Burning wood for heating

摘要

According to German tomato and sweet pepper grower Stefan Scherzer, gas is too expensive for heating his greenhouse. Therefore, he burns wood. What is special is his wood burner's feeding system and the plan to heat not only the greenhouse but also anairport. Stefan Scherzer does not consider a co-generator as an interesting option, because in Germany gas is very expensive compared to the price of electricity. For that reason, he chose wood burning. This year, heat from natural gas would cost him EUR0.05 per kWh, next year EUR0.042. So, he uses gas only when wood burning is insufficient to heat his 45,000 m2 greenhouse. To save heat, he also has a 1,000 m3 buffer. Since he started burning wood in 2007, he has occasionally had to resort to gas, butusually he has a heat surplus which he uses to also supply some extra heat to a greenhouse belonging to a colleague of his. On average, i kWh of heat from wood is EUR0.024 cents, he has worked out, including all variable costs such as removing the ashesand electricity consumption. The fixed charge for the EUR650,000 installation is not included in the costs, which is inclusive of a EUR150,000 electro filter that removes the major part of the aerosol from the smoke. The discharge of aerosol must be limited to 20 milligrammes per m3. Purification is so thorough thaton the face of it, no flue gas can be seen coming out of the chimney. The ashes and waste products that contain phosphate and potash are used for fertilising purposes.