With today’s rising energy costs, you can no longer ignore the cost savings from using a high efficiency UPS system or an inverter. Though slow, the buzz around energy efficiency is gradually picking up in India. Most of the companies have become very conscious about using more energy efficient solutions and getting a quick return on investments (ROI). Consumers are now more aware and demand cost effective and green solutions. The competition is, therefore, fierce amongst the vendors.
By Srabani Sen
Monday, January 02, 2012: However, buyers often overlook the technical aspects of UPS systems/inverters before making a purchase decision. They should always consider the technological features of these systems, their energy consumption, energy savings, output power quality, and reliability. Buyers should fully understand what their requirements are, how they can minimise their expenditure on power and reduce the total cost of ownership (TCO) while ensuring continuity of power. Considering the present environmental conditions, one must go in for an eco-sustainable product.
What is UPS/inverter efficiency?
The energy efficiency of UPS system/inverter refers to the difference between the amount of energy that is used by a UPS system and the amount of useful energy that it delivers to power your loads. In all UPS systems, some amount of energy is lost as heat when it passes through the internal components of the UPS (transformers, rectifiers, inverters, etc). Just how much energy is lost between the input and output can be significant when you consider how much the wasted energy is costing you. Energy efficiency advantages of as little as 1 per cent between one UPS and another can translate into thousands of rupees saved per year, depending on the size of the UPS.
For example, if the UPS loads are using 90 kW of power, and the UPS system demands 100 kW of power, then 10 kW of power is being lost (as heat). This makes the system only 90 per cent efficient. Since the lost power is being dissipated as heat, it means that the air conditioner will have to use more energy to cool the facility. The cost savings from using a high efficiency UPS system often adds up to the total value of the system in as little as three to five years. Such products are called ‘green’ products.
Environment friendly products reduce operational costs as well. For instance, the products lower energy costs on account of requiring less air conditioning, since less heat is dissipated during operations; energy cost savings are guaranteed by the highest available efficiency for online double conversion UPS systems that are certified up to 96 per cent; optimising power supply to the system makes it possible to reduce the use of non-recyclable materials and cut CO² emissions; and a smaller footprint also implies the requirement for less space, and hence, is also a saving, in some senses.
Green UPS systems/inverters with power saving features
With soaring energy costs and urgent environmental issues that need to be addressed, users are on the look-out for cost effective, efficient, compact and adaptable technical solutions to optimise their operational costs and to minimise their indirect capital investments. Keeping up with these demands of customers, manufacturers now offer UPS systems/inverters with green technology, offering power saving features. Earlier, the efficiency of these products was around 65-70 per cent, but now they are being manufactured with more than 95 per cent efficiency. And more efficiency results in more power saved. With a large number of good UPS systems/inverters in the market, consumers have plenty of options.
Su-Kam Power Systems offers products with optimum efficiency as compared to normal UPS systems. “Our products are extremely environment friendly as they are lead free and do not emit any fumes,” informs Kunwer Sachdev, founder and managing director, Su-Kam Power Systems Ltd. Su-Kam plans to use next generation PCBs, which have lead free soldering. On the battery side, it is moving towards lithium ion/sodium batteries. Su-Kam’s Colossal series delivers an output which is completely stable and distortion free—with total harmonic distortion (THD) of <3 per cent. This power is actually purer than power supplied from the grid.
Convergence’s online UPS systems like the Sxi and Hxi series of inverters are energy efficient. There is no energy wasted due to transmission losses. “These IGBT based products have low noise and zero emission and are more power efficient,” explains Sree Kumar, director, sales and marketing, Convergence Power Systems Pvt Ltd.
According to Jerome Rodriguez, managing director, Socomec UPS India Pvt Ltd, a product’s environmental impact can be reduced in many different ways—by reducing the use of floor space, engineering high efficiency to eliminate wastage of energy, ensure low input harmonics to downsize the upstream equipment size, using easy to recycle materials, etc. “We use IGBT based rectifiers, apart from the three level inverter/SVM topology to optimise and to improve the performance of our UPS systems. Socomec UPS systems can ensure true cost savings without compromising on the reliability of the system,” states Jerome Rodriguez. “Our UPS systems has been endorsed as having the highest efficiency in the market for true online double conversion technology —with up to 96 per cent efficiency,” he adds.
Luminous Power Technologies ensures that all its products have the smallest carbon footprint, with green practices being followed from the manufacturing stage to end use, and even to the point when the products are dumped and recycled. “The raw material used, the processes involved, the distribution channel catering to it… we make sure that the resource allocation and utilisation takes place in the most efficient manner possible,” says Manish Pant, managing director, Luminous Power Technologies Pvt Ltd. The company uses world class technologies in its products like Bravo and UPS LB+, to curb wastage of resources and harvest energy. “We invest on R&D to come out with product based solutions that are environmentally safe and comfortable for the end users,” he adds.
Microtek offers E² (E-Square), a complete series of ‘green’ UPS systems/inverters, designed with energy efficient technologies, ensuring a minimum loss of energy at every stage of manufacturing. “This product is India’s first energy efficient UPS system/inverter with zero power switching of MOSFET, and ensures zero loss of energy while conversion from DC to AC,” says Manoj Jain, vice president, Microtek International Pvt Ltd. Microtek’s UPS system/inverter, with digital fuzzy logic charging, monitors the battery conditions and sets the charging voltage and charging current as per the requirements, while conversion from AC to DC. This saves energy while charging the battery. “The high grade low current density wires used in transformers reduce the amount of heat generated, when current passes through it during the AC to DC and DC to AC conversion process. Proper sized heatsinks are placed at the right places and the units are adequately ventilated, which keeps the temperature inside the unit at a minimum level and saves energy,” explains Manoj Jain. “Our high grade low watt loss silicon steel core in transformers with a watt loss of <4 W is the lowest in the industry. Low watt loss results in saving energy,” he adds.
All Uniline UPS systems from 500 VA to 200 kVA are available with green features, that is, the input power factor is 0.99 and efficiency is > 93 per cent. “The basic difference, with respect to technology, is the use of the IGBT rectifier as against the SCR/thyristor based rectifier, which makes the product green,” says RK Bansal, managing director, Uniline Energy Systems Pvt Ltd.
upsINVERTER.com’s UPS system, under the brand name UTL, has the single card facility that minimises circuit loss, mechanical loss, stray loss and improves the efficiency of the system. The UTL range of online UPS/inverters is equipped with power factor correction (PFC) to ensure improved energy efficiency, less heat generation, and a clean and pure power supply. “PFC is combined with an inbuilt isolation transformer that removes noise, suppresses surges, blocks DC signals, while continuing to transmit AC signals assuring complete protection to expensive, sensitive electronic equipment,” informs Yogesh Dua, director, upsINVERTER.com. UTL’s high frequency combo UPS system (Hi-Lite) has pure sine wave O/P with features like auto overload re-setting and an intelligent charger. “All microcontrollers and SoC devices should have a sleep function, which would enable power consumption to be reduced dramatically, either by halting the operation of all blocks that are not essential or by switching to an extremely low operating frequency. Recent semiconductor products offer users a variety of low power modes to select from, to match the operating conditions,” he adds.
Riello PCI India’s UPS systems exceed the requirements of the European specifications for energy efficiency and quality of UPS systems. “Our UPS systems allow our customers to control their energy consumption, reduce operating costs, ensure availability of critical IT environments and the continuity of manufacturing units. Riello/Aros UPS systems have obtained ISO 14001:2004 certification, which guarantees that all procedures to reduce pollution and control resources have been followed,” says Anil Munjal, director and CEO, Riello PCI India Pvt Ltd.
Emerson Network Power’s green initiatives go beyond IT networks and encompass the entire critical power train in all industries. “All our UPS products in the market comply with international green standards such as RoHS and deliver industry leading power efficiency. For instance, the Liebert NXr delivers up to 96 per cent efficiency. The recently introduced Emerson Trinergy UPS operates on up to 99 per cent efficiency levels. Power loss cascades or amplifies across systems. So 1 W of energy saved at the processor level can save 2.84 W in energy consumption. To prevent this, Emerson’s UPS and inverter solutions is based on energy ‘Logic’ model that reduces the cascade effects of power loss and results in considerable savings,” explains B Venkat Rao, country manager, medium and large UPS systems, Emerson Network Power. Emerson products are manufactured in ISO14001 certified facilities. The products feature dynamic capacity variation systems, reduced weight-to-power ratios, effective recycling and waste management processes.
“All Delta product lines have green features, like a wide input voltage range, which helps to extend the life of the batteries; high energy efficiency, which results in lower wastage of electricity and savings on electricity bills; and advance battery management, which extends the life of the battery and reduces its consumption,” points out Deepak Sharma, country manager, sales-UPS, Delta. Delta Ampton E-series has high online efficiency resulting in lower running costs, quieter operation and less load. “It is a truly green UPS system, with the widest input voltage range to help users maximise the mains utilisation, thus saving on battery life and replacement costs. These UPS systems operate on mains mode at voltages as low as 80 V. Delta UPS an input power factor correction up to unity to reduce the input current, resulting in lower electricity bills and the minimising of harmonics,” states Deepak Sharma.
American Power Conversion (APC) offers green technology based on power saving features that can power down the loads in a situation of ‘no activity’ for some time. APC inverters, on the other hand, offer triple stage charging, which consumes less power to charge. This also helps in charging batteries faster, and therefore, results in improved battery life. These inverters offer higher efficiency, which leads to lower power losses when the battery is being charged and even when the battery is being discharged to provide power. All APC inverters come with an A-way switch, which allows the batteries to be charged but not discharged when the power supply fails. This switch has to be activated when the office is closed over the weekend. This feature helps conserve the charge on batteries, and therefore, saves power.
What is a green product?
Green products are those that are environment friendly with technologies that save energy. These products are designed in such a manner that the loss of energy is minimal, making it energy efficient. Green products are basically safe for the earth and have less impact on the environment or are less detrimental to human health. They might be made either wholly or partially from recycled components, manufactured by a more energy conserving process. These products are highly efficient with an input power factor of > 0.99, that is, there is no disturbance in the main line. This significantly lowers the operational costs and CO² emissions.
How to choose a green UPS/inverter
Customers should look for the following features in the product before making a buying decision:
- Input power factor, AC to AC efficiency
- Noise levels and temperature levels of the units
- Non-lead components
- Technologies like IGBT rectifiers and that the input power factor should be > 0.95
- Should be microcontroller based products and not old discrete integrated circuit based
- Today, mission critical applications and demanding business processes not only require UPS systems for clean and continuous power but also for low TCO, high system availability in terms of process uptime, and extreme flexibility for growth and local/remote manageability
- The UPS system should have low THDi, so that the mains are not polluted
- UPS systems with a low footprint will help in saving space in the server room
- The load of equipment and servers should be rightly calculated to arrive at the optimum UPS rating
- It is important not to choose a UPS system with a lower rating than required
- The technology of the UPS system should not be obsolete. In fact, choose a model that is of an advanced and superior technology
- A model with transformer free technology saves on space, is energy efficient and has a reduced heat output
- Look for systems that deliver low operating costs. There is a big difference in costs when operating high technology, transformer free UPS systems, compared to other models
- Battery charging technologies should ensure maximisation of battery life with little or no maintenance
Batteries for green UPS systems/inverters
Lead acid batteries like sealed maintenance free (SMF) or valve regulated lead acid (VRLA), and open vented batteries are suitable for ‘green’ UPS systems/inverters. Each cell has a 2 V potential. The higher the voltage, the higher the capacity. Batteries can be connected in series to achieve whatever voltage is required (add the number of 2 V cells), and in parallel, to achieve the capacity required (add the capacities of each parallel battery or string of batteries). For larger systems, a number of series connected strings may be connected in parallel to each other. This achieves both a higher voltage and better capacity.
Artheon offers SMF VRLA batteries, which are AGM lead acid batteries, to sectors like solar power, telecom and automation. It has 2 V, 6 V and 12 V batteries, from 4.5-3000 Ah. “We have a joint venture with North Star of USA,” says Sunil Bhatnagar, director, sales and marketing, Artheon Electronics Ltd.
Most of the battery technologies are designed to offer trouble free maintenance, higher cyclic life and excellent deep discharge recovery. Better thermal management enables batteries to operate in the absence of a temperature controlled environment, ensures a slow ageing process, offers high reliability, faster charging capability, and longer service life.
Artheon battery range integrates an intelligent system that manages the charging method based on battery room temperature, thus lengthening the life of the batteries. “We use SMF and VRLA batteries in our UPS systems as these are maintenance free, which gives more discharge cycles when used with partial discharge during power failure,” says Jerome Rodriguez.
Selecting the battery type depends on a host of factors like the application, reliability, life expectancy, and available space and funds. For the commercial/IT sector applications, VRLA-SMF batteries are selected due to high power density, lower cost, and because they are maintenance free. The life of an SMF battery largely depends on its operating temperature, making it necessary for it to be kept in an air-conditioned environment. Wet acid batteries/Ni-Cd batteries are most suitable for industrial applications such as refineries, power plants and process industries, as they are optimised to perform in harsh environments.
“In the current scenario, where a low foot print is the need of the hour, the use of SMF lead acid batteries is rising,” concludes Sunil Bhatnagar.
Electronics Bazaar, South Asia’s No.1 Electronics B2B magazine