UNSW researchers set world record in solar energy efficiency

UNSW researchers set world rec...
The University of NSW have produced a PV system that converts over 40 percent of sunlight into electricity, the highest conversion efficiency ever reported (Photo: UNSW)
The University of NSW have produced a PV system that converts over 40 percent of sunlight into electricity, the highest conversion efficiency ever reported (Photo: UNSW)
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The University of NSW have produced a PV system that converts over 40 percent of sunlight into electricity, the highest conversion efficiency ever reported (Photo: UNSW)
The University of NSW have produced a PV system that converts over 40 percent of sunlight into electricity, the highest conversion efficiency ever reported (Photo: UNSW)

Solar researchers working at the University of New South Wales (UNSW) claim to have produced a system that converts over 40 percent of incoming sunlight into electricity, thereby taking the title of highest solar efficiency for a photovoltaic system ever reported.

The researchers first achieved their record efficiency in indoor tests in a facility in Sydney, Australia, and then had these achievements duplicated and ratified by the National Renewable Energy Laboratory (NREL) using an outdoor test facility in the United States.

"This is the highest efficiency ever reported for sunlight conversion into electricity," said UNSW Professor Professor Martin Green, Director of the Australian Centre for Advanced Photovoltaics (ACAP).

The record was achieved using a combination of technologies, including heliostat mirror "power tower" concentrators from Australian company RayGen Resources and high-efficiency photovoltaic (PV) cells from Boeing subsidiary, Spectrolab, but the key component to achieving such a high-efficiency was in the use of a specifically-designed optical bandpass filter used to reject certain components of the light spectrum whilst improving the capture of others. This helped to vastly improve the conversion of light to electricity at a higher efficiency than possible using PVs alone.

"The new results are based on the use of focused sunlight, and are particularly relevant to photovoltaic power towers being developed in Australia," said Professor Green.

"We used commercial solar cells, but in a new way, so these efficiency improvements are readily accessible to the solar industry," added Dr Mark Keevers, the UNSW solar scientist and manager of the project.

Whilst other focused sunlight solar energy systems like the CSIRO’s supercritical-steam set-up or the recent Ethiopian installation of the Tulip system have been shown to produce large amounts of energy, both use either water or hot air to drive turbines to produce electricity. The UNSW system, by comparison, is potentially a lot less complex, cheaper, and safer than such systems and, as a result, may be more readily incorporated in domestic and commercial situations.

The UNSW solar researchers have produced a large number of achievements in the field of solar energy in the past four decades, including the first photovoltaic system to achieve a conversion rate of sunlight to electricity of over 20 percent efficiency way back in 1989.

The UNSW solar energy research has been funded by the Australian Renewable Energy Agency (ARENA), whose CEO, Ivor Frischknecht, praised the recent achievement as another world first for Australian solar research and development and believes that it aptly demonstrates the value of investing in Australia’s renewable energy creativity.

"We hope to see this home grown innovation take the next steps from prototyping to pilot scale demonstrations," says Mr. Frischknecht. "Ultimately, more efficient commercial solar plants will make renewable energy cheaper, increasing its competitiveness."

The work was also supported by the Australia–US Institute for Advanced Photovoltaics (AUSIAPV).

The results of this research will be presented at the Australian PV Institute’s Asia-Pacific Solar Research Conference, and a paper by the researchers is to be published soon in the journal Photovoltaics.

Source: UNSW

Isn't this the system that fries any birds flying through its beams?
Lewis M. Dickens III
This is fantastically wonderful! Keep on trucking... It won't be long before we effectively produce all the energy we need without ever using fossil fuels. Combine this with Bill Allison's 59% efficient wind turbine engines and you will really have something. bill
Martin Winlow
How frustrating it must be for them, then, that the Australian Government couldn't care less! Australians should be hopping up and down at the utter ineptitude of their sucesesive political leaders to not be forcing Australia into leading the industrialised world in PV tech, what with all that empty land, un-ending sun and Asia on its doorstep.
Responding to an earlier question, yes this is a system that can fry birds. The Arzon Solar/Amonix system, while achieving slightly less efficiency at close to 35%, relies 100% on photovoltaics so is very safe: http://arzonsolar.com/amonix-8700-solar-power-generator. Also, more here: http://www.gizmag.com/amonix-solar-module-efficiency-record/24845.
Consumer grade panels are now under $1/watt to buy but total install cost is in the ballpark of $2.50/watt after inverters, hardware, labor etc. The next stage of cheaper solar will need to come in the form of higher efficiency panels where fewer of them need to be installed to lower some of the other associated costs (hardware, labor etc.). I'm partly guessing but I think common 250 watt panels are about 15% efficiency and the 305 watt panels are closer to about 19% efficiency. Seeing 40% on roof panels is pretty unlikely but even 25% would be a big deal.
If these are triple junction HCPV cells. Then they'll require a two axial tracking system. Plus, I've not seen HCPV cells that did not in suffer at least 15% degradation due to the severe operating temps in the first year. The ones that fared best on IV curve measurements had passive cooling tubes. I worked with some of the first Spectrolab cells. I would love to know if there are any HCPV cells that have survived 8 + years in a desert environment and still produce an acceptable IV curve fill factor.
Unlike solar thermal units like the Tulip these solar PV technologies cannot follow consumer load and therefore can't be used for baseload. The biggest drawback of PV is that it is only, and can only be, a intermittent electricity generator and only works when the sun shines. The result of this PV and even wind power conundrum is that we are now installing even more fossil fuel generators to maintain baseload generation to run when the renewables aren't being powered by wind or sun. On top of this, this "baseload generation" is actually run at the same time as the solar or wind power as "spinning reserve", essentially wasting fuel just to be ready to instantly take up consumer load when wind or solar output dips. Solar thermal, like the Tulip system however can be co-fired with renewable biogas using the exact same generation equipment without modification (and no fossil fuel or water use), which give them the ability to run as baseload 24/7 at their maximum output to follow consumer load, at a similar solar to electricity efficiency and without any extra baseload fossil fuel generators. Plus the Tulip can provide the same amount of thermal energy again from the same system to run distributed heat for households etc, something PV cannot. Solar and wind simply don't cut it when it comes to energy availability unless there's a way to mass store energy nearby, like in hydro. The best way to increase energy efficiency is simply to stop converting everything to electricity first, and use the energy directly from the thermal source...most industrial and household consumption (and loss) is in heat. Total Energy efficiency simply means "stop making so much electricity and wasting all the heat in the conversion process"! ;-)
Gavin Roe
how was this efficiency calculated do the cells only convert one wavelength well of a combination, any possibility they are capturing infrared so we can salvage waste energy