The three major steps to decarbonize buildings are minimizing loads, electrification, and transitioning to renewable energy sources.

Reduce loads

Improving energy efficiency is perhaps the most straightforward and cost-effective way to decarbonize buildings. Reheat is the largest end use in most hospitals and often relies on on-site combustion of fossil fuels. There are a number of strategies for reducing reheat in both new and existing buildings - some of which may be low- or no-cost controls measures. Other reduction measures include lighting upgrades, use of energy-efficient heating and cooling equipment, and the use of advanced control strategies. These measures can significantly reduce the amount of energy needed to power a building, directly reducing carbon emissions.

In much of the US, dehumidification is a primary function of cooling systems, especially in critical environments such as operating rooms, pharmacy clean rooms, and other spaces that require low temperatures for occupant comfort - but the traditional method of dehumidification is overcooling to wring out excess moisture, then reheating to maintain comfort. There are better ways to handle dehumidification and the guidebook is here to help.

ElectrifY What remains

Burning fossil fuels is simply not compatible with decarbonization. In most hospitals, building heat (including reheat), domestic hot water heating, sterilization, and humidification rely on natural gas combustion - using either steam boilers or hot water boilers, or a combination of the two. All of these loads can run on electricity, but some are easier than others to convert. We also have to be careful about the load we impose on the hospital electrical system and the local and regional electrical grid. See Introduction: Central Plant for more on electrifying these loads.

In addition to heating and domestic hot water, hospitals have traditionally relied on steam for sterilization and humidification. These needs haven't gone away, but there are some alternatives to gas-fired boilers. See the guidebook sections Alternative steam generation and What if we didn't use steam?

One of the challenges in legacy hospitals is converting from steam distribution to hydronic heating and domestic hot water. The conversion can be disruptive and capital-intensive. See Converting from Steam to Hydronic Heating. But, the choice is really when to convert, not if. Boilers that operate on fossil gas must be phased out - and for the planet's sake, sooner is better than later.

Some of the solutions for electrification of legacy buildings involve large capital projects. First - check out the sections on financing options. But, if you need to keep your boilers in service a little while longer, there are some measures that can help. See If you must have a gas-fired boiler.

use Renewable Energy

Transitioning to renewable energy sources is another key strategy for decarbonizing buildings. Options for on-site renewable energy generation include solar PV panels, solar thermal collectors, and wind turbines. These systems can be capital-intensive - see the section on financing options - and the site may present other challenges, such as limited land or roof area for solar systems. Wind generation at a scale needed for a large urban hospital is difficult in an urban environment.

Consider off-site renewable energy sources, such as purchasing grid-connected renewable energy through your power company or participating in a community solar program. If your building has access to landfill gas or other renewable fuels, they may be an alternative that achieves carbon reduction without capital investment in a new central plant system.

Looking forward a bit, there is a possibility of clean hydrogen - but beware of greenwashing scams - most hydrogen produced as of this writing relies on fossil fuels for production and transport. Hydrogen exists today as a potential solution - but there are technical and economic hurdles that are unlikely to be overcome in the near term. The authors suggest taking action today to move away from combustion - waiting for the hydrogen economy could mean decades more carbon emissions.

For new facilities, we must not use combustion equipment. Period. We can't achieve the carbon goals set by every major health and engineering association in the world if we keep adding to the problem. This guidebook is full of ideas about how to decarbonize by minimizing loads, electrifying the loads that remain, and using renewable energy. The authors hope that these ideas are helpful, that they spark new ideas and lead to better designs. But these ideas are not a design - owners, architects, engineers, must work together to develop a design appropriate to the facility, location, and program.

To be sure, avoiding combustion is simpler on some sites and in some climates than others, but as we demonstrate in the section on Central Plants, our hospitals use a great deal of energy and most of that energy can be recovered as heat. That's a big jump on the overall heating load. The challenge is managing what remains. To a large degree, building without combustion from the start does not cost much, if any, more than our old steam-based hospital designs. What is required is the will to try new things and to learn from the work of others.

The reality is that the vast majority of the hospitals that will exist in this country by 2050 have already been built. According to the 2018 CBECS survey, that's about 2.2 billion square feet of inpatient healthcare and another 1.7 billion square feet of outpatient. That also means that the majority of the carbon emissions from healthcare facilities will come from existing buildings - especially if we eliminate combustion from new buildings. Energy and carbon retrofits of these buildings will be essential to reducing the overall carbon emissions of the healthcare sector.

This guidebook has ideas for how to tackle existing buildings. The truth is that decarbonization is harder in existing buildings, especially those that use centralized steam plants. Retrofitting these legacy buildings will require substantial investment. The first step is load reduction - smaller loads mean smaller plants to support them and smaller energy spends going forward. But load reduction will only get you so far - eventually you must stop burning fossil fuels. Eventually, you have to replace that network of steam piping - probably with hydronic piping. Eventually, you have to replace combustion boilers with heat pumps, thermal storage, renewable sources, and electric power.

A good time to eliminate combustion equipment is when it nears end of life - you have a capital investment coming up anyway, so it makes sense to invest capital in a longer-term strategy. But, these transitions don't happen overnight - they require planning and probably need to integrate with major renovations. Use this guidebook as a source for ideas and start building your plan for decarbonization.

Energy resiliency is a critical aspect of ensuring a reliable and secure energy system. It refers to the ability of a organization to withstand and recover from disruptions to its energy infrastructure. Energy resiliency is increasingly important in the face of climate change and the growing challenges healthcare facilities are facing as a result of extreme weather events and natural disasters. By incorporating renewable energy sources like solar and wind power, organizations can reduce their dependence on fossil fuels and enhance their ability to sustain energy supply during emergencies, which is critical since any disruption in the energy infrastructure can have severe consequences, compromising patient safety and healthcare delivery. Additionally, the integration of advanced technologies such as energy storage systems and microgrids can help optimize energy distribution and provide localized power during grid outages, which are increasing in frequency throughout California.

During emergencies, natural disasters, or power outages, healthcare facilities with robust energy resiliency measures in place can continue functioning and providing essential services. They can rely on backup power systems, which have traditionally been diesel generators, or emerging systems such as battery storage and fuel cells, to keep critical medical equipment running, support life support systems, maintain temperature-controlled environments for medications and vaccines, and power vital communication systems. Energy resiliency enables healthcare facilities to prioritize patient care, offer a safe environment, and effectively respond to emergencies, even in challenging circumstances.

The bottom line is energy resiliency in healthcare facilities is vital for maintaining patient care, preserving critical medical services, and enabling effective emergency response and recovery. It is a multifaceted approach that fosters long-term sustainability, adaptability, and reliability in energy systems, strengthening the resilience of the facilities and enhancing their ability to withstand future challenges and it ensures that healthcare providers can deliver uninterrupted care, protect patient well-being, and contribute to community resilience during times of crisis.

The IRA removed significant obstacles to the deployment of renewable energy, efficiency and other decarbonization and sustainability efforts, improving both ownership and financing of projects.

Not for Profit organizations can move forward faster and more productively with developers and financing structures attuned to their differences, strengths and constraints.  Healthcare bankers must provide financing products and services to their healthcare clients as they are the true project sponsors, not the energy sector developers.  These should support financing of PPAs, VPPAs, ESAs and energy retrofit ESCOs, all of which benefit from the IRA.

A number of good financing approaches are available today and better ones are developing.  It is often a matter of matching the financing/ownership approach to the constraints of the sponsoring organization in affordability and project funding.