Electrical Generation Solutions: Landscape Report and Assessment to Scale

This report evaluates various technologies for converting thermal energy produced by the thermochemical treatment of fecal sludge to electrical energy useful for operation of an Omni Processor or other thermal treatment technology. Five types of electrical generation technologies were explored for this project; these included: thermoacoustic heat engines, thermoelectric generators, Stirling engines, steam engines, and organic Rankine cycle generators. In order to be included in the review, companies had to have at least one product in one of the selected generation technologies and have a website.  Companies were identified through two Google searches; in the first search the technology name was searched (e.g. Stirling engines), in the second search the word manufacturer was added to the string search (e.g. Stirling engine manufacturers). For both searches the top 100 search results were explored. Across the five electrical generation technologies explored, 32 manufacturers offer a combined 65 products. Each product was examined to determine electricity generation potential (in kWe), commercial availability and a technology readiness level (TRL). The results of product evaluation are discussed by generation technology. Overall, our assessment is that small scale thermoelectric generators are likely most suitable for small thermal output thermochemical processors, like the Reinvented Toilet. Low-pressure organic Rankine cycle generators are more appropriate choices for medium to large scale Omni Processors.