Main applicant: Exergyn Ltd.
Technology developer: Exergyn Ltd.
Industry partners: Cummins Inc.
Demonstration capital cost: £596,000
Funding awarded: £231,000
Project timeline: November 2018 – September 2020
The cost-effective recovery of low-grade waste heat has been a long-standing missed opportunity for greater efficiency in industrial processes. This project aims to unlock and demonstrate technology to enable the generation of electricity from low-grade waste heat streams up to 100oC. The concept utilises shape memory alloy (SMA) and its properties for negative thermal expansion: SMA wires are bundled, built into a piston and then cycled through hot and cold states to drive the piston, which in turn drives an electrical generator. The technology produces no carbon emissions and does not require any refrigerants.
This project looks to test and finalise the exact specification of raw SMA material required to manufacture and prepare the SMA wires into a bundle for further testing at prototype level. The design for the modules can then be finalised and manufactured for testing and installation. The demonstration unit will be installed at one of Cummins’ engine test facilities, where waste heat from the engine cooling circuit is currently released into the atmosphere. The unit will utilise waste heat, reducing the electrical consumption for the current forced ventilation cooling radiators, whilst generating on-site electricity reducing the need for purchased energy The site trial is expected to last for 12 months and a number of in-situ tests will be carried out during this time, making the engine test facility an ideal demonstration site location.
The Exergyn drive is modular, allowing for application across a wide range of waste heat loads, and the demonstration project will be utilising three to four combined modules.
Target market: Whilst the demonstration project is being hosted at an engine test facility, this technology has the potential for wide adoption across all sectors with a low grade waste heat stream. Data from Exergyn estimates that there is approximately 14TWh of industrial waste heat every year, a significant portion of which is in the current temperature range of the technology. An immediate target market for Exergyn is the food and drink sector.
Barrier to market: The cost effective implementation of waste heat recovery technologies for low-grade waste heat and the lack of evidence of SMA in this application at demonstration scale, over an extended operational period. Information provided by Exergyn suggests the simple payback for future projects could be roughly 3 years.
Initial TRL: The project will cover multiple TRL’s between 6-7
Targeted final TRL: TRL 8
Estimated energy and carbon savings: The trial is for a single 10kWe unit utilising 200kWth from the waste heat stream. The expected savings from this will be the electricity generation of 80,000kWh per annum (or 104,000 kWh if cooling fan demand reduction is also considered).