How do BioLite products produce off-grid energy?

BioLite uses a core technology called Thermoelectrics which captures waste heat and converts it into usable electricity.

The CampStove, BaseCamp, and HomeStove house a thermoelectric generator inside their orange Power Packs. The heat generated by their fires are converted into electricity which automatically recharges a small lithium ion starter battery, which, much like a car, kick-starts an internal fan. This fan creates airflow, which, in conjunction with our uniquely designed fuel chamber, creates an ultra-efficient and nearly smokeless fire. Surplus electricity generated goes to a USB outlet allowing you to charge small electronic devices.

The KettleCharge uses thermoelectrics as well, just with a slightly different configuration. The thermoelectric generator is located on the base of the Kettle and is activated by the presence of a concentrated flame under your KettleCharge. The water in your KettleCharge serves as a heatsink, drawing heat through the TEG and producing 10W of electricity.