Burning wood or charcoal lowers the electricity bill? Who would have thought! Also, what is “low-temperature technique” supposed to mean? The open fire needs t

Burning wood or charcoal lowers the electricity bill? Who would have thought! Also, what is “low-temperature technique” supposed to mean? The open fire needs to maintain the water at 100C regardless. If low-temperature means lower water temp, then its the same as the passive method..