Net Zero Energy Buildings – What Are the Challenges?

 Recently Environmental protection organizations expressed highly concern about the abrupt increase in carbon emissions across the world from the buildings. Global concern about the environment has insisted people to adopt Building that are more eco-friendly even more than the Green Buildings.

Now what a Net- zero Energy building really is?

A zero-energy building (ZE), also known as a net-zero energy building (NZEB) is a building with zero net energy consumption, that means the total amount of energy used by the building annualy is equal to the amount of renewable energy created on the site.

 In some cases these buildings subsequently contribute less overall greenhouse gas to the atmosphere during operations unlike non-Zero Energy Buildings.

For example, if the annual energy consumption of a building is 100000 kWh. Then the annual on-site production of the renewable energy should be equal to the energy consumed.

Why Net- Zero Energy Buildings?

Indian buildings accounts for 40% of India’s overall power consumption and generate a significant amount of greenhouse gases. Because of gradual increase in population and urbanisation, the construction (and energy consumption) of buildings has seen an extensive growth. And this growth is going to be increase multiple times in upcoming decades.

Current Status of NZEB in India

While there is a strong policy-push towards the adoption of renewable energy technologies such as rooftop solar photovoltaics (RTPV), the potential for making zero energy buildings has not been explored to that extant.

The Indira Paryavaran Bhavan in New Delhi (constructed in 2014) is India’s first NZEB. The Indira Paryavaran Bhavan is one of the first buildings in India to have deployed energy efficiency and renewable energy technologies at a large scale. It is one of the exemplary projects to be rated under Green Rating for Integrated Habitat Assessment [GRIHA] and has set standards that can be emulated by upcoming buildings in the region. The building is fully compliant with requirements of the Energy Conservation Building Code of India (ECBC). It has been built with integrated energy-conservation practices and a super-efficient solar PV system of 930kW capacity. This system generates almost 1,500,000 units annually, while the overall energy demand of the building is approximately 1,420,000 units per year. The building boasts an earthquake-resistant structure with a total plinth area of 31,488 sq. m. It covers only 30 per cent of the total area, while more than 50 per cent area outside the building is a soft area with plantation and grass. The building has received GRIHA 5-star rating.

 In spite of their promising potential to harness solar power and tackle environmental challenges, only seven Indian states (including Delhi) have constructed NZEBs till date.

Challenges towards NZEB

It’s not realistic to expect the world to make a quick evolution to zero-energy buildings. As there are many challenges that creates hurdles in achieving Net Zero Energy. Eg.

• To generate large amount of electricity through renewable energy resources, it requires large area. But there may or may not be that much area available to install renewable energy resources (Solar PV ).
• Net-zero energy buildings produce as much energy on-site as they consume in a year. Many technologies needed to reach this goal, such as high-efficiency HVAC systems, are already available affordably. However, products like triple-glazed windows and solar panel installations are frequently not cost-effective for building owners compared to conventional alternatives.
• Some architectural design consideration may also lead to increment in the HVAC load, that is again a big problem.