By Srabani Sen
Although the initiative taken by BEE is commendable, industry is sceptical about whether all the parameters of the standards can be met. This would also escalate the final price of products significantly
The Indian power inverter market, which is expected to experience double digit growth rates till 2017, is a highly competitive and fragmented market, with several organised and unorganised suppliers competing for space, primarily in the less than 1-5 kVA segment. Due to the presence of a large number of unorganised suppliers with lower priced product offerings, there is stiff competition that has compelled the organised sector to demand for standards and labels for inverters, especially at the low end.
In line with this demand, in October 2010, the Bureau of Energy Efficiency (BEE), in association with CLASP/PwC, initiated preparatory studies for standards and the labelling of domestic inverters up to 2 kVA. This article encapsulates the industry’s reaction to this new development and how it feels the inverter industry will be impacted after such standards and labelling procedures are in place.
Impact of BEE standards on the industry
The inverter market is broadly divided into two categories—branded and unbranded products. Though branded inverters are more efficient, due to their high price, about 45 per cent of the Indian inverter market is still dominated by unbranded inverters.
The industry unanimously agreed that implementing standards and labelling inverters will no doubt benefit the players, particularly those in the organised sector. It will help consumers procure energy efficient products. “However, this initiative will impact the inverter industry in terms of the need to invest more on infrastructure, R&D, testing standards, and manufacturing processes. By introducing BEE standards, there are chances that the branded inverters will gain more business and feed quality products into the market,” states Kunwer Sachdev, founder and managing director, Su-Kam Power Systems Ltd.
Manoj Jain, vice president, Microtek International Pvt Ltd, believes that this initiative will reduce the size of the unbranded segment as the unorganised players will not be able to meet BEE’s standards and get its certification. “On the other hand, it will be challenging to organised players to provide customers with various star rated models,” he adds.
According to Yogesh Dua, director, upsINVERTER.com (UTL), the standards will be tough to meet, and hence, bigger players will prevail over the mid-sized and small players. “Bigger players who dominate the inverter lobby will try to modify the specifications to suit their own requirements. While the unorganised players will not bother to comply with ‘Star’ ratings, it is the mid-sized players who would suffer the most as they can neither go the small players’ way nor can they afford to comply with the BEE specifications within the required span of time,” he explains.
However, Amitansu Satpathy, director, Best Power Equipment India, feels that the standards will help to justify the price difference between energy efficient
products and their non-efficient counterparts.
How will buyers benefit?
With the implementation of the BEE standards, consumers will benefit the most as they would get a higher power output from the inverter, along with a longer power backup period due to the high efficiency of the inverter, at rated full load. BEE has not only specified the idle power consumption during mains bypass, but also the charging mode operation of the batteries. Considering that these factors will improve the input power factor and the efficiency of the system, the consumers will benefit as they have to charge the batteries less, ending up saving power significantly. This saved energy would mean financial gains as well.
“The standards will put an end to the unhealthy competition and the market gimmicks, helping consumers to choose from among reliable products only,” explains Sree Kumar, director, sales and marketing, Convergence Power Systems Pvt Ltd. “Also, consumers will be aware of the energy loses that take place in inverters,” adds R K Bansal, managing director, Uniline Energy Systems Pvt Ltd.
Technical challenges for manufacturers
Meeting BEE’s standards will, however, pose some technical and manufacturing challenges for the players. As Manoj Jain points out, one of the technical challenges that the manufacturers will face will be to increase the efficiency of their products by reducing energy losses in the conversion of electricity from AC to DC and vice versa.
However, the main hindrance will be in achieving the efficiency of 90-95 per cent at low DC/battery bank voltage, which is the most difficult task. Inverter efficiency depends upon many parameters like semiconductor components, magnetics, and also on battery voltages. The availability and the cost of these materials will also play a vital role in meeting these standards.
According to RK Bansal, it will be really challenging to manufacture well designed inverters, using quality transformers to take care of energy losses. But Yogesh Dua is of the opinion that although meeting the required efficiency may be difficult initially, these technological changes in inverters are absolutely necessary, from the environmental point of view. “Industry would now need to spend more on R&D, which is good as it would help Indian manufacturers to compete in the global markets.”
According to Kunwer Sachdev, once the BEE ratings are implemented for inverters, manufacturers will have to face problems related to the management of large batches of star rated products in their inventory. “They have to improve their infrastructure to facilitate the storage and the testing of these different star rated products,” he says. Adds Manoj Jain, “Manufacturers will also face the challenge of maintaining consistency of quality in their products.”
Is 95 per cent efficiency achievable?
Although the initiative taken by BEE is commendable, the industry is sceptical about a few issues. Can all inverter manufacturers meet the proposed efficiency standards set by BEE, that is, to achieve an efficiency more than 95 per cent? What are the types of problems that could arise?
“It is not feasible to achieve a target efficiency of more than 95 per cent in 12 V battery operated inverters. However, efficiency greater than 95 per cent can be achieved only by keeping the DC bus voltage higher than 360 V. In short, the higher the DC bus, the higher the efficiency will be. The inverter operated at 12 V can give a typical efficiency of 80-88 per cent at rated load, depending on the conversion topology adopted. But this depends on the availability of good and reliable components and materials,” explains Kunwer Sachdev.
As Yogesh Dua points out, “BEE is mostly focusing on the efficiency of the battery backup mode, which should be improved, for sure. But there are two more aspects that are equally important. Most inverters remain on mains mode for more than 90 per cent of their lifetime, during which the inverter performs two functions—charging the battery and then maintaining it in the charged position. A good number of inverters available in the market waste a considerable amount of energy in these two processes, and BEE has not yet addressed this issue. A good amount of energy can be saved in these two modes as well.”
Sree Kumar is of the view that achieving 95 per cent efficiency is quite difficult in Indian conditions as the price of the product will escalate considerably and it would be difficult to cater to a very price sensitive market. Amitansu Satpathy feels that most companies can achieve > 85 per cent efficiency. Manoj Jain stresses that the BEE standards should be achievable, otherwise they become irrelevant for execution. “BEE must study and understand the commercial viability of the inverter industry to make it buyer friendly. Achieving 95 per cent efficiency would raise the cost of the units exorbitantly and make them unaffordable to users,” he says.
However, RK Bansal believes that generally, efficiency is low in low DC voltage inverters. Efficiency can be increased by using high frequency switching systems, which is only a question of design. “Whosoever can design this, can manufacture the system,” he says.
Will price of inverters go up?
While most players believe that the price of inverters will escalate in the process of meeting the BEE’s standards, Yogesh Dua believes that initially the price will go up, but it is bound to come down with more competition in the market. RK Bansal, however, feels that there will be no price revision. “It is only a question of marketing strategy. Going by the industry’s history, even star rated inverters will not remain costly for long,” he states.
Idle performance parameters of an inverter
- Idle current consumption
50 ~100 mA (In inverters with LED displays, when the inverter output is off)
100 ~ 200 mA (In inverters with LCD displays when the inverter output is off)
0.8 ~ 2.0 A (When the inverter output is on but the load is off)
- Output power factor: 0.8 ideal for household load
- Total harmonic distortion: < 5% @ resistive and inductive load
- Capacity: 500 VA to 10 kVA single phase
10 kVA to 100 kVA three phase
- Efficiency: Depending upon the DC bus, it may vary from more than 80 per cent to 95 per cent
- Output THD: < 5 per cent
- Total harmonic distortion < 30 per cent
- Efficiency > 85 per cent
- Output THD <5 per cent
Inverters for offices and SOHO: What players offer
- Convergence offers DSP sinewave inverters and quasi sinewave inverters. These are square wave inverters, with analogue circuits and microcontrollers.
- Uniline manufactures inverters from 5 kVA onwards, which are supplied to large farm houses, households, offices, etc. “Earlier, inverters were transistor based; then came CVT based models and now inverters are available with IGBT based technology. The design and efficiency of the system has increased over the years and prices have come down,” informs R K Bansal.
- Microtek offers the complete range of sinewave inverters from 2.2 kVA to 10 kVA for the SOHO and office segment, which can be even used for fridges, TVs, air conditioners, photocopy machines, fax machines, etc.
- Su-Kam offers sine and quasi sinewave inverters, which now have been technologically upgraded by adopting three and four stage battery charging methods, which can work with all types of batteries. Apart from this, Su-Kam has also included inverter features like intelligent thermal management, remote monitoring, data logging, user configurable settings and integration of renewable solar energy sources to its inverters.
- UTL has a wide variety of UPS systems-cum-inverters for the SOHO and larger offices. “For areas where there is AC fluctuations, we offer a complete solution of sinewave home UPS systems with an inbuilt auto bypass stabiliser,” says Yogesh Dua. For export markets, UTL has a special freight-friendly sinewave UPS-cum-inverter called Hi-Lite, which, the company claims to be the lightest performing home UPS system in India. UTL came out with the first Indian SMT inverter, which proved that SMD technology is no longer a dream in power electronics. These inverters have a single card and are ultra small online UPS systems-cum-inverters. Its inverters use a four stage charging technology, and are based on microcontrollers.