I wonder why the European Union decided to implement a letter grade system for determining the efficiency of light bulbs where the A++ category represents the most efficient lamps and the G category represents the least efficient lamps?
Actually this letter grading system is mandatory for practically all electric appliances, by far not only lightbulbs. It is the most visible result of the "Energy efficiency directive".
But because of the variability of use cases and corresponding products, in most cases it is deceiving then helping.
The thing is, the charts asigning letters to the given electrical consumption differ according to e.g. the feature set.
So an example with fridges: Larger fridge is expected to consume more energy than smaller one, so the re are multiple size categories. That seems legit.
Then when it features an ice maker, it is expected to consume more, so it has different chart than without. As a result, when these letter systems were introduced, for some time fridges in the 200l range without an icemaker disappeared and all sold have one. The thing was, the icemaker actually increased the consumption less than was the difference in the charts, so adding the ice maker was the easiest way to reach for "better grades", although the device actually featured less useful volume and consumed more.
Similar issue with lightbulbs: lower wattages tend to be less efficient, so the same grades mean lower efficacy than those of higher power bulb. That made an impression of using two 40W lamps mean better grade than a single 75W, although the later consumes less and gives off more light.
Not speaking about lights used just for few seconds at a time, where because of the slow warmup, the CFLs had actually lower efficacy than incandescents, but bear 3 grades "better" label...
To me the only thing these "EEI labels" do is to obfuscate the real performance (because the place in the listing page is limited and the EEI labels are mandatory to be presented, the real figures is harder to find, mainly when shopping online). And for non tech savvy people it becomes way harder to understand, why for their application a "C" device will in their use caase actually consume less energy than a "B" or in many cases even "A" rated counterpart. When the EU morons advertise it as "an easy guide to select more efficient devices". They just "forget to tell" this is just for a "most common use case". The thing is, many devices have tens of different use cases, so the "most common" covers just barely 20% of installations. It is truly the most common, the others are less frequent; but there are many of them.
