Small Scale Renewables
 Small Scale Renewables Forestry Business Units are introducing a range of small scale
renewable or ‘alternative energy’ products for electricity generation
in a number of off grid applications, and also to reduce the energy
requirements in buildings, and so reduce our carbon dioxide emissions. The source of all Renewable Energy is the sun (and the moon in the
case of tidal power). The sun’s energy can be harnessed directly by
solar panels, which either heat water, or generate electricity in the
case of Solar PV. The heat from the sun drives the water cycle. Rain falls and flowing water can be used to generate hydro electric power. The heat from the sun also drives the worlds weather systems, causing the winds to blow, which can be harnessed by wind turbines to generate electricity. The main types of system being installed and considered by Forestry Business Units are: Micro Wind Turbines Small turbines are used to charge batteries to run radio masts and provide off grid power for wild life video monitoring etc. We are also installing slightly larger building mounted synchronous turbines, which produce 240 volts synchronised to the grid. For example a ‘Swift’ turbine is rated at 1.5kW in a 10.5 m/s wind, and in a suitably exposed site should produce 4000 kW hours if electricity a year, displacing 1.6 tonnes of carbon dioxide. Micro Hydro Turbines We have installed small ‘turgo runner’ turbines to provide power to charge batteries in off grid applications where we have streams flowing down steep hillsides, which we can capture in a small pipeline. A fall (or head) of 16 m and a flow of 8 litres per second will generate about 500 Watt of electricity. Solar PV (Photo Voltaic) Panels PV panels are made of silicon, and produce electricity when exposed to light. This is often used to trickle-charge batteries in off-grid applications. Solar Water Heating Panels There are several types of solar water heating panels, which trap energy from the sun and use it to raise the temperature of water. The two main types are flat plate collectors (of which there are many designs) and vacuum tubes which tend to be more efficient but are more delicate. Water or antifreeze is pumped through the panel when there is sufficient sunlight to warm it. The energy collected raises the temperature of water and reduces the amount of energy required from conventional sources. Heat Pumps Operate just like a fridge in reverse. They take heat from either the ground or the air (the equivalent of the ice box), and transfer it into the room, usually through under-floor heating or extra large radiators. Typically they are allowed to run continuously, and for every 1kW of electricity put in to run the heat pump, you get 4kW of heat out into the room.
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