batteries is getting better
– today there are batteries about 60% higher in
energy density – ie, with more energy for a
given weight and volume – than the batteries of
15 – 20 years ago. Within this decade, the
energy density is likely to double.
The clean-tech community is split: some believe nuclear has to
be a key part of the mix, others think that – with nuclear waste
storage still untested – it’s even worse than fossil fuels. What’s
your take on this?
I think for the next half century I would like to
see nuclear as part of the electricity mix to have
a diversified supply of electricity.
Disposing of the waste is an issue because
many people do not want it in their backyard.
But that’s mostly where it is a political issue
rather than a scientific one. There are geological
sites that are very stable, and where nuclear
waste can be stored safely. For example in the
US we have large salt deposits that have been
stable (no water intrusion) for millions of years,
and would provide safe geological confinement
of spent fuel.
And we can’t really abandon fossil fuels before
the first half of this century because they are
needed for back-up power. We need to invent a
method to transform very inexpensive electricity
into a cost competitive liquid hydrocarbon fuels
that can be shipped by tanker and stored around
the world. After that, we can begin to wean
ourselves from fossil and fission nuclear energy.
You’ve straddled politics and science… at times this doesn’t
seem to work. What’s going wrong?
Sometimes you can have sets of well-informed
people who will have different opinions on how
to deal with X, Y or Z. That’s where politics
should come in.
For example take climate change. The climate is
changing, and there is very strong evidence
much of the change is due to humans. While
there are large uncertainties as to what will
happen in the future, there are huge risks unless
we greatly decrease carbon emissions. The
proper political debate would be how to deal with
these risks, but it makes no sense to say,
“Unless science can prove unequivocally that
very bad things will happen, we can continue on
our present course.” Science cannot predict who
will get lung cancer if they smoke. With a half a
century of hindsight, we now know that the risk
is 25 times greater than non-smokers. Prudent
risk management does not use uncertainty as an
excuse for inaction, and fire and health
insurance make sense. We need leaders who are
scientifically well-informed and willing act in the
long-term best interests of their countries.