Sunday, May 29, 2022

Building for energy efficiency

A growing body of opinion hails energy efficiency and conservation as the next big thing. In fact, the International Energy Agency (IEA) says energy efficiency is the world’s most important “fuel”. A report by the organisation says investments in energy efficiency provide such vast savings that the energy saved actually completely surpasses the energy generated by most forms of generation. It argues that energy efficiency is a crucial aspect to the world’s efforts to reduce fossil fuel use as well as carbon emissions, and should be given even more attention.

Between 2005 and 2010, the IEA calculated that energy efficiency measures across 11 of its member countries saved the energy equivalent of US$420 billion (about P3.5 trillion) worth of oil. In the same countries, it was found that were it not for energy efficiency measures implemented in the three years prior to 2010, consumers would have used and paid for two-thirds more energy than was the case. Overall, in one year, energy savings from efficiency measures exceeded the output from any other single fuel source in the same countries, with 11 states avoiding burning 1.5 billion tonnes of oil.

“The energy efficiency market is increasingly delivering outcomes that can help address important public policy challenges. Energy efficiency investments can produce multiple benefits by reducing or limiting the demand for energy. This includes reducing both domestic and international pressures on energy supply systems, thereby increasing system resilience and improving security. It can also produce positive economic outcomes, such as allowing spending on energy to be redirected towards other economic sectors, and by reducing public expenditures. Energy efficiency investments can also result in improved health and wellbeing, and avoided emissions of greenhouse gases and other pollutants,” states the IEA.

Writing in the British newspaper “The Guardian”, Christian Kornevall ÔÇô project director for the World Business Council for Sustainable Development’s Energy Efficiency in Buildings project ÔÇô sounded this warning: by 2050, there will be an additional 3 billion on Earth and 70% of the world’s population will be living in cities.

“While many things about the future remain unclear, one thing is certain: more people in urban areas means an increased demand for new buildings. And unless we change the incredibly inefficient nature of today’s buildings, it means an unprecedented increase in energy use. It’s a ticking time bomb,” Kornevall says.

By Kornevall’s calculations, the world’s “inefficient” buildings consume 40% of the world’s energy and are responsible for nearly the same amount of emitted carbon ÔÇô more than in the transportation or industrial sectors.

“The good news is that the opportunity exists to drastically reduce energy use in buildings in the next 40 years,” he says. “All this is doable, in an efficient market, and we already have the technology solutions available that can reduce energy in buildings by at least 50%, possibly as much as 80%.”

A local architect, Kgosi Mphathi, managing director of the architectural firm Feature Homes, points out that architecture design is currently primarily driven by the need for energy conservation.

“Ever since global warming became a primary concern, it has been proven that buildings contribute immensely to the total carbon footprint of developed areas hence methods of reducing this in the way we design buildings has become a mainstay,” Mphathi says.

He has realised that there are clients who are aware that the way a building is designed has a bearing on the amount of energy saved; however these clients are very few, and tend to be abreast with what the industry calls active systems (such as solar energy) rather than passive systems ( such as building orientation and/or design). Most first time homeowners are the least aware of how design can impact on energy saving. Those building their second or even third house would have developed the knowledge of energy conservation in building design the hard way after investing a fortune into a badly designed building.

Mphathi points out that it is important to recognise whether the cost of implementing the system of energy conservation would be less than the cost of energy that is ultimately saved by a significant margin.

He observes that in most building designs, energy conservation is achieved by orientating the building in the most appropriate way, selecting room adjacencies that control how heat flows within the house, and using mechanical/electrical systems that can actively support an efficient use of energy.

“The most cost effective strategy on energy conservation comes in the way you orientate your building and position the rooms within the floor plan,” he says. “There are other methods classified as active measures which can cost little, such as energy efficient light bulbs, whilst some, like solar energy panels, can be more expensive.”

Ultimately, Mphathi observes, what determines the viability of a solution is whether the cost of implementing a strategy will save a client more money in the amount of energy saved.  

“The effectiveness of any strategy is also realised over varying time periods, hence it is important to measure each system over the whole lifetime of the building in order to get a full picture of the viability of that method,” he says.

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