The newest solar panel technology was on display at Solar Power International in Las Vegas. The biggest attention getters were higher efficiencies and bifacial – but there are other technologies- cut cells, string ribbons, anti-soiling coatings, and solar tiles – that also deserve some time in the limelight.
On this site, there is a huge amount of attention going toward the Tesla Solar Shingles, with installations just starting to appear in the wild, but there are plenty of other good-looking panels in the silicon sea!
First off – solar roof tiles from Hanergy – Hantiles. I’ve seen product like this in pictures on the internet, but never seen them in real life. Hanergy launched the product back in July. The company produces Hantiles by encapsulating thin, flexible thin-film solar cells into ultra-clear float glass. It claims the PV cells in Hantile offer a conversion efficiency rate of 16.5% at the production level, with a target of 17.5% by the end of 2017. One gentlemen standing next to the table admiring the product with me, suggested it’d be a real challenge for Hanergy to get these approved to be used as building materials in the USA. If approval occurs – I’d bet a lot of people would be interested in a premium 16.5% efficiency, beautiful product on their roof. Pretty cool.
Busbars – respected readers – we’re going to talk busbars! Busbars are the vertical metal strings across the front of solar cells to move the electricity. Amazingly – there is a lot of love for busbars in the solar technology world – with the world increasing from 3 to 4 to 5 before the movement to get rid of them completely, eventually – the reason: Over a traditional three-busbar module, four-busbars gain 0.76% of performance, five-busbars gain 1.13% and six-busbars gain 1.32%. The header image of a Yingli bifacial solar panel clearly shows five thick, clear and clean busbars. Cutting edge stuff! However – the LG Neon product has a 12(!!) ribbon busbar. The round wire scatters light toward the cells more so than a wide flat bar reflects.
The next item to show off – ‘half cut solar cells.’ Yes, 1/2 of a solar cell is innovation today – and the naming structure is as literal as it comes with these solar panel people. You saw in the above busbar paragraph a 1%+ efficiency gain – well check this out: When switching to half-cut cells, four-busbar-half-cut cells gain 3.59% over full-sized three-busbar modules, five-busbar-half-cut cells gain 4.01% and six-busbar-half-cut cells gain 4.24% in performance. The picture below is from Hanwha-Q Cells where I had such a great highly technical conversation with a knowledgeable member of their team. Notice the half cut solar panel comes with six busbars! That’s a year 2020 technology right there.
The last thing to show off for solar panels – anti-soiling material. Thing gets dusty. We need to clean our panels. Dusty regions in the US can knock more than 10% of performance off. DSM’s Advanced Solar line professes 3% greater performance twice – the first with an anti-soiling layer and the second with an anti-reflective layer. The left below is a wee bit exaggerated to how things will happen in real world situations with soilings, but you get the point. The image on the right comes from their catalog and breaks down their products and the benefits. Solar panels are like onions…with layers.
When we see the solar industry expanding at 30% in a year – there are going to be a lot of smart people looking at solar panels. Expect there to be other innovative paths to squeeze additional efficiency out of solar panels.