Decarbonization: Being Part of the Solution
In our last issue of Connections, we talked about energy-efficiency, NetZero, and the Living Building Challenge.
These initiatives all address the evolution of building design and our impact on the global built environment; be it upon the health and welfare of building occupants or the overall resource demands of the building itself. Further along this path, a key concept that has arisen in our collective consciousness is that of “decarbonization.” With buildings responsible for 40-45% of the global carbon emissions annually, engineering designers have a greater responsibility to understand and educate our clients on a project’s opportunity.
Strictly speaking, Decarbonization is the reduction in carbon emissions related to the propagation of human culture and civilization. In our industry, says Syska’s Senior High Performance Specialist Xun Jia, PhD, PE, LEED AP, WELL AP, “decarbonization focuses on the reduction of carbon and other greenhouse gases (GHG) in the built environment.” It is important to note that carbon or carbon equivalency is generally used as a straw man for the overall impacts towards Global Climate Change.
A project’s carbon footprint, the target for our decarbonization, is comprised of two key components: embodied carbon and operational carbon. Embodied Carbon is associated with the extraction, manufacture and transport of building materials, as well as demolition/deconstruction, construction, and waste management activities. Operational Carbon is associated with the continuous resource streams that service a building: this includes energy, water, food, waste, & material supplies.
As Architecture 2030 has published, embodied carbon is only ~28% of the current marketplace, while operational carbon is responsible for the remaining 72%. This equation looks radically different, however, when we look at a single new building as it moves through its life cycle. After 10 years (2030), ~56% of the building related carbon is embodied, after 20 years (2040), it is 38% and after 30 years (2050), it is ~29%. However, these numbers do not account for the decarbonization of the electrical grid – as the grid incorporates more renewable energy, the embodied energy component increases to 60%, 48% and 45%, respectively. We must design to a culture, an environment, and most importantly an electrical grid reflective of 2030, not 2000 or even 2015.
Looking at the embodied carbon, the building structure is the primary driver within most buildings – concrete and steel are both very carbon intensive materials. Building enclosures come in a distant second making up roughly 15% of the embodied energy, much of this due to the use of aluminum in windows systems. Beyond consulting with design teams on the structure and enclosures, Syska has an opportunity to employ low carbon alternatives towards high-carbon steel components that are typically used for piping and ductwork. Additionally, we can specify equipment that uses the next generation of refrigerants (HFOs) that can reduce Global Warming Potential (GWP) by up to 1300 times (many HFOs have same GWP as CO2).
Syska’s primary focus has long been addressing and reducing operational carbon through reductions in building energy and water use. However, since 2018 we not only saw the notion of Decarbonization advance to the forefront across many projects within Syska, but we saw it advance outside of the built environment into politics and the mainstream. In response, we have retooled our project approach. We have essentially added the 4th dimension of time – recognizing that carbon intensity of various energy sources is changing rapidly over the life of our buildings.
Nevertheless, approaching a project’s performance still begins with assessing and minimizing loads, while capitalizing on the local climate capital. We still want to properly orient a building and optimize the façade to maximize winter heat (passive solar) and minimize summer heat. We still want to maximize the natural light and daylighting opportunities. We still want to open up the building as much as possible through simple operable windows and engineered natural ventilation techniques. We still want the most efficient lighting system possible. All these strategies not only reduce operating carbon but enhance the health and well-being of the occupants and when coupled with a focus on decarbonization, enhance the health and well-being of our local communities and even have a positive impact on our global community.
Electrification is by far the biggest shift to our design approach. Simply put, electrification is the complete elimination of fossil fuel-based equipment and applies at all scales and across all building systems, including kitchens; each system is then replaced by efficient electric alternatives. The fundamental value of switching energy sources is realized as the national & regional electric grid decarbonizes, the building likewise decarbonizes. The clearest example of how this shift has affected design is in the evaluation of cogeneration. Cogeneration has long been deemed a powerful technology towards low energy hospitals, allowing us to utilize the waste heat from the electricity generation process and outperform the local power plant. The baseline assumption here, though, is that we are comparing the use of natural gas at the hospital vs natural gas/coal at the power plant. With cogeneration, we are cementing a 50-year relationship with natural gas and excluding ourselves from the quickly decarbonizing, greening electrical grid that will likely be carbon-free halfway through the life of our building.
The primary equipment change is in the aggressive application of DX technologies for primary heating. This is typically in the form of highly-efficient heat pumps and heat-pump water heaters at the small scale and, at the larger scale, chiller heat pumps and heat recovery chillers with the ability to generate simultaneous heating and cooling. Interestingly, because DX heating technologies require a source of low grade heat in order to generate useful heat, the biggest challenge becomes locating and harvesting the low grade heat…at least in colder climates.
We have applied this concept on multiple projects to date. For the LA Federal Courthouse, Syska designed a heat recovery chiller to electrify the first stage of heating, utilizing the waste heat to both minimize the combustion of natural gas and minimize heat rejection. Similarly, the design for Providence Tarzana Hospital includes a heat recovery chiller to electrify the first stage of heating, primarily using the chiller condenser water as the source of heat. Finally, the design for Fairleigh Dickenson Student Center employed an air-cooled version of the heat recovery chiller to provide either chilled water, hot water, or simultaneous chilled and hot water.
Beyond heating, we have even begun to see consideration in the food service industry, where a number of renowned Chefs are moving from gas burners to electric induction cooking to not only reduce their carbon footprint, but improve the health and comfort of the workplace. Some of our airport projects currently in design have committed to replacing all diesel Ground Support Equipment vehicles with all-electric ground support vehicles, requiring an extensive electric vehicle charging network around each gate. Even emergency power has garnered discussions of electrification to eliminate diesel generators.
It’s not just industry insiders who recognize the benefits of eliminating natural gas. At the state level, the State of California leads the country with a mandate of 100% of their electricity grid be powered by renewable and zero carbon resources by 2045. They are closely followed by states across the country with similar renewable energy mandates, including New Jersey, New York, Connecticut, New Mexico, Massachusetts, Maryland, and Nevada, amongst others. In 2019, the city of Berkeley, CA became the first U.S. city to mandate no natural gas usage in new buildings. Other cities and counties across the country have enacted or plan to enact similar legislation. New York City, meanwhile, has implemented Local Law 97 that creates a hard cap on operational carbon emissions to help achieve plans to reduce total carbon emissions by 30% by 2030.
Closely coupled to electrification is the need for renewable energy generation. With the cost competitive nature of solar energy, many Syska projects have deployed photovoltaic panels over the past few years. The LA Federal Courthouse roof quietly generates 500,000 kWh of electricity per year, while Palomar Community College installed a beautiful shade canopy that produces more energy than the building consumes! The ConRAC facility at Los Angeles International Airport includes a designed 4.7 MW PV array that will tie directly back to the utility to manage the grid, while 95 State Street in Salt Lake City, UT has added a PV canopy array to the existing top deck of parking to produce 330,000 kWh per year. Furthermore, our work on JFK Terminal One closely integrates with the Port Authority’s announced plans for a 13 MW system that includes 7.5 MW of battery storage.
The next evolution we are seeing take hold, beyond the mere ubiquity of PV on nearly every project, is the focus on battery storage. Battery storage brings an entirely new capacity and dimension to the electrical relationship with the grid, both to the benefit of the facility and the community. Given the variable nature of most renewable energy, the grid, writ large, requires storage to maintain service. It is yet to be seen whether the utility companies will accept this responsibility or would rather pass on this responsibility to facilities through demand response initiatives and distributed storage.
Recently, the building materials industry has begun to both develop lower carbon alternatives, as well as differentiate between low and high carbon materials. For steel, this generally includes alternative methods of smelting using hydrogen and electricity (there is even one solar concentrating smelter). Concrete is generally looking to chemistry to impregnate carbon into the concrete itself, sequestering the carbon and reducing the need for cement at the same time.
Operationally, we need to continue to look for means and methods to reduce energy use, while focusing on eliminating greenhouse gas emissions. As Syska’s Associate Partner and Regional High Performance Leader Kris Baker, PE, LEED AP likes to opine: “We all know that carbon is the key to life, but within our built environment that same carbon is threatening that same life. Our ongoing objective is to develop new, creative methods of decarbonization so we can protect and preserve our existence.”