Solving the world's energy problem - a photovoltaic
approach:
The UN Foundation/Better World Fund
funded this superb edition
of the UNEP magazine Our Planet . http://www.ourplanet.com/imgversn/143/content.html
includes many good
statements – notably in The
Energy Challenge by Ted Turner http://www.ourplanet.com/imgversn/143/turner.html
which includes this:
"Of the world’s 6 billion people, one third
enjoy the kind of ‘energy on demand’ that North Americans take for granted, and
another third have such energy services intermittently. The final third – 2
billion people – simply lack access to modern energy services. Not
coincidentally, the energy-deprived are the world’s most impoverished, living on
less than $2 per day. Their ranks will continue to grow. According to UN
estimates, the populations of the 50 poorest nations will triple in size over
the next 50 years. Without access to modern, reliable energy sources, social
and economic development is not possible.
The bolded phrase above also occurs in The
Future of Energy Policy by Timothy E. Wirth, C. Boyden Gray, and John D.
Podesta , Foreign Affairs , July/August 2003 http://www.foreignaffairs.org/20030701faessay15410/timothy-e-wirth-c-boyden-gray-john-d-podesta/the-future-of-energy-policy.html There is a powerful consensus.
The human stakes are high. Every second, somebody dies who has
lived their life without electricity, and somebody else dies whose material
welfare has been stunted by inadequate energy services. Conservation can only help, but
for the world to get much better, the world needs MUCH more
energy.
A proposal for study and
action:
The task of removing energy as a fundamental
constraint on human welfare isn’t manageable without much more
specification.
But sub-tasks that could contribute to that objective are manageable
tasks.
For example, it is a manageable task to state and evaluate
photovoltaic approaches that could reasonably be expected to meet world energy
needs at a cost of 2-10 cents/kWh. There are few enough of them.
The price target corresponds to fossil fuel
costs. The energy content of a
barrel of crude oil is about 1700 kWh. $10/barrel oil is priced at
the energy equivalent of 1.7 cents/kWh. $30/barrel corresponds to 5.1
cents/kWh.
It would take about 15,000 - 20,000 gigawatts
of photoelectric capacity to match the energy supplied from fossil fuels
today. That would take about
100 billion square meters of 20% efficient photocell area . At a billion square meters/year,
that would take a century to produce – at a billion square meters/month – 8.3
years – at a billion square meters/week – 2 years. A total
collection area of about .0125% of the area of the earth would be needed. Roughly the area of Pennsylvania - if
that area was on the equator. In
cloudy areas, and away from the equator, larger areas would be needed.
Wherever the energy is produced - it has to
be moved to where it is needed on an economic and secure basis.
For photovoltaic solar energy to become a
relatively substantial source of the world's energy - it is total system capital
and operating costs of the installations that are going to matter - not the
details of any particular approach or any particular installation or placement,
except as those details are embodied in costs.
But you have to start somewhere. It makes sense to work through and
prototype one approach that could do the job - not ruling out other approaches
that could also meet specifications.
Specification of what it would take to
produce silicon photocells for 2-5 cents per watt in the quantities needed is a
manageable task - applicable to many PV siting approaches. This specification task is partly
done - and prototyping of an approach that could meet cost and production
quantity requirements appears to be manageable now. An overview of the challenge
is set out in http://www.mrshowalter.net/_PhotocellCostsCanBeReduced.htm
- which includes this:
The assumption that high volume production of photocells can be done for under 2cents/ watt mostly hinges on whether or not silicon sheet or foil of the required properties can be made for less than 5-10 times the cost of a similar quantity of aluminum foil of the same thickness.
a crucial component of the job – the question
" What
would it take to get large scale, profitable production of fully interchangeable
purity silicon by direct purification of metallurgical silicon one year from
today?"
- is being addressed, with the intention of
organizing a reasonable affirmative answer, at this time.
Specification of one siting approach that
could meet the world's energy needs at an additional cost of 2-5 cents/kWh,
assuming the availability of photocells is also a manageable task. The approach places collectors on
the equatorial seas, with HVDC transmission of electricity to markets. The 100 billion square meter
collection area could be provided by 10,000 standard collectors of ten square km
area and 2 gigawatt capacity each.
Basic structural costs of these collectors correspond to a charge below
.1 cent/kWh . The HVDC transmission
components needed to move the DC electricity collected to markets can be
specified using current knowledge and design experience. Design data, including risk assessment
data - is available. If solar
power is to be available 24 hours a day according to this approach - a
circumnavigating HVDC trunk line would be required. Prototyping of the collectors is
manageable now.
Specification of the organizational tasks
involved with this siting approach is also a manageable task. One subtask - discussion with
United Nations officials who would have to be involved - has been
initiated.
Again, for photovoltaic solar energy to
become a big energy source for the world, it is costs, not technical details,
that will matter in the end.
The suggestion above may not be the only proposal possible, or the best
one possible – but I think it is
one practical proposal.
In many ways, the challenge involved is quite
close to the challenge the U.K. government handled from January 1935 on through
the Tizard Committee.
That committee supervised the development and installation of the radar
system that just pulled England through the Battle of Britain. The Tizard Committee was charged with
doing whatever it could to come up with an air defense. It was an “impossible” job that
had to be done for essential national security reasons. Now, national security and world welfare
depend on energy independence.
The idea that getting this job done with
photovoltaics is "impossible" hinges on a judgement about costs. If a workable way to produce silicon
photocells for 2-5 cents per watt in the quantities needed can be specified and
done – as I believe it can be – the rest of the proposal may come to look very
practical indeed. I'm
working, and hope to find others who will work, to convert that hope to an
accomplished fact.