Power On-The-Go: Portable Solar Chargers For Electric Cars
There are no commercially available portable solar chargers that can realistically charge your electric cars. EV batteries are too large for the small +-1kW portable solar systems available.
Key Takeaways:
1οΈβ£ Solar panels are inherently inefficient, meaning that only a small percentage of energy from the sun is converted to electricity.
2οΈβ£ The percentage of power converted ranges from 7% to 25%, depending on the solar panel technology.
3οΈβ£ For every 2kW of solar energy entering a monocrystalline panel, a maximum of only 500 watts of electricity is generated.
4οΈβ£ A workaround is to use a pre-charged battery bank to provide emergency power if the electric vehicle runs out of range before a recharging station is reached.
This article explores the topic of portable solar for EVs and its real-world application.
If you are looking for practical solutions for charging your EV on the go, then keep reading or jump straight to an answer below:
Is There A Portable Solar Charger Capable Of Charging An EV?
To determine how much solar power you need to charge an electric car’s battery, you need to know the following variables:
- The range of the electric vehicle.
- The electric vehicle’s battery capacity (kWh).
- The daily distance to be driven.
- The number of hours of peak solar power (insolation) varies by latitude.
For the example calculation, we will use the following estimates:
Range β 358 miles.
Battery capacity β 73.5 kWh.
Daily driving distance β 50 miles.
Peak solar hours available – 5 Hours a day.
By following the steps listed below, you can size the charging system.
1οΈβ£ Calculate kWh Usage Per Mile
The calculation is 73.5 kWh / 358 miles = 0.2053 kWh per mile. This means that for every mile driven, the car consumes 0.2053 kWh.
2οΈβ£ Calculate The Energy Consumed For The Daily Driving
To calculate the energy used daily, multiply the daily distance by the kWh per mile (50 miles X 0.2053 kWh = 10.3kWh per day.)
3οΈβ£ Calculate The Optimum Solar System Size
The charging system needs to generate 10.3 kW daily to provide a daily range of 50 miles. To calculate the hourly production, divide the generated power required by the peak solar power available daily (10.3kW / 5 hours = 2.1kW.)
A factor needs to be added to account for inefficiencies in the system and energy loss during the battery charging and discharging process. 20% should be added to the solar system required to cater to these losses.
This will result in a solar system needing to generate 2.52kW (2.1kW X 20% energy loss = 2.52kW.)
To charge the electric car effectively, the portable solar system must produce 2.52kW (say 3kW.)
To put this in perspective, a 500-watt monocrystalline solar panel measures approximately 7.40 feet x 3.72 feet (27.5 square feet) and weighs 71.2 lbs. (32.3 kg) each.
Six panels will be required to provide 3kW, spread over 165 square feet, and weigh 427.20 lbs. (193.9kg).
This is not a realistic portable option for the average electric car.
What Portable Solar Chargers Would Work?
The only feasible portable solar system would be one which could provide an emergency range extension for the electric car.
There are portable power packs that can charge the EV battery from an internal battery in the device.
This device is kept fully charged and, when needed, is plugged into the electric car charging socket.
Once expended, the unit’s battery must be recharged from a wall socket, solar panels, or wind turbine.
An example device is the Eco Flow Delta Pro. This unit has a 3.6KWh capacity, and although it can’t recharge the car completely, it can provide an additional 35 to 40 miles range to get you out of trouble.
The system has an optional 400-watt solar panel array that can charge the unit’s battery when convenient.
Advantages Of Using A Portable Solar Charger For Electric Cars
The advantage of having a portable charger or generator is that it can provide some extra range to an EV when needed.
Once discharged, the optional solar panels can be erected, and the unit’s battery can be recharged in approximately six hours of strong sunlight.
The system provides an emissions-free safety net for the electric car owner by using optional solar panels.
It can provide additional range on a long trip or holiday, hopefully enough to get to a nearby charging station.
After transferring its charge to the car, it can be connected to a wall plug or the optional solar panel, and the battery can be recharged.
Attached to a wall socket, this unit will recharge its battery in 2.5 hours, and when connected to the solar panels, it will take 6 hours.
Drawbacks of Using a Portable Solar Charger for Electric Cars
There is no realistically available portable solar power recharger that can be used to recharge an electric vehicle completely. In addition, the size of the solar panels would make them unfeasible.
However, as discussed earlier, a portable power station that can be recharged using a solar system is workable in an emergency where a small additional range is required.
The downsides of these devices are:
- First, they weigh more than 80 lbs.
- They are large units that use valuable storage space in the electric car.
- They are expensive.
- They only provide a minimal extended range.
- They take a long time to recharge (more than six hours via solar).
- If the weather is overcast, they cannot be recharged with solar panels.
Real-world Practical Applications of Portable Solar Chargers for Electric Cars
The only real use of Portable Solar Chargers in electric vehicles is to provide emergency power if the car’s battery runs out.
In this event, a power bank will take approximately 2.5 hours to add 35 β 40 miles of range.
The power bank then needs to be recharged.
A power bank like the Eco Flow Delta Pro can also provide power as an emergency generator if the home electricity is interrupted or as an electrical power source when camping.
Choosing and Using a Portable Solar Charger for Electric Cars
Several power banks are available commercially, which can be used to provide a small additional charge to an EV battery. Two of these are listed below.
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EcoFlow Delta Pro
Jackery Explorer 1500 Pro
The Jackery unit has half the kW rating of the Eco Flow and will therefore charge at half the speed.
Although no portable solar units can optimally recharge an electric vehicle, the technology is developing at an incredible rate, and this situation will change over time.
FAQs
How Long Does It Solar Panels To Charge An Electric Car?
Using the earlier example (with a battery capacity of 73.5 kWh), charging with a 400-watt solar panel would take 183 hours and 45 minutes to charge the battery from empty.
Assuming that 6 hours of peak solar sunlight are available each day, it would take 31 days for a full charge!
π Related Article: Can I Charge My EV With Solar Panels?
Can You Charge Electric Car At Home With Solar Battery?
A standard home charging system running a level 2 charger would require 6 solar panels (500 watts each), the solar system’s battery, and a suitable inverter.
If six peak solar hours are available each day, the car will receive 18kW of energy, representing approximately a 25% daily charge rate.
Adding more panels, bigger batteries, and more powerful inverters will increase the rate and amount of charge.
You can also maximize your EV charging by picking the best time to charge with solar from your home PV system.
Key Takeaway
A dedicated portable solar battery charger with sufficient capacity to charge an electric car meaningfully is not commercially available.
But with the speed at which the technology is developing, suitable products may be developed in the future to offer a solution.
In the meantime, high-performance battery packs can provide an additional range to an EV in an emergency. The EcoFlow Delta Flow is the best option right now:
Home EV charging will always be more efficient, especially when you pair it with home solar. Learn how to maximize your EV charging with solar and PV system investment.