Energy saving - LED: Time to replace the TV ?

In these days of multitasking and social networking how many of us are guilty of leaving the TV flashing away and chattering way to itself whilst we're doing something else, with it only occasionally catching our attention?. Whilst writing this there's a huge flat panel TV just a few metres away which has only caught my attention a couple of times in the last hour or two, but like millions of others across the country it's switched on and off more as a habit than a necessity. My excuse for this extravagant use of energy that it's currently summer and daylight hours are long therefore the the vast majority of the energy we're using is generated in-house by our own solar PV system, but importantly, with the TV encompassing LED technology it's using very little power, currently around 50W.

Money & the Environment

A large TV consuming just 50W is pretty amazing considering that the smaller plasma unit it replaced consumed 200W-250W when displaying most content and well over 300W if displaying bright sunlight conditions. The aggregated impact of adopting LED technology televisions across the country is enormous, however, most of what we're continually being told regarding energy efficiency relates to behavioural change, this currently fitting the narrative of those championing smart-meters. Almost everything I've come across over the last decade or so tells me to turn off lights whenever I leave a room, unplug chargers and anything which is on standby and 'do my bit' for the environment whilst reaping the benefit of saving 'a considerable sum' on the electricity bill. The issue here is that both the energy saving benefit to many consumers and the aggregated environmental impact from one single decision, the replacement of the main TV with one employing more energy efficient technologies (including standby power requirements of around 300mW) would likely be greater than that afforded by running around for the next ten years switching inefficient lights and appliances on & off. Reductions in energy consumption resulting from changes to behaviour last only as long as the practice is maintained, which tends to tail-off over time, however, the most effective energy efficiency improvements normally result from single decisions which provide a noticeable step change in consumption with no further action being required.

Consumption & Optimisation

In general, TV’s employing LED technology tend to use around half of the power required by an equivalent sized LCD TV, which in turn use approximately half of that required by units with plasma panels, however, much of the published efficiency data, including that contained in EU labelling is based on default factory settings or lab test conditions which are invariably brighter and produce more vivid pictures than are needed in normal domestic conditions

Reducing picture brightness levels significantly lowers energy consumption. Many LED TVs are equipped with an eco mode which allows the user to easily select picture brightness to suit ambient viewing conditions without needing to adjust preferred settings, whilst some have the ability to sense ambient lighting and automatically adjust brightness as conditions change.

In line with many other consumer products, TVs marketed in the UK have an accompanying EU energy label ( https://www.gov.uk/government/publications/the-new-eu-energy-label-explained ) which contains consumption and efficiency details relevant to specific models. Our main TV has an EU Energy Label which shows typical power consumption as being 59W with an estimated annual energy requirement of 82kWh giving it a efficiency banding of A+, however, as previously mentioned, in our home, with our settings it typically consumes 50W during the day and slightly less, around 45W, in artificial light at night. Through allowing more aggressive use of the TVs eco-sensor by lowering the minimum backlight threshold it is possible to reduce lowlight consumption to a pretty dim and almost impracticable 33W.

Improve Relevance - Assess Consumption for your own Usage Patterns

I, for one, have always been a little wary of the rational and logic behind the EU energy labels, particularly the relationship between typical power and annual energy consumption, which in this case effectively resolves to an average use of 3.8Hrs/day. This may be applicable to average TV viewing hours or average use across all televisions, however I suspect that it considerably underestimates hours and therefore energy consumed for the main TV in a household. Taking this into account, I'd always have a preference to estimate my own specific usage and apply costs and savings accordingly when justifying expenditure. Simply assessing the average number of hours of daily usage and multiplying this by the typical power consumption (watts) shown on the EU energy label then by 0.365 to convert to energy(kWh)/year should provide a more reasonable representation of TV energy consumption for most.

Assessing Power Requirements of Current TVs

Of course, the only way to accurately assess power and energy consumption on existing plug-in appliances is by using an in-line energy monitor which allows individual electrical item loads to be measured. These are readily available for around £10 and prove extremely useful when looking into the costs relative to benefits to justify replacement of devices such as televisions purely on financial grounds.

Set Priorities

This article has concentrated on the main household television as opposed to others, this purely being size and usage related. Generally, the larger the screen, the more power the TV draws and energy consumption is directly related to the hours of use, so it's logical to consider addressing the largest TV with the highest use first because that's where the running cost will be highest. Having mentioned that, inefficient TVs with high usage elsewhere also deserve to be considered for replacement, however, there will likely be ones in various rooms where frequency of use wouldn't ever justify expenditure, so these should be left alone and replaced when they would normally need to be replaced.

From a purely cost/benefit viewpoint, large screen LED TVs have only been justifiable against potential energy cost savings from late 2014 onwards, coincidentally, this is generally in line with improvements in panel technologies which resulted in the perceived picture quality advantages of plasma panels narrowing and in many cases being surpassed. Like other technology products, there is a broad range of quality and performance available on the market, therefore chasing units which provide the best energy efficiencies without meeting our quality of experience requirements may not prove the most logical option, after all the primary reason for having visual entertainment equipment is to entertain, not save energy.