Approximately 25 percent of housing in Massachusetts is heated with oil and nearly one half by natural gas. This session focuses on what can be done to rapidly decrease carbon emssions from the heating sector at low cost with a focus on the current liquid fuels market. This market is now adopting biodiesel as a low carbon, renewable fuel. For the longer-term, hydrogenated vegetable oil and wood-based biofuels are in the development stage. In parallel, the development and deployment of higher efficiency equipment are underway. This session will discuss the sources, processing, properties, and current production aspects of biodiesel. Biodiesel blends at 20% (B20) are now commonly used. Large-scale use of B50 has started. In the range of 125 homes have converted to 100% biodiesel and this is expanding. The impact changing biodiesel blend level on existing system combustion performance will be discussed in addition to large scale field experience. Upgrades to heating systems with documented savings in the 20-25% range are also an important part of reducing GHG emissions and will be discussed.