TVs from Samsung, LG and Vizio consume far more electricity at home than they do in the Department of Energy’s energy-efficiency tests

VOLKSWAGEN, a German carmaker, has been disgraced for designing clever software that allowed it to cheat on emissions tests for diesel cars. A different scandal, with shades of the VW affair, has been building up in America’s television market. South Korea’s Samsung and LG, along with Vizio, a Californian firm, stand accused of misrepresenting the energy efficiency of large-screen sets. Together, they sell over half of all TVs in America.

In September 2016 the Natural Resources Defence Council (NRDC), an environmental group, published research on the energy consumption of TVs, showing that those made by Samsung, LG and Vizio performed far better during short government tests than they did the rest of the time. Some TVs consumed double the amount of energy suggested by manufacturers’ marketing bumpf. America’s Department of Energy (DoE) has also conducted tests of its own that have turned up big inconsistencies.

Not all TV-makers are at fault: the NRDC found no difference in energy-consumption levels for TVs made by Sony and Philips. But class-action lawsuits have already been filed against the three companies highlighted by the tests—the latest was lodged against Samsung in New York on January 30th. The industry is now waiting to see whether regulators will take action.

There seem to be two main reasons for the sharp contrast between what TVs do during the government’s tests and during normal viewing. Televisions made by Samsung and LG (but not Vizio) appear to recognise the test clip that the American government uses to rate energy consumption and to advise consumers on how much it will cost to operate the set over a whole year. The DoE’s ten-minute test clip has a lot of motion and scene changes in short succession, with each clip lasting only 2.3 seconds before flashing to a new one (most TV content is made up of scenes that last more than double that length). During these tests the TVs’ backlight dims, resulting in substantial energy savings. For the rest of the time, during typical viewing conditions, the backlight stays bright.

A kind explanation is that the manufacturers have been “teaching to the test” and simply did not understand the inconsistency in energy consumption during the test compared with normal use, says Noah Horowitz of the NRDC. Another explanation is that the TV manufacturers may have been trying to outwit regulators to make their products’ energy consumption appear low to consumers.

A second reason for the discrepancy is that Samsung, LG and Vizio TVs all disabled energy-saving features without warning whenever a user changed the picture setting. On certain TVs made by LG, for example, the only setting in which energy-saving features functioned was in “Auto Power Save” mode. Selecting another setting, including “standard”, disabled the energy-saving feature without notification.

LG has updated its software so that changing display settings will not disable energy-saving features without warning. The firm disputes any suggestion that it and others were “bending the rules”, says John Taylor, a spokesman for LG. Vizio also denied wrongdoing. Samsung has not commented on the NRDC’s findings.

America’s Federal Trade Commission (FTC), which protects consumers, has the power to require repayment of profits from the sale of any TVs that misled customers. At least one former FTC official reckons the case deserves action. The DoE says it is considering whether it needs to modernise its test so that it becomes harder to game. The European Commission, which uses the same test as the DoE, is looking into the three manufacturers’ products as well.

How much regulatory attention the case gets may depend on how the political mood evolves. A Republican-controlled Congress could even try to unwind the energy requirements for all consumer appliances. One bill, introduced in January by Michael Burgess, a congressman from Texas, would prohibit the DoE from enforcing existing energy-efficiency standards or setting new ones. For consumers that would be an unwelcome channel change.