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Switching to net zero buildings is not only cheap now, it is also feasible; India also finds solutions slowly | India News


NEW DELHI: Cheap technology and enough skills already exist around the world to achieve net zero energy buildings, those that produce enough renewable energy to meet their annual energy demands, at costs in the range of traditional construction projects, a published study recently in the Annual Magazine. of Environment and Resources has found.
The study examined low and ultra-low energy buildings alongside policies internationally and found that with the right strategy, materials and appliances used, change can often be achieved quickly, often in a matter of months.
For example, Brussels transformed its buildings from the lowest performing to the highest performing buildings across Europe in just seven years, using a combination of voluntary measures to support and encourage industry leaders to innovate and demonstrate what was possible before demanding that performance level through regulation.
The study also found that since project spending related to energy efficiency was low, the cost of sustainable buildings could equal or even be less than those built using traditional methods. For example, the City of Vancouver anticipated a modest increase in construction costs as a result of increased building code performance requirements, but instead experienced a 1% cost decrease in the long term.
“Sustainable building cooling is a major challenge,” said Radhika Khosla, co-author of the study and principal investigator at the Smith School of Business and Environment at the University of Oxford. “In a hot climate, the energy use of buildings will increase even if the cooling is as efficient as possible. The growing needs for wealth, space and comfort are designed to dramatically increase the demand for energy, with corresponding increases in greenhouse gas emissions. However, there are solutions: for example, shading designs and wind channeling to block the sun and allow natural ventilation in skyscrapers, ”said Khosla.
While the study highlighted the ease with which various cities have begun the transition to sustainable housing, it also highlights several challenges, namely the technological difficulties in making high-rise commercial buildings in hot and humid climates efficient enough to low cost, while heritage buildings in need of modernization pose a similar challenge. He stated that deep upgrades were also costly in the short term, and while they may cost less over time, innovative financing is often required upfront.
The share of heating or cooling in the total energy use of buildings varies from 18% to 73%, depending on the type of buildings (residential or commercial), the climate and the world region (developing countries versus developed countries) . The lowest proportion (18%) is for commercial buildings in North Africa and the Middle East, while the highest (73%) is in Central Asia.
The total energy consumption in the BRIC countries (Brazil, Russia, India and China) has already exceeded that of the developed countries, and the continuous increase in the stock of buildings predicts the possible continuation of the increase in energy consumption in the countries.
Architect Ashok B Lall, who has worked on various green buildings, says that achieving net zero is possible in India through a fairly cost-effective approach, however the European model which involves isolating the building completely from the outside by using several layers of insulation was poorly adapted to the climate of India. Instead, Lall advises using the right combination of shading, sun protection in the form of roofs outside the windows, and ceiling fans to reduce dependency on air conditioners. “It has been established through very solid research that a combination of shading, sun protection and air movement over the skin (ceiling fans) allows you to feel comfortable in dry season temperatures of up to 32 degrees Celsius and in a wet season. up to 27 degrees centigrade. This, combined with natural ventilation whenever possible, ensures you reduce your demand for air conditioning and then you can supplement the remaining energy using solar panels to move towards net zero, ”Lall said.
He also claims that using an air-conditioned ceiling fan allows the body to feel 2-3 degrees cooler, allowing the air conditioner to run at a higher temperature, thus reducing its energy demand. While NCR buildings are slowly adapting this approach, Lall says more can be done, pointing to Unnati, a recently constructed green building in Greater Noida for the company Gainwell, which has been built on a zero emissions, zero waste model. and zero water discharge. with its energy demand significantly supported by solar energy. The LEED platinum building has shaded windows, reduced artificial lighting, controlled daylighting, a rooftop garden, and insulated walls, among others.
Delhi has ample opportunities to go green
In terms of switching to zero, or making a building rely heavily on renewable energy, Delhi has a few models that have emerged over the last decade. The Indira Paryavaran Bhawan in central Delhi, which is home to the Ministry of Environment, Forests and Climate Change (MoEFCC), is perhaps the best example as it is also India’s first net zero building. Using its rooftop to capture solar energy, the building has also been architecturally designed with best practices in mind, while using proper insulation and materials that will reduce energy consumption. Inside, the chosen appliances are also high in the energy saving quotient.
In terms of great infrastructure, Delhi Airport has also been working towards a similar goal, receiving the ‘Excellent Energy Efficiency Unit’ award this year for the third year in a row at the IIC National Awards for Excellence in Energy Management. -Green Business Center. .
To achieve key energy savings and reduce emissions, Delhi airport has adapted climate change strategies and has been making use of solar energy, along with strategies such as making better use of natural sunlight, using UV lamps in treatment units. of recirculated air and oxygen optimizers, among others. solutions.
Saswati Chetia, Senior Project Officer at Greentech Knowledge Solutions (P) and an expert in sustainable building designs, says that while solar panels are not the only solution to achieve net zero buildings, it is still a resource India is very much on. blessed.
“In addition, with all the solar technologies available in the market and the policies of the Government of India, it becomes the most attractive and economical option of renewable energy. Buildings like the office of the Ministry of Environment and Forests in Delhi (Indira Paryavaran Bhawan) is the first net zero building in India. Similarly, the HAREDA demonstration center in Gurgaon is also a good example of what can and should be done to achieve net zero, ”said Chetia.
She believes that while the concept of going to net zero remains the same: reducing energy demand by having good building design and efficient appliances, India cannot rely on Western concepts due to different climates.
“Western countries with generally colder climates will design their buildings to receive more sunlight to heat their building naturally and thus save on heating requirements. We in India have to do the opposite. We will have to design buildings to avoid the heat of the sun most of the time (while still leaving enough natural light). So we have to make sure that we don’t use a lot of glass in our buildings and wherever we do, we have to make sure they are absolutely well shaded. The heat of the walls and ceiling must also be optimized. Ceilings should definitely be insulated and have a reflective finish. The walls should also have moderate to good insulating properties. This means that external walls made only of concrete will be a no-no unless they have additional insulation, ”added Chetia.
In terms of switching to rooftop solar panels, Delhi is also realizing the benefits it can offer in the long term. In 2018, BSES provided solar panels to various CGHS companies in Dwarka under the ‘Solar City Initiative – Solarise Dwarka’ scheme, in collaboration with TERI and Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ India) under the indo solar partnership project -German. . Now these societies are saving billions a year.
Initially, seven companies were chosen for the project and reported cumulative savings of 6.5 lakh from electricity units and Rs 32 lakh annually. Now, several other societies have also joined.
Generally, a feasibility test is carried out to assess the potential of a society’s solar roofs, based on which the capacity of the solar panels is suggested. Depending on the energy that is generated and returned to the grid, each household can realize its benefits through net metering connections on solar roofs.
Global learnings:
· A study from the University of Seville in 2018 says that the operation of buildings based on adaptive thermal comfort can generate energy savings of 27.5 percent.
· A study in Morocco found that optimized overhangs (chajjas) reduce cooling demand by 4.1% for Casablanca’s Mediterranean climate and improve thermal comfort.
Another study in Singapore says: “Relative to a typical 24 ° C room design condition with a conventional air conditioning system, a dedicated outdoor air system with ceiling fans achieved a 25.8% reduction in annual energy consumption when the ambient temperature rose by 3 ° C but was compensated for by greater air movement “.
(The story is published as part of the CMS-BEEP Media Scholarship Program)

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