Straw is another biofuel that is beginning to be used more commonly in Danish CHP and district heating plants. Although this photo was taken in a small plant in Hals, in northern Denmark, straw is also a primary fuel for the new Avedore 2 power plant that serves Copenhagen. Avedore 2 generates 570Mw of electricity, meeting the needs of some 800,000 households, and the same amount of heat for approximately 110,000 homes. It is capable of using oil and natural gas, but primarily uses wood pellets and straw. The wood pellets are made from surplus wood from Junckers, the world's largest manufacturer of hardwood flooring. As such, they are totally CO2 neutral and the 300,000 tons burned annually make up half of the fuel used at Avedore 2. This is connected to a separate unit - the world's largest straw-fired boiler - that supplies the turbines with additional steam. It burns 150,000 tons of straw a year, accounting for 10 per cent of Avedore 2's fuel consumption. Not only is this process CO2 neutral, but all of the ash is returned to the fields where it was grown for its fertilizer value. (photo by Jayson Antonoff, grnNRG Consulting)