HYDROGEN PRODUCED IN NORTH AFRICA USING ELECTRICITY
GENERATED BY SOLAR-POWERED PHOTO-VOLTAIC CELLS
In this section we show you how to calculate
the cost of solar-PV electricity in North Africa and how by using solar
PV electricity and hydrogen just a small portion of the land area of
North Africa could provide all of the energy needs of Europe.
Assuming we can sort out the politics, and that's a big assumption,
the production of hydrogen in North Africa will probably become important
in the medium term, i.e. after 2010 and after hydrogen from UK offshore
wind power is well established.
But we need to start planning for this now because the political problems
are so difficult. These problems will have to be dealt with by the Foreign
Office and the EEC and will take years to resolve. However if there
is a strong environmental and economic case for developing hydrogen
production in North Africa then the political effort will be worthwhile
for the benefit of all parties. If successful the development of North
Africa as a major source of hydrogen for Europe could improve the well
being of all the people living there and change the geopolitics of Europe
and Africa.
The key to developing solar-PV electricity generation is to reduce
the cost of PV cells by increasing the production volume of cells so
that the benefits of mass production can be realised. At present the
manufacture of both silicon wafer and amorphous silicon film PV cells
is based on production in batches. When the market for PV cells is big
enough then the production of amorphous silicon PV cells, or other film
technologies, will be an add-on to a dedicated continuous process glass
factory and the economics of mass producing glass will apply and costs
will tumble. The current batch price for PV cell modules is about US$5
per peak watt whereas the target price for mass production is US$1 per
peak watt. When PV cell module costs of the order of US$1 per peak watt
is achieved then the economics of generating PV electricity and hydrogen
in North Africa can be calculated as follows:
The cost of a PV cell module is expressed as the cost per peak watt
output at standard insolation. Standard insolation ( energy from sunlight
on a flat surface perpendicular to the suns rays ) is defined as 1 kW
per square metre. So a PV cell module costing US$1000 of area 10 square
meters with an energy conversion efficiency of 10 % will generate 10
sq.m. x 10% x 1kW/sq.m = 1kW of power when subject to standard insolation
and is rated at US$1 per peak watt. ( US$1000 per peak kW )
The typical annual average insolation in North Africa is 0.25 kW per
square metre, this averages out night and day and seasonal changes.
Therefore in one year a PV cell module rated at US$1 per peak watt (
US$1000 per peak kW ) will generate:
| 365 days x 24 hours x 0.25 kW/sq.m average insolation |
|
= 2190 kWhs of electricity per $1000 of module
cost.
|
In addition to the cost of the PV cell module there are the costs of
the support structure for the module and the wiring and controls needed
to run the module and collect the electricity generated, these costs
are usually called balance of system costs or BOS costs. For hydrogen
production there is no need for an expensive current inverter to be
included in the BOS costs because the electrolysis of water requires
direct current and PV cells produce direct current. Also land values
in desert areas can be set at zero. The BOS costs for PV electricity
for hydrogen production would be an extra US$500 per peak kW
So the capital cost of a 1.0 kW peak module plus BOS costs is US$1500
Current PV cells have a life of 20 years so the capital plus interest
cost of a 1 kW peak module plus BOS costs would be of the order of US$150
per year (depending on interest rates). As already explained a 1 kW
peak cell will produce 2190 kWhs of electricity in one year in North
Africa, therefore the cost of the electricity will be approximately:
These predicted costs for PV electricity in North Africa are in the
same range as the predicted costs for second generation UK offshore
electricity by 2010 and so would make North Africa also a good place
to manufacture hydrogen for the UK if 'Green Certificates' for the electricity
used could be granted and traded internationally.
Production would have to be on a large scale to make gas pipelines
to Europe viable from the start but as we will now illustrate the potential
energy resource is vast and could supply the whole of Europe so is well
worth considering.
With current technology the conversion efficiency of amorphous silicon
PV cell modules will be approximately 10%. This means that 1 square
meter of PV cell module in the desert in North Africa will yield:
365 days x 24 hours x 0.25 kW/sq.m average insolation x 10% = 219 kWhs
of electrical energy per year.
The PV modules have to be spaced apart to avoid shading and for access
and not all parts of an area of land will be suitable and land area
is needed for other facilities at a site so assume 25% of the area of
a site is the area of PV modules.
Therefore the energy yield from a site is 0.25 x 219 = 55, say 50
kWhrs per square meter per year.
The total energy requirement for transport, electricity and heating
in the UK currently supplied by oil, gas, nuclear power and coal is
approximately 1500 Terawatthours
(1 TWh is one thousand million kWhs )
Therefore the area of North Africa required to supply the entire energy
needs of the UK using PV and hydrogen technology and assuming an efficiency
of 70% for the process of using hydrogen as the energy carrier would
be:
The areas of the four countries of North Africa nearest
to Europe are as follows:
