Enough power in one hour to meet the earth's energy needs for one year
Imagine converting that energy to power the world.
The sun is a phenomenal energy source. Plentiful, sustainable and clean, solar energy is the hot favourite of the future. So why isn’t solar energy our main energy source right now?
One issue is cost. Conventional solar cells use silicon. And turning silicon into a functional solar cell is still relatively expensive. If that cost can be brought down, solar energy has a high chance of achieving its potential as an energy source.
Researchers at Te Herenga Waka—Victoria University of Wellington are investigating new materials that can be used to create next-generation solar cells, for less.
Polymers that conduct electricity can be turned into ink, printed in sheets and applied to almost any surface, where they collect and convert the sun’s energy for daily use. This technology could slash the cost of solar energy for homeowners.
At the moment, polymer solar cells are less efficient at converting energy than silicon, but by making them cheaply the future for solar energy is bright.
If every New Zealand rooftop, for example, was coated with polymer solar material, the sun could provide all of our electricity needs, for good.
A solar revolution
There’s no denying there’s a pressing need to find new, clean and cost-effective sources of energy, says Dr Justin Hodgkiss, who is developing new ways to harness sunlight to help ensure that future global energy needs are met in a sustainable way.
“The energy in one hour of sunlight is equivalent to all the energy used around the world in an entire year,” he explains. “It’s effectively an unlimited resource, which is why I’m focused on creating low-cost, flexible and lightweight solar technology to convert it into electricity.”
Dr Hodgkiss is developing solar photovoltaic materials to replace silicon, which is currently the material most commonly used to make solar cells.
“We’re focusing on polymers, which are basically plastics. They are printable so can be made easily and cheaply, and will have a much greater range of uses than current solar technology allows.”
He says the polymers form films that are a bit like an adhesive book covering. “You can make it in long rolls, and in theory it could be applied to any surface—in the future that might include anything from mobile phone chargers to roofing material.”
Shedding new light
Dr Hodgkiss says the University is one of the best places in the world to be working in this field. “I work on tools here at the University that allow us to see the process of light being converted into electricity on a timescale of femtoseconds—a femtosecond is a millionth of a billionth of a second. We are able to try different materials to see how effectively they convert light into electricity, and design solutions.
“The University has invested a lot in our ultrafast laser facility — the laser can emit pulses of light that are 100 femtoseconds long, which illuminate things for us a bit like strobe photography on an ultrafast timescale.”
As well as being an academic at Te Herenga Waka—Victoria University of Wellington, Dr Hodgkiss is co-director for the MacDiarmid Institute for Advanced Materials and Nanotechnology, a Centre of Research Excellence that is hosted at the University's Kelburn campus.
“We are the only group in the country doing this sort of work,” he says. “The methods we’re developing and using are rare and in some cases unique—that’s why people from around the world come to us to collaborate.”