# What Are Solar-Powered Calculators and How Do They Work?

Solar-powered calculators run on solar cells. In this article, we will give you an insight into solar powered calculators, their origin and how they work.

Calculators are essential at some point of time in our lives. They come in quite handy for high school and college kids to provide solutions for their math problems.

Likewise, many times, even at our workplace, we never know when we could need the assistance of a calculator.

As students, many of us have might have used scientific calculators during math lectures. These calculators are mainly battery-powered.

Once the batteries lose their charge, your calculator stops working. For these calculators, the battery life and quality become integral aspects to ensure their smooth functioning. For this, you must charge your calculator effectively.

## How Solar Calculators Are Different From Regular Calculators?

We have heard of various gadgets that run on solar energy. Do you know that even your calculator can run on solar power? Yes, you read it right.

Solar-powered calculators, as they are called, run on solar cells. What do these calculators look like? Well, they are small, handheld gadgets, just like your regular calculators, which work in the presence of solar energy.

In this article, we will give you an insight into these calculators, their origin and how they work. We will also give you suggestions on some of the best solar-based calculators presently available in the market in case you are planning to purchase one.

## What Are Solar-Powered Calculators?

Going by their looks, solar calculators resemble regular calculators only. The difference is in the manner in which their batteries are charged.

Battery-based calculators consist of AAA batteries or button-like cells. When these batteries or cells die, they need to be replaced to get your calculator going.

On the other hand, a solar calculator is composed of solar cells or panels which feed on solar energy or light. The solar panels in these calculators are energized in the presence of light.

How does this happen? The presence of amorphous silicon, a photovoltaic material,  present within solar panels facilitates this.  This enables these solar panels to convert solar energy into electricity, which in turn automatically charges your calculator batteries.

Now we know why solar cells are also referred to as photovoltaic cells. Hence, these calculators are also known as photovoltaic calculators.

Solar calculators can come with or without batteries. Pure solar calculators come without any battery backup. They completely rely on sunlight for charging themselves. When there is less light, these calculators may not get charged up very effectively. As a result, they will stop functioning.

The other variant of solar energy calculators comes with batteries. This variant relies on batteries when there is not much solar energy available or in low-light conditions.

The best example of this type of calculator is the NEWYES Scientific calculator. Now you may wonder why batteries are essential when solar energy can do the trick. Well, whenever there is insufficient light for your solar calculator, the batteries come to your rescue. Because of the battery presence, dual-powered solar calculators continue working.

Dual-powered solar calculators are quite efficient in terms of energy consumption. These panels help in energizing the batteries that get your calculator working. To sum it up, whenever your calculator batteries are low on energy, they can utilize some energy from solar panels.

Once the batteries are fully energized, the calculator can switch back to battery mode. It is because of this that batteries within solar-panel calculators are long-lasting. This automatically increases the lifespan of your calculator.

Now that you are aware that solar panels energize the batteries and improve the life of your calculator, how long do you think you can use them without any issues?

Well, it is difficult to predict a definitive lifespan for these calculators, however, if you maintain them well, they could last for about 15 years on an average. Some people even claim to have used them for 20 years. So this guarantees one thing – solar calculators can work efficiently for a long time.

In comparison, lithium-ion battery-powered calculators last for about 3 years, again depending on their usage, battery quality, calculator maintenance, and many such factors. Now that is a huge bit of a difference.

However, keep one thing in mind. Once you have used your solar calculator for about a decade, the batteries do not charge up to their full capacity, rather, they charge up to only 60% of their complete capacity. This is a signal that the battery efficiency is on a downward trend and your calculator may not last too long. Still, its lifespan is quite high when compared to battery-powered calculators.

This was all about the efficiency of solar calculators when compared to their battery-based counterparts. However, did you realize that by using solar gadgets, you would be helping our environment as well?

After all, what could be better than using natural energy resources like solar energy and conserving battery usage? These gadgets also give an insight into their power consumption analysis, thereby encouraging people to start using solar-powered devices.

## Origin of Solar-Powered Calculators

If you are wondering that solar calculators are quite new in the digital world, you may be wrong here. These calculators arrived way back during the late 70s.

The very first solar calculator called the Sharp EL- 8026, also known by the name Sun Man, made its first appearance in 1976.

The solar panels within this calculator are mounted on the rear portion from where it powers up the batteries. The photovoltaic cells within this module in-housed the S-225 silicon monocrystal which came with a 10% cell-conversion efficiency.

The Sun Man was a major contrast to the age-old calculators that were quite dominant in the 60s decade, the latter being quite bulky and costly. With the arrival of this model, transistor technology and screen technology started coming into the picture.

However, the Sharp EL – 8026 had a major disadvantage. The problem with this one was that the solar panels were installed in its rear portion. Hence it became a little inconvenient to use it while on solar power.

Fast forward two years later, in 1978, came the Teal Photon. This completely ran on solar energy, without any batteries. However, the Teal Photon required very bright light to charge up. Moreover, there was no battery backup either.

A few years down the line, somewhere during the early 80s, both Sharp and Texas Instruments started bringing out solar panels that could work well even if the light was not very bright. With this invention, solar calculators began making a mark and establishing their presence in this area. By 1982, scientific solar calculators had started to come on board.

Sometime in 1984, Texas Instruments, as part of their promotional activities, offered free solar calculators to those firms and organizations which purchased their computers.

Sometime later, Texas Instruments struck a big deal with Chicago Public Schools when the latter when on to purchase a lump sum quantity of 167,000 solar calculators for a whopping \$1.1 million.

## How did Solar Calculators Find a Place in the Education Industry?

Gradually, solar calculators began replacing log books and students began using them quite extensively in their math classes. Although teachers were not quite happy initially with this development, later on, they gave in to the idea of solar calculators becoming a part of math classes as they made students’ lives much easier. And these calculators ran on a natural energy source, hence there was no worry of batteries dying out.

These solar calculators were quite compact in terms of size and came with basic operational symbols like addition (+), subtraction (-), multiplication (x), division (/), and equal (=). These basic functionalities could easily work on solar power. They could function efficiently even in the presence of artificial light.

### How Did Battery-Powered Calculators Gain Importance Over Solar Calculators?

Although solar calculators manufactured by Texas Instruments continued their popular run, school children began opting for TI-89 models as they proved to be quite useful for them to solve their math problems. Students started relying on TI-89s for their calculus and trigonometry solutions.

These calculators required a lot of energy and solar power was not enough to recharge their batteries. Thus, battery-operated calculators slowly began to take precedence over solar calculators.

Presently, many people are opting for solar-powered gadgets as a part of the “Go-Green initiative”. Solar panels are being set up on house rooftops as well as on parking lot covers. We also have batteries that can store solar energy.

## How Do Solar Calculators Work?

Solar calculators require natural sunlight or bright light to get working. Going by the looks, solar calculators resemble our regular calculators only.

For battery-based calculators, the charging happens through the batteries. You can recharge a battery-powered calculator under bright light, however, keep them away from normal light.

When the battery life is over, it simply means that you need to replace them. Regular calculators can be used easily anytime and anywhere once they are completely charged.

Now coming to solar calculators. The solar panels or solar cells on these calculators, also known as photovoltaic cells, need sunlight to get charged up.

Now how does charging happen under sunlight? Well, the silicon element housed within these photovoltaic cells converts solar energy into electricity, thereby automatically recharging the batteries within them.

Solar calculators have an LCD display. The remarkable thing about LCD screens is that they are quite efficient and can operate pretty well within a low voltage range of 1.5V to 2V. A few solar calculators like TI-701 LOOK (Graffiti), house a light pipe within them. With the help of this pipe, the light rays can meet properly on the solar cells. This in turn guarantees efficient charging.

The buttons on a solar calculator are like the buttons on any regular calculator. Different models carry buttons with different features. Some calculators could have the tax, currency, and profit margin calculation feature, some could have the square root feature, and so on.

All solar calculators will have the basic math symbols like +, -, x, /, and = along with the power OFF/ON button. The calculations within a solar calculator are designed to work just like any other battery-based calculator.

## How Can You Recognize a Pure Solar Calculator?

If you are using a solar calculator, you will observe some very distinctive features in the way it works when compared to an ordinary calculator. Calculators that are completely dependent on solar energy for their functioning will not work properly when they do not get sufficient light, or when their solar panels are obstructed.

During such situations, notice that the numbers do not appear very bright on the screen and they start fading gradually. Moreover, you could find a slight time delay between pressing the buttons on the calculator and their appearance on the screen.

In simple words, when your solar calculator does not receive the intended amount of light, you could find it a little slow in terms of its working. Hence, you need enough light to operate a solar calculator.

To find this out, you can test your solar calculator on whether it works as it should within a dark room. You can even try to deliberately cover the solar panels. If your calculator solely relies on solar power, observe that its screen does not appear as bright as it should.

If your calculator works efficiently even in darkness, this simply means that it is utilizing its battery energy (in the case of dual-powered calculators). Purely battery-operated calculators will have no problems operating in the absence of light.

### Does Bright Sunlight Damage Solar Calculators?

Although these calculators solely depend on solar energy, this does not mean that you have to expose them to direct sunlight. Whenever you need to charge your calculator, you can place them where there is lots of light, however, just see to it that the sun’s rays do not fall directly on your gadget.

Exposing your calculator to direct sunlight for very long periods tends to damage the sensitive receivers present within the solar panels.

## How Long Does It Take to Charge a Solar Calculator?

To answer this question, the charging time of a solar calculator depends on a few factors. If your calculator is quite old, or the solar panels have worn out a bit, chances are quite high that the capacity of its charging system could have gone down considerably.

In that case, the charging time could be longer. Moreover, if the sunlight is not too powerful, you may not see quick results.

On the other hand, if you choose to charge your calculator at that time of the day when the sun’s rays are at their strongest point, the charging could be better and faster. If your calculator is quite new with the latest features, don’t be surprised to see it getting completely charged in as less as 30 minutes!

## Can You Charge Your Solar Calculator Indoors?

The spectrum of sunlight has a wavelength ranging anywhere from 400 to 700nm. Artificial lightings consist of visible wavelengths within the range of 400 to 700 nm.

This includes your incandescent bulbs and fluorescent lighting. If your solar calculator has been designed to work well within these light wavelength ranges, then it should charge pretty well under artificial light as well.

So, to answer your question, yes, you can charge your solar calculator under artificial lighting. However, it may not be a very efficient technique for charging your gadget. Let us look at the reasons for the same.

### 1. Loss of Energy:

Sunlight is natural whereas artificial lights consume electricity. Hence, when you use incandescent bulbs to charge your calculator, imagine the amount of electricity that you would be consuming. Natural light comes free of cost and also helps you in achieving your carbon footprint

### 2. Less Intense:

You cannot compare the spectral intensities of artificial lights with that of sunlight. Undoubtedly, sunlight scores much better in this aspect when compared to your fluorescent bulbs.

Moreover, the spectral intensities of artificial lights do not remain consistent. This causes a significant reduction in their power, ultimately reducing their energy.

### 3. Light Obstructions:

Artificial lights can never reach solar panels directly. They are obstructed by various elements like glass (which covers the bulb). The glass absorbs some of the light, and this could even cause the light rays to deviate and spread out across the room. Hence, your calculator could take longer to get charged.

To sum it up, you can use artificial light to charge your calculator only when you do not have access to sunlight, like on cloudy or rainy days or even in darkness. However, your primary preference should be natural sunlight only.

## Can Solar Calculators Have Fake Panels?

Many manufacturers put up fake solar panels in calculators. You may find such calculators to be relatively cheaper, but in the long run, they won’t be useful.

Fake solar panels cannot convert solar energy to electricity. Eventually, when your calculator batteries die out, your calculator too would wear off. Hence it is always better to check for the authenticity of all these products before you purchase them.

## The Best Solar Calculators to Buy

Now that you have understood how solar calculators can go a long way in protecting our planet by conserving energy, you might be planning to own one for yourself in case you rely on calculators.

Each one of us could have a different purpose for buying a calculator. The needs of students and professionals when it comes to owning calculators could be poles apart.

Keeping all of these factors in mind, here are some of the best picks that we have shortlisted for you. Check them out and go for the one which suits your needs best.

You will also get an idea of how much each solar calculator costs on average. The prices will vary depending on the inbuilt features within each calculator.

### 1. Helect Standard Function Desktop Calculator

The Helect Standard Function Desktop Calculator has been designed to make the lives of accountants and finance professionals much simpler.

If you belong to either of these two categories, then consider purchasing this one. Let us check out the features of this calculator:

• It is a dual-powered calculator. This means that it can last for many years since it works both on solar power and batteries.
• In the absence of solar power, it needs AA batteries for its functioning. It is better if one AA battery is always present within the device to avoid any sort of interruptions in the absence of light.
• Contains big-sized keys and a wide 12-digit display.
• Contains all general keys (+, -,X, /, =, %). Hence it can provide solutions to your daily math problems.
• Can be used for calculating profit margins and tax. It also assists in currency conversion.
• You can choose this calculator in any of the following colors: Black, Blue, Orange, White, or Plum.
• The price of this calculator ranges from \$9.99 to \$11.99. The price variation is due to the different colors.

### 2. Casio SL-100L Basic Solar Folding Calculator

The Casio SL-100L is a desktop calculator with a folding mechanism. When folded, it becomes so compact that it can easily fit within your pockets. Let us have a look at some of its key features:

• This is a true solar calculator. It completely works on solar power. When idle for 8 minutes, it automatically shuts off.
• The hinges are quite stiff; however, you can completely open it and can comfortably view its screen when kept on a flat surface.
• Consists of a wide 8-digit display. This ensures good readability for everyone.
• Comes with an independent memory.
• Includes all basic operations. Also comes with the percentage and square root key.
• A comma marker is present after every third digit.
• This one costs \$5.43.

Although the Casio SL-100L is not very big in terms of its size, it scores huge points in the solar calculator category. The only drawback in this one is the absence of a backlit.

### 3. EastPin 12-Digit Dual-Powered Solar Calculator

This scientific calculator manufactured by EastPin consists of a large 12-digit LCD display with big-sized keys. This one can run on solar energy as well as a single AA battery. This simply means that you can use it even in low-light conditions. The calculator automatically switches OFF when it is in an idle position for a long time. Let us check some of its features at a glance:

• Works on both solar power and battery power. A single 1.5 V AA battery is sufficient.
• The big-sized buttons make it simple for people to use it. Made of ABS plastic, these are quite comfortable to touch and press.
• The 12-digit display screen is ideal for businessmen and teachers to use in math classes.
• This one costs \$8.99.

### 4. Casio MS-80b Standard Function Solar-Powered Desktop Calculator

The Casio ms-80b solar calculator is again a desktop calculator. Considered to be one of the USA’s top calculators, this one is a good choice of calculator for business people and finance professionals. Even students will find this one quite useful. The size of this calculator is such that it can easily fit within your bag.

Again, this is compatible with both solar and battery power.

Some key features of this calculator include:

• Again this calculator is dual-powered. It works both on solar power and battery power.
• It comprises a large 8-digit LCD display.
• The display screen is placed at an angle of 25 degrees.
• If you are someone dealing with tax, currency, and profit-margin calculations, then this one is quite helpful for you.
• This calculator is available in three colors: Brushed Nickel, Blue, and Silver.
• The price of this calculator ranges from \$7.39 to \$10.69. The price varies depending on its color.

### 5. Sharp Electronics 8-Digit Dual-Powered Calculator

This 8-digit dual-powered calculator manufactured by Sharp Electronics is a very cute dual-powered, pocket calculator. The calculator measures 4.25 x 2.5 x 0.7 inches in size, and hence, you can carry it with you anywhere you want to.

All your daily math solutions can be provided by this one and hence, you can use it for both your home and office needs. Some of its characteristics are as follows:

• Contains a hinged protective cover that ensures high protection.
• Has a large 8-digit LCD display which provides a lot of clarity.
• Consists of 3 memory keys (memory plus, memory minus, and recall/clear memory keys).

Although this calculator can be used by everyone, students will find it quite useful. Even professionals can use it during their meetings and business trips.

## Conclusion

Well, we hope that now you have a very fair idea of solar-powered calculators regarding their origin, history, and how they work.

You also know the best ones to go for in case you are planning to purchase one. Apart from helping yourself with the calculator, you will also be doing your bit for our planet by using natural energy sources. So go ahead and get one if you intend to!

### Are solar-powered calculators real?

Yes. Solar calculators are real and quite helpful.

### How long does a battery last in a calculator?

The battery life in a calculator depends on its usage, maintenance, and its quality.

### Can solar-powered calculators store energy?

Solar calculators convert solar energy into electricity, which helps in the charging process.

### Do solar-powered calculators need batteries?

A few solar-powered calculators come with batteries. These are known as dual-powered calculators. These are useful when there is no light or less light.

### Are Casio calculators solar-powered?

A few Casio calculators are solar-powered. Some of these are really good ones.

### Who invented the solar calculator?

Solar-calculators were first manufactured by Sharp in 1976.