Smart home gadgets: Pricey toys or handy, energy-saving kit?

Dan Wright | 15 October 2019 | Loughborough, UK

Alexa, please play my favourite song. Oh, and Alexa, please set the lights in my main bedroom to come on between 10pm and 11pm.

Smart home technologies are moving from being guest-gimmicks and convenience-hacks to a critical means of monitoring, measuring and controlling energy use in our homes. In this article, we look at voice-activated assistants, smart plugs and smart lighting and consider what role they could play in supporting a transition to low-energy, sustainable homes.

Voice-activated assistants

Voice assistants are fast becoming a must-have for smart homes. These assistants can go beyond hands-free recipe reading and instead become an accessible way for occupants to harness the power of installed tech without the barriers of complex user-interfaces.

(image by Jonas Leupe)

Lifestyle change rating: Low/Medium/High

Could this be a gateway to a hands-free future? Let me ask my voice assistant…

Energy reduction rating: Low/Medium/High

On its own, voice-activated assistants don't offer too much potential for reduction of home energy use, however, this form of user interface could be beneficial for reducing home energy use when combined with one of the technologies below. This could also be an additional way to highlight new energy-saving actions or even recommend cheaper tariffs to occupants.

Smart plugs

Okay Google, please turn off all the plug sockets in the living room.

When we think about home energy use, the value of smart plugs may be linked to reducing standby times from energy vampires around the home. 'Vampire appliances', like televisions and computer monitors, may continue to consume electricity despite not providing any functionality while doing so. Regulations from the European Commission [1] limit standby electricity demand, but these appliances could account for as much as 15% of domestic electricity use [2].

Figures from the UK government [3] suggest that the typical electricity bill could be as much as £58.25 per month. Therefore, very roughly, we could propose that preventing devices going to standby could reduce monthly electricity bills by as much as £8.73. Secondly, there may also be benefits to home safety and avoiding electrical fires through heat build-up or short circuits by cutting current to unused appliances. For more information on preventing electrical fires at home, please see guidance from Electrical Safety First [4].

(image by Frederick Tubiermont)

Lifestyle change rating: Low/Medium/High

Unless you take comfort from the red glow of the stand-by light, turning the appliance off completely may have little impact on your life besides from a little bit of inconvenience of turning the appliance back on via the plug as opposed to using the remote control.

Energy reduction rating: Low/Medium/High

While a 15% saving is highly, highly optimistic (to the extent it's doubtful), savings seem to come with limited detriment to lifestyle so may be an easy win for reducing energy use in the home.

Smart lighting

Alexa, please turn off the lights upstairs.

One of my favourite journal papers is on 'Seven Centuries of Energy Services: The Price and Use of Light in the United Kingdom (1300-2000)' by Foquet and Pearson (2006) [5] . Before you try to convince me that you don't have a favourite academic paper, this one discussed how price of lighting has plummeted while efficiency has sky-rocketed with LED bulbs becoming common-place. Smart lighting offers additional functionality such as hands-free and automated switching on/off and some models offer colour changes.

It's outside of my realm of expertise to comment on whether coloured lighting my support restoring 'psychological energy', but when considering electricity, the benefit of smart lighting may be similar to smart plugs in avoiding use when not required or not providing some sort of benefit. To quantify this potential saving, let's assume that we fit five 10Watt smart LED bulbs in five rooms (three upstairs and two downstairs). If we also assume that bulbs are used for five hours a day and, for simplicity, that electricity costs £0.10 per kWh. If we were to leave all of our bulbs on for five hours a day, this could equate to £0.03 per day. If we used the smart system to remotely switch on the three upstairs lights for one hour and twenty minutes before bedtime, that cost is reduced to approximately £0.02 per day. For this unlikely situation, a marketer could propose that smart lighting could reduce energy use by one-third, however, the savings in this scenario equate to £0.01 less electricity use per day (and who is leaving all their lights on for that baseline to be realistic?).

In the same way that turning off appliances at the plug could reduce the risk of electrical fires, smart lighting could be used to simulate occupancy of a dwelling to ward off burglars, which could be a comforting added benefit of smart lighting.

(image by Mattias Wong)

Lifestyle change rating: Low/Medium/High

If you enjoy mood-lighting and do not enjoy wall-based light switches, smart lighting could be a game changer.

Energy reduction rating: Low/Medium/High

As explored in the example, the roll-out of LED bulbs means that lighting is more efficient and cheaper to achieve than ever, however, a saving is a saving, but only as long as occupants don't decide to double the number of lights in their home (e.g. by adding garden lighting) as a result of this new found control.


Okay Google, please tell me the infamous quote from Bill Clinton's 1992 presidential election campaign.

With an eagerness of remaining brand-impartial, I've maintained distance from mentioning any specific commercially available smart lighting or smart plug solution (discussing voice assistants without mentioning Amazon and Google was a lot more difficult…). A quick search on your favourite e-commerce site can reveal how the price can vary for these technologies, which beckons the question: At what point might I start saving money as opposed to simply making a return on my technology investment?

As has been shown with some light, 'envelope' calculations, payback period may be considerable, however, focusing on payback could occlude the considerable benefit of these types of devices. The smart home technologies decribed in this blog can save energy, but they are much more likely to enhance experiences and facilitate new actions that enable responsible energy use. I hope that the future may hold more energy demand reduction-targeted technologies, so will be watching this space intently.

Dan Wright is a doctoral researcher with the School of Architecture, Building and Civil Engineering at Loughborough University funded by the EPSRC London-Loughborough (LoLo) Centre for Doctoral Training in Energy Demand (Grant No. EP/L01517X/1) and supported by Simble Solutions Limited, an innovative, Australia-based SaaS specialist.


[1] As of 2013, the European Commission specifies that electrical equipment in standby mode should not consume more than 1Watt (National Measurement Office, 2012)

[2] Does having appliances on standby use power? (Senior, 2016)





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