Networks Europe Jul-Aug 2019 - Page 14

14 ENVIRONMENTAL IMPACT considerations when purchasing, to ensure the continual rightsizing of the UPS. Battery technology Most UPS systems can operate in an ambient temperature of 400°C without de-rating, however, VLRA (lead-acid) batteries used in UPS start to degrade at above 200°C. For every 100°C above 200°C, the useful working life of the battery is halved. So, a VRLA battery with a 10-year design life working at 200°C will last five years at 300°C, and just over two years at 400°C. In addition to the battery replacement costs and/or the requirement for air conditioning, there’s the environmental cost of replacing many tonnes of batteries that current legislation classifies as special waste. An alternative is Li-ion battery technology. Li-ion has a higher purchase price, but because Li-ion batteries can operate at higher ambient temperatures without degrading, the need for air-conditioning is significantly reduced. In Northern European locations such as the UK, this means UPS cooling could be provided by the natural air temperature resulting in significant savings on data centre running costs and, equally importantly, reducing its carbon footprint. Li-ion batteries also have a much longer useful working life. Five-year design life VRLA batteries operated at 200C are normally replaced every 3-4 years. With Li-ion, this is a more significant 13-15 years. Maintenance When it comes to UPS purchases, there are usually two budgets: one for the capital expenditure and one for maintenance. Traditionally, the employee selecting the cheapest UPS were misguidedly praised for saving money, but the cheapest UPS are invariably built with the cheapest components which have much higher repair and maintenance costs and are therefore actually ‘costing money’. A top-quality UPS using Li-ion batteries will need only one capacitor change 15 years, whereas an inferior solution will typically need three capacitor changes plus three sets of replacement VLRA batteries in 15 years. Commercial UPS installations can learn from Industrial UPS installations where up to 25 years working life is normal. It’s true that IT technology is changing rapidly, but the same 230V/50Hz being used 20 years ago will be the same in 20 years. So, by using UPS that are engineered to last, commercial organisations can contribute positively to environmental impact by reducing the need for maintenance, replacement parts and scrappage. Correct decision making The increase in UPS efficiency from 85% in the 1980s to 97% today is a 12% improvement that reduces the UPS’ carbon footprint, but purchase decision makers are often still focused only on the bottom line, missing the bigger environmental picture. Of course, increased efficiency and lower total cost of ownership are closely linked, and the most environmentally friendly systems enjoy ongoing operating cost savings. However, given a choice, decision makers still take an ill-informed short-term view and purchase the lowest cost system thinking they’re saving money for their company and often contrary to the company’s environmental and sustainability policies. While this behaviour is understandable, it’s old school and needs to change from the top down. Employees need to be incentivised and educated help the make the right environmental choices for all our sakes. n