IBM says it hasdeveloped more efficient photovoltaic cells- the technology thatconverts
light directly into electricity- that
couldreduce the cost of producing solar electric
power.
Any way to
save money by using renewable energy would help IT managers
scale their IT infrastructures while cutting energy costs.
According to analyst firm IDC, about 50 cents is spent on energy
for every dollar of computer hardware. This is expected to increase
by 54 per cent to 71 cents over the next four years.
IBM scientists are using a large lens to concentrate the Sun's
power to capture a record 230 watts onto a centimetre square solar
cell.
The technology is called
concentrator
photovoltaics and employs the principle of using a magnifying
glass to burn a leaf. IBM's concentrator photovoltaics (CPV)
concentrate the sun's energy to produce more electricity per square
centimetre than conventional CPV solar cells. The IBM CPV produces
approximately 70 watts of usable electrical power, about five times
the electrical power density generated by typical solar cells using
CPV technology in solar farms.
If it can move the project from laboratory to fabrication, IBM
believes it can significantly reduce the cost of a typical
CPV-based system.
Solar cells have many applications. Individual cells are used
for powering small devices such as electronic calculators and
photovoltaic arrays can generate a form of renewable electricity,
particularly useful in situations where electrical power from the
grid is unavailable, as in remote areas.
Search engine giant Google has
converted part of its Californian headquarters to run partly on
solar power. It aims to eventually produce 30% of the power it
needs at its headquarters from the sun.
The solar electricity system has a total capacity of 1.6
megawatts. It is expected to be the largest solar power
installation on a business site in the US, with 9,212 solar
panels.
But IBM said its system uses a much lower number of photovoltaic
cells in a solar farm and concentrates more light onto each cell
using larger lenses. This reduces the number of components needed
and saves money.
A 'sun' is a unit of measurement equal to the solar power that
can be generated at noon on a clear summer day. By moving from a
200-sun system - where about 20 watts per square centimetre of
power is concentrated onto the cell - to the IBM Lab results of a
2300 sun system - where approximately 230 watts per square
centimetre are concentrated onto the cell system - the IBM system
cuts the number of photovoltaic cells and other components by a
factor of 10.
The trick lies in IBM's ability to cool the tiny solar cell.
Concentrating the equivalent of 2000 suns on such a small area
generates enough heat to melt stainless steel, something the
researchers experienced first hand in their experiments. But
borrowing innovations from its own R&D in cooling computer
chips, the team was able to cool the solar cell from greater than
1600° Celsius to just 85° Celsius.
IBM has developed liquid metal thermal cooling taken from
microprocessors.
GB Patnaik from the Alternative Energy Department of India has
overseen the deployment of
solar
panels to schools in villages without power lines, to power
computers.
"The cost of running solar panels to power computers in one
school would cost about £1,000, which is expensive, but because
some have no power at all it makes it necessary," he said.
GB Patnaik said the announcement of a breakthrough from IBM was
welcomed if it eventually lowered the cost of powering computers
with solar energy. However, he that factors such as bad weather
affects solar energy as the primary source of power in
computing.
"Solar power is useful in areas where there is no power to begin
with, but even at a reduced cost, businesses would be reluctant to
make it their primary source of power," Patnaik said.
IBM is exploring four main areas of photovoltaic research: using
current technologies to develop cheaper and more efficient silicon
solar cells developing solution-processed, thin-film photovoltaic
devices concentrator photovoltaics and future-generation
photovoltaic architectures based on nanostructures such as
semiconductor quantum dots and nanowires.
In addition to the photovoltaic research, IBM is focused on
several areas related to energy and the environment. These include:
energy efficient technology and services carbon management advanced
water management intelligent utility networks and intelligent
transportation systems.