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The smart energy revolution

Making the most of our electric cars

With the right system in place, electric vehicles can decarbonise our transport system

28 September 2019

9:00 AM

28 September 2019

9:00 AM

One of the biggest contributors to our carbon footprint — and one of the clearest symbols of the polluted world we are trying to consign to the past — is our cars. With the average new car emitting 120.4g of CO2 for every kilometre driven, it’s clear we need to make the switch to electric transport sooner rather than later. That means a big shift in how we plan and manage our energy system to cope with the extra demand — and smart meters will play a significant role in making it happen.

Last year, 59,911 new electric vehicles (EVs) were registered in the UK, giving EVs a 2.6 per cent share of the market. While it may not sound like much, this is more than a 400 per cent increase — up from just 0.59 per cent in 2014 — and shows the increased appetite for more eco-friendly transport. The rate of increase is expected to grow, with experts predicting that electric cars will be as cheap as fossil-fuelled cars by 2025. The government is also doing its bit, pushing to bring forward plans to ban the sale of all new petrol and diesel vehicles from 2040 to 2032.

Notwithstanding this progress in the UK in decarbonising our transport, other countries are doing even better than we are. In Norway, for example, almost half of new cars sold are electric.

Great news for the planet, right? Maybe. The problem is electric cars are no good if all we do is shift the carbon footprint from the internal combustion engine to the power station. So along with switching to electric vehicles, we need to make our energy system not just green, but more efficient and reliable: electric vehicles require a lot of power. The National Grid has estimated that by 2040, peak demand could increase by 8 per cent due to the rise in EVs. We could build new wind farms — but we’d have to hope that the wind is blowing when we need it.

With the combination of intermittent renewable generation and increased electricity demand, what can be done to keep us on the path of decarbonising our transport? We need to make the grid, our homes and the wider energy system smarter.

Traditionally, power grids are not particularly sophisticated. The power station generates energy, and the powerlines take this energy to our homes where it is either used or lost during the process of generation to supply owing to the low level of battery storage in the current system.

This waste is further exacerbated by the uneven way in which we collectively consume energy: consumption fluctuates throughout the day, and is at its lowest overnight and highest during the evenings. However, when demand surges it can sometimes exceed the supply from renewable sources, and — without the battery storage we need to save renewable energy when it’s not needed — networks are often still dependent on fossil fuels to meet our needs. This makes it harder for Britain to decarbonise its energy generation. If we stick with the current system, the increase in demand from electric cars will make the problem even worse and increase our reliance on unsustainable, energy sources.

Imagine if in the future we all arrive home from work and plug in our electric cars to charge up during the evening. Given how much power electric cars require, this would add an additional strain on the grid at the worst possible time of day, i.e. when demand is highest. Unless we get smarter about our energy usage, this extra demand will most likely have to be met by burning fossil fuels.

Now, imagine if instead of your car charging as soon as you plug it in, you could schedule the charge to take place overnight — the time of lowest demand. Don’t worry if you do need your car in the evening: you would still be able to charge it up at this time, but the default would be during the night.

This wouldn’t just benefit the planet — it could benefit your bank balance too. Households with smart meters that sign up to smart time-of-use tariffs, which charge differently depending on the time of day, could benefit even further as they will be rewarded through cheaper bills for taking pressure off the grid and using energy during off-peak hours.

And this sort of intelligence works even better when you pull all your energy usage together: our cars could help us reduce our carbon footprint even when they’re not actually being driven.

Imagine your EV has a range of 200 miles. You’ve driven to work and back during the day — that’s only 60 miles. You get home for the evening, switch on your lights, heating and TV. You load the dishwasher and fire up the washing machine. These all require power. But what if, rather than drawing from the grid at peak demand times, you take the energy you need from your car battery — saving money and relieving pressure on the grid.

The average home uses roughly 10kWh (kilowatt hours) of electricity every day. An entry-level electric car has a battery capable of storing about 55kWh. So your car could be storing more than enough energy to power both itself and your home appliances.

These efficiency gains can be multiplied further through a smart energy system which — drawing on the data gathered by smart meters — can understand our energy usage in near real time. Smart meters installed in households will enable the use of so-called dynamic tariffs, which price energy in real time in order to match demand with supply, meaning that owners can set their electric vehicles to charge at the cheapest time. This will help households use renewable, low-carbon electricity rather than that generated by fossil fuels, ensuring that we’re reducing the carbon output of our energy networks.

The government is clear that electric vehicles must become an essential part of decarbonising our transport and meeting the country’s climate change objectives. But to realise the benefits we need to bring our energy system into the 21st century. It is technology such as smart meters that will help Britain progress towards a digitised, flexible system more responsive to the changing demands on electricity usage. If we can get that right, a greener future awaits.


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