Homefire Ecoal 50 is the most environmentally-friendly solid fuel on the market, as well as being one of the most efficient. It is manufactured from 50% olive stones, which are natural wastage from the production of olive oil. Its advantages over traditional house coal include producing 80% less smoke (and 50% less than kiln dried logs) and 40% less carbon dioxide. It also burns 38% hotter than house coal, so although it’s more expensive per bag, it works out more cost-effective as you get considerably more heat per kilo. This also means less reloading the fire and more time to bask in the ambience.