Cities across the globe are responsible for 75% of the world's energy and 80% of the greenhouse gas emissions. They have a central role to play in mitigating climate change and collaboration is key to achieve the best results. A trend-setting initiative is C40, which is a group of the world’s largest cities, including London, New York, Delhi and Beijing among many others, who have joined together to tackle climate change. The strength of this initiative is that it can use the combined buying power of the cities involved to significantly reduce the price of energy-saving products, and encourage the development of new energy-efficient options. C40 encourages the development of building codes and practical measures to create cleaner and more energy efficient buildings.
As a city, London produces 8% of Britain’s carbon emissions, which is the equivalent of the whole of a nation such as Greece’s total carbon output. These statistics come from the Greater London Authority (GLA) Action Plan which was presented to a meeting of the Insurance Institute of London on 14 February. The GLA aims to reduce carbon emissions in London by 60% by 2025 and Andy Deacon, Climate Change, Energy and Air Quality Strategy Manager at the GLA Environment Team explained ways in which businesses and houses can cut down on their carbon footprint.
Combined heat and power (CHP)
One of the latest trends for low-carbon living is CHP, or combined heat and power systems. CHP is the generation of usable heat and power (usually electricity) in a single process. The basic principle is that the turbine or engine drives an alternator which creates electricity, while the heat created during the process is recovered to provide hot water, space heating or cooling. CHP systems can be used over a range of sizes, applications, fuels and technologies.
Wind turbines
Wind turbines are another option, although one immediate problem is the size of the turbines and related noise levels. Despite having 40% of Europe’s total wind energy, the UK only actually uses it to produce 0.5% of its electricity. For home use, another issue to consider is the position of the turbine, which should be on a smooth-top hill with a flat, clear exposure, free from excessive turbulence and obstructions such as large trees, houses or other buildings. These specific criteria mean that using wind turbines to supply energy in the home is not always the best option – in fact some public figures have faced ridicule for proposing to build wind turbines for their homes in unsuitable locations, for example urban areas.
Solar photovoltaic
Solar PV (photovoltaic) uses energy from the sun to create electricity. Photovolvtic cells are used convert sunlight to energy, and can be installed on roofs or walls that faces within 90 degrees of south. Solar electricity is popular in terms of low-carbon housing and can be bought and installed within any domestic system, although it is quite expensive for the average member of the public, costing between £10,000 and £20,000.
Housing developments
Greenwich Millennium Village is a 1,500 home low-carbon development which uses a combination of local electricity generation, improved insulation, and energy-efficient devices for the apartments. This was the first private housing development in the UK to incorporate community heat with a combined heat and power system (CHP). The buildings were purposely shaped and positioned to make full use of the sun for both light and heat.
An iconic example of carbon neutral livability and the direction of things to come is the Beddington Zero Energy Development (BedZED) in Sutton. The heating requirements of BedZED homes are around 10% that of a typical home built to 2000 Building Regulations, and all heating and hot water requirements are designed to be met by a wood fuel community heating network.
Business and low-carbon developments
Businesses can also play their part in supporting the development of low-carbon buildings. The UK Government’s Department for Business, Enterprise and Regulatory Reform (BERR) launched their Low Carbon Buildings Programme in 2006, and businesses were encouraged to participate. Grants were awarded towards the costs of installing a variety of technologies, including solar photovoltics, wind turbines and ground source heat pumps, and businesses were eligible to apply. A BERR spokesperson explains that around £26 million has been allocated to 5,600 projects: “Government is working closely with the Carbon Trust on 11 of these projects, aiming to raise awareness in the business case for developing low carbon buildings. Through these projects, we are encouraging the development of commercial scale projects - both new build and refurbishment - as standard 'best practice' buildings for subsequent replication.”
Examples of business taking the low-carbon buildings agenda further are springing up. Glyndebourne Opera House is planning to build a 70m-high wind turbine, which will reduce its carbon emissions by 71% - a move which is being supported by Sir David Attenborough.
Although there is much work still to do, it is clear that business and government alike are more aware of the need to work towards lower carbon emissions from homes and buildings. Each new environmentally-friendly development is another step towards mitigating the man-made effects of climate change and collaborations such as C40 will continue to drive prices down and make low-carbon buildings economically viable.
