A flexible organic solar cell.
Credit: The Victorian Organic Solar Cell Consortium
WATERLOO: One technology won't fit the needs of all, but the right mix and distribution could meet the electricity demands of many by 2050, experts heard at an international energy conference this week.
Among some of the potentially transformative technologies that could limit the growth of carbon-based fuels into the next century are ultra-thin, rugged plastic films that can be spread onto windows and roofs to capture solar energy, and nuclear reactors that can 'eat' radioactive waste.
At the Equinox Summit: Energy 2030 being held in Waterloo, Canada this week, scientists, emerging leaders, entrepreneurs and policy advisors debated the merits and shortcomings of emerging technologies to figure out how to curb the use of fossil fuels.
Global energy consumption is expected to rise considerably by mid-century, from around 16 terawatts (16 trillion watts) to between 28 and 35 terawatts. Scientists and policy experts say that much of that electricity gap must be filled by energy technologies that emit little to no carbon dioxide into the atmosphere.
Rolling over energy poverty
About three billion people in the world use almost zero energy and as many as 1.6 billion live in remote villages that don't have access to an electrical grid. These off-grid customers could benefit from energy produced and stored locally.
Researchers hope that organic solar cells - thin plastic films - could be used to charge cell phones or provide power to small medical refrigeration units. Alan Aspuru-Guzik, a chemist at Harvard University in Boston, is searching for organic molecules that could help bring organic solar cells to widespread use.
The Clean Energy Project, a computational chemistry project, scans millions of potential candidates to find the molecules that are able to convert 10-15% of the energy from the Sun into electrical energy. The approach has long been used by the pharmaceutical industry to find drug candidates.
"Right now we have demonstrated efficiencies at slightly above 8%, but at 10% they are commercialisable," said Aspuru-Guzik. The other challenge scientists face is finding a way to double or triple the lifetime of the materials to 5 or 10 years.
Cost-effective solar cells
Because the cost of organic photovoltaics - generating electrical power by converting solar radiation into direct current electricity - relative to electricity derived from oil, gas and coal, remains high, they would be best suited to customers who are willing to pay more for a little bit of electricity, summit participants concluded.
But by 2030, organic solar cells could become as cost effective as silicone solar cells. Providing power to 500 million households might cost US$100 billion - about one-sixth of the U.S. military budget.
These communities would also need a way to store the energy, to provide power when the Sun wasn't shining. One way would be to produce hydrogen from water and store it underground, creating a personal energy system for the home or neighbourhood, without connecting to the grid.
