Olive oil is deliciously useful, but the pits may be even more advantageous than the oil — a company in Madrid is now juicing more than 300 buildings on power from olive pits. The pits, which are basically compressed wood, are compressed and turned into ethanol — and the resulting energy sent to buildings. It takes about 220 pounds of olive pits to make 12.5 pounds of ethanol, so it’s not a great source of energy, but if the pits were to be thrown away otherwise, it could reduce the waste stream from olive farms. Spain, the world’s largest producer of olives, is hoping to cash in on the hype about biomass, though some ecologists say that burning olive pits emits more pollutants than letting them rot or finding another use for them.