Victoria, Australia [RenewableEnergyAccess.com]
Solar thermal heat and evaporative power have long been used for salt production worldwide, but a new research consortium in Australia is planning on taking that process a step further into electricity production and aquaculture.
In Australia there have been various experimental solar ponds. While there aren't yet any commercial applications of solar ponds in Australia, and only a few globally, the technology is now poised for commercialization.
The consortium is made up of Royal Melbourne Institute of Technology (RMIT) University, Geo-Eng Australia and Pyramid Salt. They completed a project using a 3,000 square meter solar pond located at the Pyramid Hill salt works in northern Victoria to capture and store solar energy using pond water, which can reach up to 80 C.
Pyramid Salt is using the pond's heat not only in its commercial salt production but also for aquaculture, specifically producing brine shrimp for stock feed. Phase two of the project will work on generating electricity using the heat stored in the solar pond, thus making the local salt industry more energy self-sufficient.
Solar ponds have been installed overseas, with at least 60 systems having been constructed around the world, mostly for the provision of process heat to industry. In Australia there have been various experimental solar ponds. While there aren't yet any commercial applications of solar ponds in Australia, and only a few globally, the technology is now poised for commercialization.
As a concept, solar ponds are becoming increasingly attractive as the cost of constructing them is decreasing compared with the rising costs of conventional energy. Additionally they offer a form of renewable energy that is increasingly attractive as countries seek to reduce greenhouse gas emissions.
Solar ponds can produce process heat from 60 to 80 C for a wide range of applications at an average cost of about AUD 10 (USD 7.6) per gigajoule, or two-thirds the cost of liquid petroleum gas or fuel oil in rural areas. Natural gas is not available in most rural areas so solar ponds for low-temperature heating applications are likely to be very cost-effective. Projections indicate that successful commercialization of the solar ponds in salt-impacted areas of rural Victoria, greenhouse gas emissions could be reduced by over 10 megatons per year and generate in the order of 2000 GWh per year of green electricity.
The consortium believes the technology offers a range of benefits for regional Australia. Geo-Eng and Pyramid Salt are planning to commercialize solar ponds for a range of rural industrial applications such as drying fruit and grain and for production of dairy products, as part of salinity mitigation schemes where practical. In addition, by replacing some of the demand for process heat traditionally drawn from fossil energy sources, not only will greenhouse gas emissions be reduced but the reduction in fuel costs will offer flow-ons for local economic development and job creation.
Pyramid Salt is confident that installing the solar pond will enable production of more competitively priced salt. This improved cost effectiveness will boost sales, turnover and profits over the next five years. At the local level this will be a significant boost in an area with high unemployment and a depressed economy.
At the same time, farmers adjacent to salinity mitigation schemes incorporating solar ponds will be able to bring land currently too high in its salt level back into productive use. A grant of AUD 550,000 (USD 421,000) from the Renewable Energy Commericalization Program helped to fund the solar pond demostration project, which began in 2001 and researchers hope will aid in the reduction of Australia's reliance on fossil fuels and boost economic prosperity.