I’ve worked on four appliance MEPS projects (colloquially also known as ‘Energy Star Rating’), one of which was approved for implementation by the Bureau of Energy Efficiency (BEE).
MEPS are a comparative rating system through which appliances are rated on their energy consumption. It’s called Minimum Energy Performance Standard because anything that is rated below 1 star is not allowed to be sold in the India any longer. Each star symbolises a bin, or interval scale, indicating energy consumed by appliances. The most efficient appliances find themselves in the highest bin, and the least are in the lowest.
The first stem while creating an MEPS is to choose the appliance. If the appliance is not widely used, or generally does not consume too much energy, the impact on national energy consumption statistics will be limited (think bread toasters). The next step is to understand the market itself. A thorough market survey of the products in the market for a particular appliance- for example, if the appliance is an air conditioner, what are the kinds of air conditioners being used? Air conditioners are primarily sold to households, so the the right people to collect data from for this appliance are the companies that make and sell them. If the appliance is used primarily by commercial entities, such as a Visicooler, a comprehensive primary research of the brands, models, usage hours, product lifecycle, whether it has any inbuilt energy saving mechanisms (such as automatic sleep mode), and other relevant data points is the way to go forth. Also, BEE does not care about any feature of the product that does not relate to energy consumption- so if your refrigerator deoderises its insides, or your fan can play music- these extras are not relevant to the star rating process (but they will consume more energy than the same product without them). A systematic literature review of other jurisdictions who have regulated the energy consumption of the product is beneficial at this stage- it makes sure we don’t miss anything important, and also allows us to learn from their work.
Once the data is available and sorted, we can find the range for each level of capacity for all the products- for example, a 36 inch television will have a lower range of minimum and maximum rated energy consumption (as provided by the brand) when compared with a 52 inch television of the same type- Since the greater the resolution of a television, the more energy it will consume, on average. This is why the same scale cannot be applied to all devices of a particular type of appliance.
Electrical appliances have outputs, and for producing the output they use electricity. For example refrigerators (of any sort) deliver cooling per unit time, and use electricity as fuel to do that. To find out how much energy a device consumes, we divide the electricity used by the time the device was used for. Nota bene, not every appliance is run 24 hours a day, 365 days a year- but some certainly are- a refrigerator will usually run the entire 24 hours, daily, but a an air conditioner is a seasonal product and will be used only in summers. Consequently, to estimate the energy consumed by the average device of a particular type of appliance, we will also have to estimate the number of hours they will be used. A year has (24 hours a day x 365 days a year) 8,760 hours. If we assume that the appliance we are regulating is used for 5 hours a day daily on average in all households, then it is on average used for 1,825 hours every year. So the formula for finding out the average energy consumed by a particular type of device, say, an LED television of 40 inches by Brand A is:
Average annual electricity consumed = electricity consumed through the year/ time used through the year
We find this number out for each device in the market. How would we get the information? Well for an organised market, the manufacturers usually have an idea (whether they advertise it or not, or whether that product is regulated or not). To understand the kind of products I mean here, think of walking into a snazzy consumer durables store- most products there (laptops, geysers, most types of space conditioners, etc.) are too sophisticated to be manufactured by back alley producers. On the other hand, products like water coolers or desert coolers are easier to put together, and finding enough small manufactures is a skirmish with listings on websites like India Mart. Finding enough manufacturers is vital to understand the size of the market, the types of devices being sold, the energy they consume, etc. Since in such cases small manufacturers are unlikely to know the annual energy consumption of the units they sell, a test at an NABL certified laboratory for the same is part of the picture.
Once all this information is received and processed, the next step is to estimate the growth of that product’s market in the next ten years, and make the star rating table. The table will naturally disqualify some devices from being sold, since anything under 1 star will not be allowed in the market any longer – which is another reason it’s important to have an inclusive table of manufacturers rather than just the large corporations: it affects livelihoods. Further, the government may find ways to offer such small businesses compliance aid, or decide to make the rating discretionary for a few years. The rating scale selected is usually one where most devices in the market fall within 2 stars and 4 stars. Over time, usually every 1 – 1.5 years, the scale is shifted so that what was once a 5 star becomes a 4 or 3 star, and the baseline energy efficiency in the market increases (since what was once a 2 or 3 star product is now rated 1 star, anything less energy efficient will be retired from the market).
Once the scale is selected, we can multiply the current sales data for each device with the projected sales data for the next 10 years and the average energy consumed for each star rating bin (accounting for upward shifts in the rating scale), and we will have an estimate of the energy saved by the implementation of this policy for the time period.
I hope this blog post inspires you to always purchase a 5 star energy rated product, since a lot of thought, effort, and money goes into making sure your devices consume as little electricity as possible.
Chasing Tales 