Charging Electric Vehicles At Home

Electric Cars Are The Future

With the government’s recent announcement that sales of petrol and diesel-powered cars will be phased out by 2035. More and more people are starting to think about purchasing an electric car.

Electric cars are great, they’re quieter, less polluting and much cheaper to run. The problem with electric vehicles is the charging infrastructure is nowhere near comprehensive enough to meet the demands of mass electric car ownership. Electric car buyers, therefore, need to think about installing recharging infrastructure in their home.

Several options are available including plugging your car into a standard electrical socket. But this will result in slow recharging times and incur significant costs. A more efficient solution could be to install a fast-charging point powered by solar panels in your home.

So in this article, we are going to look at several things you need to think about before installing solar panels to charge an electric vehicle.

Can solar panels be used to charge a car?

This is the first question most people ask. The answer is an emphatic YES. Solar panels can be used to power all electrical appliances in your home, including your car.

However, your new electric car will use more electricity than all the other appliances in your home put together. So you need to figure out how much electricity your car needs to charge and add this to the amount of electricity you already use. This will give you an idea of how many panels you need to provide enough power for your home and car. We’ll cover this in more detail later.

Methods used for charging cars at home

First, let’s look at the different methods available for charging an electric car at home. Most electric cars come with an adapter which can be used to plug into a standard 13A, 3-pin plug. This may seem like the most practical solution, but it’s not the recommended one, because it will take more than 12 hours to fully charge the battery.

Installing a home charging point is a more practical solution as this means more power output to charge your EV and in less time. They’re available in a range of power outputs from the slower 3kW to the faster 7kW (kW charge per hour) – there’s also 22kW forms. The higher the output the faster the charging time, albeit at a higher cost.

A Nissan Leaf for example would take 20-21 hours to fully charge with a slow 3kW charging point, and 7-8 hours with a fast 7kW.

When choosing a charging point the first thing to think about is the storage capacity of your car’s battery. Battery capacity is increasing all the time, but most new cars come with a 10kWh – 40kWh battery. (Teslas come with a 75kWh – 100kWh battery).

Next, you need to think about how you intend to use the car. Will it be parked up overnight, or during the day? Will you be jumping in and out of it all day, or will it be parked for long periods? Will you be using it for long journeys or short hops to the shop? These things and more will dictate what output of charging point you need.

How much will a home car charging point cost?

According to the Energy Savings Trust, the typical cost of a home charging point is around £1000. Homeowners can offset some of this cost by applying for a £500 grant from the Electric Vehicle Homecharge Scheme (EVHS) however.

To be eligible for EVHS homeowners must:

• Have purchased an electric vehicle or plug-in hybrid with CO2 emissions less than 50g/km, on or after the 1st October 2016.
• Have installed a ‘smart’ charging point approved by the EVHS scheme.
• Have off-street parking.
• The date of installation must not be more than 4 months ahead of the date of delivery or date the customer becomes the registered driver of the electric vehicle.

Homeowners in Scotland are also eligible to receive a further £300 grant towards an EV home charging point from the Energy Savings Trust Scotland.

How much will you save?

When you make the switch from the internal combustion engine to electric, you will save a considerable amount on fuel. According to The Car Expert, the average UK driver spends £67.63 a month on fuel. But you won’t have an extra £70 a month to spend because you’ll have to pay for the electricity to charge your car.

The good news is, no matter where you get the electricity from, an electric car costs around a third less to run than a petrol/diesel car. For most UK drivers that equates to a saving of around £542.00 each year. But by using solar energy to charge your car, you could save even more.

Installing a domestic solar panel system with solar storage, will not only provide enough energy to power your home. It will also allow you to charge your car for FREE. This is one of the few times when you can actually have your cake and eat it.

Let’s look at some figures:

Assuming an average cost of 14p per kWh we can look at how much it would cost to charge an electric vehicle based on the following formula.

Size of battery (kWh) x electricity (pence per kWh) = cost of charge

Car	Battery Capacity (kWh)	Cost of charge (14p/kWh)
Car: BMW i3	Battery Capacity (kWh): 33kWh	Cost of charge (14p/kWh): £4.62
Car: Nissan Leaf	Battery Capacity (kWh): 40kWh	Cost of charge (14p/kWh): £5.60
Car: Jaguar iPace	Battery Capacity (kWh): 90kWh	Cost of charge (14p/kWh): £12.60
Car: Tesla Model X 100D	Battery Capacity (kWh): 100kWh	Cost of charge (14p/kWh): £14.00

Now let’s compare the cost of running a diesel car vs electricity from your supplier vs generating your own electricity using solar.

Fuel Type	Cost per mile (average)	Annual cost (7,900 miles average)
Fuel Type: Diesel	Cost per mile (average): 15p	Annual cost (7,900 miles average): £1,185
Fuel Type: Electricity (energy supplier)	Cost per mile (average): 4p	Annual cost (7,900 miles average): £316
Fuel Type: Electricity (solar)	Cost per mile (average): 0p	Annual cost (7,900 miles average): £0

Homes with solar panels installed may also benefit from payments received through the Smart Export Guarantee Scheme (SEG). This will help offset the upfront cost of installing the system.

Save more with a solar battery

Solar panels only generate electricity during the day, this creates an issue if you are charging an electric car at night. In this scenario, your car will use energy directly from the grid, which as you can see in the table above, is expensive.

A solar battery can help maximise your savings by storing the electricity your solar panel system produces during the day, so you can use it at night. This allows you to charge your electric car using FREE energy even when the sun isn’t shining.

How many solar panels will you need?

So now you know how cost-effective solar panels are, how many do you need to ensure your car remains fully charged? This is a difficult question to answer because it depends on the type of solar panels you install and the capacity of your car’s battery.

To help you out, let’s look at an example using one of the most popular electric cars, the Nissan Leaf, combined with average data for solar panel performance and home electricity usage in the UK.

• A Nissan Leaf can roughly cover 4 miles of driving per 1kWh of charge.
• A typical 5kW south facing solar PV system produces an average of 18kWh of solar energy per day during March to October.
• A typical UK home that cooks with an electric stove on average consumes 9kWh of electricity per day.

What does all this mean? Well… Let’s say you used 9kWh for home usage (electrical appliances) per day, this still leaves you with 9kWh left to charge your EV, in our instance the Nissan Leaf, which would give you 36 miles per day usage – more than enough for a daily commute.

And this still isn’t the full picture as the average driver only travels around 7,900 miles per year which averages around 21 miles each day (according to The Department For Transport).

With a 5kW south facing solar PV system, it is more than capable of providing enough energy to power your home and electric vehicle for FREE. But to achieve this you will need to maximise the efficiency of your system by installing a solar battery to store energy produced during the day.

Think about the future

If you’re thinking about installing solar panels you should consider the possibility of adding a charging point in the future. Even if you have no plans to buy an electric car today, there is a strong possibility that you will own one in the next five to ten years. So it’s a good idea to make sure any system you install has the capacity to power both your home and car.

Solar panels are without doubt one of the most cost-effective ways of charging an electric vehicle. But to get the most benefit you must make sure that the system you install has the capacity to generate the energy you need. Get the sums right and you could run both your home and car for FREE. What could be better than that?