Solastor’s aim is to conduct research and development that improves the efficiency of all components and processes used in the technology whilst reducing cost. As such, Solastor is engaged in a constant research and development program in conjunction with the patent holder GSPL.
The program commenced in 2001 with an investigation into the properties of graphite. Many blocks of graphite were heated using a variety of methods. This extensive testing program not only confirmed the well documented physical properties of graphite, it enabled design parameters for heat transfer coefficients, thermal loss rates and other “non-documented” properties to be evaluated.
Following years of “energy-in” and “energy-out” prototype testing with electrically heated storage, a solar heated prototype was developed. In 2006 a graphite block was located on top of a tower and heated using a field of heliostats. This system was very successful in converting the energy from the sun into electrical energy by producing steam from heat exchangers in the graphite and directing it to a steam turbine.
Meanwhile, Solastor has been working with Device Logic, a subsidiary company of GSP, in the design and development of the control systems for:
- The ability for the heliostats to track the sun;
- Continuous automatic calibration of the heliostats to maintain accuracy; and
- Managing the heliostat operations.
Solar Thermal Receiver (STR)
- Controlling the temperature of the STR; and
- Managing the operations of the STR.
- Managing the temperature and pressure of the steam between the STR and the turbine.
- Operation and oversite of the plant.
Besides the STR and control system, the design of the heliostats is constantly reviewed. Heliostats are the largest cost item in a plant hence development of more highly efficient heliostats will lead to capital cost reductions and ultimately lower electricity production costs.
Working in conjunction with Heliosystems Pty Ltd, the heliostats have evolved from being spherical to toroidal (doughnut-shaped). Spherical heliostats are approximately 35% efficient in capturing the sun’s energy, whilst toroidal heliostats are up to 70% efficient.