Carbon Management & Greenhouse Gas Mitigation
Planning for Mitigation
Reducing the output of greenhouse gas emissions is one of the most critical responses to climate change, which is why it plays a central role in implementing the Carbon and Climate Commitments. The direct reductions of on-campus emissions is often a tangible and highly successful demonstration of sustainability policy; something to bring together many disparate members of the campus community around a common action.
A key lesson we have learned in the ten years since the American College & University Presidents’ Climate Commitment (ACUPCC) was first created, is that setting a bold aspiration to carbon neutrality often drives deeper cuts in emissions beyond what would be achieved with the simple desires to use resources wisely and save costs. At the beginning of the process a campus might not know how it is going to achieve carbon neutrality, it may not even seen possible or realistic at the time, but as the momentum and learning behind the commitment grow over time, new policies, know-how, technologies, funding, and collaborations are ultimately brought to bear on the problem. Higher education is one of society’s driving forces of innovation and new ideas. It is in this spirit of discovery and learning that you can start to address the challenge of carbon neutrality.
For purposes of the Carbon and Climate Commitments, carbon neutrality is defined as having no net greenhouse gas (GHG) emissions, to be achieved by minimizing GHG emissions as much as possible, and using carbon offsets or other measures to mitigate the remaining emissions. To achieve carbon neutrality under the terms of the Carbon and Climate Commitments, all Scope 1 and 2 emissions, as well as those Scope 3 emissions from air travel paid for by or through the institution and regular commuting to and from campus, must be neutralized.
This is an exciting time to undertake a path to a low-carbon future. Each year new technologies and applications appear or are perfected to the point of becoming economical for wide-scale implementation. The majority of the technologies required to achieve carbon neutrality on a national scale are already in the marketplace and many of these are cost-saving. The task for you is to find the combination of these practices, policies, and equipment that are applicable at the campus scale to produce the greatest reductions in the shortest time scale with the least cost.
Carbon Management Hierarchy
To help focus planning and determine a starting point for carbon mitigation efforts, it is often useful to follow a carbon management hierarchy. Many different examples and variations have been written about in academic literature, and this short summary can be a starting point for developing a model specific to an institution. You may be familiar with the waste reduction hierarchy generally described as: “Reduce, Reuse, Recycle”. A carbon management hierarchy is very similar, and generally outlines broad categories of mitigation strategies that are more favorable than others. This is often started as: “Reduce what you can, Offset what you can’t” and similar phrases. Typically this is applied as:
- Avoiding or reducing emissions through Efficiency & Conservation
- Eliminating emissions through switching to Renewable (zero carbon) sources of energy
- Sequestering or Offsetting any remaining emissions.
Efficiency and Conservation are often low-cost or cost-saving endeavors and so can be placed as your first-choice solutions. Efficiency generally involves technological improvements to equipment and infrastructure. The advantage of efficiency work is that it typically has a very high return on investment and does not require major changes in the behavior of your community (many people may be unaware of the energy efficiency upgrades that occur around them). The drawback is that it typically requires a certain expenditure of up-front capital to be able to capture the cost savings over the lifetime of the project. A Green Revolving Fund (GRF), described in Financing, is a great method for overcoming this challenge.
A great advantage of conservation work is that the projects typically do not include significant capital investments. However, these efforts do require significant behavior change by members of your community, so it is important not to think of them as “no cost”. There will be investment of your staff time in education and outreach (and any related communications expenses) that must be consistently maintained for at least several years (particularly as new students arrive and existing students graduate) before significant shifts in behavior begin to occur.
Shifting to low-carbon sources of of energy typically requires significant advance planning particularly when involving changes to on-campus infrastructure. These types of changes could be timed to coincide with retirements of existing campus energy infrastructure. Additional strategies would include using the accumulated revenues from lower-cost efficiency efforts to finance larger projects as part of a Green Revolving Fund (GRF) or using the sale of Renewable Energy Credits (RECs) from the project for a predetermined time span (before they would be retired to meet any carbon targets) to help offset project costs. Development of renewable energy sources does not need to be confined to the campus. Many options exist for off-site development through Power Purchase Agreements (PPAs) or purchase of RECs – Financing.
Decisions related to interacting with the carbon markets to offset any remaining emissions are detailed later in this chapter including the requirements for purchasing legitimate offsets.
Target Dates & Interim Targets
According to the Intergovernmental Panel on Climate Change (IPCC), in order to limit the global mean temperature increase over historical norms to 2-2.4 degrees Celsius (the temperature at which there is a high probability of catastrophic impacts), global emissions need to be reduced 50-85% below 2000 levels by 2050, with CO2 emissions peaking before 2015. As you consider your own targets, you are encouraged to keep this broader context in mind, by initiating emission reductions as soon as possible in order to slow down the adverse effects of greenhouse gases (including carbon dioxide and chlorofluorocarbons) that can remain in the atmosphere for several centuries.
To aid the target-setting process, your planning team will want to develop a comprehensive list of potential measures for avoiding or reducing GHG emissions from each of the sources included in the GHG inventory. The planning team can then evaluate each emissions mitigation strategy according institution-specific criteria that the structure itself has established. Example criteria that you may wish to consider when evaluating mitigation options include:
- Potential to avoid or reduce GHG emissions
- Flexibility as a step towards future emissions-reduction measures
- Return on investment or financial impact
- Potential to create positive and/or negative social and environmental side-effects
- Relationship to other potential measures and opportunities for synergistic measures
- Potential to be scaled upward if successful
- Potential to involve students and faculty
Once the measures have been evaluated, they can be prioritized based on the same criteria, and early actions can be identified. In many cases, early actions can reduce costs or generate savings. To facilitate the financing of steps toward climate neutrality, you may wish to consider establishing mechanisms to reinvest these savings in the secondary and tertiary measures that may have higher upfront costs.
Careful analysis of the emissions-reduction measures will enable you to envision possible courses of action and establish targets that are in line with the Commitment to achieve climate neutrality as soon as possible, but that is also realistic, flexible and affordable.
Project evaluation and ranking is one of the most important parts of a mitigation plan. This section discusses techniques and methods for undertaking these tasks.
Typically, GHG emissions reduction projects are compared – and can be listed in a chart in your plan – on this basis:
- Initial project cost
- Dollar savings (if any)
- Payback, return on investment (ROI), net present value (NPV), or internal rate of return (IRR)
- Carbon reduction
- $/MTCO2e (emissions reduction efficiency)
There are, however, many other considerations which weigh in project selection decision-making. These include:
- Project life cycle costs/benefits including consideration of maintenance costs/savings; impacts on safety, health, comfort, or productivity; capital improvement, etc.
- Availability of funding from various sources including campus budgets, borrowing, incentives from government and utilities, and grants from foundations
- Relationship to other possible energy saving or GHG emissions mitigation measures and opportunities for synergy
- Interaction with state or regional GHG mitigation initiatives (e.g. the Regional Greenhouse Gas Initiative which affects fossil fuel power generators of 25 MW or greater in 10 Northeast and Mid-Atlantic states)
- Potential to scale upward
- Transferability to other projects, schools, or the wider community
- Project lifespan
- Academic and research impacts
- Public relations value
- Organizational capacity to undertake and manage the project
- Alignment with campus capital development plan, strategic, and other plans
- Stakeholder support and enthusiasm
Some of the above decision-making criteria don’t lend themselves to quantified data. But comparative information could be captured in a comprehensive matrix that could rank projects on the relevant criteria. Conceivably, most or all of the above decision-making factors could be considered in a comprehensive lifecycle analysis of prospective carbon mitigation projects and measures.
Evaluating projects based on the GHG reduction efficiency is a particularly powerful way of prioritizing your actions. This can be calculated by dividing the lifetime cost of the project (which will be a negative number in the case of projects that are cost savings) by the amount of the GHG the project will reduce to calculate $/MTCO2e. The value of reduction efficiency will give the cost (negative or positive) for reducing one metric ton of carbon by that project.This will help you immediately identify the least-cost solutions for emissions reductions. Projects with a low (or negative) cost per ton should generally be undertaken sooner than more expensive projects (particularly if the cost saving will be used to reinvest in most costly projects).
It could be a reasonable strategy to only undertake projects that have a cost per ton below a certain threshold. For example, if the cost of purchasing a carbon offset was $25/ton, it may be decided to only pursue on-campus projects that cost less than that (over their lifetime) to implement. In this case, once all the cost savings projects and the projects that had positive costs lower than the threshold were implemented, the remaining emissions would be reduced though offset purchases.
Modifying the Plan
The Carbon and Climate Commitments require that signatories revise and resubmit the climate action plan not less frequently than every five years. Signatories are expected to review and modify (if necessary) their mitigation actions and targets over time as circumstances change and new regulations, technologies, and priorities emerge.
Energy Conservation & Efficiency
Burning fossil fuels – and the subsequent release of carbon dioxide – is the primary cause of global warming and climate change. Burning fossil fuels, including burning them to generate purchased electricity, is also the primary source of GHG emissions at colleges and universities. It follows, then, that the first and foremost campus GHG emissions mitigation strategy is energy conservation and energy efficiency improvements to reduce the use of fossil fuels to a minimum.
Energy production and consumption have social and environmental impacts. Energy conservation avoids these impacts. End-use energy conservation has great power because units of energy saved at the point of use can save many times that amount of energy when the inefficiencies of energy production and distribution are taken into account.
Here are key components of an effective campus energy conservation program that will reduce energy use and GHG emissions from campus operations:
- Strong Program Leadership
- An energy officer to develop energy conservation measures and projects and catalyze the entire effort
- Full support from facilities leadership, the chief business officer, and the president
- Enhanced Energy Awareness
- Aggressive Energy Conservation Policies which address:
- Heating and cooling season temperature settings
- Building HVAC and fan operating schedules
- Computer operations and “green computing”
- Ban on all incandescent bulbs and halogen torchiere lamps (the latter is also a safety issue)
- Energy purchasing (including buying green power)
- Energy efficiency purchasing standards for various types of equipment – hopefully going beyond Energy Star compliance
- Improved space utilization to avoid new construction or heating/cooling of underused space
- Energy efficiency standards for new construction
- Restrictions on the use of portable space heaters
- Energy practices in on-campus residence halls and student apartments
- Residential appliance policies (e.g. load limits per room, ban or restrict refrigerators, TVs, microwaves, etc.)
- Campus curtailment or shutdown periods when campus use is minimal
- Engaged Facilities Operations
- An active facilities energy conservation committee which meets regularly and is encouraged and empowered by facilities and campus leadership to push the envelope and aggressively pursue all conservation opportunities
- Comprehensive implementation of no cost/low cost operational measures – e.g. temperature set-points, equipment run-times and building occupancy hours, etc. – that push the envelope, i.e., risk complaints
- Adequate facilities staffing levels – especially HVAC controls technicians, heating and power plant operators, mechanics, and electricians so that the campus physical plant can be operated efficiently and energy conservation measures and projects can be implemented in-house
- Periodic re-commissioning of all existing buildings to optimize energy efficiency
- Facilities staff performance appraisals that evaluate staff on commitment to energy conservation
- Rewarding of highly motivated staff who identify conservation opportunities and implement conservation measures
- Energy Smart Capital Improvement Program
- Tough energy efficiency standards for all renovations and capital improvement projects
- Prioritization of projects that conserve energy and improve efficiency
- Deliberate Targeting of Energy Intensive Systems
- Specific, aggressive, comprehensive targeting of the most energy intensive and energy wasteful buildings and energy systems, e.g.:
- Electric heating
- Large outside air ventilation systems (e.g. in lab buildings)
- Fan systems which operate at full capacity when actual occupancy is usually a lot less
- Super-cooling supply air in air handling units to 55 degrees and then reheating (during the cooling season)
- Heating and power plants
- Specific, aggressive, comprehensive targeting of the most energy intensive and energy wasteful buildings and energy systems, e.g.:
- Green Computing
- Require that all computers on campus have their power management features engaged and be shut off when offices are closed
- Match the number of operating computers to actual customer load in computer labs (e.g. most of the computers should be turned off during slow periods)
- Full cooperation of campus IT departments in the design and operation of networked and campus-wide computer systems
- Highest standards of efficient design for server farms
- Incentives for Energy Conservation
- Innovative strategies to assign energy costs to campus energy users or cost centers so that there are real dollar incentives for energy conservation for campus building occupants
- Elimination of “split incentives” that discourage full cooperation with the energy conservation program
- In multi-school college and university systems, a policy which allows all or part of the energy conservation dollar savings to remain with the school that achieved them
- Super Energy Efficient Planning and Green Design for New Construction
- Schedule semesters when outdoor climate is least challenging and weather-related building energy loads are likely to be less
- Reduce conditioned space and avoid new construction by consolidating operations and improving campus space utilization
- When new construction is necessary, only build the most energy efficient buildings to reduce legacy energy costs and minimize the need for future energy conservation retrofitting
- Documentation of Savings
- Keep a log to document conservation projects and savings
- Publicize savings to gain support and raise awareness
Campus energy conservation programs may find reinforcement through participation in LEED-EB (Leadership in Energy and Environmental Design for Existing Buildings: Operation and Maintenance). LEED-EB is a green building rating system emphasizes energy efficiency and renewable energy strategies. Thus, if your school seeks LEED-EB certification for existing campus buildings, the rating system will focus attention on making those buildings more energy efficient.
Energy Conservation Measures
Standard techniques for conserving energy and improving energy efficiency in commercial or institutional buildings are well known to the vast majority of campus facilities managers. These strategies are discussed and explained in many places including in publications available through:
And on websites such as these maintained by the U.S. Department of Energy:
- Building Technologies Program – Commercial Buildings website
- Energy STAR Buildings
Here is a list of some of some energy conservation measures that can be used in campus buildings:
- Building Envelope Improvement
- Weather/infiltration sealing
- Increased insulation
- High performance window replacement
- Low emissivity reflective window film (to reduce unwanted solar gain in the summer and increase the R-value of windows in the winter)
- “Delamping,” i.e., permanently turning off/disconnecting unneeded light fixtures
- “Relamping,” i.e., replacing inefficient light fixtures or lamps with high efficiency fixtures/lamps
- Convert T-12 fixtures/lamps to T-8 or T-5
- Relamp 32 watt T-8 lamps with 28 watt T-8
- Eliminate incandescent bulbs
- Convert all exit lighting to LEDs or photoluminescent signs that require no electricity
- Beware of retrofitting with indirect lighting – while aesthetically pleasing it may require more fixtures and more wattage to achieve comparable lighting levels
- Increase reliance on task lighting in order to decrease general illumination without adversely affecting productivity
- When converting to T-8 or T-5 lighting from T-12s, design for lower lighting levels (as measured in foot-candles) since the newer lamps produce higher quality lighting and appears brighter to the human eye than foot-candle measurements would suggest
- Improve lighting controls
- Occupancy sensors
- Timers (stand alone or energy management system/EMS-interfaced)
- Daylight harvesting sensors and controls including simple photocells
- Convert outdoor lighting to high pressure sodium or LED
- Eliminate/reduce outdoor decorative lighting
- Consider LEDs for general indoor and outdoor illumination
- Consider outdoor solar powered-LED light fixtures
- Require white or off-white wall paints for maximum light reflectivity – so adequate lighting levels can be achieved with minimum lighting wattage
- When renovating spaces, design new lighting to achieve a connected lighting load of less than 1.0 watts per square foot
- Replace old boilers with new high efficiency boilers
- Do not oversize replacement boilers
- Retrofit boilers with variable flame burners
- Consider multiple high efficiency modular boilers to improve efficiency by better matching hot water heating loads
- Consider replacing boilers with cogeneration units (which produce both electricity and heat)
- Control boiler output water temperature with outside air temp reset so boiler does not heat water hotter than necessary
- Retrofit boilers with flue gas/stack heat recovery
- Replace old chillers with new high efficiency chillers whose efficiency curve best matches your load profile
- Do not over-size replacement chillers
- Be aware that a lighting retrofit will reduce cooling load and therefore chiller capacity requirements
- Operate at peak efficiency (by adjusting water flow, load, condenser/evaporator water temps, etc.)
- Replace old cooling towers with new high efficiency towers
- Air Conditioning
- Replace older AC equipment with maximum efficiency models
- Discontinue use of inefficient window units
- Reduce AC operating hours
- In less humid climates, stop or significantly reduce super-cooling air (e.g. to 55 degrees) and then reheating in order to control humidity during the cooling season
- Where dehumidification is required in buildings with variable air volume systems, try super-cooling the supply air to wring out moisture while reducing air volume to reduce reheat energy requirements
- Clean cooling coils on a regular basis
- Maximize use of “free cooling” with economizer cycle and enthalpy sensors
- Use open windows and passive cooling when mechanical air conditioning is not needed
- Close all windows when air conditioning is in operation
- In dry climates consider evaporative cooling
- In humid areas consider desiccant cooling
- Temperature Control
- Reduce temperature settings in winter
- Increase temperature settings in summer
- Maximize night, weekend, and holiday temperature setbacks
- Install tamper proof or remote thermostats
- Control space temp remotely by Energy Management Systems
- If occupant controlled thermostats are required, then limit range of adjustment to ensure compliance with campus temperature policy
- Motors, Fans, and Pumps
- Adjust operating schedule to minimize run hours (review and update periodically)
- Replace old motors, pumps, and air handling units with high efficiency
- Control motors serving fans and pumps with variable speed drives (VSDs)
- Operate VSDs at maximum acceptable turn-down; vary by time of day and occupancy; also vary by season
- Convert constant volume fan systems to variable air volume (VAV)
- Completely close outside air dampers during morning warm-up cycle
- Reduce outside air ventilation rates consistent with actual occupancy through the use of variable speed drives, modulated outside air damper settings, CO2 sensors, and demand control ventilation
- Reduce needless pumping by eliminating three-way bypass valves
- Laboratory Ventilation and Fume Hoods
- Switch to a “green chemistry” teaching program that doesn’t require fume hoods or as much outside air ventilation
- Turn off 100% outside air ventilating systems whenever possible, e.g. in teaching labs whenever classes are not in session; shutdown or slowdown related supply fans
- Decommission/remove unneeded fume hoods and reduce fan system outside air volume
- Eliminate unneeded fume hoods by using ventilated storage cabinets instead of fume hoods for chemical storage
- Retrofit constant volume fume hood ventilation systems to variable air volume
- Retrofit conventional fume hoods with low-flow hoods and reduce outside air volumes
- Retrofit these systems with heat recovery
- Heat Recovery
- Run around loops
- Heat wheels
- Heat pipes
- Desiccant wheels
- Air-to-air heat exchangers
- Swimming Pools/Natatoriums
- Install pool covers (these significantly reduce the evaporation of pool water – reducing pool heating and boiler loads as well as outside air ventilation and space heating requirements; pool covers save chemical water treatment too)
- Use high efficiency boilers for pool water heating
- Limit natatorium ventilation to that required to meet code
- If code outside air ventilation requirements seem excessive in a particular application, consider applying for a code variance to reduce ventilation rates consistent with energy efficiency, safety, and proper humidity control
- Install heat recovery
- Energy Management Systems (EMS)
- Switch to direct digital control (DDC) systems
- Purchase EMS systems which are easy to program (so programming capabilities will be fully utilized by facilities staff)
- Fully train staff operating DDC and EMS systems so they can operate this equipment for maximum efficiency
- Utilize and optimize use of EMS energy conservation programs, e.g.,
- Optimal start/stop
- Night setback
- Demand shedding
- Remote programmed lighting control
- Fuel Switching
- Consider converting electric space and water heating systems to natural gas
- Information feedback systems
- Accessible display units that show energy use and savings can have dramatic results in energy use behaviors
Evaluating opportunities for natural gas-fired cogeneration and fuel switching from electric heating to natural gas requires a different mind-set when your ultimate goal is a reduction in your carbon footprint (as opposed to simply reduced energy costs). While cogen and fuel switching are typically regarded as methods for improving overall efficiency, on your campus these measures could decrease or increase your carbon footprint depending on the carbon intensity of your purchased electricity – so it bears analysis.
Aiming for “Deep Conservation”
In order to achieve significant GHG emissions reductions colleges and universities must think differently about energy conservation on their campuses. What is needed is not just an efficient campus but a super-efficient one. That means not just doing conservation but doing what might be called “deep conservation.” Even campuses that have already done extensive energy retrofitting and have exemplary energy conservation programs need to do more. If you’ve already reduced energy consumption in campus buildings by 25%, then try for another 10, 20 or 25%. Resting on one’s laurels should not be an option, especially if deep cuts in greenhouse emissions are envisioned.
To identify advanced strategies, techniques, and products for achieving deep conservation, your campus facilities unit may want to team up with interested faculty and students as well as an expert consultant or two and focus on one or more campus buildings in order to determine what is possible. Is a 40 or 50% cut in energy use possible and still have a livable, functional academic building? While constructing very low energy new buildings may be possible, the biggest, most important challenge for most institutions is figuring out how to significantly reduce energy use in existing buildings. A serious campus climate commitment is your excuse to give it a try.
Of course, at some point our efforts will bang up against the limits of what can be done in existing buildings and there will be no more practical retrofitting options to explore or exploit. In most cases, however, opportunities abound.
Cogeneration or “combined heat and power,” is an option for coal, oil, natural gas or biomass heating or power plants. Cogeneration is the simultaneous generation of electricity and heat, thus increasing the efficiency of fuel use. A variety of technologies can be used to generate both electricity and heat including turbines and internal combustion engines with heat recovery.
Cogeneration tends to be most cost-effective when the price of purchased electricity (which is avoided through self-generation) is relatively high while the price of the fuel used by the cogenerator is relatively low.
The most cost-effective cogen applications are those where there is a constant year round demand for all the electricity and heat the cogeneration unit can produce. Thus it is important to match the electrical and thermal output of the cogenerator to campus loads on an hourly basis. To provide an adequate thermal load during the summer months, some facilities use absorption chillers which use heat to make chilled water for air conditioning.
In some regions, local electrical utilities may discriminate against cogeneration because they view any kind of self-generation of electrical power as direct competition for the electrical power they may generate or distribute and sell. The utility can discourage its customers from installing and using cogeneration by imposing a tariff or rate structure that assigns high costs to the “stand-by power” cogen facilities will need whenever their cogeneration units fail or are shut down for maintenance. These punitive tariffs can be reversed by lobbying state public utility commissions or state legislatures. The tariffs can also be avoided entirely by disconnecting from the electrical grid (sometimes called “islanding”) though that tends to be a very expensive proposition because redundant equipment is needed to guarantee operation when some units are down.
While a properly sized cogeneration unit typically is very energy efficient, implementing cogen at any given college or university could decrease or increase the school’s carbon footprint – depending on (a) the carbon intensity of the fuel used to cogenerate and (b) the carbon intensity of the purchased electricity cogenerated electricity replaces.
Alternatives to Fossil Fuels
What fuel options besides fossil fuels exist for campus heating or power plants? More climate-friendly choices include biomass, landfill gas, and geothermal.
Biomass fuel consists of organic material such as wood chips, oat hulls, corn husks, etc. Finding a long-term reliable supplier with enough biomass fuel to operate a campus heating or power plants can be a challenge. Ensuring that the biomass is produced sustainably is also a challenge. Other issues associated with biomass are biomass’ relatively low heat density (requiring greater volumes of fuel), the need for specialized handling equipment, and its air emissions and ash waste products. However, addressing the latter should be no more difficult than using coal.
Biomass is not only renewable but also theoretically carbon neutral because the carbon that’s released into the atmosphere when biomass is burned can be captured and sequestered into new biomass fuel crops as that biomass grows. Sustainable biomass presumes that annual biomass production equals consumption and is accomplished without environmental damage, e.g. cutting down forests. Since some fossil fuel inputs are generally involved in growing, harvesting, chipping, and transporting biomass fuel, it can be argued that biomass is not actually carbon neutral despite often being regarded as such. Calculating the life-cycle net carbon emissions of biomass-based heating or electricity production would be a great project for students and faculty.
Sustainable biomass can include waste products like wood waste from furniture plants, urban tree trimmings, or clean wood extracted from a municipal solid waste stream, and agricultural crop waste. While the waste-to-energy industry sometimes claims that general municipal solid waste is an acceptable biomass fuel, it is not regarded as such by environmentalists because of the dirty air emissions and toxic solid waste by-products its combustion produces and because burning municipal solid waste generally undermines municipal recycling programs.
Before proceeding with plans to convert to biomass campus heating or power generation it is essential that a fuel availability study be conducted. While a consultant can be hired to perform this study, it could be a great project for students with support from faculty and facilities management staff. Students could study the net availability of suitable biomass resources within a given distance from campus. This research would examine existing resources as well as the potential biomass resource if a market for biomass were created by demand from your proposed plant. Students could identify sustainable forestry or crop practices that your school could require for biomass purchases including consideration of the Forest Stewardship Council’s best practices. If you proceed with a biomass plant, once it is up and running students can study the supply chain to determine and evaluate what is actually happening on the ground.
While converting your heating or power plant from fossil fules to biomass may be a long-range strategy due to the costs involved, in the meantime – depending on boiler type – it might be possible to co-fire biomass and thus reduce GHG greenhouse gas emissions. Co-firing generally involves displacing some fossil fuel combustion by burning biomass and fossil fules together.
Landfill gas is methane produced by the decomposition of garbage in landfills. Since methane is a powerful GHG gas which on a mass basis and 100 year time horizon has over 20 times the global warming potential of carbon dioxide, it is important that it not be vented to the atmosphere. Collection systems can be installed in landfills to harvest methane. It is then scrubbed and often burned on-site to generate electricity or both heat and electricity. Landfill methane can also be delivered elsewhere via pipeline. While burning landfill gas produces carbon dioxide, it also prevents methane emissions – and thus produces a net reduction of GHG emissions. While not readily available to all college campuses, landfill gas can be a suitable fuel for campus power plants or any kind of natural gas-fired boiler or cogenerator.
Renewable Energy Technologies
Conservation and efficiency can take us far but not all the way. Even after we have reduced our energy load to a bare minimum, we will still have to meet that remaining load with some form of energy. In order to achieve climate neutrality or deep cuts in GHG emissions, campuses will need to transition as much as possible to carbon-free renewable energy technologies – solar, wind, biomass, geothermal, and hydro (though the latter is pretty much tapped out in most regions). We can either build renewable energy capacity on campus or buy green power. This section discusses on-campus renewable energy sources for non-heating or power plant applications.
Solar Photovoltaic Electric Arrays
Many campuses are installing photovoltaic (PV) solar electric arrays. While rarely as cost-effective as energy conservation, PV becomes more cost-effective when conventional electric rates are high and ample incentives are offered by state government or local utilities.
Obviously, the amount of available sunlight is another important factor though PV can work well in all regions. Where there is less sun, more solar panels are needed to meet a given load. This adds cost and stretches out payback but it works. Where snow may cover panels during winter months, panels can be tilted to shed snow or PV array output can be pro-rated downward to allow for a number of weeks or months when output is reduced. The performance of grid-interconnected PV is generally measured in terms of annual power production and most PV production occurs during the sunnier summer months when days are longer and there is less cloud cover. In areas where winter days are cold and clear, angling panels to take advantage of those conditions becomes more important. While winter output will be less, PV panels actually have a higher sunlight-to-electricity conversion efficiency when cold.
There are a variety of financial models for installing PV on campus. Your school can design, purchase and install its own system – typically with the technical assistance of a consultant or supplier. The relatively high cost and long payback of this kind of investment can be tempered by incentive dollars that reduce the initial or “first cost” of the system. Another financing strategy is to include the cost of the solar energy system in a larger self-financing energy conservation program and, in essence, allow the energy conservation measures (and the dollar savings they produce) to pay for the solar.
A solar energy system can be installed on campus through a power purchase agreement (PPA) with a renewable energy power provider who will install and own a PV system located on campus. A PPA will oblige a school to purchase power from the PV system for a number of years at rates established by the contract. The primary advantage of this arrangement is that the school is not responsible for the installation, operation, maintenance, or cost of the PV system. Also, this arrangement may allow the energy supplier to take advantage of tax credits which may not be available to the campus.
Maximum output from PV arrays occurs mid-day on hot summer days – precisely the time when regional grids in many areas are under strain because of high air conditioning loads. At these times, hourly rates for electricity may be much higher than average rates. This coincidence suggests that an analysis of PV cost-effectiveness should be sophisticated enough to factor in the additional dollar savings associated with avoiding that very expensive conventional electricity. PV arrays can also reduce peak demand and peak demand charges. PV project simple paybacks tend to be long though factoring in these additional savings will shorten it somewhat.
In order to claim a CO2 reduction from a campus-owned and operated PV system or from a PV PPA, you must own the renewable energy certificates or RECs associated with the output of your system. In the case of a PV system your campus owns, that means “retiring” and not selling them. In the case of a PV system installed under a power purchase agreement, to claim a CO2 emissions reduction your school must buy the RECs produced by the PV system. The REC purchase may be in addition to buying the actual power produced by the array.
Other Solar Options
Other on-site, on-campus solar options include:
- Passive solar
- Solar hot water
Not only can all three of these technologies be considered for new construction, all three can be either made to work or installed in existing buildings. For example, you may already have buildings with rooms or corridors with ample south-facing glass that allows solar gain during the winter months. This gain may be a nuisance now, causing localized over-heating. Building occupants may be fighting that sunlight with pulled down shades. Your maintenance staff may have solved the problem by installing reflective window film to block the sunlight from entering the building. An alternate approach would be to let the sunlight pass through the windows and put that heat to work by installing thermal mass to store it for use later in the day or by modifying the HVAC system so the heat is captured, transported, and used in another part of the building. Engineering or architecture students may want to study passive or active solar heating options for that kind of campus building as a class or volunteer project.
Similarly with daylighting, you may already have daylit spaces but are not taking advantage of their energy saving opportunity because of inadequate controls on electric lighting. Installing photocells or sensors may be all it takes to keep electric lighting off when daylight from the sun is adequate to illuminate those spaces. Facilities staff or students can survey the campus to look for opportunities of this kind.
Solar hot water systems can be more cost-effective than PV solar electric systems yet are generally less common. Why is that? Maybe it is because piping is harder to install than wiring and there ends up being more maintenance with solar hot water systems. Maybe it’s because fewer incentives are available. Also, unlike PV (whose output can always be used by the building it’s mounted on or by the local power distribution grid its connected to), solar hot water systems must closely match daily hot water production with daily hot water demand. And hot water needs may not coincide with those times when solar hot water systems readily produce hot water. On most campuses, hot water demand predominantly occurs in the fall, winter and early spring when the fall and spring semesters are in session. However, in many parts of the country solar gain is not ideal during much of that period: the sun is low in the sky, days are short, and there may be lots of cloud cover or snow. Also, while most campus buildings have hefty appetites for electricity, not all campus buildings have adequate hot water loads to justify a solar hot water system. Buildings with above average hot water needs include athletic facilities, student residences, and food service facilities.
While solar hot water presents some challenges, it is a viable option for campuses interested in demonstrating solar energy. If the “first cost” of such a system is daunting, consider a power purchase agreement with a solar provider that would build, own, and operate “your” solar hot water system while selling you its hot water output. Students and faculty can even study the possibility of using solar hot water technology for seasonal solar storage – collecting and storing solar heat collected in the sunny summer for use in the cold cloudy winter.
Some colleges and universities have installed wind turbines on or near campus to meet a portion of their electricity needs. The huge size of the most efficient turbines, i.e. utility scale turbines whose blades reach as high as 400 feet, make them “out of scale” to the rest of a campus. These giant turbines are often better suited to be installed on the periphery of a large campus or on outlying campus property. Some campuses may own distant property and that too can be considered for wind turbine installation – though in that case getting the power to campus may involve additional delivery costs. It is generally financially advantageous to install wind energy capacity on the campus side of the electric meter.
There are a variety of wind turbine financing options to consider – from campus ownership to buying the output of an on-site turbine through a power purchase agreement – with advantages and disadvantages to each. If your campus is pursuing wind energy, it is important to design your project to take advantage of federal and state incentives, tax credits, and tariff mechanisms which are now in place and are being developed to promote wind energy as well as other renewable energy technologies.
As with PV, the campus must own the RECs produced by the turbines in order to take credit for GHG emissions-free power – though, ironically, it’s the introduction of electricity from the turbine (not the RECs) which actually changes the mix of generation away from polluting fossil fuels.
Geothermal energy takes many different forms. For example, in some locations it’s possible to tap hot water or steam through deep wells and use that heat energy to directly heat buildings or generate electricity. While some colleges and universities can tap this renewable resource, most cannot. But all schools can consider geothermal or ground source heat pump heating and cooling systems. Typically these are applied to single buildings but they also can serve entire campuses and eliminate the need for central power plants.
Ground source heat pump (GSHP) systems rely on the more or less constant temperature of the earth below the frost line and the ability of the earth to store and release heat. Of course, these systems also rely on heat pumps which are mechanical devices that use refrigerant gases, compressors, expansion valves, and evaporator and condenser coils to move heat from one place to another. Heat pumps make refrigerators, freezers, air conditioners, and dehumidifiers work.
GSHP systems transfer heat in and out of the ground (depending on the season) by either an open loop pipe system that extracts and re-injects ground water or a closed loop pipe system that is sealed and contains a mixture of water and glycol to prevent its freezing. Heat is transferred into or out of the underground loop system by heat exchangers which are also connected to one or more water pipe loops within the building. Heat pumps tap into these interior loops, extracting or rejecting heat into them – depending on whether the heat pumps are in a heating or cooling mode. The interior space of the building gets heated or cooled by warm or cold air that is produced by the heat pump and introduced into each room via ductwork.
GSHP systems require electricity to run conventional pumps, heat pumps (which contain electrically driven compressors), and fans. If this power is conventional, grid-supplied electricity, then GSHP should be regarded as an energy efficiency technology. On the other hand, if the electricity comes from wind turbines or another renewable energy source, then the GSHP system is an example of renewable energy technology, producing carbon-free heating and cooling. This latter approach makes new zero-energy/zero-carbon buildings possible.
For signatory institutions, climate neutrality is defined to include reducing, eliminating, or offsetting the GHG emissions associated with the operation of fleet vehicles; student, faculty and staff commuting; and business air travel. Even schools which have not made a total commitment to addressing these emissions will be interested in minimizing them along with the other environmental, social, and public health impacts associated with these campus-related activities. Of the three, commuting generally involves the largest carbon footprint. Significantly reducing these emissions poses a huge challenge.
Fleet Vehicles and Campus Buses
Facilities managers and staff can address GHG emissions associated with fleet vehicles in a variety of ways which include:
- Buying only the most fuel efficient vehicles
- Choosing the most fuel efficient vehicle appropriate to the task
- Using vehicles which run on alternative fuels like electricity, biodiesel or compressed natural gas whenever possible
- Implementing policies to reduce vehicle miles driven
- Implementing a no-idling policy
The latter is an issue on campuses where facilities staff leave their vehicles running much of the day during very colder winter months to keep them warm and comfortable even though they are only driving them a few minutes a day. You can see whether this is happening by direct observation or by analyzing data on vehicle mileage and gas fill-ups (if your facilities unit keeps this information). If winter mpg drops to single digits, it may be due to excessive idling.
Campuses may be in the habit of buying fuel inefficient vehicles for a variety of reasons. For example, it may be assumed, mistakenly, that all facilities staff need to drive around in trucks or four wheel drive vehicles. Or for state schools, it might turn out that these fuel-inefficient vehicles are on state contract at discounted prices, thus encouraging their purchase even when they are unneeded and environmentally destructive. Inappropriate incentives like these need to be reversed. In general, barriers to buying highly fuel efficient vehicles (and then driving them as little as possible) need to be addressed and overcome.
Electric vehicles, even those powered by a regional electric grid that is not especially clean, tend to be less carbon-intensive than standard gasoline-powered vehicles. Small GEM type electrics are better suited to warmer climates or to summer-only use in campuses with cold winters. Facilities staff could also ride bicycles to meetings on other parts of the campus if the dress code is relaxed. Wearing informal clothing also makes it possible to air condition less – another benefit to your “low carbon bottom-line.”
Using biodiesel for fleet vehicles raises some issues. Remember that B20 biodiesel fuel is only 20% biodiesel and 80% conventional diesel fuel, and even the biodiesel portion is probably not fully carbon-free because fossil fuels have been consumed in its manufacture or shipping. Switching to biodiesel blends which are richer in biodiesel is desirable though can be problematic in colder climates due to the increased viscosity of biodiesel as the temperature drops. One solution might be to use B100 (100% biodiesel) during the summer months and switch back to B20 during colder weather.
Biodiesel is a good fit for campus buses as well as larger facilities vehicles. While most college and university facilities units will not be interested in manufacturing their own biodiesel (since it’s an extra task and they are probably already short-staffed), some have been approached by students interested in seeing campus food service waste fryer grease converted to biodiesel to run campus buses or fleet vehicles. Creating a small campus biodiesel production facility would have significant educational value. It could be designed, operated, and monitored by students – perhaps majoring in chemical engineering – under faculty and facilities supervision.
Conversion of fleet vehicles to compressed natural gas generally requires the installation of a CNG refueling station on or very near campus. This can be an expensive undertaking – though might be subsidized by state energy offices that are promoting alternatively fueled vehicles or by local natural gas utilities interested in selling more natural gas. Duel-fuel CNG vehicles can be purchased or existing gasoline-powered vehicles can be kit-converted to CNG. Campus buses also can be CNG powered. If campus bussing is provided on contract by an outside vendor, then new contract language can be developed specifying that an alternative fuel must be used. That new language can be used the next time campus bussing service goes out to bid. Operating a car, truck or bus on CNG will reduce GHG emissions by about 25% compared to gasoline operation. There can be substantial fuel cost savings associated with the use of CNG vehicles (in comparison to gasoline vehicles) but this benefit vanishes when gasoline prices are low and natural gas prices are high.
The larger transportation problem is commuting. At most colleges and universities, commuters dominate and typically arrive and depart from campus in single occupancy vehicles – many with poor fuel economy. Commuting by students, faculty and staff may add up to many millions of miles of driving per year at larger schools – and thus represent a substantial part of the campus carbon footprint.
Here are some strategies for reducing commuting and its GHG impact:
- Create an effective transportation options program
- Raise awareness of transportation alternatives
- Include messaging with billing statements for campus parking permits
- Provide alternatives to single car/truck commuting
- Encourage the use of high efficiency vehicles when car/truck commuting is unavoidable
- Provide incentives for using alternatives to single-occupancy vehicles (SOVs)
- Increase use of public transit by students, faculty and staff
- Better publicize existing public transit options
- Work with your regional transit authority to add public transit routes
- Encourage your regional transit authority to equip its busses with bike racks
- Increase the frequency of public transit service
- Extend late night public transit service, especially on Friday and Saturday nights
- Provide free public transit passes or subsidize public transit fare
- Utilize gps technologies to alert riders of next arrival time
- Stop building new parking lots
- Increase carpooling
- Establish a rideshare program to safely match interested drivers and carpool riders
- Provide incentives for carpooling, e.g. priority parking, reduced parking fees, etc.
- Provide emergency ride home service for carpoolers who miss their ride
- Increase bicycling
- Make campus bicycle-friendly
- Establish bicycle-friendly campus policies that actively encourage and reward bicycling and don’t penalize it
- Create an extensive and effective network of campus bike paths
- Address campus bicycling safety issues
- Install or increase the number of secure bike racks on campus
- Provide weather-protected bike racks and bicycle lockers
- Establish an on-campus bicycle repair shop and free air pump
- Equip campus buses with bike racks, and instruct riders how to use them
- Create or join local bicycle sharing programs
- Make bicycle commuting more practical
- Work with local communities to improve and expand the network of local bike paths and bicycling safety
- Create safe bicycling commuter routes to campus through the surrounding community, especially from areas with a high density of off-campus student housing
- Provide on-campus shower facilities for bicycle commuters
- Relax formal or informal dress codes to accommodate bicycle commuters
- Make campus bicycle-friendly
- Reduce on-campus driving
- Make campus more bicycle and pedestrian friendly
- Improve scheduling and routes of campus buses
- Locate new buildings to encourage walking and bicycling
- Minimize or don’t provide additional parking for new buildings
- Consider banning cars for on-campus resident students
- Provide resident students with a special parking permit that only allows them to park near residence halls
- Make campus more bicycle and pedestrian friendly
- Reduce the need to single occupancy vehicle (SOV) commute
- Increase remote work
- Increase distance learning
- Build more on-campus housing (which ironically will reduce your campus’ commuter carbon footprint while increasing your campus housing carbon footprint)
- Work to improve neighborhood safety and privately owned off-campus housing near campus in order to make it more likely that students living off campus will chose to live near campus
- Provide shuttle service to nearby off-campus student housing developments and neighborhoods
- Create employee vanpools
- Allow compressed work weeks, i.e. 4 ten-hour days/wk instead of 5 eight-hour days/wk to eliminate one commute per week
- Decouple transportation fees that package parking and public transportation fees all together so faculty, staff and students who do not bring a car to campus can pay less
- Pay employees not to drive
- Explore alternative course scheduling to reduce the number of days per week most students need to come to campus
- Begin charging for or increase the cost of on-campus parking – in most cases on-campus parking is heavily subsidized; remove subsidies and allow parking cost to follow market rates
- Contract with car-sharing programs/companies to make it easier for people to avoid car ownership
Waste disposal and waste management practices impact your school’s carbon footprint. If garbage and trash are burned, there are additional releases of carbon dioxide – though some of those emissions can be mitigated or offset if the waste is burned in a waste-to-energy plant because such a plant displaces fossil fuel combustion.
If the end point for your campus garbage and trash is a landfill, methane will be produced through decomposition. On a mass basis, methane has around 20 times the global warming potential of carbon dioxide – so landfills can have a substantial climate change impact. This impact is reduced if the methane is captured and either “flared” (burned in the open atmosphere – releasing water vapor and carbon dioxide) or burned in a boiler or power generating unit to produce useful heat or electricity that displaces the fossil fuels that would otherwise be used to produce that heat or power.
Campuses can cut waste through waste reduction programs (buy and use less, reuse, etc.) and by improved recycling and composting programs. Recycling keeps waste out of both the incinerator and landfill. It also contributes to the manufacture of new products made of recycled materials which are more energy efficient to make and, thus, are responsible for less GHG emissions. Composting prevents organic waste (kitchen produce leftovers plus landscaping trimmings) from being needlessly transported to the landfill – plus, of course, it turns these waste products into a useful product that helps keep the campus green!
Participating in the annual Recyclemania competition is a great way to improve and boost recycling on your campus.
 WRI, Putting a Price on Carbon: A Handbook for US Policymakers http://www.wri.org/publication/putting-price-carbon
 IPCC, Fifth Assessment Report. https://www.ipcc.ch/pdf/assessment-report/ar5/syr/SYR_AR5_FINAL_full_wcover.pdf
 Although the issue of permanence raises challenges around ensuring that biological sequestration projects can produce high-quality offsets, such projects will be necessary in achieving the goal of returning atmospheric concentrations of CO2 to the 350 ppm level. As such, they can be imported parts of viable reduction strategies and valuable components of climate action plans.
- 1 Planning for Mitigation
- 2 Target Dates & Interim Targets
- 3 Mitigation Strategies
- 3.1 Energy Conservation & Efficiency
- 3.2 Energy Conservation Measures
- 3.3 Aiming for “Deep Conservation”
- 3.4 Cogeneration
- 3.5 Alternatives to Fossil Fuels
- 3.6 Biomass
- 3.7 Landfill Gas
- 3.8 Renewable Energy Technologies
- 3.9 Solar Photovoltaic Electric Arrays
- 3.10 Other Solar Options
- 3.11 Wind Energy
- 3.12 Geothermal
- 3.13 Transportation Solutions
- 3.14 Commuting
- 3.15 Waste Minimization
- 4 Carbon Markets and Offsets Guidance