The city of San Francisco recently announced its plans for a grease-to-diesel plant [CNET]. Through the program SFGreasecycle, the city had already been collecting “yellow” grease from restaurants and other establishments for no charge, which it processed and sold to bio-diesel producers. Now, the city will expand its program to include pickup of “brown” grease, which is tougher to process. This brown grease will be processed into three grades of biofuel: high-grade American Society for Testing and Materials (ASTM) certified biodiesel for vehicles, lower grade biofuel source for running sewage treatment plant turbines and pumps, and rich energy for cogeneration – the process of capturing methane gas at the sewage plant and converting that to heating/electrical needs [SFWATER.ORG].
Although I don’t know much about biofuels and associated technologies, my general preconception is that the fuels suffer from horrible inefficiencies. I have heard and read a lot of criticism of the food for fuel cycle, and so am usually hesitant to get excited about biofuels. However, I like the approach of recycling a waste product such as grease to create fuel. San Francisco is able to claim several advantages from their program. Because the city picks up waste for free, business owners benefit directly from saved costs of disposal. In addition, the city can mitigate cleanup costs associated with illegal dumping from owners who pour out grease rather than pay to dispose of it properly.
The scope of the SFGreasecyle program is relatively small, with a daily production expectation of 500 gallons of fuel [CNET]. The program will also receive over $1 million from the state of California to fund the plant’s development. I am definitely interested in seeing how this development plays out. If SF can produce these fuels economically, I would love to see other cities implement a similar system. I think this is an excellent example of how policy can affect multiple problems with innovative solutions.