Temperature-weighted assessment of waste heat availability with matched end-use applications for optimal primary energy usage in the USA

Approximately two-thirds of all input energy used for power and electricity generation in the USA is lost as heat during conversion processes. Additionally, 12.5% of primary fuel and 20.3% of the electricity generated through these processes are employed for space heating, water heating, and refrigeration where low-grade heat could suffice. The potential for harnessing waste heat from power generation and thermal processes to perform these low-grade tasks is assessed here. By matching power plant outlet streams with applications at corresponding temperature ranges, this study identifies sufficient waste heat to satisfy all residential, building, and manufacturing space and water heating needs. Sufficient high temperature exhaust from power plants is identified to satisfy 27% of residential air conditioning demand with thermally activated refrigeration or all industrial low temperature (100-150°C) process heating and refrigeration needs. Exhaust from vehicle engines is sufficient to satisfy all in-vehicle air conditioning and 68% of electricity generation demand. Energy usage and waste heat availability and application information collected for this study is compiled in a thermodynamically informed database. By providing SQL queries, this database can answer detailed questions about energy sources and demands delineated by temperature, energy scale, process, and location. This capability can inform future infrastructure and development to effectively capture waste heat that would be lost today, substantially reducing the USA national energy intensity across all end uses.