Wind and Solar

• Wind and solar energy have no carbon footprint and are easily adapted into a greenhouse situation. Solar power can be used in a greenhouse in two ways. The first is to install solar panels that will convert the heat from the sun to electricity that is stored in batteries. The electricity stored can both heat the greenhouse via an electric heat system and run the electrical system in the building. Solar thermal collectors convert the heat from the sun into hot air which can be used to heat the greenhouse. Wind power is used in the same way as solar. Wind turns turbines that move a shaft. The shaft leads to a generator where it stores the power. The power is used in the form of electricity.
  
  

Biomass Technology

• Biomass fuels are harvested locally and include crops, crop residues and animal waste. Urban settings, where there is no agricultural land, can use organic and mill waste. There are boilers and furnaces made that operate on corn, wood pellets or grass pellets. This type of furnace uses gasification. The crop material is burned at a high temperature eliminating creosote formation inside the chimney. Anaerobic digestion uses a digester tank to create an enclosed system for bacteria to metabolize waste and convert it into heat for the greenhouse; bio-gas to operate machinery; and an effluent solid that is used as organic compost.
  
  

Orientation, Preventive Maintenance, Insulation

• A greenhouse heated by an alternative source will benefit from the use of orientation, preventative maintenance and insulation to conserve energy. Single bay greenhouses should be oriented east to west. Multiple bay, gutter connected greenhouses need to be oriented north to south. Plant tables that run north to south will have the best use of the sun. A wind break in the form of trees, buildings or fences will reduce heat loss. Add insulation to all gaps in the structure, including around doors and vents. Check that vents work properly and doors have a good seal when closed. Use double layer glazing; it uses air between the panels for insulation. Growers can also use insulating material on the foundation, the north wall, and up the walls to the plant level to reduce heat loss.