Solar Energy in a Stick

“One of the best ways to address climate change is to use more wood, not less.”

Patrick Moore, co-founder of Greenpeace

Trees use photosynthesis to capture the sun's energy. Trees also absorb carbon dioxide from the atmosphere and use the solar energy captured to convert carbon dioxide and water into organic compounds such as cellulose to grow the tree. Oxygen is released to the atmosphere as a by-product of photosynthesis. In photovoltaic cells solar energy is directly converted into electricity, which can be fed into the grid or stored in batteries. In the leaves of trees solar energy is effectively stored in the organic compounds. When deposited into the trunk, roots and branches of a tree as wood this energy will be stored until the wood rots away, unless it is used as fuel. Firewood is not often recognised as "green" energy, probably because it comes from trees. But, unlike other sources of "green" energy, firewood does not need major capital investment or infrastructure. Every tonne of dry firewood contains approximately 20,000 Megajoules of stored energy. This means that a typical 660 kW wind turbine will generate around the same amount of energy in one year as that contained in 315 tonnes of firewood. Recent estimates made by Driscoll et al., (2000) place Australia's annual firewood consumption at around 4,000,000 tonnes. This is equivalent to the annual output of nearly 13,000 wind turbines or six large (550 MW) coal fired power stations. Atmospheric carbon dioxide than is released when the wood from the tree's trunk is burnt. The reason that sustainable firewood is so good for the environment is that all of the carbon that is released during combustion is reabsorbed by trees as they grow. The only increase in atmospheric carbon dioxide comes from the fossil fuels used to process and transport the wood. It is worth noting that even "green" alternative energy generators such as wind farms, hydro stations and solar collectors create a lot of carbon pollution during manufacture and construction.

Wood fills the gap

Got solar? You still need wood!

Wood heating is vastly cheaper than adding a home battery. Wood heats your home during the mornings, evenings and when there is lower daytime solar radiation in winter. If you think about it, solar doesn’t produce energy at the times of day that you most require it for home heating.