Higher education campuses across the U.S. have begun exploring their carbon footprints, with many already making specific commitments to some level of carbon reduction or carbon neutrality in line with the 2030 Challenge. The result most often includes frameworks for decarbonizing MEP systems through retrofits, such as reducing natural gas in domestic hot water systems and providing guidance for retrofitting existing campus buildings.
And, while it is true the easiest strategies campuses can pursue include upgrading aging, combustion-heavy mechanical, electrical, and plumbing (MEP) systems, or incorporating electric or renewable systems in their new construction projects, it all must be done with an understanding of how the local energy grid operates. Here, we’ll discuss these strategies as well as how to use an understanding of energy grids to inform your campus’s decarbonization approach.
Energy Efficiency Retrofits
Reducing the energy use in existing buildings is central to creating a sustainable university campus. Energy efficiency retrofits often help higher education facilities decrease operating costs while reducing their carbon footprints.
For example, at California State University (CSU), Long Beach, Glumac found more than 567 energy efficiency projects that could result in annual energy savings of up to 20,280,000 kWh and 658,000 therms. This would reduce energy costs by $2.6 million annually, based on 2017 utility rates.
FIGURE 1: A step-by-step guide to campus carbon reduction. Image courtesy of Glumac
ASHRAE provides recommendations for varying levels of energy audits that can help identify facilities that would result in the highest energy savings. An ASHRAE Level 1 audit consists of a high-level overview with the intention of identifying glaring issues by conducting interviews with key personnel, reviewing utility bills, and walking the facility. A Level 2 audit includes additional analysis, such as summarizing the buildings’ energy by end use, analyzing utility rates, and estimating returns on investments (ROIs).
The framework for conducting an energy audit process consists of the following steps:
- Compiling utility data from each building on campus. Some campuses may need to invest in infrastructure, such as energy meters, to obtain this data.
- Identify buildings suited for ASHRAE Level 1 or similar energy audits. During this phase, it's recommended to choose buildings with high energy usage (which results in greater energy savings), a variety of occupancy types and operations (residential, dining, offices, maintenance, or classroom facilities), and a variety of buildings sizes.
- After the ASHRAE Level 1 audits have been completed and the results analyzed, identify the facilities that have the potential for the highest savings to undergo energy retrofits. Conduct ASHRAE Level 2 or similar audits for these facilities. It's recommended to also select facilities that have scalability (facilities with multiple, similar, or identical counterparts) or are more likely to undergo retrofits within five years.
- Evaluate any campus or building energy management systems or building automation systems for real-time and trended data, calculating energy use intensities (EUIs) for each building, and identifying any irregularities in the trend data.
- Summarize EUIs, ROIs, and recommendations for each facility and any similar counterparts. The summary should include recommendations for which facilities have the most potential for energy savings and the highest ROI.
Without touching any other system on the campus, these energy efficiency retrofits will reduce the operational carbon associated with operating the facility. With a reduction in total energy across the campus, decarbonization strategies in centralized systems can be less costly and more efficient.
Electrification of Central Systems
Centralized systems are known across the building design industry to be more efficient than localized systems. However, existing facilities with localized systems may benefit from infrastructure upgrades to create district systems.
Most higher education campuses have expanded and renovated facilities over time as funding becomes available or needs change. As a result, older buildings may have stand-alone or aging systems. Where tying these buildings into a central utility system may not be feasible, electrifying local combustion sources is key to decarbonizing an entire campus.
FIGURE 2: An analysis of options to electrify California State University, Long Beach’s, central utility plant. Image courtesy of Glumac
Glumac’s assessment at CSU Long Beach found that the central utility plant (CUP) accounted for 42% of the total campus natural gas usage, while the remaining 58% of use was scattered throughout the rest of the campus. By electrifying the campus, the study showed the entire EUI of the campus could be reduced by about 12% to 60.5 kBtu/square foot.
Many strategies can be assessed in campus systems to reduce or eliminate combustion sources, such as:
- Replacing existing chillers with heat recovery chillers (HRCs);
- Utilizing water-to-water heat pumps (WWHP) for hot water production and supplement chilled water production;
- Electric boilers in lieu of condensing boilers or replacing noncondensing boilers with condensing;
- Adding variable frequency drives (VFDs) to cooling tower fans, pumps, and other constant volume equipment;
- Retiring ice harvesters/thermal energy storage (TES); and
- Optimizing controls and sequencing strategies.
Glumac’s study at CSU Long Beach showed that fully electrifying the central utility plant was the strategy that resulted in the highest energy savings. With HRCs and electric boilers, energy modeling showed a savings of around 1 million kWh and more than 350,000 therms annually.
However, results may vary in campuses in other climates with different utility rate structures, occupancy mixes, or existing equipment. For example, some higher education campuses have a larger provision for on-campus living than others, making hot water demand for cooking, hygiene, and cleaning more prevalent.
In a study Glumac conducted at the University of California, San Diego’s, Hillcrest campus, the firm found that a fully electric CUP would have a negative return, mostly due to the cost of electricity, from their utility. For similar campuses, where negative returns do not provide financial incentive to fully electrify, a commitment to the financial investment would have to outweigh the need for lower operating costs to reach carbon neutrality goals.
Renewable Energy Systems
Investments in on-site renewable energy systems are critical to decarbonization strategies. Where local utility rates may be prohibitive for fully electric building systems, renewable energy systems with high returns on investment can make central plant electrification more cost-effective.
Additionally, the cleanliness of energy produced by local utility providers may vary dramatically. While some providers have a moderately clean energy generation, such as solar and wind power, other utilities rely on coal-fired plants to generate electricity. And some campuses may generate their own power from carbonized processes.
Evaluating different utility grids on the West Coast, Glumac found that utility providers, such as Seattle City Light in Washington or Pacific Gas and Electric in Northern California, utilize little to no combustion sources in their electricity generation. However, Pacific Power in Oregon or San Diego Gas and Electric in Southern California still rely heavily on natural gas for the time being.
Even where campuses can fully electrify, if the source of electricity is generated by a carbon-producing process, then the campus has not truly achieved decarbonization. By integrating renewable energy systems into their infrastructure, these “dirty” electricity sources can be reduced or eliminated.
Evaluating a utility provider’s source for electricity production and its long-term plan for eliminating combustion sources is imperative when developing a framework for a campus. In jurisdictions where utility providers show commitment to eliminating combustion sources, campuses may look for renewable energy systems with shorter term returns on investment. Conversely, where the local utility provider has not developed plans for sustainable electricity production, the campus may consider investing in larger scale, renewable energy production, either on- or off-site.
FIGURE 3: A look at the “cleanliness” of various utility providers on the West Coast. Image courtesy of Glumac
Framework Commitment and Implementation
When developing a framework for decarbonization and electrification, a campus often needs to make deep organizational changes to fully implement recommendations and achieve real results. These frameworks should include the four “P's."
Project: Identify the project (decarbonization and electrification of campus or facilities);
Purpose: State the purpose (reduce the threat of climate change and eliminate risks associated with combustion sources and fossil fuels);
Particulars: Define the steps necessary to achieve the purpose (recommending efficiency improvements through energy audits and developing high-performing building standards); and
- People: Hold stakeholders across the campus, such as facilities personnel, project managers, sponsors, and external partners, responsible and accountable.
The framework should be developed in conjunction with all user groups across the campus. Soliciting feedback often results in a higher level of commitment and interest in the bigger picture, achieving the desired results.
Operational policies often consist of low- or no-cost energy efficiency measures and should play a sizable role in any carbon neutrality plan. While these policy measures are very cost-effective, in practice, they can be difficult to successfully implement without the buy-in and commitment from numerous campus groups.
Some of the organizational policy changes that could be considered include:
- Commit to implementing efficiency improvements through regular maintenance of existing buildings and following through with infrastructure upgrades or investments, especially where returns on investment may help fund future high-capital projects.
- Reduce the number of hours buildings are unnecessarily operational or underutilized. Many campus buildings tend to operate during large ranges of time, such as 6 a.m. to 10 p.m. every day of the week, regardless of occupancy, which results in wasted energy to condition unoccupied spaces. Consolidating facilities and scheduling shutdowns during unoccupied periods can result in sweeping energy savings.
- Maintain high-performance building standards for new construction and major renovation projects. Provide design teams with aggressive EUI targets and prioritize maximizing additional incremental on-site renewable energy, when possible. Committing to these standards requires buy in from stakeholders, such as campus project managers, maintenance teams, and occupants as well as faculty and students.
- Implement a clean energy vehicle policy. Electric vehicle infrastructure will increase the demand for electricity, which requires a holistic source energy plan to implement without increasing the use of “dirty” electricity sources. Standards should be established to determine the vehicle type that will replace each of the existing vehicles in the fleet. These standards should determine a target efficiency standard for each vehicle type.
Specific system replacements or retrofits alone are not enough to achieve campus-wide carbon neutrality goals. The operational “business as usual” needs to change on a fundamental level, and that begins with understanding your utility grid, creating an upgrade strategy that’s based off that knowledge, and enacting organizational policy changes that enforce best practices.