Pioneering the transition to all-electric hospitals

The need for decarbonisation in healthcare is becoming increasingly critical. Healthcare represents almost 20 per cent of the US national economy, 8.5% of US carbon emissions, and 5% of global carbon emissions, with these figures continuing to grow. Traditionally, healthcare is known for its principle of ‘doing no harm’; however, it significantly contributes to the carbon footprint. The built environment, which includes healthcare facilities, is a major contributor to global greenhouse gas (GHG) emissions, accounting for almost 40% of total energy-related emissions. Decarbonising hospitals is an essential step towards a low-carbon future and meeting global climate goals.

Major health organisations, including the World Health Organization (WHO) and the International Hospital Federation, emphasise the urgency of addressing climate change to prevent a rapidly expanding public health crisis. Similarly, engineering and design organisations such as the International Federation of Healthcare Engineering (IFHE) and American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASRAE) advocate for significant reductions in the collective carbon footprint by 2030. This means not only halting the increase in carbon emissions but also reducing existing emissions by 50%.

The transition to all-electric systems in hospitals is a crucial part of this decarbonisation effort. Traditionally, hospitals rely on natural gas for heating, hot water, and steam, while simultaneously using chiller plants to remove heat from buildings and reject it to the atmosphere. A more efficient and less carbon-intensive approach involves using heat pumps and heat recovery chillers. These systems, which run solely on electricity, require zero on-site combustion and recover waste heat from within the building to be repurposed for other heating needs.

Current reliance on fossil fuels in hospitals

Most hospitals heavily rely on fossil fuels for their energy needs, particularly for heating and hot water systems. In 2012, the Integrated Design Lab at the University of Washington published a study titled Targeting 100! which found that 50-60% of hospital source energy is thermal, derived from fossil fuels either on-site or from a district heating plant, with the remaining 40-50% being electric. This reliance on fossil fuels not only contributes to GHG emissions but also increases the vulnerability of hospitals to fluctuations in fuel prices and supply disruptions.

The combustion of natural gas and other fossil fuels for heating and power generation in hospitals leads to significant emissions of carbon dioxide (CO2) and other GHGs. These emissions contribute to climate change, which in turn affects human health by increasing the frequency and severity of heatwaves, storms, and other extreme weather events. The healthcare sector, with its mission to protect health, is thus in contradiction by contributing to a major health threat through its reliance on fossil fuels.

Environmental and health impacts of fossil fuel use

The environmental and health impacts of fossil fuel use in hospitals are significant. According to the WHO, climate change is the greatest threat to global health in the 21st century. The main cause of climate change is the increasing concentration of GHGs, such as carbon dioxide, in the atmosphere. Human activities, including the burning of fossil fuels, deforestation, and industrial processes, have greatly increased these concentrations, leading to rapid and unprecedented warming of the planet. These gases trap heat from the sun and warm the Earth’s surface, resulting in rising sea levels, more frequent and severe weather events, and shifts in the availability of clean water, air, and other resources. Climate change also worsens air quality and increases health conditions such as respiratory diseases and heat-related illnesses.

The combustion of fossil fuels releases a variety of pollutants, including particulate matter, nitrogen oxides (NOx), sulphur dioxide (SO2), and volatile organic compounds (VOCs). These pollutants can have direct harmful effects on human health, causing respiratory and cardiovascular diseases, and exacerbating conditions such as asthma and chronic obstructive pulmonary disease (COPD). Hospitals, being centres for health and healing, should lead by example in reducing their environmental impact. By transitioning to all-electric systems and eliminating on-site combustion of fossil fuels, hospitals can significantly reduce their emissions of both greenhouse gases and air pollutants. This will not only help mitigate climate change but also improve air quality and public health in the communities they serve.

Goals and mandates for decarbonisation in the healthcare sector

Recognising the urgent need for action, various organisations and governments have set ambitious goals for decarbonisation. The White House-HHS Health Sector Climate Pledge, launched in the spring of 2022, is a voluntary commitment to reduce emissions and improve climate resilience. Signing organisations agree to cut their greenhouse gas emissions by 50% by 2030 and achieve Net Zero emissions by 2050. The healthcare sector, accounting for 8.5% of U.S. emissions, plays a crucial role in advancing these goals. This commitment aligns with President Biden’s aim to reduce nationwide greenhouse gas emissions by 50-52% by 2030 and reach Net Zero emissions by 2050.

In addition to national goals, various US states and municipalities have enacted their own climate policies and targets, which often include specific requirements for the healthcare sector. For example, California has set a target to achieve carbon neutrality by 2045, while New York City has mandated that large buildings, including hospitals, reduce their carbon emissions by 40% by 2030 and by 80% by 2050. These policies provide a strong drive for hospitals to transition to all-electric systems and adopt other measures to reduce their carbon footprint.

Key areas of electrification 

• Space heating

Traditional fossil-fuel-based systems for space heating are widespread in hospitals. These systems typically involve burning natural gas to generate heat, which is both carbon-intensive and inefficient. For instance, in hospitals, a significant portion of thermal energy is used for reheating air to meet ventilation requirements. This practice results in high energy consumption and carbon emissions.

In contrast, electric alternatives such as heat pumps offer a more efficient and sustainable solution. Heat pumps use a refrigeration cycle to move heat from one location to another, extracting heat from a low-temperature source and releasing it at a higher temperature. They use electrical power to move heat rather than combusting fossil fuels, which reduces carbon emissions. The efficiency of heat pumps is measured by their coefficient of performance (COP), the ratio of energy output over energy input. Heat recovery chillers may have a COP of 3 or more, as they deliver three units of heating energy for every unit of electrical energy input — compared to combustion equipment that operates with a COP of less than one.

Heat pumps come in various types, including air-source heat pumps (ASHPs), water-source heat pumps (WSHPs), and ground-source heat pumps (GSHPs). ASHPs extract heat from the outside air, while GSHPs and WSHPs utilise water as a heat source. GSHPs, in particular, are highly efficient and can provide both heating and cooling, making them ideal for hospital applications. They involve installing a network of pipes underground, through which refrigerant or water circulates to store excess heat in the ground and extract it when needed.

•  Heat recovery chillers

Heat recovery chillers recover energy from a building chilled water system, making both chilled water and hot water simultaneously. In traditional cooling systems, a chiller absorbs heat from returned chilled water and vents it into the atmosphere. However, heat recovery chillers repurpose this heat for other heating needs, maximising efficiency. These chillers can utilise heat from various sources, including IT cooling equipment, refrigerators, freezers, and medical equipment, integrating them into the chilled water loop.

Recovered heat can be used for space heating, domestic hot water, or other thermal needs within the hospital. By recovering and repurposing heat that would otherwise be wasted, these systems can significantly reduce energy consumption and emissions.

In addition to reducing carbon emissions, heat recovery chillers can improve the overall efficiency and resilience of hospital energy systems. By using the same type of equipment for both heating and cooling, they can eliminate combustion boilers and reduce maintenance costs.

•  Cooling systems

In cold weather, buildings use cold outside air for ‘free’ cooling, known in the US as ‘economiser’ mode, 
where dampers modulate the blend of outside air and return air to deliver cool air without using a cooling coil and chilled water. While these systems do eliminate the need for mechanical cooling, they treat the warm air from the building as waste, discarding it despite its potential value — even as boilers burn fossil fuels to create more heat.

A more sustainable approach involves transitioning from a single use to a circular heat economy. Most hospitals have more heat than needed and reject the excess to the outside, even in cold weather. Heat pumps and heat recovery chillers recycle and reuse building heat, reducing overall energy consumption, potentially reducing operating cost, and reducing or eliminating on-site GHG emissions.

In most climates, building systems can also benefit from the integration of thermal energy storage (TES) systems. TES systems store thermal energy during periods of excess and withdraw it when heat recovery is not sufficient. This can help balance energy loads, reduce peak demand, and improve the overall efficiency of heating systems. TES systems can be particularly effective in hospitals, where thermal storage can supplement heat recovery and potentially eliminate the need for combustion.

• Domestic hot water

Traditional hot water systems in hospitals typically rely on natural gas or other fossil fuels for heating water. These systems are not only carbon-intensive but also require significant maintenance and operational costs. Transitioning to electric hot water systems can reduce emissions and improve energy efficiency.

Electric heat pump water heaters (HPWHs) are a viable alternative to traditional fossil-fuel-based hot water systems. HPWHs use a refrigeration cycle to extract heat from the surrounding air and transfer it to the water, making them highly efficient. They can provide reliable hot water with significantly lower energy consumption and emissions compared to traditional systems.

Heating hot water can also be a source for domestic hot water, so that heat recovery chillers and heat pumps can provide both building heat and domestic hot water, without the need for dedicated HPWHs.

•  Ventilation

Ventilation systems in hospitals are another source of heat that can be optimised for energy efficiency. Traditional systems often involve constant airflow rates to meet code requirements, resulting in excessive energy use for reheating air.

Direct exhaust air heat recovery systems capture heat from exhaust air and use it to preheat incoming fresh air. This reduces the need to heat ventilation air and lowers energy consumption and emissions. These systems can be particularly effective in hospitals, where ventilation requirements are high and continuous.

• Laundry services

Most hospitals outsource laundry services to off-site facilities, which often rely on fossil fuels for heating and hot water. Transitioning to on-site electric laundry facilities can reduce carbon emissions for both transportation of laundry and for process heat. Heat pumps transfer wastewater heat, normally disposed of in sewer systems, to heat incoming wash and rinse water.

In addition to reducing emissions, on-site electric laundry facilities can provide greater control and flexibility in managing laundry services. Hospitals can optimise their laundry processes, reduce costs, and improve service quality by building and operating these facilities in cooperation with other hospital systems.

The role of solar energy

Solar energy offers a free and carbon-free source of energy that can be harnessed for various applications in hospitals. There are two primary means of harvesting solar energy: photovoltaic (PV) production of electricity and solar thermal systems that produce heat. Solar thermal collectors are more efficient at converting solar radiation to useful energy than PV systems, making better use of limited roof or site area. However, solar thermal systems may be more costly to install, more complex, and require more maintenance than PV systems. Hospitals must weigh these factors to determine the right mix for their facilities.

Solar thermal collectors can be used to provide space heat and domestic hot water, with storage options such as insulated water tanks offering a cost-effective alternative to lithium batteries. Although these systems require more engineering and construction labour, they offer significant advantages in terms of efficiency and sustainability.

PV systems, on the other hand, generate electricity that can power various hospital systems, including lighting, HVAC, and medical equipment. Advances in PV technology have improved the efficiency and affordability of these systems, making them a viable option for hospitals looking to reduce their carbon footprint and operating cost. PV systems can be installed on rooftops, parking structures, and other available spaces, providing a renewable source of electricity with minimal environmental impact.

To maximise the benefits of renewable energy, hospitals can integrate solar energy systems with other electric systems, such as heat pumps, heat recovery chillers, and thermal energy storage. This integrated approach can enhance energy efficiency, reduce emissions, and improve the overall sustainability of hospital operations.

For example, PV systems can provide electricity to power heat pumps and heat recovery chillers, reducing the need for fossil fuels and lowering carbon emissions. Solar thermal collectors can provide a renewable source of heat for domestic hot water and space heating, further reducing reliance on fossil fuels.

In addition to solar energy, hospitals can explore other renewable energy sources, such as wind and geothermal energy, depending on the suitability of the site.

Challenges and considerations

While the transition to all-electric hospitals offers significant benefits, it also presents challenges that must be addressed, including a backup power source when utility power fails and the high initial cost of design and construction. While these systems can provide long-term savings through reduced energy consumption and maintenance costs, the initial investment can be substantial.

Creative financing options, including grants, loans, and incentives from government programs and utility companies, can help overcome this challenge. Hospitals may prioritise energy efficiency measures to reduce overall energy demand, making it easier and more cost-effective to transition to all-electric systems.

Another challenge is ensuring the reliability and resilience of electric and renewable energy systems. Hospitals require continuous and reliable power to ensure patient safety and care. On-site energy storage options include batteries and thermal energy storage, or traditional diesel-engine generators to provide backup power and balance energy loads. These systems can store excess energy generated from renewable sources and release it during periods of high demand or power outages.

Finally, hospitals must consider the impact of electric and renewable energy systems on their existing infrastructure and operations. Implementing these systems may require modifications to building systems, electrical infrastructure, and operational processes. Hospitals can work with engineers, architects, and other stakeholders to develop comprehensive plans that minimise disruption and ensure a smooth transition to all-electric systems.

Conclusion

The transition to all-electric hospitals is not only feasible but also essential for achieving decarbonisation goals and addressing the urgent public health crisis posed by climate change. By replacing traditional fossil-fuel-based systems with electric alternatives such as heat pumps, heat recovery chillers, and solar energy, hospitals can significantly reduce their carbon footprint and improve energy efficiency. This transition requires a comprehensive approach, integrating various systems and technologies to recover and reuse heat, optimise energy use, and reduce greenhouse gas emissions.

Healthcare organisations, policymakers, and industry stakeholders must collaborate to drive this transition, supported by goals and mandates for decarbonisation. By pioneering the future of sustainable healthcare, hospitals can fulfil their mission of ‘doing no harm’ not only to patients but also to the environment, ensuring a healthier and more resilient future for all. The journey towards all-electric hospitals represents a critical step in the broader effort to combat climate change and protect public health, setting a powerful example for other sectors to follow.