For the best part of a decade, the smart home has been on the cusp of becoming a reality, writes Alex Bardell, co-founder of Sustainability for London, founder of SDAdvocate and active member of the BCS Green IT SG.
If we follow the Gartner adoption curve, the technology has progressed from being just hype, to the trough of reality and now, we find ourselves on an adoption curve. The point where smart home technology is becoming the norm in new builds and retrofit projects.
Just what is a smart home?
Let’s try to break down a smart home into its constituent elements and understand the role of technology and the services it can deliver. It has evolved from analogue home automation where labour-saving machines and building services, for example heating and washing, could be scheduled. Today, computers and digitalisation have become part of our household devices; it became inevitable that they would integrate and connect using communication protocols and fundamentally change the way we manage our houses.
The word ‘smart’ in ‘smart home’ refers to the system being aware of the state of its devices, which is done through the information and communication technologies (ICT) protocol and the internet of things (IoT) any electrical device found in the home can now be managed autonomously or remotely and devices can integrate to deliver systems. As we grapple to combat climate change by significantly reducing the energy consumption of our buildings, technology is increasingly being needed to manage these systems.
The modern house is full of these devices which can be configured to deliver an endless number of services - from security to in-house entertainment. So, how does smart digital technology work with climate change mitigation?
The home energy efficiency rating
Greenhouse gas emissions for homes arise primarily from the fossil fuels burned for heating, followed by electricity to power devices. A Building Energy Performance with an energy rating of A, must have an energy footprint under 32 KWH/m2/year (Kilowatt hours of energy, per square metre over a year). Unfortunately, the majority of existing UK houses have a rating of D 101-135 KWH/m2/year.
Improving the energy rating of UK homes
Going forwards, new houses must be much more energy-efficient and existing buildings require retro-fitting (including taking into account the embedded carbon in the materials used). A super energy-efficient house creates its own set of challenges, which can only be addressed by using smart buildings technology. All houses need to breathe, which is not a problem for my single glazed Victorian terrace.
Once all the drafts and thermal bridges have been removed, different approaches are needed to manage ventilation. Clearly, opening a window results in heat loss, so the inclusion of a mechanical ventilation heat recovery system manages airflow while minimising heat loss. By including sensors within the smart house, ventilation is efficiently managed.
An energy-efficient house is designed to optimise solar gain (using the sun as a heat source). In the summer, when the sun is strongest, there is a risk of overheating. By including a smart shading system which can be programmed to reduce the effect of the sun within the user’s defined tolerances, an ideal building ambience can be maintained. During the colder months, when solar gain is at its lowest, all but the most energy-efficient houses require additional heat sources.
At this point in time, the most popular choice that does not involve burning hydrocarbons, is a ground or air source heat pump which works like a refrigerator in reverse. The caveat is, they would struggle to deliver enough heat to warm a house which has not undergone energy efficiency improvements. In the future, we may have gas boilers powered by zero carbon emitting hydrogen, which would be able to deliver the energy needed to heat some of our legacy building stock.
Making a difference with solar panels and photovoltaics
In the smart cities for the future, buildings will have solar panels and photovoltaics (PV), to reduce the building’s KWH/m2/year. A normal domestic PV should deliver around 3.5 KWh of electricity over the year, which is roughly 50% of the average household energy consumption.
Providing your house is energy efficient, PV can generate more than enough electricity to deliver the required energy. The obvious caveat is that energy usage is higher in winter when PV is at its least efficient. Additional battery storage can even out consumption patterns, but it is most likely that energy will be fed into the grid over the summer and any shortfall will have to be made up from additional supplies.
Up to now, I’ve largely talked about what we can do today. Now, let’s try and look in our crystal ball to understand what we might be able to do soon, based on the technologies available to us and some of the research projects which are currently delivering results.
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Making home controllers smarter
At a high level, smart connect devices can deliver data in a digital format which, in turn, is processed either by human interaction or via software to deliver a positive outcome.
In its simplest form, the house owner can use information to make informed decisions on how to reduce energy consumption. Applications such as GIRA and HIVE can integrate with smart phones, allowing the owner to better control heating and lighting. The next stage involves automating these processes.
The algorithms within applications can understand your behaviour patterns and automatically optimise lighting and heating. The inclusion of motion sensors allows heating and lighting services to be delivered based on occupancy, as well as providing useful data to further predict consumption patterns.
Currently, renewable energy suppliers are using artificial intelligence to predict weather patterns and future energy supply. By providing this data directly to the smart home, the availability of (cheap) electricity could be predicted and consumption patterns matched to supply energy when it’s needed.
Taking advantage of free electricity
We’ve already seen scenarios where excess renewable energy has effectively been given away for free, in this case demand patterns are allowed to increase to match supply. This is particularly beneficial with regards to electric vehicle charging. With 60 to 80 kWh batteries becoming the norm, in electric cars, there is going to be a huge amount of storage capacity connected to the grid ready to consume any excess supply as it becomes available. Similarly, understanding supply from domestic PV will reduce imbalance between supply and consumption.
In this, together
As our houses have become digitalised, these smart devices are able to work together as systems - the biggest challenge facing the digital house is cross-system integration. Certainly, they integrate well with their devices but each function is effectively in a silo. Unfortunately, this is a well-known problem with technology solutions.
Before the development of integration services, common open standards, and well documented application programming interfaces, we faced similar problems. Over time, with the development of digital platforms, we have enjoyed a more improved information integration.
We have a long way to go before the smart house achieves its full potential, but the rise of domestic technology solutions shows they can significantly help us on our carbon reduction path.
