3 main sources. 1- Natural Gas 2- Renewable Natural Gas (capping waste emissions from waste water treatment or municipal solid waste and coverting to Hydrogen).

3 main sources. 1- Natural Gas 2- Renewable Natural Gas (capping waste emissions from waste water treatment or municipal solid waste and coverting to Hydrogen). Net negative CO2 but smaller supply 3- Electrolysis (electricity + water). Source of electricity determines the cleanliness of the H2. Still requires water which is not ideal (especially in california)