Sure, most people just use the built-in calculator on their phones nowadays…and sometimes even try to have google solve the problem for us, but it seems like everyone has an old-school calculator in a drawer at their house. You know the ones, small buttons, basic functions, and…weirdly enough…a little solar panel.
Typically, a calculator will have a solar panel because it charges the battery that powers the calculator. When this battery gets low, it will automatically start to use power from the solar panel until a full charge is reached again and then switch back over to using just the battery.
While this may be an unusual way for calculators to make use of renewable energy sources, they offer a number of other benefits as well:
- Long-Lasting Batteries – Unlike other battery-powered electronics, solar panel calculators can last for decades with the original batteries…this is why the one I used in High School in the 90’s still works!
- The Environmentally Friendly Alternative – Rather than having to constantly buy new batteries, a calculator will only need one set of replacements every few years or so. This means that fewer disposable items are going into landfills and less
- Simple Reminder To Save Some Energy – They provide students with valuable information about how much power their devices consume in comparison to others which can help them reduce their environmental footprint and save money.
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How Long They Last
A well taken care of solar calculator can last for decades…and even a lifetime. With few parts that require energy and don’t produce any heat, they are also one of the most environmentally friendly calculators.
Sure, most people will just whip out their phones to do some quick math, but solar-powered calculators are great if you are camping or in the field and don’t want to waste precious battery life on your other devices.
Some nicer grocery stores have also started providing shopping carts with solar calculators built right into the handles. They provide a convenient tool for shoppers and, since shopping carts sit outside for many hours of each day, always have plenty of charge at no additional cost to the shopper or store.
In short…solar calculators are going to virtually last forever, but I go into more details about that over here in this article:
Do Solar Powered Calculators Work With Artificial Light?
Since most artificial light shares aspects of the sun’s light spectrum, many calculators have a light sensor that will automatically detect the brightness of their surroundings and power themselves accordingly.
The sun produces a light spectrum between 400 and 700nm (1). These wavelengths are the ones that produce that yellow hue from artificial light sources like bulbs, so they can be used to tell if a solar-powered calculator will work in low-light situations or not.
Since most artificial light is made up of the more visible wavelengths in that range (400 to 700 nm), then they will work well for solar-powered calculators which are designed to operate on these same wavelengths of light.
Fake Solar Panels
Some calculators have a fake solar panel instead of the traditional battery with a built-in light. This typically has an LED light that appears to go off when the battery is full, but there may be many other different signs that it needs recharging.
Though this might seem like it’s saving you some money in the short term, they will eventually stop working when their batteries die since these fake panels don’t actually produce any electricity.
How Much Power Does A Solar Powered Calculator Require?
The battery and solar panel in a calculator take up the majority of its weight, so it doesn’t usually need much power to run. This is why calculators with this particular setup can last for decades on just one set of batteries.
Solar-powered calculators often use LED screens which consume little energy compared to LCDs found in smartphones and tablets.
How They Work
Solar-powered calculators use a solar panel to collect energy from the sun and convert it into electricity. A battery inside stores this power for later use, so you can see your calculations any time of day or night.
While not nearly as complex as a home’s solar power system, a solar calculator works similarly in that a solar panel collects light from the sun and delivers it to batteries for storage.
But a solar calculator won’t use a complex inverter (a device that turns DC power into AC power) like a home’s solar array. For more information on solar inverters, check out this article:
Recycling Solar Calculators
Modern solar calculators are typically made of plastic, metal, and glass. These materials can all be recycled when the time comes to replace your old calculator with a new one!
The majority of modern solar-powered calculators will contain nothing but plastics, metals, and glasses which are easily recyclable in most locations. Solar panels themselves often have some metal in them, so these panels will also need to be recycled.
Final Thoughts
Solar calculators are a great way to save money on power or reduce your carbon footprint. They work great under artificial light and never need charging once they’re fully charged in the sun.
And while they’re not totally necessary anymore, it may not be a bad idea to keep one around the house or with your road trip gear or shopping bags…why put the extra strain on the battery of your phone when you can use a calculator that is virtually immortal!