Solar chargers FAQs
What should I look for when buying a solar charger?
Before buying a solar charger, it’s important to factor in what kind of trips you will be using it for. Typically, there are three things worth considering – output capacity, surface area and the flexibility of the panels.
- Output capacity: Solar panels are rated in watts. The higher the number, the more electricity is generated during a given time period.
- Surface area: The larger the solar panel, the more sunlight it can collect and, in turn, the faster it gets converted to battery-stored power. For this reason, a large surface area is a good option for times when the weather conditions are less than favourable, including cloud cover or low-intensity light in winter.
- Semi-flexible or rigid panels: Flexible solar panels are great for those with limited bag space as they can be simply rolled or folded up for easy transport. They are also a great choice as they can be folded out to a greater surface area than a rigid model.
How long do solar chargers last?
While performance varies from model to model, most models can last upward of three years, with some of the more premium designs claiming to last an impressive 25 years.
Do solar chargers work through a window?
Yes, but the amount of energy harvested by the panel will be greatly reduced, especially if the glass is tinted or has UV light-blocking properties. According to Sol Volatics, a website that provides advice on solar panel installations, the efficiency of a panel can be reduced by up to 50 per cent, depending on the thickness and cleanliness of the glass. So yes, a solar panel left in a car on a sunny day will continue to work, but it’ll charge up a battery far less quickly than when outside in direct sunlight.
What are the best uses for solar chargers?
Portable solar chargers are best used to power small electrical items, such as smartphones and portable battery packs. They can be perfect for topping up the batteries of devices you might take on a camping trip, but generally aren’t much help when it comes to feeding more power-hungry products, such as televisions, portable fridges and kettles.
Some portable solar panels, such as the Ecoflow 220W (£449, Hampshiregenerators.co.uk) highlighted earlier, cost much more than others, are significantly larger, and therefore will harvest more energy. Such panels can, eventually, fill up an equally large portable battery pack capable of running anything with a domestic three-pin plug, but how quickly the battery charges will depend on weather conditions and how much sunlight the solar panel is exposed to.
Also, don’t forget that a solar charger with a higher output, measured in watts, will charge up a battery more quickly. So the 220W panel from Ecoflow will charge a phone more quickly, in the same sunlight, than one rated at a lower wattage.
Will using a solar charger save me money?
As ever, it’s complicated. The energy harvested by the solar charger costs absolutely nothing, so yes, if a smartphone or portable power bank is charged exclusively from a solar panel, that energy will have been free. However, you have to factor in the initial purchase cost of the charger, before working out whether using the panel will save you money.
The long-term answer is yes, but only once you have harvested enough energy to have saved more money than the panel cost in the first place. A top tip is to carry an empty portable battery each time you use your solar panel. That way, even once all your devices are charged up – while out hiking on a camping trip, for example – you can top up the spare, empty battery whenever the sun is shining, so that free energy will be ready to use later.
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What are the alternatives if there is no sunlight?
Obviously, solar panels don’t work without sunlight to power them. If you live somewhere with reduced or zero sunlight during the winter months (which includes the UK and parts of North America), you’ll see a dramatic downturn in solar panel energy output when the sun is low in the sky.
To supply electricity in a remote area with little sunlight, you’ll either need a very large battery pack to store up what little solar energy is available, or a fully fuelled diesel generator. The latter is by far the cheapest way of powering remote sites or an entire home, and, to deal with emergencies, they can be set up to kick into action in the event of power loss.
The verdict: Solar chargers
The Goal Zero nomad 2 has everything you might need in a solar charger: high wattage, an abundance of USB ports and a business-like folding design and the leading monocrystalline panel type.
For mains-style power output on demand, the Ecoflow portable power station and 220W panel is highly recommended.
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