Future Proofing Your Solar System for Electric Vehicles

Whenever we at Total Solar Solutions advise our customers looking to purchase a solar system, we take a good look at their current energy consumption, but we always ask if they have any reason to believe their energy usage will rise in future, or conversely, any reasons why their energy usage might fall in future. For example, a young couple might be planning a family, which would lead to a future increase in energy usage. Some people might have plans to install a pool or spa in the next couple of years, whilst others might be planning to upgrade to an electric induction cooktop, electric hot water, and reverse cycle heating in order to remove their gas connection altogether.

There are many reasons why your energy consumption might rise in future, and there is one reason in particular that people need to start seriously considering. With recent announcements from both Federal and State politicians promoting the widespread adoption of electric vehicles (EV’s), and with the price of EV’s coming down and the price of fuel going up, even at current prices EV’s are proving to have a lower lifetime cost than traditional ICE (Internal Combustion Engine) vehicles, lending to the old adage “Pay more now, to save more later”! So EV’s are becoming more and more attractive, not least of which is because they are good for the environment, and help improve air quality in congested cities.

Widespread adoption of EV’s is going to lead to greater demand on the grid, as more homes demand more energy than ever before. You might not be thinking about it right now, but there is a reasonable chance you might be driving an EV in 5 to 10 years from now. If you are looking at purchasing a solar system, it might just be worth future-proofing your solar system to ensure you have enough capacity to run your home, and keep your EV charged. Essentially, this means up-sizing your solar system, or at least up-sizing your inverter to allow more panels to be easily added in future.

Future proofing your solar system also means choosing a solar panel with higher efficiency, more output per square meter. Most people only have limited space available on their roofs for solar. If you are choosing a cheaper and lower efficiency solar panel (these days anything under 320W), you could be limiting the total capacity of solar you can fit on your roof, and once the panels are up there, that’s it, you’re stuck with it, unless you want to waste money removing the inefficient system in order to start over again with better panels.

For example, a certain roof might only be able to fit a maximum of 20 solar panels. Now, if you were to use some older technology, cheaper 270W panels, you would only be able to fit 5.4kW. If using some higher spec LG NeON R 370W panels for example, you could fit 7.4kW, which is a very big difference. Not only have you just fit 37% more solar capacity on the roof in the same area, but given higher spec panels like the LG NeON R outperform just about every other panel on the market in terms of watt for watt output, in real terms, you could have just added up to 50% more actual generation capability.

So all of this should be taken into account when considering a solar system. So, if you believe you might be driving an EV in future, how much extra solar capacity do you really need?

Most of the EV’s on the market today require between 12-17kWh/100km. What that means is that for every 100km you drive, you will need 12-17kWh to charge your EV. The average Australian drives 15,500km per year, or an average of 42km per day. With the energy required by most EV’s, that works out to about 5-7kWh per day. For people living around Melbourne, that would mean you would potentially need an extra 2kW worth of solar panels. Of course, we are talking about averages here, over a full year. It is important to take note of when you are likely to be charging your EV. If you are going to charge your EV at night, topping it up every evening rather than fully depleting your car battery and requiring a full charge, you might prefer to charge it up from the grid during the off-peak periods, or after 11pm and before 7am during weekdays.

If charging your EV during off peak times, you would be paying a rate of about 16c/kWh. If you are feeding your excess solar power into the grid during the day, and not into a home battery, you would be earning about 12c/kWh. If your EV required 7kWh to bring the car’s battery up to full charge every day, that would mean you would need your solar system to feed about 9.5kWh into the grid during the day, in order to have paid for the 7kW you draw from the grid during off peak times, due to the difference in what you earn for feeding power into the grid, compared with what you pay to buy off-peak grid power. If that is the case, you’d need an extra 2.5kW worth of solar panels, to generate that extra 9.5kWh every day on average.

All of the above serves as a rough guide, but it should encourage you to think more carefully about the quality and size of the solar system you are going to invest in. As an aside, it is very interesting to consider that the average Australian who drives about 42km per day, would be paying about $5.35 a day for fuel, assuming fuel consumption of about 8.5lt/100km, and a fuel price of about $1.50/lt. That amounts to $1,950 a year. On top of that, you have the expensive servicing and maintenance costs potentially running into thousands of dollars every year. Yes, an EV will cost you more to purchase now, but considering their very low servicing and maintenance costs, and the potential that you don’t have to spend a cent on electricity if you have a sufficiently large solar system, an EV with a quality solar system to match could prove to be a great long term investment.

If you would like advice about getting the perfect solar system installed on your roof, please call us on (03) 9729 0894, and we will have one of our highly trained consultants get in touch with you.