Posted 12 February 2009
Sunlight technology may be solution to Ireland’s energy needs
Imported fossil fuels account for over 90% of the 185 TeraWatt-hours of energy used by Ireland annually. Less than 10% of Ireland’s energy needs are produced at home. To secure a sustainable energy future, Ireland’s energy needs must be increasingly met by the renewables energy sector and there must be a significant improvement in Ireland’s overall energy efficiency.
“As an island nation, we are overly dependent on imported fossil fuels to meet our energy needs,” says Energy Minister Eamon Ryan TD who officially launched the Science Foundation Ireland (SFI) Advanced Biomimetic Materials for Solar Energy Conversion Strategic Research Cluster on 11 February 2009.
“With volatile fuel costs and declining supplies, there is an urgent need to secure our own energy supplies and develop our indigenous resources. The development of cutting-edge solar energy technologies and deployment of commercially available solar technologies will play an important role in moving the world onto a low-carbon development path.”
Even though solar irradiance on the surface of the Irish landmass is approximately half that compared to more tropical regions, with the current technology at 10% efficiency, less than 2% of the land area of Ireland would be required to satisfy all of Ireland’s energy needs. Compared to other available renewable resources, the energy from solar power is, in principle, hundreds of times more accessible. This offers a huge impetus for improved solar energy conversion technologies.
The Advanced Biomimetic Materials for Solar Energy Conversion Strategic Research Cluster was awarded €4.74m from SFI for its three to five year research programme, with an additional contribution from Industry Partners. It offers a unique approach to solar energy conversion by combining expertise in engineering, physics, chemistry and biochemistry from University College Dublin, University of Limerick and Dublin City University, alongside industry expertise from Airtricity, Celtic Catalysts and SolarPrint Ltd, with support from German SME ODB-Tec.
“Sunlight can be trapped using traditional photovoltaic (PV) technology, using silicon-based solar panels and cells, where the PV cell converts solar energy directly to electric power. However, the traditional systems tend to be too costly for widespread deployment,” says Prof Don MacElroy from the UCD School of Chemical and Bioprocess Engineering at University College Dublin, who is leading the group.
“Our Cluster is investigating potentially cheaper PV materials and cells which are suitable for diffuse sunlight, which is very important in a country like Ireland with cloud cover,” says Professor Don MacElroy. “Building on research performed in Switzerland, led by Professor Michael Grätzel, we are investigating a new type of PV cell that mimics part of the structure in a plant which is responsible for their natural solar energy conversion process - photosynthesis.”
Another way to use solar energy is through photoelectrochemical (PEC) materials, which provide a key solution to the storage of energy. In these materials, sunlight is utilized in chemical reactions to split the water molecule into its constituent parts, oxygen and hydrogen.
According to Professor MacElroy, this offers two options for the conversion of solar energy, firstly through the production of hydrogen, which is valuable as a fuel. And secondly, the hydrogen produced can be further utilized to produce compounds like methane and fuels such as methanol, by reacting it with carbon dioxide. Nature combines hydrogen and carbon by weakening the carbon dioxide molecule and opening it to attack by hydrogen. Scientists at the SFI Advanced Biomimetic Materials for Solar Energy Conversion Strategic Research Cluster are interrogating new catalysts and cell designs which will enable them to do the same thing synthetically.
This latter approach provides a unique solution to a carbon dioxide issue. In general, the most common approach to solving the issue of carbon dioxide is to develop technologies to capture it and, most importantly, to sequester it, in effect storing it in subterranean aquifers and depleted gas and oil wells. But this new research group is investigating methods of recycling the carbon dioxide to form organic compounds with solar produced hydrogen. In 2007, carbon dioxide emissions were reported as 69 MegaTonnes in Ireland alone and this situation can be ameliorated in the long term with the aid of PEC cells. This overall system, will in effect, embody the philosophy of photosynthesis.
“A portfolio of renewable energy sources will provide the best approach for securing Ireland’s energy needs. However, in principle we can get all our energy requirements from the sun. The Cluster is looking at the development of a technology that should be at the forefront of industry and be very important to Ireland’s economy in the long-term,” concludes Professor MacElroy.
