Page 29 - Sphere No.28 (Mar 2011)

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Sphere
means good exposure to the resources. However the city
has, at present, severely limited usable space in which to po-
sition the panels, and the cost of installing systems remains
a deterrent factor.
“Land is precious in Hong Kong, thus making solar
power system installation very difficult,” observed Mr Lau.
“The cost for the implementation of solar energy is also
higher than that of conventional thermal power plant.”
That does not mean, however, that adoption of solar
power systems in the city will not be more widespread in
the future, particularly as costs come down. It is possible
that systems could be developed to suit Hong Kong’s unique
conditions.
Although the roofs of most tall buildings in the city are
used as a platform for air-conditioning plant and other
building services equipment, it is possible in the future that
the sides of new developments could be covered with TFPV
modules.
Solar panels for skyscrapers
“These panels can be installed to act as a curtain wall. Light
can penetrate through them, but the cost of the panels is
still relatively high, and building developers may not find
the idea attractive yet. However the market trend is that
the cost of PV panels is coming down very quickly. Within
the next three years the cost will come down to a point at
which building developers and power utility companies
may become interested in revisiting this concept,” Mr Lau
reflected.
In the long term, solar power has too many advantages
to be ignored as an electricity source, and will become pro-
gressively more attractive as technology costs come down.
“It’s clean energy. There is no doubt about that. There
are no emissions and very little maintenance is required.
Once the solar panels are connected to the power grid
they are producing electricity every second, and very little
attention has to be paid to them. However due to solar
energy’s intermittent nature, the growth of its adoption
worldwide will be constrained until reliable and low-cost
technology for storing solar energy becomes available,” Mr
Lau concluded.
Think ing Thin
Solar panels – also called photovoltaic panels or mod-
ules – convert solar radiation into electricity using sili-
con as a semiconductor. Solar energy absorbed by the
modules drives electron flow to produce electricity.
Because solar energy can be generated in any
location with suitable light conditions, and because
the technology produces no emissions in operation,
systems of solar panels have emerged among the
front-runners of renewable energy sources.
Considerable progress has accordingly been made
in panel design and construction, and units capable
of achieving significantly higher levels of efficiency
are more readily available.
The amorphous silicon thin film photovoltaic mod-
ules made by DuPont Apollo use a semiconducting
layer of silicon only micrometers thick deposited on
a glass panel, and require less energy to manufac-
ture than crystalline silicon units.
HK Electric’s Frank Lau says that increased de-
mand for the panels is exerting gradual downward
pressure on their cost, and this should lead to even
more widespread adoption of the technology.
“R&D has continuously made improvements
in existing technologies and developing new
technologies achieving significant cost reductions
and efficiency improvements. Concurrently the
use of energy and materials in the manufacturing
process will become significantly more efficient,
leading to considerably shortened PV system en-
ergy payback times and lengthened operational
lifetime,” stated Mr Lau.