A Mexican green energy start-up is harnessing the unused parts of the prickly pear cactus to create biomass.

The thick outer layer of the cactus, which has always been a waste product, will be recycled as compost by a business called Energy and Environmental Sustainability, or Suema, by its Spanish acronym.

Suema is piloting a project in an area to the south of Mexico City, Mail and Guardian reported.

Cactae are abundant in the area, where 200,000 tonnes of prickly pear cactus are produced each year.