This week the schools have gone back, so we thought it would be good to share the maths challenge that we’ve been struggling with at Rural Techs. In 2030 sales of new petrol and diesel cars will be banned and then in 2035 so will hybrids. Many car manufacturers are already saying they will go full electric (EVs) earlier.
So, if everyone switches to an EV, can the current electrical network support the additional charging needs? In the world’s shortest blog; the answer is yes, we have generation capacity, we’ll need improvements, it’ll cost money but we’ll be ok.
But, it’s significantly more complicated than that. The actual question needs to be: “Considering the future risks related to climate change, and the positive, negative impacts and the intended and unintended consequences of policy decisions, can the electrical network support future demand (including EV’s)?”Let’s work through that problem for the District of the Forest of Dean.
Some Basic Data
In 2019, following trials, Western Power estimated that 1 EV equals 1 additional householdsworth of energy use given EV home charges are generally 7kW.
The District in round terms has 38,000 households. Currently there is an average of two cars per household, but here we will assume only one. So, everyone changing to EVs is equivalent to doubling the households’ electricity needs in the district.
For ease we’ve excluded the following that make the maths way more complicated:
- Solar / Wind local generation (load on the distribution system)
- Population Growth (7,500 new homes to be built in next 20 years)
- Electrical device usage increases
- Gas hob to electric hobs
- Climate change impacts on system performance
But we cannot exclude the gas boiler phase-out due to start on new builds in 2025 (oil boilers are 2028). This, will eventually mean everywhere. So, households will have to move to electric boilers or a full electrical heating refit. Let’s assume:
- the cheapest solution is electric boilers on a pre-existing wet system, which for simplicity is also 7KW and
- 50% of houses have Gas or Oil Boilers which would be replaced in next 20 years.
So, add another 19,000 household’s worth of electricity.
British houses are not optimally designed. Their thermal performance is woeful and their ability to withstand peak temperatures in the future is questionable. Most weren’t designed for hot summers.
Given the summers, there is going to be an increase in air-con usage to cope with new peak temperatures. Let’s assume a fixed installation of a 7kW system and a 25% uptake in the District which adds another 9,500 household equivalents.
Answers to the problem
Given the above what is the additional number of household electricity use in the district for summer and winter?
The answer is in winter, we will require additional capacity equivalent to 57,000 households and in the summer 47,500
The danger for our future energy strategy is substitution models (Fossil Fuels to EVs). This merely moves issues from one place to another. Western Power talk in £Billions to underpin an EV-dependent future and related network investment ie ensuring a robust transmission system.
If we think EV is the main future simply replacing fossil fuel cars, we could well be walking blindfolded into an expensive energy network build paid for out of our home energy bills. Whilst at the same time actually gaining very little overall for the wider issues of sustainability. And if we want to talk money, an EV strategy, could ultimately mean that those in fuel poverty, will be subsidising those that can afford to buy EV’s.
The maths is logical; the conclusions madness. And for those who prefer English Lit to Maths try Stephen Spender’s 1930’s poem Pylons for an older answer.