As solar increases in popularity across the world, more investments are being funneled into the development of solar cell technology.

The goal is to continually improve solar cell efficiency, while also making these cells durable and applicable to everyday situations like powering your phones, vehicles, clothing, and other smart devices.

One solution that scientists and engineers came up with are solar cells that have the ability to flex and curve around objects. Flexible solar cells, as they are referred to, can be fit to objects and devices that would otherwise not be suitable for a more rigid solar cell like the monocrystalline and polycrystalline cells used in residential and commercial solar panels.

As flexible solar cell technology continues to improve, more consumer options become available. In this post, we will look at some of the latest updates in flexible solar cells for your smart devices.

Where is flexible solar panel technology today?

There are several flexible solar cell products that are currently on the market for consumers to purchase. One great example of this technology is SunPower’s flexible panels.

These panels are lightweight and portable, which allows you to take them with you on the go. Portability is a huge value proposition for flexible solar cells, especially since they are not nearly as practical for use on your home like the more rigid panels are.

SunPower’s 110-watt flexible panels weigh 5 pounds, are 46 inches in height, and 22 inches in width. They are used to charge portable batteries, which can then be used to power or charge any compatible device.

This type of flexible panel uses high-efficiency, ultra-thin silicon wafers that are stacked upon each other to make up the photovoltaic cell. Although SunPower’s Maxeon solar cells may be superior in quality to other cells, this category of ultra-thin silicon panels has existed for several years.

The Latest Developments in Flexible Solar Panels

There are new advances in flexible solar panels being made all the time, but the most prevalent problem that arises from this research and development is a question of how to convert these discoveries into a viable commercial product.

Scientists from around the world are working on this problem to help move this technology forward. There are two main issues that the current form of flexible solar panels encounter: 1) The cost of production, and 2) The lifespan of the modules.

1. Cost of Production – To decrease the cost of production, flexible solar panels must be manufactured through roll-to-roll processing, which means that they must be produced on a flexible plastic or metal foil that can be rolled up. One method to accomplish this is through ink-jet printing, which would allow the dye and electrolyte components to be inserted into the foil.
2. Module Lifespan – It is important that the amount of energy a flexible solar cell produces in its lifespan is greater than the amount needed to produce and transport the solar cell itself. If this wasn’t the case, then the solar cell in question could not be considered a renewable resource. The rigid nature of silicon-based solar cells makes it more prone to damage when curved. To solve this, new materials are being experimented with to manufacture solar cells that can withstand these conditions easier.

One example is the flexible, transparent and organic solar cells being developed by MIT. The MIT researchers involved in this project developed these cells using graphene that can easily attach to almost any surface. A 1-atom layer of graphene electrodes is combined with organic (carbon-containing) materials to produce these transparent and durable solar cells.

The coolest part of these solar cells is that they can be fit onto things like clothing, phones, bicycles, stop signs, sidewalks, and almost anything else you can think of. Unfortunately, it will still take some time before we see this form of technology adopted on a large scale.

A Flexible Future for Solar

It seems that the future of solar technology is naturally leading towards flexible photovoltaic cells. Flexible solar cells bring many benefits, namely increasing the number of devices, objects, and surfaces that can be converted into a source of renewable energy.

If we want a future where almost any available space can passively generate solar energy, then we need technologies like this on the market. Keep your eyes open for new advances being made in this area. If you’re interested in learning more about (rigid) solar for your home, get in touch with one of our energy advisors!

Cover image source: infinityPV

It’s easy to confuse heat energy and light energy since we often experience them in tandem. But when it comes to solar panels, there is a big difference between the two.

This is because of the unique characteristics of a solar panel. This difference plays a major role in answering the question of whether or not solar panels work less at certain temperatures.

The Science of Solar Energy Conversion

The number one (often forgotten) rule of solar electricity is that solar panels generate electricity with light from the sun, not heat.

While temperature won’t change how much energy a solar panel absorbs from the sun, it actually can change how much of that energy is converted into electricity. If a solar panel is extremely hot or extremely cold, its efficiency does drop. This is typical of most devices and electronic equipment, so it shouldn’t come as too big a surprise.

What might be somewhat surprising though, is that solar panels actually seem to be able to handle a bit more cold than a bit too much heat. Here’s why.

A Hot Solar Panel vs. A Cold Solar Panel

Inside a hot solar cell, atoms vibrate at a faster rate than when the solar cell is cool. Electrons within the atoms are normally energized to a higher level with sunlight, and thus generate electricity.

In rudimentary terms, when excess heat causes the atoms to vibrate faster, the electrons inside the atoms have a harder time getting out. When this happens, the energy never makes it like an electrical current.

Another way of looking at this is that solar cells produce power by the electrons moving from one energy state (rest) to a higher one (excited). When a solar panel is hot, the difference between the rest state and the excited energy state is smaller, so less energy is created.

The opposite happens when a solar panel is cooler. Inside a cool solar cell, the electrons are still getting excited by the sunlight and they’re easily able to move up to the higher level of energy. This is because the atoms aren’t vibrating. Though the electrons move slower, the ones that make it through carrying more energy than the electrons in a heated state.

How Big a Difference Can It Make?

Solar panel efficiency drops by around 0.05 percent for every degree Celsius increase in temperature. On the other hand, efficiency increases by 0.05 percent for every degree Celsius decrease in temperature. It’s important to note that we’re talking about the temperature of the panel itself, not the outside temperature, though air temperature can obviously affect panel temperature.

Exactly how much efficiency changes depends on the hardware and how solar panels are designed. Solar panel manufacturers measure how well a panel handles heat or cold as a “temperature coefficient”. It’s a range for the temperatures at which a panel can produce at its best. Here’s an example. A 200-watt panel at 20 degrees Celsius (68 degrees Fahrenheit) might only produce 180 watts when the panel reaches 45 degrees C (113 degrees F).

Cooler Is Better for Solar Panels, but More Sun Makes up the Difference

The ideal day for a solar panel is actually cold, sunny and windy. Under these conditions, the panel gets plenty of energy from the sun, keeps cool, and the wind sweeps away the normal levels of heat generated within the solar panel itself. Of course, bitterly cold arctic temperatures can eventually slow down production too. At a certain temperature, everything slows down.

So, while cooler temperatures are actually better for solar panel production, the warmer regions make up for their heat with extra sunshine. Cooler regions tend to be at slightly less advantageous angles from the sun and the equator but make up for it in great efficiency when the sun is shining. All in all, whether you live in a warmer or cooler region, you can get great solar efficiency.

Curious about temperature coefficients? Read more about them and other features of major brands in these posts. This one compares Hyundai and Panasonic. Or read about the differences between LG vs SunPower here.