Good Energy Blog: A tour through a solar panel factory. Also, a big leap forward for battery technology.

We get a close up look at how solar panels are manufactured at Silfab’s factory. And Manufacturer CATL expects to change the battery industry by the end of 2023.

Silfab Solar walks us through what goes into a solar panel

The beloved sci-fi author Arthur C. Clarke once wrote that “Any sufficiently advanced technology is indistinguishable from magic.”

And for many, solar energy is just that—indistinguishable from magic: Black panels bolted to your roof, powering your refrigerator, your lights or even your car.

But they aren’t magic. They’re the result of science, engineering and lots of hard work. In ADT Solar’s Good Energy blog, we talk about solar energy a lot, and we can even tell you the science of how solar panels work. But those panels still feel like magic to us. What goes into a solar panel? How does it all come together? We wanted to know. So we took a road trip to Mississauga, Ontario, to see how some of our favorite solar panels are made at Silfab’s solar panel manufacturing facility.

Silfab’s founders brought 40 years of solar experience to the venture when the facility opened in 2010. The original production line was just one-third the size of the current facility floor. With three production lines running two shifts, the facility’s output is complemented by two newer facilities in Bellingham and Burlington, Washington.

Ryan Adams, Silfab’s Director of Business Development, toured us along production line number one.

The first step in making a panel is to create a solar cell. Currently, Silfab imports those cells for panel assembly in Ontario, but creating solar cells is a fairly standardized process. Ingots of silicon are sliced into thin wafers. After being treated and having conductors attached, those wafers generate current from sunlight.

Robots and testing

On production line number one at the Silfab plant, the process of building a solar panel starts with a robot assembling an array of these cells together. Once soldered, the assembled cells roll to a testing station, where it’s tested with simulated sunlight.

Testing and robots play key parts in Silfab’s assembly process. Testing happens at multiple spots along the assembly. Occasionally, a partially assembled panel will fail a test and a technician will take it off the production track to remedy any shortcomings.

Once the assembled cells pass the first testing station, they move on to encapsulation, where they are sandwiched between sheets of anti-reflective, tempered glass using a paper-thin sheet of ethylene vinyl acetate, a type of high-tech glue. The whole assembly is heated to cure the glue.

After that, a back sheet layer is applied. The panels on production line number one are destined for the residential market, so the panels get a black back sheet. This gives the panels that sleek look which many consumers want.

The panels are close to finished now. A frame is attached to add strength and allow for mounting. The only thing left is the installation of the junction box. Sealing the box off from the elements ensures that it remains operational even under harsh conditions.

The panels are then graded. After the continual testing throughout assembly, only a small number don’t pass muster. The rest of the panels will be shipped out before the end of the day, as demand for Silfab’s panels continues to surpass projections.

The company has already announced plans for a new plant in the Southeastern U.S.

A new type of battery is about to change everything

Imagine flying on a plane that doesn’t burn fuel, but instead runs on batteries. Or driving your electric vehicle (EV) from Jacksonville, Florida to New York City without needing to charge it once.

To make that happen, we don’t need bigger batteries, we need better batteries with a higher energy density.

A battery with higher energy density stores more energy for the same amount of weight. Energy density matters a lot because an EV doesn’t just need to carry passengers—it needs to carry its battery, as well. So, building an EV with a longer range is not just about adding more heavy batteries—it’ is an efficiency challenge. Along with making a car more expensive, the additional batteries weigh the car down, making it much less efficient. If a driver takes a couple of 500-mile road trips every week, then hauling all that battery capacity makes sense. But if he or she just commutes 30 miles back and forth to work every day, hauling 1,000-miles worth of heavy batteries is very inefficient and expensive.

Energy density is measured in watt-hours per kilogram (Wh/kg). The lead-acid battery that has been starting internal combustion cars for over a century gets around 25 Wh/kg. (1) The alkaline batteries that powered those old school Walkmans and boomboxes comes in at around 120 Wh/kg. —That’s pretty good, but those batteries are n’t rechargeable. (2) The 21st century batteries we use every day can pack in around 255 Wh/kg. (3) That huge jump in energy density has driven much of the difference in how we use technology. Our phones, our cars, the power tools in our garages and our whole home energy backup systems are all made possible by the energy density of lithium-ion batteries. These batteries are so life-changing that in 2019, M. Stanley Whittingham won the Nobel Prize for the research that led to batteries with 255 Wh/kg.

Getting even higher energy density unlocks many possibilities. In 2020, Tesla’s Elon Musk said that batteries with 400 Wh/kg would allow for electric planes. He predicted the technology was three-to-four years away. (4)

Last month, Contemporary Amperex Technology Co (CATL), the largest lithium-ion battery manufacturer in the world, announced it had perfected a condensed state battery with an energy density of 500 Wh/kg, and that they would start rolling off the assembly line by the end of the year. (5) The breakthrough is based on a semi-solid-state chemistry, unlike current lithium-ion batteries, which are more dependent on liquid. That difference also brings safety improvements, according to the company.

The China-based company made the presentation at the Shanghai Auto Show and said it would produce batteries for EVs in 2023 but was also actively developing the tech for planes.

CATL has a long track record of delivering on announced battery innovations. If they can deliver this technology to customers in the near future, you can expect to see big changes in our cars and devices soon.

The Weekly Sunsong

No, despite the rumors, we did NOT commission this song.