Zero net energy in buildings: A guide

by Ofentse Sefolo
Zero net energy in buildings: A guide

“Sustainability” is more than just a buzz word. It is, and should be, a priority for every individual and every business. According to the 2018 Global Status Report compiled by the Global Alliance for Buildings and Construction, the building sector is responsible for 39% of all emissions, ahead of the industrial sector by over 7%!

Luckily, industry experts, researchers and companies have been on a mission to find more sustainable solutions in this regard. Zero-net energy, in particular, is one of those solutions and is a concept that is being incorporated into the design and structure of more and more buildings all over the world.

What is a zero-net energy building?

A zero-net energy (ZNE) building, also commonly referred to as a zero-energy building, is a building focused on sustainable operations. Ultimately, it is a building that produces the same amount of energy as the amount of energy that it consumes over a period of twelve months.

ZNE building produces the same amount of energy as it consumes over a twelve month period.

Zero-net energy is most commonly achieved by incorporating solar PV on site. Contrary to popular belief, a zero-net energy building maximises its energy efficiency without it having a detrimental effect on the overall environmental quality of both its interior and exterior portions.

What are the benefits of zero-net energy buildings?

Obviously, the leading benefit of zero-net energy buildings is the fact that they are sustainable and kinder to the environment. They offer numerous benefits for property developers, commercial real estate owners and building occupants alike. For example, property developers can gain advantage from the fact that there is a growing demand for ZNE buildings, ultimately profiting by remaining ahead of the curve and catering for this demand.

Swift Lee Office’s Net Zero Energy High-Performing School Prototype has been successfully built on three sites in California.

Commercial real estate owners benefit from the energy resilience of ZNE buildings. They will be protected from ever-increasing energy costs and grid vulnerabilities through low to zero utility bills.

Finally, building occupants can relish in the fact that they are doing their “bit” for the earth.

The great news is that zero-net energy buildings are not limited to residential and commercial buildings – they are a viable solution for industry too.

“Obviously, it is not plausible to cover 11 million acres in PV panels. However, with improved energy efficiency that results from a ZNE goal, the land requirements are lower,” comments David B Goldstein, the energy co-director of the Climate & Clean Energy Programme at the Natural Resources Defence Council.

“While ZNE standards prefer on-site renewable generation, most standards worldwide allow some methods of counting off-site generation, especially if it is dedicated to the facility in question. It follows that ZNE is a plausible goal for most, or at least many, sites.”

Examples of ZNE buildings

There are hundreds of ZNE buildings around the globe, with more being planned and developed every single day. Some of the most notable include:

• The Samsung Zero-Energy House: Located in East Asia, this building boasts zero emissions and 68 impressive green design features.

The Samsung Zero-Energy House in East Asia.

• District Office and Applied Technology Training Centre at San Bernardino Community College: This ZNE building is based in California in the United States of America and is set to meet a target site EUI of 23 kBtu/ft2-yr by way of a solar carport canopy, a number of light pipes and upgrades of HVAC systems and lighting.
• Beddington Zero-Energy Development: This building in London, United Kingdom, makes use of 100% renewable energy sources. It is also home to a combined heat and power plant, which is fuelled by wood, in order to generate heat and electricity.

Beddington Zero Energy Development

Will ZNE buildings become commonplace in Africa too? Only time will tell.

Full thanks and acknowledgement are given to www.arup.com and www.nrdc.org for some of the information in this article.


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