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RENEWABLES
The future of
PV technology
Most of the early grid tied photovoltaic power projects in South Africa are using
crystalline silicone based modules, which dominate the industry, accounting for
some 90% of the total installed. However, arguments can be made in favour of
thin film technologies.
T he case in general for photovoltaic
(PV) generated energy has grown,
since its prices have become
competitive with conventional energy
sources. While having the drawback
of intermittency based on when the
sun shines, PV energy is more price
predictable than that from fuels such
as gas, and once installed operating
costs are low. Companies and utilities
are including solar PV into their mix to
balance their power generation portfolios
and to mitigate fuel price volatility. Gas
and oil producing countries themselves
see their hydrocarbons as being worth
more when exported or converted
to value-added products than when
consumed domestically at subsidised
rates. Thus they seek substitution, and
many of these countries are rich in
sunlight. Africa has begun to pay attention to
this technology because the continent
has some of the highest levels of solar
irradiation on the planet. This is in
comparison with Germany which has the
highest installed capacity of solar PV but
some of the lowest irradiation levels.
It cannot be overemphasised how
much this trend has been driven by
solar PV having experienced dramatic
cost improvements over the past few
years. Interestingly, it was US based
integrated PV group and thin film module
producer, First Solar, which manufactures
cadmium-telluride (CdTe) panels, that
first broke the US$1/Watt barrier. CdTe,
an alloy by-product from copper and
zinc mining, does not display the toxic
characteristics of elemental cadmium
and has been certified safe for use by
independent agencies.
In a price comparison done by
First Solar with other energy sources,
the grid tied cost of its PV energy of
between about US7c/kWh and 15c/kWh
is lower than that of diesel sources, all
above 20c/kWh, and peaking gas plants
(that range from 20c/kWh to 38c/kWh),
assuming gas prices as they stood in
2013 across Europe, the US, Australia
and Japan. In comparison with base
load options, its solar power was more
cost competitive than combined cycle
gas in Japan (15c/kWh to 20c/kWh), but
less so than combined cycle gas in the
US, which comes in at under 10c/kWh,
showing the sensitivity of gas power to
the price of fuel obtained. Energy from
a First Solar PV system is relatively on
a par with the cost of nuclear energy
but more expensive than coal whose
prices typically range from US4c/kWh to
8c/kWh. Overall, this is probably a fair
assessment of the cost comparison of
PV with other energy carriers as things
stand. Joseph Kishkill, First Solar’s chief
commercial officer, says that costs of
PV systems will continue to decrease,
though it may be an asymptotic reduction
from now on. He says that at one point
the cost of the panels amounted to 50%
of the total for a PV facility, and this has
come down to 20% or 30%. As a result
companies are trying to drive down costs
in the balance of system. “There are
steps to integrate tracker mechanisms,
and developers are trying to make gains
by integration across components.”
Apart from the technology
perspective there is a focus on the
The Mohammed bin Rashid Al
Maktoum Solar Park, 50 km
from Dubai in the UAE.
ESI AFRICA ISSUE 1 2014
83