Every year, 50% of the energy produced globally from coal, oil, natural gas, nuclear and renewable energy sources is lost as heat. This untapped resource could be a promising additional source of useful energy, and for decades scientists have worked to develop efficient systems to convert waste heat into electrical energy.
In a recent study published in Joule, researchers at the Berkeley Lab developed a techno-economic model to predict the economic viability of different waste heat conversion technologies. Their model will help guide future research by directing scientists to new designs and technologies that are more likely to enable cost-effective and efficient conversion of waste heat.
Until now, most research focused on waste heat conversion technologies has focused on the physics of waste heat conversion engines, such as thermoelectric generators that recover heat from exhaust gases in heaters. internal combustion engines. Berkeley Lab’s technical-economic model allows researchers to take a more holistic approach to the system, which focuses on technological requirements for commercial viability, such as the temperature of the waste heat source, the cost of heat exchangers or the minimum capacity factor – the fraction of the time the waste heat source is available.
“Although over 60% of the waste heat is available below 100 degrees Celsius, our analysis shows that converting the waste heat is only economical above 150 degrees Celsius,” said Ravi Prasher, associate laboratory director at the Berkeley Lab. “This discovery is very important to prioritize research and development of heat engines with waste heat conversion. “
The technical-economic model of this study allows researchers to better predict which sectors and circumstances will be best suited for waste heat conversion technologies.