Students in a capstone design course designed, built, tested, and deployed a biochar reactor. Biochar is the material remaining after biomass is heated in a controlled environment without oxygen; a process known as pyrolysis. Biochar can be used as a soil amendment with the added benefit of carbon sequestration. Furthermore, excess process heat generated in the pyrolysis process can be harvested for other uses. The biochar reactor designed and built by the students in this project was deployed at a local hydroponic greenhouse. The reactor consists of a chamber within a chamber; the outer chamber holds the fuel to drive the pyrolysis process while the inner chamber holds the biochar feedstock. Several trials were run to demonstrate that biochar was being produced and to estimate the amount of process heat available to heat hydroponic pond water.