Sustainable Energy
It is important when looking at renewable energy to first and foremost look at how you currently use energy across your site. Reducing energy consumption to reduce both bills and carbon dioxide emissions can be tackled three fold:
- Use less energy
- Energy Efficiency
- Implementation of on site low carbon and renewable energy technologies
So how do you achieve this? Can you make small changes to the way you operate to reduce energy use, are there opportunities for improved energy efficiency? These can be as simple as turning off lights as you leave a room, remembering to switch computers off rather than leaving them on standby, ensuring you have basic energy efficiency measures in place such as low energy light bulbs, loft insulation and double glazing to name but a few.
These are often easier and lower cost ways to reduce energy use and make savings; and have little impact on how you live your life. In parallel to this you can look at renewable energy options. Small scale renewable energy deployment generally looks at on site generation of electricity or thermal energy (heat).
The right renewable energy package will depend on a whole range of factors that are unique to your individual requirements. Are you looking at heat or electricity generation, what space is available to incorporate the different technologies, how often the site is occupied, levels of energy efficiency and whether there is scope to improve on this and what most importantly what natural resources are available?
So what are the options?
The main technologies include (but are not exhaustive):
Wind Power
Wind turbines capture the winds energy with two or three propeller like blades, mounted on a rotor, to generate electricity. Systems can be on and off grid. There are two potential options for small scale on site generation; ground mounted turbines and roof mounted turbines.
For more information on wind energy please visit the British Wind Energy Association website at www.bwea.org.uk
Hydro Power
Hydro power uses moving water to generate electricity. The energy of the flowing water turns a turbine which is connected to an electricity generator. The power produced is dependent on the rate of flow of water (which is dependent on how far the water falls over a given distance, this is known as the head), the volume of water available and the efficiency of power conversion.
For more information on Hydro Power please visit the British Hydropower Association website at www.british-hydro.org
Biomass Heating Systems
The use of biomass (this could be a woodchip, log or pellet boiler) is carbon neutral as for every tonne of CO2 released into the atmosphere an equivalent is being absorbed by growing trees assuming the timber has been sourced from sustainably managed woodlands (of which the majority in the UK are). Combustion of woodfuel is the easiest way to release energy which in turns provides heating and hotwater.
For further information on woodfuel heating please visit the Renewable Energy Association website at www.r-e-a.net
Solar Water Heating
Solar water heating harnesses the suns energy to directly heat water which is pumped round roof mounted panels and the associated water tank. The water becomes preheated in the tank therefore less energy is used to bring the water up to temperature. In the summer months it may generate close to 100% of a buildings requirements. It is thought to average out at about 50% of hot water needs over the course of the year.
For further information on solar water heating please visit the Solar trade Association website at www.solartradeassociation.org.uk
Solar Photovoltaics (PV)
This is the generation of electricity from the suns energy. Panels can either be bolted on or integrated into the roof as either panels or tiles. Alternatively panels can be mounted on the ground. Systems can be both on and off grid connected. Output decreases as you move from the optimum sough facing position and panels are very susceptible to shading with output dropping to virtually zero.
For further information on Solar PV please visit the Renewable Energy Association website at www.r-e-a.net
Heat Pump Systems
Heat pumps utilise thermal energy taking low temperature heat from its surrounding. This could be the ground, surrounding air or a local water resource. This low grade heat is then upgraded to a higher, more useful temperature.
Although some electricity is used to operate the pump the amount used is not significant compared with the amounts that would be required to heat the building by conventional means. The efficiency of heat pumps lies in the fact that they use low temperature heat created from renewable energy sources. Heat pump systems usually produce twice to three times as much heat from the same amount of fossil fuel by using it to enhance the renewable energy of the land. For example for every 1 kW of energy used to run the pump 3kW’s of heat are produced.
For further information on Heat Pumps visit the ‘The UK Heat Pump Network’ website at www.heatpumpnet.org.uk and ‘The Heat Pump Association’ site at www.heatpumps.org.uk
Also, the Ground Source Heat Pump Association www.gshp.org.uk
Energy Efficiency
Energy Efficiency measures ensure that a building retains generated heat and maximises on natural heating and cooling. These range from basic low cost measures such as roof and cavity wall insulation through to more costly options like double glazing. It also includes the use of natural heating and cooling systems for example passive stack ventilation systems.
Different technologies are appropriate in different environments and it is developing the right integrated package of renewable energy and energy efficiency measures dovetailed with a new energy management strategy that maximum savings can be made. This package will be different for every site.
This is where Elizabeth Bruce Associates can help. As an independent company we have expertise in all areas of sustainable energy management without being linked to any installers which would lose our impartiality.
Whoever you are - a business, local authority, community group, school or household we can work with you to help deliver the right sustainable energy package for you.
