Charging Electric Vehicles with Solar Power – What's the Duration?

Charging Electric Vehicles with Solar Power – What’s the Duration?

January 22, 2024February 23, 2024

Table of Contents

Introduction

More and more people are choosing electric vehicles (EVs) to help the environment and save money on fuel. This has increased the demand for convenient EV charging solutions. Home solar EV charging is becoming popular because it offers a sustainable and affordable way to charge EVs without relying on the grid. Using rooftop solar panels is the best method to harness solar electricity.

However, it’s important to know how long it takes to charge an EV using solar power. In this blog post, we’ll cover everything you need to know about the time it takes to charge your EV at home with solar power. We’ll discuss factors that can affect charging times and share tips on how to set up your charging system for maximum efficiency.

Factors impacting solar EV charging time

When figuring out how long it takes to charge your electric vehicle (EV) using solar panels, there are a few important things to think about. In this article, we’ll focus on the key factors that matter: the size of your solar panel system, the capacity of your EV’s battery, the weather conditions, and the type of EV charger you’re using.

Solar panel system’s size

Let’s start by talking about how solar panels do their job. They take sunlight and turn it into a type of electricity called DC (direct current). However, this DC electricity isn’t suitable for running your appliances, like the charger for your electric vehicle (EV), which needs AC (alternate current). So, we use something called solar inverters to change the DC to AC.

After this conversion, the electricity is ready to be used. The amount of electricity a solar panel system produces depends on the size and efficiency of the panels, as well as how much sunlight they get. Rooftop solar systems usually range from 5kW to 15kW. Bigger solar systems generally make more electricity, meaning you can charge your EV faster.

EV battery capacity

When it comes to charging your electric vehicle (EV) with solar power, the size of the EV’s battery matters. If your EV has a bigger battery, it usually takes more time to charge it fully using solar energy because it needs more power to reach a full charge. We measure this power in kilowatt-hours (kWh), and EV batteries can range from 24kWh to 100kWh or even more.

Most common EVs have a battery capacity of around 65kWh, which allows them to travel about 350km on a full charge. Depending on how efficiently you drive and the conditions, each kWh of battery capacity generally gives you a driving range of about 5km to 8km.

Weather Conditions

The weather in your area plays a big role in how well your solar-powered electric vehicle (EV) charging works. Solar panels need sunlight to make electricity, so if it’s cloudy or overcast, they won’t generate as much energy. Also, bad weather like heavy rain, snow, or hail can harm the solar panels or make them work less effectively. The temperature matters too—very hot weather can make the panels less efficient, and freezing temperatures can make them not last as long.

Home EV charger types in use for EV charging

When it comes to charging your electric vehicle (EV) at home, there are two main types: Level 1 and Level 2. They have different speeds. A test done by Clean Energy Reviews used the BYD Atto 3 EV to compare a portable 10amp charger (Level 1) and a 7KW wall box charger (Level 2). The results showed that the 10amp charger was about 10% less efficient than the home charger. This was because the Level 1 charger had a slower charging rate and some energy was lost in the charging cable.

In Australia, Level 2 EV chargers are popular in homes, and EVPowerhouse recommends them to get the most energy from your solar panels. These Level 2 chargers come in two types: Single-phase (7kW) and Three-phase (22kW).

Single-phase (7kW) EV charger

Normally, it takes about 8 to 10 hours to charge a regular electric vehicle (EV) using a typical 7kW wallbox charger. If you’re charging a solar-powered EV with a 10kW solar system, it can work well when the weather is good. However, a smart EV charger is a smart choice. It can adjust the charging speed based on how much solar energy you’re making, making the whole process more efficient.

Three-phase (22kW) EV charger

The three-phase version of EV chargers can give three times more power compared to the single-phase version, providing about 22kW of charging power. This high power level can give an electric vehicle (EV) a range of 120 to 150km per hour at the fastest charge rate. With a 22kW three-phase Wallbox charger, it’s possible to fully charge a typical EV in less than three hours.

However, if you’re relying only on solar power for EV charging, especially during cloudy weather, achieving this high charging power can be tough, even with a big 15kW+ solar system. To tackle this challenge, you can use a three-phase EV charger set at a lower charge rate, like 12kW. Even better, go for a three-phase smart EV charger that can adjust the charge rate based on how much solar power is available.

Calculating Solar-Powered EV Charging Time

To figure out how long it takes to charge an electric vehicle (EV) using solar power, we consider two things: the size of the solar panels and the EV’s battery capacity. We use this formula:

Charging Time = (Battery Capacity in kWh) x (Charging Efficiency) / (Solar Panel Output in kW).

For example, let’s take the popular BYD Atto 3 charging from 20% to 80% using home solar charging. Assume the solar panel size is 6kW, the usable battery capacity is 60kWh, and the charging efficiency is 0.85.

Charging Time = 60 kWh x 0.85 / 6 kW = 8.5 hours.

So, it would take a full sunny day to charge a BYD Atto 3 or similar average EV.

But, this calculation doesn’t consider factors like the type of EV chargers, weather conditions, and other things. Often, household electricity demand is high, and the weather isn’t always sunny. In such situations, a Smart EV charger helps by allowing you to switch between grid or solar power. This ensures you don’t unknowingly use expensive grid power.

If these calculations seem complex, you can use a free solar calculator to figure out how much solar power you need to charge your EV.

Tips for Maximising Solar-Powered EV Charging Time

To make the most of your solar-powered electric vehicle (EV) charging, you need to plan carefully and follow some tips:

Optimise Your Solar Panels:

Make sure your solar panels are set up in the best way to catch the most sunlight.
Remove anything casting shadows on the panels.
Keep the panels clean for maximum energy production.
Consider investing in top-quality, high-efficiency solar panels and a good inverter to boost energy generation.

Use Smart Charging Technology:

Smart charging technology is a big help in maximising solar-powered EV charging.
A Smart EV charger can talk to your solar panels, ensuring your EV charges when the solar energy is highest.
This way, you use the energy from your solar panels when it’s most available, ensuring your EV is fully charged and ready when you need it.
Smart chargers can also balance the electrical load, preventing overloads and making the overall charging process more efficient.

Future of Solar-Powered EV Charging

Charging electric vehicles (EVs) with solar power has become popular, and it’s only going to get better. Thanks to improvements in solar panels, batteries, and charging stations, we can expect even more efficient and cost-effective solar-powered EV charging systems in the future.

One exciting development is putting solar panels directly onto EVs. Companies like Hyundai and Toyota are already working on cars with solar panels on the roof that can charge the battery while you’re driving. This could mean less reliance on traditional charging stations and a more eco-friendly way to keep EVs powered up.

Another cool thing is that storing extra solar energy is becoming cheaper and more effective. This means EV owners might be able to save up solar power generated during the day and use it to charge their vehicles at night, making the whole process even more sustainable and convenient.

Conclusion

Switching to eco-friendly transportation is a big step for a better, more sustainable future. Home solar electric vehicle (EV) charging systems are a key part of making this happen. Thanks to improvements in solar panels and EV batteries, charging times are getting faster, so worrying about how far you can go on a single charge is becoming a thing of the past. When you use the sun’s energy to charge your EV, you not only cut down on your carbon footprint but also save money on your energy bills.

Also, thanks to different incentives from both state and federal levels, more people are getting into EVs and solar-based power systems. These incentives make EVs more affordable and available to a wider group of people while encouraging the use of clean energy. If you invest in a home solar EV charging system, you can take advantage of these incentives and be part of making the planet cleaner and healthier for the generations to come. Leap solar-powered transportation and join the movement for a greener world today.

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