KN Hemanth Kumar, Chief Manager-EE Motors & Distribution Transformer, International Copper Association India
What measures are needed to promote rationalisation of energy use in transformers?
Implementing regulatory framework to assess long term benefits is helpful in the promotion of rational energy use. Policy makers may consider the following steps:
Setting Minimum Energy Performance Standards (MEPS) will remove inefficient transformers from the market. International benchmarking will help defining adequate performance levels. Build a periodic review process into the regulation.
Establishing a voluntary scheme to define premium levels of efficiency, preferably in the context of a broader programme for energy conservation. If such a programme already exists, include distribution transformers in it.
Designing regulatory schemes will ensure that investment is made at minimum lifecycle cost.
Whatever programme is chosen, ensure it contains a clear product labelling requirement.
What are the benefits of high efficiency Transformers?
Efficiency transformers create economic benefits for society in addition to the reduced green-¡house gas emissions, improved reliability and potentially longer service life if lower temperature rises are experienced through the energy-efficiency improvements. With these benefits in mind, many countries have taken policy initiatives to establish mandatory and voluntary programmes to conserve energy and to help the domestic markets by adopting energy-efficient transformers.
What are the segments in which Indian manufacturers are adopting global benchmarks in technologies and in which sectors we are lagging?
In India, the test method for measuring distribution transformers is based on the International Electrotechnical Commission (IEC) 60076 series of test standards. As India is harmonised with IEC 60076, Both Parts (Part-1 & Part-2) of IS cross-reference, a series of Indian Standards (IS) are based around the IEC 60076 standard. In January 2010, India adopted a mandatory labelling scheme for specific types of liquid-filled, naturally air-cooled, three-phase distribution transformers. These are the units referred to under Indian Standard IS 1180 (part I) and cover power ratings up to and including 200 kVA.
The testing code and procedure for the distribution transformers would be as per the Indian Standard (IS) 1180 (part 1): 1989 with all amendments to date. The Energy label/star system constitutes a useful tool for differentiating between models at the same rating. In August 2010, the Central Electricity Authority (CEA) of India notified that all utilities in India must procure at least a 3 star distribution transformer. Hence the transformer purchase orders issues by the utilities prescribe minimum 3 star distribution transformers.
The scope of coverage in India is currently under review by the Bureau of Indian Standards and the Bureau of Energy Efficiency. Most likely the revision of the national distribution transformer standard (BIS standard) extends the scope of coverage beyond 200 kVA and up to and including 2500 kVA and 33 kilovolts. This extension of the scope would bring India´s coverage more in line with other major economies such as Australia, China and the United States.
What are the precautions that are necessary to avoid failure of transformers?
An accurate estimation of the load losses is critical. A sound evaluation of the risk of failure, depending on the ageing state of the transformer, is also crucial. This will require the correct interpretation of maintenance measurements. The replacement issue mainly comes down to the question whether the energy efficiency can be improved sufficiently to reduce the life-cycle cost of the transformer. As the cost of the energy losses mount to a multiple of the investment cost of the transformer, a minor energy efficiency gain can already be enough to justify replacement.
That is the reason why one should rely on life cycle cost method during buy decision, taking into account the cost of energy losses, failure risk and maintenance into account, as well as the investment cost and the residual value of the transformer at the time of retirement.
Please narrate the importance of testing standards?
Testing standards support all product standards and labelling programmes because they are the means by which product energy performance is measured and compared. Harmonisation of energy performance test procedures is a means of facilitating technology diffusion and trade objectives. Harmonised test methods can encourage trade, conformity assessment, comparison of performance levels, technology transfer and the accelerated adoption of best practice policy.
What are the policy instruments through which high efficiency transformers can be promoted?
The promotion of high efficiency transformers is supported by a number of policy instruments and programmes around the world. Examples of these policy instruments include:
Minimum Energy Performance Standards (MEPS)
Voluntary or mandatory product labelling
Financial incentives, subsidies and tax breaks
Communication and outreach materials
Tools including on-line calculators
On-site metering and audits
Technical support and advice on procurement
Support for R&D and demonstration projects
Of these policy instruments, MEPS are one of the most powerful tools, as they require that entire markets shifting to higher levels of efficiency. When combined with supporting policies including financial incentives and communications programmes, and with monitoring, verification and enforcement activities to ensure regulatory compliance, MEPS will change markets and ensure the realisation of national benefits from cost-effective energy savings.