Hiking the Inca Trail and want to keep your camera charged for those once-in-a-lifetime pictures? Enjoying the view from the top of a volcano? Overlanding in Africa, or deep in the Amazon jungle? Maybe you’re just somewhere the electricity supply isn’t guaranteed?
These are all scenarios I’ve dealt with, most recently in Namibia, southern Africa. As a result, the idea of having portable, clean, green energy available when I travel is one that’s close to my heart.
What is Green Energy?
Green energy is the energy generated from natural resources such as the sun, wind, water, geothermal, hydrogen, tidal, biomass, and the human body (kinetic), typically with little to no harmful impact on the environment.
Wherever I am, I try to reduce my impact on the environment as much as I can, and that includes using green energy options. As well as environmental concerns, though, the practical aspect is that access to a mains power source is far from guaranteed when I travel. Having the ability to use nature and my body to generate energy provides more freedom on the road.
For travelling, the best green energy options are solar, kinetic (movement), and wind energy, due to their accessibility and portability.
Solar is the most common portable green energy option for travellers so far. If you’re considering it for yourself, factors to consider include battery capacity, size, weight, efficiency, and of course, cost.
There are two main styles of solar charger:
- A small handheld device around the same size as a cell phone, which functions as both solar panel and battery;
- A “wallet” that unfolds to contain several solar panels. These are often around the size of an iPad, and many don’t contain their own battery.
Due to their size and features, I prefer the small, pocket-sized solar panels with inbuilt battery. Most of these smaller models only output to USB, so that’s what this discussion will stick to. Note that almost all of these types of device can also be charged from mains power, a good fallback option when it’s available.
I wouldn’t consider anything with a battery capacity under 10,000mAh. The formula for calculating how many times you can fully charge your phone from a given battery is a complex one, but in a perfect world, you could charge an iPhone 6 as many as four times from one that size.
If you’re an outdoor adventurer, it’s also worth checking if the product you’re considering is waterproof, or at least splash-proof. Better safe than sorry when you’re caught in a downpour, right?
The three products at the top of my solar charger list right now are as follows. They all designed for the outdoors, with a high battery capacity. In terms of bang for your buck, go for the Jetsun.
- 2 USB-A, 1 USB-C ports
- 1 micro-USB port (input)
- LED flashlight (400 lumens)
- 6.93 x 3.26 x 1.3″
- 2 USB-A ports
- 1 micro-USB (input)
- Dual LED flashlight
- 6.3 x 3.3 x 0.8″
- 11 oz
- 2 USB-A ports
- 1 micro-USB port (input)
- Quad LED flashlight
- 6.5 x 3.2 x 0.8″
- 13.3 oz
All devices can be charged from mains power, with solar usually recommended as a backup option. They also all come with a hook or clip of some kind, allowing easy attachment to a backpack.
Like a lot of people, I spend a great deal of my time walking when I travel. For me, it’s the ideal (and most cost-effective) way to explore a new city, plus I also quite like to hike. For this reason, the idea of harnessing kinetic energy is really appealing to me, Sadly, while there are devices out there targeting this approach to green energy, the reality falls behind the promise.
There are two main ways of generating kinetic energy:
- A magnet moves up and down within a copper coil to generate energy, which is then stored in a battery;
- A sensor triggers an electrical impulse, which is captured and stored in a battery.
The AMPY Move is a product I backed when it first appeared on Kickstarter a number of years ago. It uses the first method of kinetic energy generation, a magnet with copper coil. The Ampy Move device is reasonably small and light, and comes with a belt clip and arm strap. There’s a matching app that can be used to monitor your phone’s energy consumption, along with the energy generation of the Ampy Move.
The battery works really well as a backup charger, and can be charged from movement or a power outlet. Even with the Ampy Move strapped to my ankle for maximum “impact,” however, I found that after walking 20+ kilometres a day for three days, I had less than a quarter charge in the battery. I haven’t given up on Ampy, but I’m disappointed at the charging rate.
Somehow I was contacted for market research into a new kinetic energy product, StepCharge. It’s a product that’s still in development, but is available for pre-order. It uses the second method of kinetic energy generation, capturing the electrical impulse triggered by (in this case) a heel strike on a sensor.
Based on my knowledge of kinetic energy, I feel this method is more reliable, in terms of knowing that each heel strike will generate energy. The question is simply how many are required in order to get a decent charge into your battery.
StepCharge are aiming to gather energy from a heel strike or similar, and with that in mind, their products are all hiking-oriented. There’s a hiking boot, insole, and a type of crampon that fits over the shoe. My personal preference would be the insole, as the other two designs are single-purpose. I appreciate the versatility of the insole by comparison.
I would love to support their designs and ideas, but without proven results, I consider the price point of the products too high for a trial run (no pun intended) at this point.
HandEnergy is another crowdfunded product that’s still in development. It’s a ball-shaped gadget that contains a magnetic rotor. A starter ring triggers an impulse to start the rotor, which then spins as a result of hand movement. The rotor generates electrical current, which is captured and stored in a battery. It has an app that syncs with the device, to allow monitoring of energy generation.
At this stage, HandEnergy is something to keep an eye on — it’s available for pre-order, and due to be released to backers by the end of the year. Battery capacity is low (only 1000mAh), but if it can charge quickly enough, it might still be useful for travel.
Harnessing wind power is the least-developed portable green energy technology, and is something I haven’t heard much about. While there seem to be a number of devices in design and development stages, there’s nothing in production right now.
The devices also appear to be reasonably large, with some setup required, so I’m not yet convinced this is a practical energy method for most travellers yet. Just like the kinetic gear mentioned above, it’s more of an area to keep an eye on for the future.
Some of the products I’ve come across include:
- The Micro Wind Turbine from Nils Ferber appears to be a proven successful wind turbine, but as far as I can tell it isn’t in production.
- The WaterLily is designed to work with water or wind; it’s small but not tiny, and is in pre-order stage.
- Windpax (The Wisp) and Trinity were both funded on Kickstarter, but neither seemed to get produced or released.
Something that doesn’t fall into the above categories but is receiving a reasonable amount of attention is the BioLite camping stove , a wood stove with a component built in to convert heat to electricity via a thermo-electric generator.
The BioLite CampStove doesn’t appeal for the type of travel I do, but is worth looking at for avid campers and hikers. If you’re out in the wilderness and cooking your own meals on a camp stove, it’s definitely worth considering this dual-purpose stove/energy generator.
Portable green energy is an evolving field, and I’m particularly looking forward to seeing the developments in kinetic power generation. It is the type that most appeals to me — I love the idea of using my body to power my tech gear, and hope to see some efficient designs and products come to market in the near future.
In terms of what’s already on the market and proven to work, I’m excited by the range and affordability of solar products for the general consumer. Right now, if you’re after an inexpensive way of keeping your electronics topped up while away from the grid, solar’s the place to start.