In the UK, more than 60% of our power comes from burning fossil fuels. Therefore, anything that uses power has an environmental impact. UPS require power to run and air conditioning to cool batteries. There are also environmental implications when it comes to the delivery of new equipment, its ongoing maintenance and the disposal of used equipment containing VRLA (lead acid) batteries which current legislation classes as ‘special waste’.

Most companies have environmental policies. However, the majority still reward staff for buying the ‘cheapest’ option rather than incentivising staff to reduce environmental impact. Understandably, executives at board level are driven to improve profit margins and they have responsibility to their shareholders to grow revenues, but at what cost to our environment?   Surely, they also have a responsibility to reduce carbon footprints to protect the world we all, including shareholders, live in.

The latest research paints a bleak picture of our future, if immediate action to reduce carbon footprints is not taken. For example: In October last year, the UN issued a landmark report which stated Greenhouse gas emissions must be cut almost in half by 2030 to avert global environmental catastrophe, including the total loss of every coral reef, the disappearance of Arctic ice and the destruction of island communities. Scientists stated that we need keep temperature increases below 1.5C to avoid the worst effects of global warming. Unless we see a significant move away from fossil fuels to renewable energy and introduce new technology to reverse global warming by removing CO2 from the atmosphere, scientists believe this figure will be exceeded within around 20 years.

So, what can we do?


Select the Most Efficient UPS

Selecting the most efficient UPS is essential to minimise its carbon footprint. If we consider a 100kW UPS operating 24 hours per day/365 days per year, every 1% of efficiency loss wastes 1kW every hour. At only 10p/kW hour this equates to £8,760 over a ten-year period and does not include the energy wasted by additional air conditioning.

Beware, operational efficiencies are often stated by manufacturers as being ‘greater than 99%’. However, this usually relates to offline operation or ‘ecomode’. Datacentres don’t use this mode as it means they would be operating on raw mains and only transferring (with a short break in power) to full UPS operation when there is a problem. True online efficiency is the important percentage to compare UPS solutions as this indicates the real UPS operating efficiency.


Choose a Scalable, Flexible UPS

A UPS needs to operate at the optimum point on its efficiency curve. Systems which are too small will be overloaded, compromising availability while those that are too large, waste energy are costly to run and to maintain. Scalability and flexibility are therefore essential considerations to ensure the continual ‘right sizing’ of the UPS.

Today’s 4th Generation modular UPS technology has a flat efficiency curve for loads above 15%. This is why CENTIEL’s CumulusPower UPS offers >97% efficiency even at low loads and combines the benefits of increased flexibility, scalability and lowest running costs.



Cheap UPS are inevitably built with cheap components which require more maintenance and repair, all adding to the system’s total cost of ownership (TCO) and carbon footprint.   A top-quality UPS such as CENTIEL’s CumulusPower, using Li-ion batteries will need one change of the capacitors in 15 years with no battery changes. An inferior solution will need three capacitor changes plus three VLRA battery changes in the same period. Consider the environmental impact of selecting a UPS which reduces the need for maintenance and replacement parts.

Naturally, increased efficiency and lower total cost of ownership for UPS are closely linked with the most environmentally friendly systems enjoying ongoing operating cost savings. However, given a choice, decision makers still purchase the lowest cost system thinking they are “saving money” for their company despite the company’s environmental and sustainability policies. While this behavior is understandable, it needs to change, and employees need to be incentivized to make the right environmental choices before it is too late.


Move to Li-ion

Most UPS systems can operate in an ambient temperature of around 40°C without de-rating, however, VLRA (lead-acid) batteries used to support the UPS start to degrade at above 20°C. VRLA batteries need to be cooled by continual air conditioning and its associated environmental cost.

An alternative is Li-ion battery technology.   Li-ion has a higher initial purchase price but can safely operate at higher ambient temperatures so the need for air-conditioning is significantly reduced. In Northern European locations this means cooling could be provided by the natural air temperature, if cooling is needed at all. This would result in significant savings on both datacentre running costs and reduced carbon footprints.

Li-ion batteries also have a much longer useful working life. Five-year design life VRLA batteries are normally replaced every four years. With Li-ion this is every 15 years.

Article origonally featured in Data Centre Management Summer 2019

03300 567 567 Sign up to our mailing list Follow us on LinkedIn