Tapping into the power of ‘wasted’ energy

solar panels

Monash University researchers have developed and patented new materials that can store energy, and are designed to ultimately transform ‘wasted’ energy into useable electricity.

Until now, traditional methods of energy storage have not been cost effective, which is critical as most renewable energy sources, such as solar or wind, are intermittent and require energy storage to provide power when energy generation is low.

“While significant advances have been made in the efficiency of solar generation and other renewable energies, advances in energy storage have been slow and incremental since the early 90s,” said Professor Doug MacFarlane, who leads the Monash research team investigating new chemical material  for energy.

“Domestic energy storage is still relatively expensive compared with on-the-grid energy costs.

“But our new technology potentially offer better efficiencies and better economic performance.”

Professor MacFarlane’s group recently patented a range of materials known as Phase Change Materials (PCMs) which absorb large amounts of energy when they melt.  This energy can be recovered at a later stage when the material freezes.

“The technology provides a stable, reusable and dependable energy storage medium,” said Professor Macfarlane.

Solar heat energy can be harvested using solar vacuum tube arrays, similar to solar hot water systems, and fed to the PCM tank during the day. These solar arrays can harvest more than 70 per cent of the sun’s energy – far more than solar PV panels.  The heat energy is then released  over the course of the night when it cools down. A small Organic Rankine Cycle engine (ORC) is able to turn this heat energy into electricity, as well as provide space and hot water heating.

“A significant advance made by our research team is around the temperature range where these PCMs are most efficient,” Professor Macfarlane said.

“Current technologies, such as molten salts, operate at very high temperatures (more than 600°C) and require industrial scale generators to operate, but our PCMs operate at only 100 - 200°C, which is easily obtainable in a light-industrial, or even domestic setting.  And the  cost of the material and the surrounding system is substantially lower than battery storage.”

Professor MacFarlane’s team is working with Melbourne company Green Thermal Energy Technologies to build demonstration energy storage systems based on these materials.  The team is also seeking investor partners to fund the scale up activities.