Organic fluids hold key to more efficient solar thermal power

In an EPSRC-funded project, researchers at City University are investigating different types of Organic Rankine Cycle (ORC) power plants, in a bid to reduce the cost of the technology.

Unlike conventional steam power plants, ORCs pressurise and heat an organic fluid to produce vapour, which is then expanded to generate electricity. This allows lower temperature heat sources of between 100 to 300 degrees Celsius to be converted into power more economically than using steam.

As a result, the technology could be used to produce electricity from low cost distributed concentrating solar power collectors, or from waste heat generated by large internal combustion engines, such as those found in trucks and small ships, according to Prof Abdulnaser Sayma, who is leading the project.

However, while ORCs have already been successfully applied on an industrial-scale, more research is needed to understand the fundamental physics behind the devices when operating at these smaller scales.

In particular, devices need to be developed that can operate efficiently over a range of different conditions without altering their fundamental design, to allow them to be manufactured at high volumes and therefore at a lower cost, said Sayma.