Rapidly advancing healthcare technology is transforming the way patients are being diagnosed and treated. From sensitive medical imaging equipment to connected devices, data monitoring and lab tests, the future of healthcare lies in working hand-in-hand with technology and with that, comes the need for efficient power generation and protection.
When compared to other hospital technologies, the visual progression of an uninterruptible power supply (UPS systems) has seemed somewhat gradual. This is predominantly down to the critical requirement of a power supply to be running 24/7 and the knowledge that using proven technology means it will simply work when needed so why reinvent the wheel?
However, over the last decade or so, a UPS system’s internal components have advanced to be more efficient, driven mainly by the commercial market to improve overall efficiency or PUE (Power Usage Effectiveness) within data centres and IT applications. The improvement in UPS efficiency also contributes to reducing the client’s carbon footprint, operating costs, and cooling demands. These advances also mean the units have also become smaller and lighter with less heat dissipation.
Although the demand has been mainly centred around other market sectors, there has been a positive knock-on effect to the healthcare market, allowing estate managers to benefit from these UPS advancements. For example, due to the lower loads typically found in healthcare, high efficiency UPS could save 40%-50% in energy consumption. The reduced UPS footprint means hospital plant room space can be optimised and reduced.
How does Lithium-ion shape up?
The high market demand for lithium-ion batteries has also started to creep into the UPS standby market. This is an exciting advancement for the UPS industry and could provide a wealth of benefits to the healthcare facility.
As advancements are made to hospital equipment, the need for additional power to older facilities also increases. Lithium-ion batteries can be used as an additional supply of mains power to cope with the temporary spikes that are often caused by advanced medical technology.
Although not mentioned in the HTM 06-01, battery technology is evolving. Over recent years, lithium-ion has been one of the most anticipated developments in the UPS industry. When paired with a UPS, lithium-ion batteries present not only an efficient and reliable tertiary power supply but also present numerous benefits to the healthcare industry.
The chemistry behind lithium-ion batteries gives them the ability to store large amounts of electricity and increases the number of times they can be charged/discharged during their lifetime making them the perfect catalyst for peak shaving.
In the energy industry, peak shaving refers to the levelling out of peaks in electricity used by energy storage systems. This is commonly used to take advantage of drawing and storing energy during times where electricity from the grid is cheap and using the stored electricity during peak times of the day. While this is a benefit in itself for preserving healthcare budgets, it also branches into load control whereby the UPS provides short bursts of additional power above what is available from a mains supply.
For example, if the maximum available supply is 100KW, where a lithium-ion UPS is installed, the input supply can be limited to the maximum 100KW and any additional power needed to support equipment will be drawn from energy stored in the batteries of the UPS system. In this scenario, the UPS is being used as both an energy storage system and a tertiary power supply in line with the relevant regulation relating to medical applications and backup power.
Lithium batteries also offer a reduced footprint, greater tolerance to cycling, and the ability to cope with various environmental conditions. Lead-acid batteries are limited in how much charging current they can handle, mainly because they would overheat, whereas lithium-ion can handle a higher amperage from the charger. In some cases, the batteries can charge up to 2x more quickly, making them the ideal battery for applications that require constant use.
Where a VRLA battery handles on average 300 cycles, a lithium-ion battery handles 5000, 10x the amount. This is critical for an application that requires many charges and discharges, for example, if a UPS is used for energy storage to power a medical imaging device in a mobile application or regular use.
It is not only the battery cycling capabilities of lithium-ion that make them an ideal choice for powering sensitive applications. With a longer design life, the technology also improves the reliability, efficiency, and flexibility of the facility’s overall backup power infrastructure.
The HTM 06-01 recommends that batteries used for tertiary power supplies, such as those for a UPS, should have a design life of 10 years. Whilst specialist VRLA batteries do meet these guidelines, a standard lithium-ion battery has an average lifespan of 15 years, with no battery replacement necessary.
Despite the benefits presented by this technology, it is still significantly more expensive than traditional VRLA batteries which is why uptake of lithium-ion UPS systems across the healthcare industry is still low. Runtime and power configurations are also still limited within lithium technology and due to the battery management, not all UPS are currently compatible.
If choosing lithium-ion for hospital tertiary power over traditional VRLA batteries, UPS designers should consider the greater need for individual cell monitoring and charging control.
Are Hospitals Ready for Lithium-ion?
Currently, UPS specialists can typically choose from a range of UPS and battery products to provide a preferred solution. In theory, lithium batteries can be used for a diverse range of UPS and runtimes. Although realistically this is difficult at present because there are many technical considerations when installing lithium with UPS technology.
UPS manufacturers are fundamental in developing compatible UPS technology and providing set menu lithium solutions.
At present, lithium UPS are available for smaller plug and play single-phase systems and large data centre UPS systems. The smaller lithium UPS are used for comms and telecoms cabinets, perhaps in remote and warm environments. The large data centre UPS, using lithium batteries are at the cutting edge of UPS technology and are most likely the driver for technology that filters down into the mid-range commercial market.
Unfortunately, at present, there are not many Lithium solutions suited to the UPS and runtime required for Hospitals especially operation theatres. Lithium UPS will most likely make their introduction into larger centralised UPS or the IT areas first.
Within hospitals and healthcare HTM applications, there will be advancements in UPS technology. However, more importantly than UPS technical progress is the reliability and maintainability of UPS and compliance to the healthcare requirements.
We anticipate that in another decade, lithium-ion batteries will become more commonplace across a plethora of industries including healthcare.
Can UPS and Battery Technology Support an all-Electric Hospital?
Following commitments made by the NHS in 2019 to reduce carbon emissions by 51% against 2007 by 2025, with key initiatives including phasing out coal and oil fuel for primary heating uses, power and efficiency feature high on the board’s agenda.
The approaches to carbon reduction are multi-faceted, including implementing low carbon systems and offsetting carbonised fuel sources. This can be done via renewable technologies or greener electrical systems.
With that in mind, there are areas that UPS and battery technologies can be used to replace carbonised fuel sources. Aside from IT load, UPS are used in hospitals to support healthcare environments under the HTM regulations as tertiary power supplies.
As defined by the HTM, a tertiary power supply is a third power supply that supplements the PES (primary energy supply) and the SPS (secondary power supply), usually in the form of a UPS or battery system.
The SPS are usually standby generators but may also be CHP or alternative energy plants. Standby Generators are proven and used worldwide for a wide variety of standby backup requirements. However, recent health and safety and environmental pressure have pushed designers to look at alternative methods of backup power as alternatives to storing multiple litres of diesel and restrictions around emissions.
Over recent years we have seen batteries begin to replace standby generators in life safety systems and commercial standby applications. Batteries are preferred in city locations where generator emissions are harder to manage and fuel storage is a concern, especially on public buildings.
However, standby diesel generators are a reliable and cost-effective method of providing standby power and many would argue they don’t produce exhaust emissions while in standby which is the majority of the time.
Can UPS or standby batteries replace standby generators?
There is no doubting that the technology is there as UPS with standby batteries are being installed in 1MW and 2MW applications. However, there is a limit to the autonomy that the batteries can provide and the autonomy if a generator is always available if there is diesel in the system.
Generators can also be connected to the high voltage (HV) substation while most UPS and battery storage systems need to be connected to the 3-phase low voltage (LV) supply.
Another potential drawback is price. Battery systems are much more expensive than a standby generator including the maintenance cost. Most standby batteries only have a 10-12 year design life while Generators can prove reliable for 20years + if well maintained.
The advantage of battery storage is the clean power supply that is always on. Whether inline or in standby mode, they are always available. There’s no start-up issue to worry about, no fossil fuels, no lubricants and no dirty emissions.
While batteries systems are replacing sub 1MW standby applications, especially in an industrial and dense commercial application, the likelihood of larger hospitals using them to replace SPS is slim at present.
Where we will likely see the introduction is when it’s being used to supplement the PES (primary electrical supply). The PES is the hospital’s main supply. Battery storage can be used in conjunction with the PES for peak shaving, reducing the peak electrical loads created by the hospital and reducing the supply-demand and costs.
Additionally, battery storage can be used to supply and work in conjunction with solar in supplementing the PES and shifting the load demand to a different time period.
Until recently, lead-acid batteries (VRLA) have been the go-to battery technology for providing stored energy for UPS applications. The high prices and lack of knowledge meant the superior lithium-ion chemistries seemed out of reach for the budget-constrained healthcare sector.
However, with demand going up and prices coming down, the availability of lithium-ion based UPS systems is on the rise and progressing into a viable option for healthcare.
