Many governments are beginning to take steps to develop renewable energy sources as a viable alternative to fossil fuels. However, in order to build sustainable climate change, simply implementing renewable energy is not enough. It is vital to also address inefficiency with regard to energy usage, along with the supply of energy. With the rapid urbanisation of emerging economies such as South Africa and the sheer amount of energy used by buildings alone, improving building efficiency is a cornerstone of developing sustainable climate change initiatives.
President Jacob Zuma announced that the government aims to install one-million solar geysers by the year 2015, as part of the Green Economy Accord, first announced in November 2011 by President Zuma. This accord hopes to create 300 000 new “green” jobs by 2020 and will investigate, among others, renewable energy sources such as solar power and biofuels. While these initiatives are important in the quest for climate change, there may be advantages in shifting the focus somewhat when it comes to addressing current and future energy shortages.
Globally, commercial buildings consume nearly 40% of energy used. The heating, ventilation and air-conditioning (HVAC) equipment used in a commercial building alone contributes up to 40% of its running costs. In South Africa, almost all the energy we use is from dirty sources, namely coal, oil and gas, and the burning of fossil fuels is responsible for 95% of the global carbon dioxide (CO2) emissions. Now consider that some 70% of the world’s population will live in cities by 2050.
As South Africa, which is counted among the emerging economies, become increasingly urbanised, the CO2 output from buildings is set to rise, ultimately contributing to greenhouse gas and carbon emissions. Improving the efficiency of buildings therefore will not only help to reduce carbon emissions, but will also lessen the demand for energy, which in turn will make renewable energy sources more viable. This can also be linked into the Green Economy Accord, as developing energy-efficient technology has just as much job creation potential as alternative energy sources.
Improving energy-efficiency in the built environment seems to be low on the list of priorities for the majority of countries that participated in the COP17 climate change talks in Durban in 2011. The majority of submissions around policies and actions to take regarding climate change did not mention building efficiency as a point of action. By the time Rio+20, the United Nations’ Conference on Sustainable Development, rolled around in June 2012, numerous green building initiatives were being launched by organisations with global green credentials. Recognising the high impact of energy use by commercial and residential buildings on global CO2 emissions – and thus on environmental and human health – these initiatives aim to engage private sector leaders, civil society and governments to focus on achieving greater energy-efficiency in buildings and develop sustainable cities.
Optimising energy usage and reducing energy requirements is a logical first step to take before renewable energy sources can be delivered. From simple steps such as reducing the running temperature on geysers and installing timers for lights, right through to intelligent building management solutions that link systems together for optimised usage, the possibilities are enormous.
Improved building efficiency not only lowers the carbon footprint, but it can also save organisations substantial sums of money, effectively paying for itself in the medium to long term. A project completed at the South African Broadcasting Corporation (SABC) in 2010 serves as proof of this concept. The SABC’s Auckland Park complex consumed about 85-million kilowatt hours (kWh) a year at the start of the project, with a maximum demand per month of 11 600kVA. An energy audit of the site revealed that certain office air-conditioning and lighting were left on for longer than necessary, that there was unnecessary over-cooling and re-heating, that economiser cycles were not optimised and that there was excessive hot and cold water flow.
Simple measures such as more intelligent use of heating and cooling as well as basic energy management solutions were implemented to maximise efficiency of existing equipment. These measures included reduced optimised operating hours for lighting and air-conditioning with remote after-hours switching, reconfiguring the cooling and heating control, re-commissioning the economiser control and decommissioning excess boiler capacity. Savings of close to 20-million kWh a year, that’s a 25% saving, were achieved. In monetary terms, savings as high as R1,5 million per month were reached.
Improving building efficiency has a far greater effect than just energy and money savings, however, particularly in light of the need to introduce positive climate change. For every kWh of electricity saved in a building, 1,4 litres of water are saved, and power stations will generate one less kilogram of CO2. This is due to the fact that the majority of South Africa’s energy is produced from coal-powered turbines that use evaporative cooling towers.
To put that kWh of electricity or one kilogram of CO2 into perspective, consider that each of the following add 1kg of CO2 to your personal carbon footprint: operating your computer for 32 hours (60 watt consumption assumed), the production of five plastic bags or two plastic bottles, or driving your car the equivalent of 6km (assuming fuel consumption of 7,3 litres of petrol per 100km). This makes the SABC’s saving of almost 20-million kilowatt hours quite a feat. However, the simple energy-efficiency measures it applied to achieve these savings are something every responsible facility manager or owner can consider.
In the fight to reduce CO2, and in light of the need to conserve both water and fossil fuels, improving building efficiency is a vital step. Not only will energy-efficient buildings reduce the energy consumption of the built environment, but they will also reduce the amount of energy that needs to be produced. This in turn reduces the pressure on alternative, renewable energy sources, which makes energy supply strategies more viable. The less energy that is wasted on inefficient buildings and building systems, the more sustainable energy solutions become.
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