If you’re deciding whether to have a smart meter fitted, you may come across claims that they can help reduce carbon emissions and combat climate change.
But is there any truth in this?
Aiming for a smarter grid
A big challenge for the electricity grid is to balance supply and demand on a second-by-second basis, both locally and nationally.
The theory is that by knowing where and when electricity is being used the grid can perform more efficiently with a lower carbon intensity.
Smart meters could be one piece of this puzzle. These devices, which are being rolled out in millions of homes, record and store electricity usage 48 times a day per home. That’s compared to a manual meter that may be read a couple of times a year.
The changing energy mix
Changes to the sources of electricity used in the UK and beyond present new challenges.
Until recently, electricity was produced by a small number of gas, nuclear and coal-fired power stations, which could be fired-up or fired-down as demand rose and fell.
But in order to reach its target of net zero by 2050, the UK will need to look at generating more than half of its power from renewable technologies.
This will mean an increasing proportion of variable generation on the grid, as renewables such as wind and solar depend on the weather and so have variable output.
More electricity demand
Meanwhile, demand for electricity is likely to increase.
It has been projected that by 2030, there could be as many as 10 million electric vehicles (EVs) on UK roads. What’s more, the electrification of heating - that is, the switch away from the traditional dependence on gas - could see up to 15 million electric and hybrid heat pumps installed in Great Britain by 2035.
While it might be assumed that electrification will place unprecedented demand on the grid, in fact, peak demand has fallen by around 16% since 2002, due to, for example, solar panel installation.
But that’s not to say that these technologies do not present a challenge: home EV chargers typically deliver 3 or 7 kW of power, creating the potential for a huge surge in electricity demand if every household plugged in their EV as they came home from work in the evening.
However, these technologies may not only be part of the problem but also part of the solution.
An EV may only require a few hours to fully recharge the battery and this could be done overnight when the demand is low. For a well-insulated home, switching off the heat pump for a few minutes will not affect its ability to maintain the house at a comfortable temperature. By allowing these technologies to turn on and off in line with real-time demand, they could become an integral part of supply and demand management.
The challenges of low demand
While high demand on the grid needs to be carefully managed, low demand poses its own set of challenges.
This spring, electricity demand fell by 17% due to the Covid-19 pandemic and there was record solar generation. To manage excessive generation, the grid must either reduce supply, by switching off generators, or raise demand. So how might they increase the demand for electricity?
Wholesale energy prices change on a half-hourly basis with low prices corresponding to low demand. Time-of-use electricity tariffs, which have a different unit rate (price per kWh) for different times of the day and/or different days of the week, offer one way to raise demand, incentivising consumers to use electricity during periods of excess supply with low or even negative prices and, conversely, raising prices to discourage consumption during periods when supply is limited.
Encouraging energy consumption during periods of plentiful supply – for example, when solar generation is high due to sunny weather - can have significant benefits for the environment, as demand does not need to be met by switching on gas or coal-fired power stations.
Monitoring your energy use
In order for consumers to optimise periods of low or negative prices, they need to be able to both see how much they’re using in real-time and adjust their behaviour accordingly.
This is where smart meters come in. These devices send usage data to an in-home display, allowing a household to see their electricity consumption in real-time.
Imagine that this information could be communicated to your home appliances. Your washing machine or tumble dryer, for example, could then switch on automatically when prices are low, albeit with some suitable delay to mitigate the effect of everyone’s appliances turning on at once. This kind of automation may help to overcome resistance to time-of-use tariffs from some consumers, who may be unwilling or unable to shift their patterns of usage away from the times of peak demand.
Installing a smart meter won’t in itself reduce carbon emissions. But smart metering is one element of a smarter grid, and a smarter grid could lead to faster adoption of electric vehicles, electric heating and smart appliances, all powered by cleaner, greener electricity.
About the author
Ruth is one of Loop’s data scientists, developing models and algorithms to help customers understand their energy usage. Before starting work with Loop, she completed a PhD, where she used fMRI imaging data to model human brain connectivity.
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