Eco-ups

Eco UPS is a term that is regularly used in the UPS market to refer to highly efficient uninterruptible power supplies that can dramatically reduce electricity bills, CO² emissions and reflected mains distortion. The term “ECO UPS” normally applies to machines that are designed with a combined IGBT Rectifier and Inverter, it is the combination of both an IGBT input and output stage that enables this technology to achieve such high efficiency characteristics. The use of IGBT power devices is affectively a step up from technologies such as six and twelve pulse thyristor based topologies, which many informed electrical and electronic engineers would now consider as dated technology.

ECO UPS explained

One way to illustrate how an ECO UPS varies from a normal UPS is to view it in terms of a modern motor vehicle. While a petrol and a hybrid car do the same job, and can potentially look the same, they are fundamentally different in how they achieve motion. The hybrid car is designed around both a different technology and environmental ethos, making it much more efficient and less polluting. This is almost the exact same scenario the ECO UPS, although it may look like a conventional UPS, although always smaller, it is more technologically advanced and substantially more efficient, but unlike a hybrid car its production and end of life disposal are also less polluting.

Efficiency

Green House Gas Reduction

Over the last few years power supply efficiency has dramatically improved leaving many larger companies unknowingly running outdated inefficient machines; this comes at great financial cost to the user and to the environment as CO2 emissions are not being limited. To illustrate, a six pulse UPS which just a few years ago was the standard format for a UPS rectifier would today be considered as dated and electrically dirty technology, IGBT technology is simply too efficient and too well proven as a reliable ECO friendly alternative to be ignored.

Double Conversion Efficiency Savings

The major discussion point of an ECO UPS is its efficiency savings. A true “double conversion” ECO friendly UPS must use input and output IGBT technology, only then can a UPS hope to reach a 95% AC to AC efficiency, this efficiency is typically more than 10 to 20% higher than a six or twelve pulse alternative. An ECO IGBT UPS should also benefit from a high input power factor (.99pf) and low reflected harmonics, these two crucial features, apart from reducing running costs, also dramatically lower installation costs as smaller cables and MCB’s (Fuses) can be used.

An ECO UPS should always have a IGBT input stage and as a benefit of this, reflected electrical noise back to the utility supply should be less than three percent (<3%), this low reflected distortion results in electronic equipment up stream from the UPS being much less susceptible to interference (ideal for hospitals).

Another important consideration, with regard to THD is that most European countries are looking at imposing penalties on companies that excessively pollute the electrical grid, distortion levels should be low from any reputable ECO UPS and as such should not fall foul to these proposed financial penalties.

A secondary but very important feature of a quality ECO UPS is when considering using a generator to support your UPS, because reflected distortion is so low a substantially smaller engine and alternator can be used. Typically when calculating the size of a generator to run with a none ECO UPS a factor of 2.5 would be applied, example, a standard 100kVA UPS would require a 250kVA generator, the same 100kVA requirement but with ECO UPS features would only require a 120kVA set, a factor of 1.2, this is 52% smaller and offers profound ecological and financial benefits.

Monetary Savings

The use of ECO UPS technology has allowed for higher efficiency and in turn lower electricity bills. It is estimated that over one third of direct and indirect energy (such as air conditioning units) used to power a UPS is wasted because of low efficiency, poor load arrangements and unnecessary equipment being attached.

A 100kVA ECO UPS over a three year term with just a 6% efficiency advantage (most ECO UPS offer an average of >10%) can save the user approximately £21,000, if extrapolated over eight years this becomes an even more impressive £56,000, (calculations based on current utility costs 2010), of course as the size of the UPS increases so do the savings. Organisations that have numerous large power supplies (for example 800kVA) on one site can easily make a six figure saving in the space of a couple of years, which is massively beneficial for the company.