Can you charge an electric vehicle with solar power?
When operating at maximum output, many of the solar power systems installed on Australian homes create more electricity than their households use. When this occurs, a solar power system’s inverter will send the excess electricity back to the grid.
Back in the early days of residential solar, homeowners around Australia could receive up to 60 cents per unit of electricity they sent to grid, making exporting any excess a highly desirable prospect.
Unfortunately, that’s no longer the case. These formerly high feed-in tariffs have been reduced to from 3 to 17 cents, depending on where you are in Australia and what kind of electricity plan you are on. At night, these same electricity users must pay at least 26 cents to purchase this electricity back in the evening.
These changes have led to many solar panel owners are looking for ways to maximise the consumption and storage of their solar energy, in some cases by buying either a home battery system or an electric vehicle (EV). In this blog we’ll examine the practicality of charging your EV with solar power.
EVs in Australia
To begin, we’ll quickly run through the common types of Electric Vehicles predominately found throughout Australia.
- Hybrid Electric Vehicles or HEVs
Hybrid Electric Vehicles or HEVs have been on Australian roads since the early 2000s. HEVs are predominately normal cars and have a small electric battery. These cars will often run on the battery alone at low speeds, but as soon as the car needs to go faster, the petrol or diesel engine kicks in. HEVs cannot plug into external sources of electricity to charge the battery, instead using regenerative braking and the internal combustion engine to charge.
A popular example of this type of vehicle is the Toyota Prius Hybrid.
- Plug-in Hybrid Electric Vehicle or PHEV
Plug-in hybrid electric vehicles (PHEVs) use batteries to power an electric motor, as well as another fuel, such as petrol or diesel, to power an internal combustion engine. PHEV owners can charge their car’s batteries through external charging equipment and regenerative braking. For short trips, you can be 100% electric in a PHEV, but for longer trips, you are electric in the beginning in a PHEV, but once your stored electricity runs out, you will switch over to the petrol or diesel engine.
Popular examples of these kinds of vehicles are the Mitsubishi PHEV and the Hyundai Ioniq PHEV
- Battery Electric Vehicles or BEVs
Battery Electric Vehicles or BEVs are 100% pure electric vehicles and run only using electricity, no petrol or diesel required. This means that they produce zero direct carbon emissions while running. These vehicles must be charged using an external source like an EV charger.
The most popular examples of these types of vehicles are the Tesla Model 3 or the Nissan Leaf.
While less environmentally friendly, PHEVs usually have a longer driving range than BEVs, thanks to their additional petrol or diesel engine. However, when operating in electric-only mode, PHEVs have a lower driving range due to the added weight of their internal combustion engine.
How do I charge an electric vehicle’s battery?
All plug-in EVs sold in Australia utilise a lithium-ion battery, usually very similar to the technology found in a lot of solar batteries. However, because plugs and connectors differ between vehicles, types of charge points cannot always be used interchangeably.
As a general rule, there are three ways to charge a plug-in EV.
- Level One: Fast Charging
Fast Charging is done through a high-voltage DC charger at a public charging station. By supplying power directly to the battery, your EV can fully charge in just twenty to thirty minutes.
RAC has established an electric highway in WA that utilises Fast Charging technology.
- Level Two: Wall Charger
Wall chargers, commonly knowns simply as EV chargers, convert AC to DC, and are often found in homes, restaurants, hotels, and shopping centres. Fully charging your EV will take around eight hours. Infinite Energy supplies EV changers for residential, commercial and for strata and apartment buildings.
- Level Three: Electric Socket
This way of charging can be the easiest or most convenient, where an EV’s mobile charge cable is simply plugged into a normal electrical socket or outlet. This is also the slowest charging method and your EV will take approximately 14 hours to fully charge.
Is it cheaper to run a petrol or electric vehicle?
In Australia, the average price for electricity is around 26 cents per kWh and it takes approximately 18kWh to power a standard EV to travel 100km. This means, when using power supplied from the grid, it will cost approximately $4.70 in electricity charges to travel 100km.
In contrast, the average petrol car uses 10.6 litres of fuel per 100km. If fuel is $1.40 per litre, which is the average Australian fuel price for 2021, it then costs $14.84 to travel 100km.
As the average kilometres travelled in Australia for private vehicles is around 13,250km, vehicles owners switching from petrol to electric could save up to $1,300 per year.These savings can increase even further if some (or all!) of the electricity used to power the EV is your own, free solar power.
Is it possible to charge an electric vehicle with solar panels?
In a word, yes! Your solar inverter will ensure your home always uses your own solar power that your system energy system generates first, only accessing additional energy from the grid when your own supply is not enough.
Instead of exporting any solar electricity that you don’t use to the grid for a small feed-in tariff, you can instead use the electricity to charge your EV. This is similar to how excess electricity is stored in a battery, except that you will use it to power your car instead of your home appliances.
If you’re able to charge your EV in the morning or during the day, your solar power system could easily partially or fully charge your EV.
If you are like many Australians who do the majority of their driving during the day or will have their car at work during the day and plan on plugging in your EV to charge in the evening, your solar power system may not do much in the way of helping charge your EV.
In this instance, where you may not be able to charge your car using just solar electricity, using just five units or solar power instead of grid-supplied power a day could lead to savings of $440 per year, so it might be worth seeing if you can charge your car in the morning before work or trying to catch some afternoon sun when you get home.
Driving your solar power further
Because your EV is like any other device in your home, maximising the savings your solar power system produces will depend on how smart and efficient you can be with your usage. By making smarter choices in how you use your energy, you can make the most of the carbon footprint reducing power of your EV.
Information stated correct as of July 2021