Electric bikes are an increasingly popular mode of transport in the United States for individuals looking to be more environmentally friendly.
More recently, the possibility of powering those electric bicycles by solar charging system is something that is beginning to be explored.
While it is possible to do this, currently it doesn’t come cheap, and it can be rather complex and burdensome.
In this article, we aim to offer you some general guidance on how this could work in practical terms.
Hopefully, this will allow you to decide if it is something you would want to investigate further.
Why Would You Want to a Solar Powered Electric Bike?
Some people may say why even bother with worrying about solar power. Here are a few of the reasons people may find it beneficial.
The Environmental Impact
If you opt for an e-bike over a car or even public transport, you can drastically reduce your carbon footprint.
For those individuals that want to fully maximize their eco-friendly potential, they may decide they want to try to make their electric bike even more sustainable. One option is to look at recharging it through solar power rather than directly from an electrical socket.
The Possibility of Battery Charging Where this is No Electricity
If you use your bike to travel to more remote areas, you may not have access to a powerpoint. Being able to recharge by the power of the sun could offer a lot more flexibility and freedom. It means you could camp out away from the hubbub of normal life but know that you would still have sufficient charge in your battery for the next day.
Increasing Your Bikes Range
If you want to take your bike further, by being able to top up the battery by solar power can increase your range without having to find a powerpoint. This can be appealing for long-distance riders and, again, those who go off the grid, especially if you can ride and charge at the same time.
Is it Really Possible to Run Your Electric Bike Through Solar Power Alone?
Absolutely, yes. It is just that at the moment the technology is not very advanced. A lot of the time, there has to be a ‘do it yourself’ element to make it work and it can be a bit of a burden lugging all the extra gear required.
Of course, if you are technically minded, up for a challenge and don’t mind the possibility of carrying a heavier load, then it could be worth the time and investment.
The Sun Trip Solar Bike Rally
If you want to be inspired by other solar e-bike riders, then you should check out the Sun Trip website. This is a race that happens every two years in which the competitors must travel over incredibly long distances using solar-powered electric bikes only.
In 2018, the participants had to cover a gruelling 12,000+km to reach Guangzhou in China, after travelling from Lyon in France.
All the participants design their own setups, and they vary in their complexity and cost.
Options for Solar Chargers For Electric Bikes
The range of options for solar-powered e-bikes includes transportable and stationary solar panels, bikes that are already designed to charge using solar energy, and solar power trailers. We will discuss each of these below.
Hooking Your E-Bike Up to Solar Panels
To generate enough power to charge the battery on an e-bike, the solar-panels you select need to be a fair size and with a decent wattage output.
Stationary Solar Panels
One option is to invest in large panels that are robust and designed to be stationary. You can then hook your bike up them at home at the end of your trip to charge.
Alternatively, the panels could be charging a separate battery during the day when you are out and when there is maximum sunlight. This battery could then be hooked up to your bike once you are home to charge it.
Although it may cost more to order multiple or very large panels, by going bigger, you will have greater charging potential.
Being stationary, they are also less likely to get damaged, and there is less risk of them being stolen.
This option may suit electric bike riders that do a short daily commute.
There is a wider choice of rigid panels, they tend to be less expensive, and you don’t have to deal with any additional weight on your bike while riding.
Foldable, Portable Solar Chargers
Using foldable solar panels this gives you more flexibility for taking them on the road with you. These can be helpful if you are planning to do longer distances or overnight trips. They come into their own when you are traveling somewhere that you won’t have access to any electrical outlets.
You will be limited on the size and power capacity for storage reasons. There is not as much choice when it comes to folding panels, and they can be more expensive and not always as efficient or reliable. They will also add more weight while on your journey, and you will have to consider how you store them as they still take up space, even when folded down.
They can’t always be charging while you are riding either. If this is the case, you will also need to consider how and when you are going to get an opportunity to charge them.
Weather can also play its part. If you are reliant on these and you hit a patch of bad weather, there may not be enough natural light to charge your bike. If you do not have any backup, this could prove a challenge.
Solar Panels on a Trailer/Rear Rack
Some people set up a solar panel bike trailer. This allows you to have larger, more powerful solar panels attached to a trailer that you can take on your travels. It also means that, sometimes, depending on the setup, the panels can be charging as you are riding. This is what the competitors racing the Sun Trip do, some with extremely creative results.
It does mean you will be restricted as to where you can take your bike. You won’t be able to do any major off-roading or squeezing into tight bike lanes, and it will also add considerable weight too. If it is on a rear rack, you have to keep in mind balance and stability issues too.
It is also likely to be the most expensive of the three options as you will have the cost of the panels and a trailer and the required attachments too.
The Advantages of a Recumbent Trike
Some people that want to harness solar polar while travelling prefer to do this using a recumbent trike rather than a traditional e-bike. This is because it can be easier to attach a frame to the trike that can accommodate the solar panels above the rider.
It will not impede on your riding capabilities as much either. You also get more stability, and this can be an issue when trying to balance a large, inflexible panel on your bike.
This option means there is no need for an additional trailer and a long panel can be utilized to offer more power. To do this, you would need the skill and the patience to be able to create the frame that could hold the panels and attach to the trike.
For some inspiration, check out some of the models that have been created for the Sun Trip race.
Can I Buy an Electric Bike That Has Been Manufactured Specifically to Harness Solar Power?
Currently, there are no major suppliers of off-the-shelf electric bikes with integrated solar power capacity. This is a shame as this would, of course, be the easiest option.
Several specialized models are in development, though, and it is a market that will, no doubt, grow with demand.
One of those at the forefront of the field that looks like they are close to officially launching are the Sun-E Bikes. They have photovoltaic cells on their frame and wheels which allow the bike to charge as it is being ridden.
For the moment, however, this is not an option available on the general market. Watch this space for more developments in the future.
Now For The Technical Stuff
Always make sure that you do your research and pick high-quality components and read instruction manuals fully.
Setting up a solar panel charging system for your e-bike can be complicated and costly. It is not something you should do without doing comprehensive research and only after much consideration.
Be aware that the basic guidance below is just an outline of what you could consider for a stationary set up that could charge the bike directly.
It is the most simplistic of options, but it also means it is the least versatile. If you are using this off-grid, then you would want to consider folding panels or have the panels set-up on an attached trailer.
Pick Powerful Panels
The panels need to provide enough watt and volt power if you plan to use them directly to power the bike. Anything less than 100w will be a bit of a waste of time. A lot of people opt for two, or even four, panels providing a minimum of 200w of power. Most bigger panels will be at least 12 volts too.
These non-folding panels from amazon are a possible option if you are going to be working with a stationary set up.
You would need a couple at least to generate enough power. Some people even use four of them.
You Will Need a DC-DC/Boost Converter or Inverter
You will also need to buy an MPPT boost or DC-DC convertor so that this can be hooked up to your e-bike. This converter will increase the voltage that the solar panel has produced, making it suitable for charging the electric bike battery.
Always make sure that the voltage output will be compatible with your battery.
You will then need output wires that can run from the converter to the e-bike charger.
How to Set the Convertor to Charge
Before setting the battery to charge, you will need to set the converter to the correct voltage conversion amount to enable a full charge. To do this, you need to check what the voltage of your ebike battery pack is. You should then check what the number of cells in the series will be for this voltage.
Once you have this, you then multiply that by 4.2 to calculate what to set the booster at. So, for example, if you have a 48-volt lithium-ion battery, this will have 13 cells in Series. 13 x 4.2 means that you would need to set it at 54.6v for a full charge.
We are not technical specialists, so we always recommend further research to make sure you are comfortable with the set up you are going for.
It Won’t Be For Everyone, But Watch The Technology Develop Down the Road
If you do decide to go down the road of experimenting with solar panels, don’t forget that it is not a solution for all e-bikers. Not only can it come at considerable expense, but you also have to consider the technical complexities, portability, and the safety of the setup.
You should also think more about how you are riding to help conserve battery power. The more weight you have on the bike, the more you ride it using higher speed modes, and the more hills you tackle will all drain the battery more quickly.
If you are economical with how often you use power assist and you minimize hill riding this will be useful when relying on solar power alone.
We would love to hear from any e-bikers that use a solar panel set up.
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