Alternative Fuels Startups funded by Y Combinator (YC) 2026

Intelline makes fuel agnostic engines for practical, clean, and low-cost industrial power. Our first customers are in data center energy infrastructure and oil & gas production. Our engine generate electricity with even the most difficult fuels like flare gas, while reducing fuel OPEX by 40%. There are 1,000,000 new heavy duty engines produced per year, and at an average $50k per heavy duty engine this is a $50B market opportunity. Our generator can efficiently run emerging fuel types that traditional diesel engines can't use (flare gas, syngas, ammonia, hydrogen), and can switch between fossil fuels and any other liquid/gaseous fuel while running. Full size running prototype successfully tested April 2025.