Decarbonization Goals and Challenges

Based on the IPCC Special Report on Global Warming, over 100 countries have proposed or are considering a net zero target. This decision to create carbon goals and reduce carbon emissions is significantly influenced by catastrophic natural disasters such as flooding in India, wildfires in California, and widespread water shortages, to name a few.

Within one month, there were fourteen occurrences across the world correlated to the temperature increase and elevated amount of greenhouse gases (GHGs) in the environment. This behavior has led corporate, and state and federal government entities to set climate goals to reduce carbon emissions across the world. This includes “net-zero by 20XX.” What does that mean?

In addition to improving the environment, net zero goals can help corporations and government save money. The government incentivizes companies to reduce carbon emissions through tax credits or utility incentives. Since buildings consume about 40% of the energy produced by the U.S., reducing emissions within our infrastructure is key to meeting emission-reduction goals. For businesses reducing their carbon emissions, there are also some non-energy benefits such as increased production, efficiency, and reliability amongst equipment and employees, as well as improving indoor environmental quality (IEQ).

According to Michael Lenox, author of The Decarbonization Imperative: Transforming the Global Economy by 2050, there are three types of net-zero building designs: net zero energy, net zero carbon, and zero carbon. “Net zero energy buildings maximize energy efficiency then produce as much energy on a site as they use annually. Net-zero carbon buildings institute energy efficiency measures and then produce enough carbon-free renewable energy on site or purchased elsewhere to meet annual energy consumption.

Zero-carbon buildings take it a step further, eliminating all fossil fuel equipment and powering the remaining building operations using only clean energy or low-carbon fuels”.¹ This can be done through selecting an electricity supply provider if the building is in a deregulated energy state, where generation and distribution/transmission can be provided by different companies. With “net-zero” goals, the business and building owners strive to optimize an existing building and create a more sustainable ecosystem.

Understanding Carbon Emissions

Some corporate strategic net zero goals have targeted emission goals. For example, in 2018 JLL defined itself as a leader in the real estate industry by creating a goal to reduce their Scopes 1 and 2 emissions by 68% and to reduce Scope 3 emissions by 53%, all by 2034. Another example is Boland’s partner Trane Technologies announcing they will reduce GHG emissions across the globe by 90% for Scope 1 and 2, and a 97% reduction in Scope 3.

But what are these scopes?

Carbon emissions are classified under three scopes. Scope 1 measures direct emissions from owned or controlled sources such as company facilities and vehicles. Scope 2 covers indirect emissions from the generation of purchased electricity, steam, heating, and cooling such as leaving the lights on or over-cooling a building. Finally, Scope 3 consists of indirect emissions that occur in a company’s value chain; this includes company leases, commutes, business travel, and transporting capital goods.

Scientists and market leaders are focusing on carbon emissions (carbon dioxide), as this makes up 74.1% of GHG emissions. The following gases also contribute to GHG emissions: Methane (CH4), Nitrous Oxide (N2 O), and Fluorinated gases (including HFCs and PFCs²). Projects that achieve net-zero goals also have a significant impact on the industry and transportation sector, as well, since manufacturing and transporting the building materials for these structures can have a large impact on global carbon emissions.

“Energy consumption is by far the biggest source of human-caused greenhouse gas emissions, responsible for a whopping 75.6% or 37.6 gigatonnes of equivalent carbon dioxide (GtCO2 e) worldwide. The energy sector includes transportation, electricity and heat, buildings, manufacturing and construction, fugitive emissions and other fuel combustion”.²

Therefore, a big step in reducing carbon emissions is electrification. This has come up in the news frequently because many new construction and deep energy retrofit projects will require buildings to transition to electric HVAC as electric grids become less emissions intensive. NEBB’s practices and certifications have a significant impact on both the commercial and residential sector.

NEBB’s Impact

There are a few NEBB practices that have a direct impact on energy and decarbonization. For example, building enclosure testing, building system commissioning, and retro-commissioning.

Building enclosure testing is the first step to attaining a holistic view of the building. Investigating and enhancing the building envelope will confirm there are no leaks in the fenestration that could cause air leakage and condensation. Therefore, a need to no longer over-condition the space would improve comfort, health, and the environment.

For a typical office building, HVAC is approximately 40-50% of the electric bill. Ensuring a building is operating as expected based on design and specification requirements through building system commissioning can reduce energy consumption and carbon emissions by confirming the HVAC equipment is operating optimally. In addition to checking the mechanical system, looking at the lighting and electrical systems improves visual equity, thermal comfort, employee safety and potentially retention.

With retro-commissioning, the building systems are analyzed to identify opportunities to implement energy conservation measures (ECMs) for an existing building. These opportunities can also include non-energy projects that reduce carbon emissions. An example of this would be to replace old equipment with high GWP refrigerants to equipment with lower GWP; for example, R-11 has a significantly higher global warming potential (GWP) than R-514a. A recent project that Boland completed yielded a carbon emissions reduction of 369 metric ton/year by installing more efficient chillers with a low GWP.

Across the world, there are many companies and service providers assisting with carbon emission reductions. This includes innovative solutions in all sectors. Specifically, in the energy and building sector there are items such as electric stovetops, solar panels for hot water heating or powering a building, Variable Refrigerant Flow (VRF) HVAC systems, and electric vehicles. Trane Technologies, and similar companies, might offer remote services; this can reduce the Scope 1 emissions since service technicians are able to view systems and resolve problems remotely rather than traveling to and from the site.

Act:

Building owners, operators, engineers, and property managers can collaborate with local energy service providers to determine how to finance emissions and efficiency projects. In the Washington DC and surrounding areas, there are utility incentive programs that provide rebates for building owners to perform energy efficient upgrades and implement monitoring-based commissioning programs, and building tune-up programs.

These programs pay owners money to maintain efficiency and perform regular maintenance tasks such as cleaning coils in an AHU. Partnering with a building automation system technician or having a service contract for the Building Automation System (BAS) will help save money and reduce carbon emissions generally at a quick payback.

To have an overall impact on the building, there are options to choose the right HVAC equipment which could include a mechanical plant redesign. This includes energy efficient, low GWP refrigerants, electrified heating, specifically, heat pumps.

Modifying a control or BAS for specific programming such as demand management, time of day schedules, and setpoint resets will reduce energy usage as well. Additional control optimizations such as schedule changes, temperature and setpoint resets, and chiller plant sequencing are identified in ASHRAE Guideline 36 (High Performance Sequences of Operation for HVAC Systems).

The last part to factor into a building is its purpose – understanding how the building is occupied and operated. Each person has an impact on the buildings they touch, live in, or work in that can shape the planet’s future. People are investing in net-zero; this investment is visible through ESG-focused companies in the stock market, grants provided by the government to assist with building envelope evaluations, and incentives provided by local utility companies. All of these efforts will help building owners and engineers tackle “low hanging fruit” to reduce carbon emissions.