If you are thinking about buying an electric car, you have probably already started thinking about home charging.
But there is another question worth asking before the new EV arrives:
Should you install solar panels first?
For many homeowners, an electric vehicle can significantly increase household electricity consumption.
You may stop visiting petrol stations, but that energy demand does not disappear. Instead, a greater proportion of it moves to your electricity bill.
That is where solar becomes particularly interesting.
If you are already planning to invest in an EV, designing your solar system around that future electricity demand could help you generate some of the energy used by your home and car yourself.
So, should solar come before the electric car?
For the right household, there is a strong argument for planning the two together.
What Happens to Your Electricity Usage When You Buy an EV?
One of the biggest changes after switching to an electric vehicle is your household electricity consumption.
Before owning an EV, your electricity might primarily cover things like:
- Lighting
- Cooking
- Washing machines
- Tumble dryers
- Dishwashers
- TVs and computers
- Home working
- Other appliances
Once you start charging a car at home, you introduce another potentially significant electrical load.
Exactly how much additional electricity you use will depend on:
- How many miles you drive
- Your vehicle’s efficiency
- How frequently you charge at home
- Whether you also charge elsewhere
- The size of the vehicle battery
- Your driving habits
Someone driving a few thousand miles each year will have very different requirements from someone commuting long distances every day.
But in either case, your electricity profile changes.
And your solar design should take that into account.
Can You Charge an Electric Car With Solar Panels?
Yes.
Electricity generated by your solar panels can contribute towards charging an EV at home.
When your panels are producing electricity, that energy can be used by electrical loads within your property, including a compatible home EV charger.
In simple terms, instead of purchasing all the electricity required for charging from the grid, some of it could potentially come directly from your roof.
How much depends on when you charge, how much your panels are generating and the size of your solar system.
Does Solar Mean You Can Charge Your EV for Free?
This needs a little context.
You will often see phrases such as “charge your car for free with solar”.
Technically, once your system is installed, solar electricity generated on your roof does not have a per-unit electricity bill attached to it.
But the solar system itself obviously costs money to install.
You also cannot assume that every mile you drive will be powered entirely by solar.
There will be:
- Cloudy days
- Winter months
- Evening charging
- Periods of high household electricity consumption
- Times when the car needs more energy than the panels are producing
So while solar can potentially reduce the amount of grid electricity used for EV charging, it is more realistic to think of it as reducing your charging costs, rather than making all driving permanently free.
Should You Install Solar Before Buying the EV?
There can be a real advantage to doing so.
If you know an electric vehicle is arriving within the next year or two, your solar installer can design your system with that additional electricity demand in mind.
Without that conversation, your system might be sized purely around what you use today.
Imagine your household currently consumes 3,500 kWh of electricity annually.
A system is designed around that consumption.
Six months later, you buy an EV and begin charging regularly at home.
Your annual electricity consumption increases significantly, but your solar array remains exactly the same size.
If your roof had room for additional panels from the beginning, you may wish the future demand had been considered when the system was originally designed.
That is why we always ask homeowners about their future plans.
Should You Install More Solar Panels If You’re Getting an EV?
Potentially.
If your electricity consumption is expected to increase, installing additional generation capacity may make sense.
But that does not mean simply filling every available piece of roof.
Your installer should consider:
- Your current electricity consumption
- Annual mileage
- Expected EV charging requirements
- When the car will be at home
- Available roof space
- Roof orientation
- Solar generation
- Battery storage
- Your electricity tariff
- Your budget
The aim is to design a system that makes financial sense for the household you are becoming, not simply the household you are today.
When Is the Best Time to Charge an EV From Solar?
The simplest scenario is when the car is at home during daylight hours.
Your panels are generating electricity and your EV is available to use it.
This can work particularly well if you:
- Work from home
- Work shifts
- Are retired
- Have a second vehicle at home
- Drive mainly at weekends
- Have flexible working arrangements
Depending on your charger and system, charging can potentially be managed to make greater use of available solar generation.
But many people face an obvious problem.
They take the car to work during the day.
What If My EV Isn’t Home While My Solar Panels Are Generating?
This is where the wider energy system becomes important.
If your EV leaves home early in the morning and returns at 6pm, your strongest solar generation may have already happened.
That does not make solar pointless.
Your solar can still reduce electricity consumption elsewhere in the home during the day, while your charging strategy can make use of suitable electricity tariffs.
Battery storage may also help shift some household solar generation into the evening, although using a home battery specifically to charge a much larger EV battery is not always the most efficient or financially sensible strategy.
The whole system needs to be considered together.
Do You Need a Home Battery If You Have an EV?
Not automatically.
An EV battery and a home storage battery perform different roles.
A domestic solar battery stores electricity for your property to use later.
An EV battery stores electricity for your car.
Some households with an EV will benefit significantly from home battery storage.
Others may find solar plus smart EV charging works perfectly well without one.
It depends on:
- Your household electricity usage
- When you charge the car
- When you are home
- Your solar generation
- Your electricity tariff
- Your battery requirements
The important thing is not to add a battery simply because you are buying an EV.
It needs to earn its place in the system.
Solar, EVs and Cheap Overnight Electricity
Another interesting part of owning an EV is access to electricity tariffs designed around off-peak charging.
Some tariffs offer cheaper electricity during particular overnight periods.
That creates the opportunity for a smart energy strategy.
For example, depending on your tariff and equipment, you might:
During the day:
Use solar electricity to power your home.
During the evening:
Use stored solar electricity from a home battery.
Overnight:
Charge your EV using cheaper off-peak electricity.
This can reduce the need to purchase electricity at more expensive periods.
The exact strategy depends on the tariff available to you, which is why solar, batteries and EV charging should increasingly be thought of as one connected home energy system.
Can Solar Charge Your EV During Winter?
Yes, but expectations need to be realistic.
Solar panels generate throughout winter, but total generation is lower because daylight hours are shorter.
At the same time, EV efficiency can also reduce during colder weather, meaning the vehicle may require more energy for the same journey.
You should therefore not design your solar system assuming your panels will fully charge your car throughout winter.
Instead, look at solar generation across the entire year.
Strong spring and summer generation can make a significant contribution to annual household and EV electricity consumption, while grid electricity will continue to play a larger role during lower-generation periods.
What Size Solar System Do You Need for an Electric Car?
There is no standard answer.
A homeowner driving 4,000 miles per year does not need the same system as somebody driving 20,000 miles.
Similarly, somebody with a small efficient EV has different requirements from someone driving a large electric SUV.
Your solar installer should ideally ask:
- What EV are you buying?
- How many miles do you drive annually?
- How often will you charge at home?
- When will the vehicle normally be at home?
- What is your existing electricity consumption?
- Are you planning any other major electrical changes?
Only then can your expected EV demand be factored into the solar design.
What If You Already Own an Electric Car?
Then you have an advantage when designing solar.
You already have real charging data.
Instead of estimating how much electricity the EV might use, your installer can look at your existing household consumption and charging habits.
This can make system sizing considerably more accurate.
If your electricity bill has jumped since buying your EV, solar may be worth investigating as a way of reducing how much electricity you need to purchase from the grid.
What About Installing an EV Charger at the Same Time as Solar?
This can make a lot of sense.
Rather than treating your solar panels and EV charger as completely separate purchases, planning them together can help ensure the equipment works effectively as part of the same home energy setup.
Depending on the charger chosen, smart features may allow you to prioritise available solar generation when charging your vehicle.
It can also mean your electrical setup is planned with both technologies in mind from the beginning.
At Novus Energy, we install both solar PV systems and EV chargers, allowing the wider energy requirements of the property to be considered together.
Could Solar Make Switching to an EV More Financially Attractive?
Potentially.
One of the major attractions of an electric vehicle is the ability to charge at home rather than buying petrol or diesel.
If some of that charging electricity can be generated by your own solar panels, the running-cost calculation can become even more interesting.
But it is important not to exaggerate the numbers.
Your actual savings depend on:
- Your previous vehicle’s fuel economy
- Petrol or diesel prices
- Your EV efficiency
- Electricity prices
- Your EV tariff
- Solar generation
- How much solar electricity reaches the vehicle
The combination can work extremely well, but every household will see different results.
Should You Buy the EV or Solar Panels First?
If your EV purchase is still several years away, there may be no reason to delay installing solar.
Your panels could already be reducing your household grid consumption in the meantime.
If the EV is arriving soon, it is worth telling your solar installer before the system is designed.
The key is not necessarily which one physically arrives first.
It is making sure both investments are planned together.
If you know your electricity consumption is going to rise, your solar system should reflect that.
What Else Should You Think About for the Next 5 to 10 Years?
An EV may not be the only change coming to your home.
You might also be considering:
- A heat pump
- Air conditioning
- A home extension
- A second EV
- More home working
- Electric underfloor heating
- A hot tub
All of these can change your electricity consumption.
Solar panels are designed to remain on your roof for decades.
It therefore makes sense to think beyond this year’s electricity bill.
The Best Solar System Is Designed Around Where You’re Going
One of the biggest mistakes homeowners can make is designing solar entirely around their current circumstances.
Your energy consumption is unlikely to remain identical for the next 20 years.
Electric vehicles, electric heating and other technologies are gradually moving more household energy demand towards electricity.
If you are already planning an EV, that information should form part of your solar design from day one.
That might mean more panels.
It might mean choosing a particular inverter.
It might influence battery storage.
It might affect your EV charger.
Or it might simply confirm that the system you were already considering is suitable.
So, Should You Get Solar Before Buying an Electric Car?
For many homeowners, it is certainly worth considering.
You do not need an electric car to benefit from solar, and you do not need solar panels to own an EV.
But the two technologies can complement each other extremely well.
If you are investing thousands of pounds into an electric vehicle and plan to charge it at home for years to come, it makes sense to ask where that electricity is going to come from.
Solar gives you the opportunity to generate some of it yourself.
And by planning your solar system before, or alongside, your EV purchase, you can design your home energy setup around your future requirements rather than trying to adapt it afterwards.
At Novus Energy, we look at more than your current electricity bill.
Tell us if an EV, heat pump or other major electrical change is in your plans and we can factor that into the system we recommend.
Get in touch with Novus Energy today for your free, no-obligation solar quote.
Simply fill out the form below or give us a call on 01422 768113.