Technological advancement in the solar panel industry in Australia over the past decade has resulted in homeowners becoming increasingly curious about solar power, batteries, and how to connect them to electric vehicles. The real pinnacle of solar energy use is when your home is fully equipped to store solar energy and incorporate an electric vehicle into your all-electric home to completely disconnect from the coal and gas industries.
It has recently been estimated that a staggering 1 in 5 premature deaths can be attributed in part to air pollution. Therefore, a transition to electric vehicles powered by renewable energy will be a huge advancement for Australia’s health and of course the environment.
Solaray is pleased to be leading Australia’s transition to renewable energy on a budget. In this guide, we’re going to gather and answer the most frequently asked questions about this topic.
How many panels do I need in my house to provide enough energy for an electric vehicle?
First, we need to understand the use of kilowatt hours [kWh]. This is different from a kilowatt [kW]. As with the liter per 100 km measurement, which indicates the average amount of fuel used to drive a gasoline car 100 km, EVs use a different unit of measure to show the distance they can travel in 1 kWh.
This number varies depending on the electric car, but in general most electric vehicles achieve a range of about 6 km for every 1 kWh of electricity that they store in their battery pack. If the Australian drives an average of 50 km per day, the EV needs around 8 kWh of electricity to fully charge the battery.
Around four solar modules (1 kW solar capacity) generate an annual average of 4 kWh of electricity per year, with more electricity being generated in summer and less in winter. Therefore, installing around eight solar panels (or 2 kW of solar capacity) in your home should provide the 8 kWh needed to charge an electric vehicle that drives around 50 km a day.
You can find more information on this here: How many solar modules charge an electric vehicle?
Why does 1 kWh of solar energy not mean 1 kWh of EV charge?
You may want to install additional solar panels to meet your electricity needs as the efficiency losses can be greater than 10%. For example, around 900 Wh of energy can reach the battery in your car if your panels produce 1 kWh of electricity. This discrepancy is due to inefficiencies between inverters, your EV’s batteries, and solar panels.
When is the best time to charge my electric car?
If you charge your electric vehicle with your solar panels on the roof, the easiest way is to connect the vehicle to the house in daylight and sunshine. If the solar energy produced is higher than what you use at home, the excess solar energy can be used to charge your vehicle.
However, remember that if the solar energy produced is less than the amount the electric vehicle needs (e.g. on a cloudy day), electricity from the grid will be used to make up for the shortage. You will then need to check your energy tariffs as some households in Ausgrid pay different tariffs depending on the time of day:
Do I need battery storage to charge my EV at night?
The answer is no; not you. It is likely not cost effective to use solar energy to charge a home battery in daylight and then use that stored energy to charge an electric vehicle at night. You will likely get better value if you sell your excess solar energy to the grid for a “feed-in tariff” paid by your energy retailer as a credit on your electric bill, rather than opting for a controlled load tariff to unplug your electric car load.
A good eco-friendly option is to charge your vehicle overnight with off-peak power and sell your solar energy to the grid in daylight. The excess solar energy you send offsets the electricity produced by fossil fuels.
Should I choose a single-phase or three-phase power supply for my newly built home?
Consider future proofing your home and choose a three phase power supply. This allows you to install a much larger solar array (10 kW is the average for a new home) that will provide a reliable amount of electricity to your home. In the long run, you are likely to have increased energy demands if you consider installing a household battery and an electric vehicle (or two).
What is the difference between charging level 1, 2 and 3 EVs?
The chargers used for electric vehicles are divided into three different charging states (“levels” 1, 2 and 3). The standard power outlet in your home is only used when charging at level 1.
Level 1 charging uses your normal home electrical outlets, but the slowest charge rate is achieved. It gives an electric vehicle a range of approximately 20 km per hour (although this depends on the vehicle), so a 10 hour charge from a level 1 charger can give your vehicle a range of approximately 200 km overnight.
If you are charging at level 2, you will need a special EV charger installed in your home. This can provide a range of over 40 km every hour. It costs around $ 2,000 to install (but it can vary greatly) and there are many brands of electric vehicle chargers in the market. Note that your vehicle manufacturer may require a level 2 charger to ensure the vehicle is under warranty.
Level 3 charging uses certain public charging stations for fast charging. The best-known example is probably Tesla SuperChargers. These are generally used by people who travel long distances or when the batteries run out on the road. These quick chargers can achieve a remarkable range of 400 km every hour.
However, not only electric cars are equipped in such a way that they can use the full power of the level 3 chargers. If you are planning a long trip with level 3 charging stations, make sure your vehicle is compatible.
Recharge away from home. How should I deal with “range fear”?
Unlike a gasoline car, which can be refueled at any gas station in minutes, even an electric vehicle that uses a level 3 charger can take an hour to fully charge (and if you are using a charger, it takes a long time longer). Charge point level 2 ‘or’ level 1 ‘).
“Range anxiety” encompasses the considerable time it takes to charge an electric car and the (current) shortage of level 3 quick chargers. There is a concern that your vehicle will not charge quickly enough to get to your destination as planned or that it doesn’t have enough charge to get there.
However, fears of range fears can be disproportionately blown out. Most cars now have trip planning features that allow you to plan a longer trip with planned stops at approved charging stations.
As long as you plan ahead and stick to the itinerary suggested by the car, you are unlikely to get caught with a dead battery. The current solution for some households is to have two cars that use a spare gasoline car when the electric car’s battery runs out or for long journeys.
Caravan parks may also offer level 1 charging from 15-amp sockets if you’re caught with no level 3 chargers nearby. Some companies and exhibition centers have also publicly promoted EV charging stations (others may require you to politely ask if you can use their charging stations).
Opt for solar energy for your electric vehicle
When thinking about the number of solar panels needed to support an electric vehicle, there are several factors to consider. These include:
- The usual driving habits of EV drivers, especially the average daily driving distance
- The make and specifications of your electric vehicle – Tesla batteries for example – are far larger than most other electric vehicles
- How much energy your household uses and how much energy it would like to use in the future
- The fact that the average Australian electric vehicle needs approximately 2 kW of solar energy to offset daily driving consumption
Now that we’ve helped thousands of households prepare for a fully electric future with battery storage and electric vehicles, we recommend households install at least 10 kW of solar power. Solar power is now so cheap that you can install a large system and still get a quick return on your investment even if you feed a lot of excess electricity into the grid. Even if you are not currently installing a battery, the feed-in tariff is still higher than the cost per kWh of your solar system. So you can take your time and install a battery along with your new electric vehicle when you are ready.
Solaray is recognized as the leading solar power installer in Australia by the world’s leading solar companies such as LG Solar and Enphase. We can help you install a high quality solar system that is future proof. When you’re ready to take the plunge, we can help you with battery storage and transition to an all-electric lifestyle, including a plug-in hybrid or an electric car.
Contact our experts today for advice and pricing: