Yesterday I mentioned a plan to build the equivalent of ~1,500 fission
reactors with wind and solar thermal plants, and ~1,500 advanced
next-generation fission reactors. This would produce all the energy needed
in the world today including liquid and gas chemical fuel for
transportation. Energy consumption is increasing in China and India so more
would be needed in the future.
I split these plants 50:50 for a reason: wind and solar are intermittent
and they cannot be dispatched on demand. EPRI says that most distribution
networks today can handle up to 20% wind or solar electricity without
expensive upgrades. If 50% of electricity came from wind, we would have to
have very expensive long-distance transmission, or massive overcapacity, or
some other solution. So, perhaps this ratio should be something more like
30:70, assuming that future distribution networks will be better at
handling intermittent power. Or perhaps most of the hydrogen gas should
come from the renewable side, and the electricity from the nuclear side.
Hydrogen is stored in tanks, and if hydrogen production is reduced for a
few days in cloudy weather, it would not matter.
The Luz solar thermal plants in California have built-in dispatchable
buffers. They generate steam from solar power, and the steam is superheated
with natural gas. When it is raining they use more gas, and in a pinch they
can run on gas alone. ~80% of the energy they provide year round is solar.
This is a very clever design. The principal is similar to that of a plug-in
hybrid car: you use the renewable clean energy first, and you reserve the
expensive nonrenewable energy as a backup, or to augment the clean energy.
Conventional nuclear plants are not good at turning on and off quickly, so
we would need a buffer of dispatchable generation capacity, probably
natural, hydrogen or biomass.
In some regions of the country, other interesting ways may be used to get
around the problem of intermittent generation. Take hydrogen. Thermal
processes will probably be more cost-effective than electrolysis. In Nevada
this might be solar thermal, while in Connecticut it would have to be a
nuclear thermal plant. In North Dakota, however, they might build thousands
of wind turbines and use the excess electricity at night to generate
hydrogen, even though electrolysis is less cost-effective. You might even
build 10 times more wind turbine capacity (nameplate) than the people in
Dakota need. The wind is always blowing somewhere in the state, so this
would guarantee electricity nearly all the time, without a nuclear power
plant. (You would still need some dispatchable power.) During most daylight
hours, and nearly all the time at night, the system would generate more
electricity than the people there can use, so the excess would be converted
into hydrogen which is shipped by pipeline to other parts of the country.
If we get lucky and develop superconducting power lines, North Dakota might
ship the electricity across the country. This would be better than gas. We
would get renewable electricity from North Dakota, and renewable solar
thermal hydrogen gas from Nevada. In states without wind, solar or biomass
resources, these imports would be augmented by locally generated nuclear
electricity and hydrogen.
Sometimes, a process such as electrolysis which is inherently less
cost-effective in most regions, under most circumstances, works well under
special circumstances.
This system would be tremendously complex and expensive. It would require
years of expert planning, and decades of construction. It would be
inflexible. It would require upgrades and an expansion of the power
distribution network, which is unsightly and triggers a NIMBY reaction. If
our needs changed quickly we would be stuck with the old mix of electricity
and hydrogen for a long time. Cold fusion would be more flexible, easier to
implement, and FAR cheaper.
The complexity does have one advantage. You could slide something like
Jones Beene's Brazilian nuclear/biomass energy into it without difficulty.
The system is already so complex, with many different inputs and delicate
balancing required, so you would hardly notice the extra expense required
to accommodate yet another input. It is like an urban road in India: it
already accommodates peddled cars, bullocks, bicycles, buses and
pedestrians; you could throw in slow moving electric jitneys or elephants
and nobody will notice. Cold fusion would be dead simple and
all-encompassing, with no other inputs either necessary or possible. It
would be like a US highway instead of the Indian road. No mopeds allowed.
What I am advocating here is an unusual mixture of hardcore
environmentalist alternative energy and nuclear energy. As I mentioned
before, I do not like nuclear power but I think we can live with it for the
next few hundred years without producing an untenable amount of nuclear
waste. Experts such as Ed Storms have grave reservations about nuclear
waste and potential terrorism. While I am sure there is much to worry
about, I am even more worried about coal and oil.
Incidentally, here is another idea for solar hydrogen generation, from the
Weitzman Institute in Israel:
http://www.energycooperation.org/solarh2.htm
"The new solar technology . . . [creates] an easily storable intermediate
energy source form from metal ore, such as zinc oxide. With the help of
concentrated sunlight, the ore is heated to about 1,200°C in a solar
reactor in the presence of wood charcoal. The process splits the ore,
releasing oxygen and creating gaseous zinc, which is then condensed to a
powder. Zinc powder can later be reacted with water, yielding hydrogen, to
be used as fuel, and zinc oxide, which is recycled back to zinc in the
solar plant."
- Jed
