This three-part series on Building a Decarbonization Roadmap guides you through the process of achieving sustainability, illuminating the path toward a greener future with insightful guidance. This approach aligns well with locations such as military campuses, airports, and higher education institutions.
In Part I, we discussed the definitions of Scope 1, 2, and 3 emissions, setting the boundaries for decarbonization, data gathering, and goal setting as part of the master planning process. In Part II, we will discuss benchmarking and the steps you can take to reduce emissions under the categories of Scope 1, Scope 2, and Scope 3 emissions—and how to negate the effects of each to meet your decarbonization plan.
Emission Scopes 1 and 2: Know Where You Came from to See Where You’re Going
When you embark on a road trip, whether you drive an electric vehicle, hybrid, or gas car, you have to know the type of fuel you need and how much is required to reach your destination. When it comes to decarbonization planning, you should account for the types of emission scope reductions you want to accomplish.
Once the boundary of decarbonization has been set, then data gathering begins. Ideally, you already have meters in place to gather metered data on Scope 1 and 2 emissions. Scope 3 emissions may take a little more time to determine how the data will be gathered consistently from year to year. But it is not enough to just report the data. After reviewing your existing data trends, you want to compare your data to other similar facilities.
The benchmarking process is helpful because it identifies how your buildings compare against similar facilities. You can focus on achieving the average of the same type of building or facility if you are way over the benchmark or focus on exceeding the average of buildings of the same type. Or perhaps you want to be a leader and become the first to set the goal of achieving carbon neutrality by a certain date before others in your industry. The benchmarking process is used to set overall goals and develop scenarios for your future carbon reductions that are realistic and achievable.
Steering Your Focus & Strategies
The decarbonization of Scope 1 and 2 emissions typically focuses on the major sources of emissions, namely:
- Efficiency: the lowest hanging fruit typically that is most cost-effective. Achieved through energy audits and retro-commissioning.
- Renewables: determining where renewables can be applied – on building rooftops, ground mounted, as carports, and if there are any restrictions on their location, such as environmental, or in the case of airports, glare requirements by the Federal Aviation Administration.
- Electrification: fossil fuel reduction on-site accounts for 8% of total U.S. GHG emissions. Switching to electric sources not only saves emissions (if the utility has clean power or has adopted a clean energy policy), but also reduces indoor and outdoor localized air pollution.
Other strategies that should be analyzed in more detail for large-scale campuses include:
Capturing Ambient Energy
There are so many sources of waste energy on campus that people don’t think about. Waste heat (or “ambient energy”) is all around us, and we should capture it when we can—from waste heat from chillers to waste heat from sewer pipes to ponds or other water sources on site. All this waste can be converted to useful energy that will significantly reduce emissions. At Mead & Hunt, we’ve worked on projects that have captured waste heat from sewer lines, district chilled water, steam and hot water return lines, non-potable irrigation lines, and water conduit lines, all to help improve efficiencies and reduce emissions from buildings.
Additional waste heat recovery projects our Engineering Procure Construct (EPC) team has worked on include:
- Food processing facilities treat waste to anaerobic digesters which are then used in internal combustion engines to generate electricity that is sold back to the local utility.
- Biogas utilization and anaerobic treatment for cheese producers, dairy processors, wastewater treatment plants and breweries. In the brewery industry, waste heat from high solids waste streams through anaerobic digestion systems is used to generate renewable electricity and steam.
Refrigeration
We may not often consider the overall impact of refrigeration leakage in our cooling and other systems, but refrigeration can be a major source of emissions over time. For example, a project we worked on at Appleton International Airport showed that over a 60-year horizon, refrigerant usage would add up quickly—from 6% of total emissions in year one to 25% of total emissions in year 60. Fortunately, new codes and standards are pushing the industry in the US towards cleaner refrigerant types.
Resiliency
Although not a direct emissions reduction measure, as we electrify more of our systems, we need to think carefully about redundancy of systems, particularly electrical systems—what critical loads we have on campus and determining which need to be backed up and for how long. If we only have a single source of power, the system is vulnerable. Batteries, dual sources of electricity feeds (we see these at larger airports, for example), and microgrids need to be part of the solution to reduce power vulnerabilities at critical locations.
If your decarbonization boundary includes Scope 3 emissions, some of those pathways could include embodied carbon of building materials, tenant fuel, business travel, employee and visitor travel, and many more. Consider your main sources of Scope 3 and see how you can influence those. For instance, at airports, 80–90% of total emissions come from aviation fuel, so airports that want to take on Scope 3 should focus their efforts on setting up a pathway for airlines to use sustainable aviation fuel.
Knowing where your emissions come from allows you to steer your strategy based on your carbon reduction goals and plan a more direct route to arrive at your ideal decarbonization destination.
Coming up Next on the Roadmap…
In Part III of the Decarbonization Roadmap series, we’ll explore financial strategies, scheduling, and forecasting for successful decarbonization planning.
