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Is mega solar power on the way, or
will high costs keep it at bay?
It’s 35 ˚C in the shade. Often.
In Upington, a town in the arid, ironed-flat expanse of the
Northern Cape, the extreme and persistent heat may cause some to
become hot and bothered, but to Eskom it’s good news – because
this is where the utility is consider-ing building its
(In fact, the Northern Cape every year records some of the
highest aggregates of sunny days a year worldwide.) If Eskom
takes the decision to go ahead with the project, it will be the
first major solar-energy project in Africa, especially where the
elec- tricity generated will be directed into the main power
grid of a country.
It has been a long time in the making, with Eskom in 2001
already initiating a feasibility study to determine the choice
between either a trough or central-receiver system for a 100-MW
plant. In the end, the molten-salt type central-receiver
technology was appointed the favourite.
In 2003, it was estimated that the project would cost around
R2,2- billion. Now Eskom prefers not to talk about costs until a
fresh feasibility study has been com- pleted, this time
specifically on the central-receiver system.
However, the cost of such a system may seem less severe these
days, especially against the background of Eskom’s preparing to
fork out R97-billion in capital expenditure over the next five
years as it moves ever closer to its maximum genera- tion
capacity as South Africans scurry for their heaters with each
But, yes, R2-billion-plus for 100 MW of electricity remains
However, again, what makes electricity from the sun such a
heavy- weight in the power-generation ring is that it is clean,
renewable energy, unlike the electricity produced by South
Africa’s coal-fired power stations. These stations are currently
used to produce more than 90% of South Africa’s power – also
churning out vast amounts of carbon dioxide and some other
rather nasty pollutants.
Eskom’s solar-power project is currently in the feasibility and
environmental-impact assessment (EIA) phase. This is scheduled
to be completed at the end of 2007, says Eskom resources and
strategy division renewable-energy corporate specialist Dr Louis
“If approval is obtained, based on satisfactory results from the
above phase, construction work can start as early as 2008,” he
tells Engineering News in an exclusive interview.
The project has to satisfy three prerequisites before implement-ation,
he notes, namely a positive record of decision on the EIA;
resolving all outstanding technical issues; and an acceptable
business case. The project will most likely be located in the
Upington area, and will have a maximum capacity of 100 MW.
Van Heerden explains that central-receiver technology, which has
now emerged centre stage, concentrates the sun’s energy through
multiple large mirrors, using the concentrated thermal energy to
produce steam to drive a conventional steam turbine for
electricity generation. The energy concentration is achieved by
a field of large sun-tracking mirrors (called heliostats), which
reflect the sunlight to a receiver, mounted on a central tower
in the middle of the mirror field. A heat-transfer medium
(molten salt) is pumped through the receiver, absorbing the
highly-concentrated radiation reflected by the heliostats. The
heated fluid is then circulated through a heat exchanger, where
the thermal energy is used to generate steam and power a
turbine. Temperatures within the system can reach in the region
of 600 ˚C.
Central-receiver technology is only one of many renewable-energy
options currently under investigation by Eskom, says Van Heerden.
“However, given South Africa’s significant solar resource, Eskom
feels that this technology could potentially provide significant
benefits into the future. “Eskom has spent several years
evaluating various concentrating solar technologies. The studies
conducted have indicated that the central-receiver system has
signifi- cant potential for local content in its manufacturing,
as well as the highest potential for future cost reductions.”
Cost is one of the pivotal issues around renewable-energy
solutions, as they are not developed, researched or
mass-produced on the same scale as conventional energy
solutions, such as those around coal.
However, as resistance to pollution grows, so does the research,
development and production of renewable-energy systems.
The cost projection of the Upington project will be finalised
through the feasibility phase, says Van Heerden. However, it is
anticipated that the generation cost will be substantially more
than conventional methods currently in use in South Africa.
(This is not surprising, as South Africa is currently credited
with producing the world’s cheapest electricity – which makes it
a difficult fight for any alternative energy source to win.) As
far as capital expenditure goes, rudimentary maths shows that
Eskom’s proposed new 2 250-MW coal-fired power station, in
Limpopo, at a cost of R26-billion, requires a payout of
R11,6-million a megawatt. Should the R2,2-billion still apply to
solar technology – even then as nothing more than an estimate –
it comes to R22-million a megawatt. However, as renewable-energy
pundits have often pointed out in the past, coal is a depleting
feedstock, while sunlight is abundant, free, nonpolluting and,
galactic disasters aside, not likely to run out.
One of Eskom’s first forays into solar energy did not quite
illustrate this technology to be the answer to the country’s
The 18-m-high, R3-million, 25-kW solar dish erected next to the
N1 between Tshwane and Johannesburg in 2001 served to illustrate
that small production volumes and lack of research and
development are still major inhibiting factors to some areas of
the renewable- energy market. “The dish research project was
completed earlier this year, with all the research questions
answered,” says Van Heerden.
Eskom will not be proceeding with the technology, he adds.
“Mechanically, it works quite well, but the operating and
control system is not sufficiently robust in this generation
system and, as such, we regard the technology as pre-commercial
at this stage. “The US-based supplier is planning on installing
several units of the next-generation dish systems in the US,
which may eventually move the technology to a
commercially-viable and stable technology in future.”
The newly-crowned sun king resides in South Africa.
The University of Johannesburg’s Prof Vivian Alberts, from the
department of physics, has developed solar panels that may just
take this technology further into the main-stream, owing to the
cost reductions he has achieved.
Alberts’ solar panels are thinner and cheaper than those
produced anywhere else in the world – in fact, up to 50% cheaper
– and they are set to be manufactured locally.
Currently, the standard panels used locally are imported. (Alberts’
cost estimates have in the past been scoffed at by many
solar-panel importers, either on the grounds of impossibility,
or that thin solar panels have a much shorter lifespan than
conventional ones. However, he responds by saying that their
reaction springs from a fear of losing business on a
cost-comparison basis.) To use the sun as an electricity source,
one needs a photovoltaic device, such as a solar panel, to
transform solar radiation – sunlight – into electricity,
The semiconductor used up to now to achieve this has been
silicon, which is a rather expensive option, he adds.
Alberts, who, ironically, read his masters and doctorate in
silicon- solar technology 12 years ago, decided there must be a
less expensive, more effective semiconductor than silicon for
the purposes of solar devices. “Silicon is actually a poor
absorber of sunlight.” The solar panels typically in use in
South Africa are based on a 350-micrometre-thick layer of
silicon – which is the minimum requirement to absorb sunlight
effectively. Alberts’ invention is five micro-metres thick,
combining several semiconductor materials which are as
effective, if not more so, than silicon, he believes.
As it uses no silicon, costs are dramatically lower. It makes
use of normal window glass as a substrate, with – and this is
where it gets complex – molybdenum applied as back contact,
followed by the core component, being a compound semiconductor
comprising five elements – copper, indium, gallium, selenium and
sulphide, replacing the silicon – with cadmium sulphide as a
buffer layer, followed by an intrinsic zinc oxide layer and,
finally, a conductive zinc-oxide layer. “The most expensive part
of the panel is the glass,” says Alberts.
“The pilot plant has shown the production cost per watt to be
€0,95, verified for a 25-MW production facility, assuming a 10%
efficiency and average production yield of 85%,” says Alberts.
All of this means a 60-W panel could finally have a price tag of
roughly around R490, or R8 a Watt, compared to imported panels
entering local soil at R30 to R40 a Watt, he notes. Worldwide
production of Alberts’ solar panel is in the process of scaling
The University of Johannesburg has, for purposes of
commercialisation of the photovoltaic technology, formed the
company, Photovoltaic Technology Intellectual Property (PTIP).
Following a technical and commercial assessment of the
technology, PTIP, in August 2005, entered into a licence
agreement with Germany’s IFE Thin Film Technology. Following
restructuring, IFE became Johanna Solar Technology (JST), the
universal successor of IFE. This completed, JST has now started
construction of a €72-million manufacturing plant of 30-MW
capacity in Brandenburg, Germany. Production is set to start in
March 2007. JST has seven shareholders, including South Africa’s
State-owned Central Energy Fund, Richemont-Venfin and Anglo
Alberts says Germany has been granted the first production
licence of the thin-panel owing to the fact that the country has
a well-established solar market, while South Africa’s is still
in its infancy.
“While the details are at this stage confidential, PTIP
concluded a second international licence and technology-transfer
agreement in July,” says Alberts.
The second licensee is also an established and prominent role
player in the existing international photo-voltaic markets, and
produces, markets and distributes well-known silicon-based solar
modules worldwide. This second company will start construction
of a 30-MW manu-facturing plant in Europe, in January 2007, says
Alberts, with production kicking off in December 2007. However,
South Africa will not lose out on gaining economic benefit from
the home-grown technology. PTIP, in association with its German
partners, is currently developing a business plan which is
intended to serve as a basis for procuring “not more than three
strategic South African investors in a new local company to be
formed by PTIP – which will be called NewCoSA”, Alberts tells
PTIP would license NewCoSA on an exclusive basis for the manu-facture
of the thin-film panels in South Africa – which will be the
first-ever large-scale solar-panel production line in the
country – as well as the right to sublicense the technology in
Africa, and islands in the continent’s proximity. PTIP and the
IFE group will under- take the general planning and project
management functions for the procurement, construction and
erection of the first manufacturing plant in South Africa. It is
projected that construction of the South African solar-panel
manufacturing facility will start in 2007, with the first panels
coming off the pro- duction line in early 2008.
It is intended that the solar modules produced in the respective
plants in Europe and South Africa will be marketed and
distributed under a unified brand name, which is still being
negotiated. “The South African market presents unique challenges
and it is foreseen that complete photovoltaic systems (including
solar modules, storage devices and inverters) will be developed
mainly for off-grid applications. “The ultimate aim is to
develop the local markets in the medium to long term, while
excess products will be exported to Europe, in the short term,
to ensure an economically- viable industry,” notes Alberts.
He adds that he has been engaged in negotiations with a variety
of prominent international and national companies and
organisations that have shown support and interest in the
project. “However, until now, we have had no formal discussions
with Eskom.” Alberts has been patient in doing his bit to undo
the high-cost straitjacket that has, to a large degree, kept the
solar industry from develop- ing faster.
“The project has been developed over a period of more than 13
years from a research-and-development level to a commercial
level. The success of the technology depends ultimately on the
support of strategic investors internationally, as well as
locally. The current developments, and especially the magnitude
of the commercial ventures internationally, have exceeded all my
initial expect-ations, and even my wildest dreams. The
technology is now supported by a combination of strategic
investors with a global presence and vast commercial experience
in photovoltaics. “I truly believe that we have now set a solid
platform from which we can develop and build a sustainable
photovoltaic industry in South Africa,” says Alberts.
Pay up to clean up
Solardome is a solar hot-water system manufacturer, also
specialising in solar-energy systems. It has been in the
solar-power business for more than 35 years. The company is also
a member of the Sustainable Energy Society of Southern Africa.
The company’s James Venter agrees that bringing down costs is
pivotal to furthering solar technology, but that even more is
He notes that for solar-generated electricity to become a
reality in South Africa, it requires government support in the
form of incentives for grid-tied systems, which is the case in
many European countries that are actively promoting the use of
Government grants or rebates for using cleaner energy will aid
the customer in paying for the solar system he or she has
installed, the price of which can vary around R150 000, says
On a cost comparison basis, he notes that the US Department of
Energy estimated the consumer cost of coal vs photovoltaic at a
ratio of 1:5 for residential, and 1:4 for commercial and
industrial; how- ever, this does not take into account the
procurement methods, environ-mental consequences or hidden costs
“In general, the cost of solar systems has decreased 700% over
the last 20 years and costs will continue to decrease – owing to
technology, sure, but mainly manufacturing volume as more and
more countries become involved.” He adds that South Africa has,
to date, pursued mainly off-grid applications – which generally
means providing solar energy, which is an expensive solution, to
poor rural communities – while a grid-tied system is the most
“Stand-alone battery systems are the most popular in South
Africa, and also the most uneconomical option for photovoltaic
systems,” says Venter.
Stand-alone systems require battery backup, which is expensive,
while a grid-tied system can use the grid as a battery bank,
pushing electricity into the system when not in use.
Venter adds that the economic return on a homeowner’s investment
in solar energy is almost always measured in the value of the
electri- city generated.
“This is a very narrow way of thinking as the displacement of
electricity that you would have otherwise bought from your
utility or energy service is of more importance in South Africa,
which is currently short on electricity.
“This, along with protecting your electronic equipment and
lights against erratic supply and power spikes, with the added
benefit of a little self-efficiency, can double the value of the
system. “Grid-tied systems can be metered separately and
rewarded at a defined rate, related to the domestic tariff, or
set by a government initiative.” Venter is fully supportive of
any form of renewable energy, but does not regard Eskom’s
Northern Cape solar project as the only solution to producing
alternative electrical energy in South Africa.
“If the same funds are used to promote and subsidise
privately-owned grid-tied alternative-energy systems, it would
be of great benefit to the average homeowner as well as to
Eskom,” says Venter, who views electricity from solar solutions
as ideally suited to South Africa. Places like the Sunbelt
states in the US, Latin America, most of Africa, the Middle
East, India and Australia have an average of 5,5 hours of
effective sunshine. However, South Africa, the Sahara, Saudi
Arabia, central Australia, Peru and Bolivia have higher
Professor Thomas Harms, of the University of Stellenbosch’s
department of mechanical engineering, says for South Africa to
generate electricity using the sun is certainly feasible.
However, feasible does not equate with affordable, which is why
the current industry mainly supports a number of local
manufacturers of solar thermal domestic water- heating
equipment. “At the on-grid end-user level, while technological
progress is still being made, it is not yet economical to
install photovoltaic panels on your roof, especially given most
municipalities’ low resale tariffs of Eskom’s power.” Harms did
an electricity-gener- ation cost comparison for Engineering
News. “If you look at base-load generation, such as a coal-power
plant able to sell power to the grid 24 hours, located next to
an easily-mined, sufficient-quality coal mine, and discounting
the environmental footprint and rehabilitation costs at the end
of the life cycle to simplify the matter, only a few people
would, at present, argue that a first-off, bulk solar-power
station could compete with the 15c/kWh generation cost of such a
plant,” he explains.
However, Harms notes that the picture changes quite
significantly if one looks at servicing morning and evening peak
loads. “A shortage of peak power-generating plant capacity in
South Africa means that base-load plants have to run
intermittently at, say, more than 84 c/kWh. This is an arbitrary
figure and depends on the load factors, such as during which
part of the day the coal plant feeds power into the grid – the
shorter the period, the more expensive it is.” Therefore, says
Harms, a solar power station in South Africa, such as the one
planned near Upington, would ideally first have to deliver at
peak demand times to render it competitive, which means it has
to incorporate energy storage. This does not make it only more
expensive in terms of capital spend, but also more versatile as
a power station.
“I would expect it to be able to deliver below the threshold of
84c/kWh suggested.” He adds that the high-temperature
central-receiver option chosen by Eskom lends itself
particularly well to thermal storage. He does note, however,
that a hybrid of the central-receiver concept with the more
proved parabolic- trough concept, could eventually lower the
visual impact of such a plant, and reduce performance risks.
In general, Harms is optimistic about the envisaged plant.
“Depending on how quickly it is realised, the solar power
station will be one of the largest single-site solar power
plants in the world. “The innovation should lift us to where we
belong, namely being the world leader in solar-energy tech-nology
and exporters thereof.” In addition, he expects that the plant
will act as a net scientific and tourist attraction, which he
regards as an important consideration. “I would regard it an
unqualified wise and welcome contribution to the diversification
of our energy production landscape, and a good step forward
towards the long-term solar-based energy future many foresee.”
Harms does, however, note that South Africa’s attempts at
implement- ing renewable energy in general could do with some
generous aid, such as increased funding prioritised for
renewable-energy research and skills development.
“We also need higher electricity tariffs, which will, no doubt,
come with Eskom’s R97-billion five-year capital-expenditure
“While this will be detrimental to some sectors of the economy,
it will lead to the development of new sectors,” he notes.
This also applies to tighter emission controls. “This is
painful, but that is what change for the better is all about,”