Late last year, Bloomberg reported on a remarkable turning point: Solar is becoming the cheapest form of new energy in many parts of the world. This headline would be significant regardless of external events. But at a time when commitment to renewables in the United States is in question, the prospect of subsidy-free solar that can outcompete fossil fuels is a big deal.
But has solar gone as low as it can go? Solar is a technology, not a finite fuel, so most experts suggest that technology and installation costs should keep dropping due to economies of scale. There are also several researchers and companies promising a next generation of solar products, products that could mark a significant leap in cost, efficiency or adoption.
If and when that happens, all bets are off for the future of traditional energy industries. Here are some of the innovations to watch:
Perovskite solar cells: A simpler, cheaper technology
Hybrid perovskite-silicon solar cells have the potential to reach 30 percent efficiency, and may be ready for commercialization in the next few years. (Photo: Oxford PV)
Perovskite solar cells use hybrid organic-inorganic lead or tin halide-based materials as the light-harvesting active layer, making them cheap to produce and simple to manufacture. They can either be used alone (printed directly onto glass, for example, for building-integrated applications) or they can be used in tandem with traditional solar to boost efficiency by adding an extra layer of light harvesting.
So far, they've not achieved widespread commercial adoption due to their relatively low efficiency, concerns about potential toxicity and unknowns about stability and potential lifespan. However, efficiency in lab-based situations has advanced from 3.8 percent in 2009 to 22.1 percent in early 2016. This is a rate of improvement that surpasses the development of silicon-based solar technologies most commonly in use today, and researchers have made good progress on reducing toxicity too.
Earlier this year, a company called Oxford Photovoltaics announced 8.1 million pounds in equity funding from major energy investors like Norwegian Statoil to help finance the commercialization of its thin-film, perovskite-based solar modules. Science Magazine recently reported that commercially-produced tandem perovskite-silicon solar cells could be ready for field testing by 2018, and that the technology has the potential to achieve 30 percent efficiency.
Rayton Solar: 60 percent cheaper, 25 percent more efficient?
California-based start up Rayton Solar takes a different approach, working with widely adopted silicon-based solar technology but using a radically different approach to manufacturing. As explained in the Bill Nye-backed pitch video above, Rayton claims it can radically reduce the inherent waste in the solar manufacturing process, and by doing so it can create thinner, more efficient panels while slashing costs too.
The secret, they say, is instead of sawing off wafers of silicon from a large block — which creates a lot of waste — they use a particle accelerator to implant ions just 3 microns deep into a block of silicon, before removing just that thin layer using an attached substrate. The result, they say, is a wafer that uses 100-times less silicon, is considerably thinner, and 60 percent cheaper. The reduced waste also allows them to use ultra-pure electronic grade silicon, which has the potential to achieve efficiency rates of 24 percent. That makes them the most efficient panels commercially available.
As with many of the technologies in this article, it should be noted that Rayton has yet to produce a commercially available solar panel. Scan some of the (many!) articles about this company, and you'll find plenty of commenters urging caution about their claims — perhaps most notably with questions about the company's ability to scale. The company recently had a record-breaking equity crowdfunding campaign approved by the SEC, with more than $7.2 million in reservations of shares made so far. (Investments are open for another 12 months.) When I spoke to founder Andrew Yakub a few months ago, he said that this initial share offering would be used to build a small, pilot manufacturing plant which would serve as proof of concept, and he expected this to be up and running in the next 18 months.
Tesla's sexy solar shingles
Tesla's sleek solar shingles could financially benefit homeowners after electricity savings are factored in. But they will also have a lower upfront cost compared to traditional roofing options, according to Elon Musk. (Photo: Tesla)
There can't be many solar-watchers who don't know about Tesla's sexy solar shingles that it's aiming to bring on the market in the next couple of years. Looking, from the ground at least, almost indistinguishable from premium roofing materials like slate or tile, the main benefit of these shingles is less about efficiency, and more about curb appeal. Plus, there's the fact that they could directly replace other roofing materials which produce no additional benefits to their owners.
It's important to note that Elon Musk has been known to make some pretty hyperbolic statements. So when he claimed these would be "cheaper than a regular roof," Lloyd over at TreeHugger promptly pointed out that we are not talking about asphalt shingles — the most commonly used roofing material in America. But if they do turn out to be cheaper than premium roofing materials, then they could potentially mean a lot of new solar in high-end markets, not to mention in countries where ugly asphalt shingles are less common than they are in the U.S. (In my native England, many villages have almost entirely slate roofs.)
Regardless of cost, a good-looking, building-integrated solar system that blends seamlessly with the overall aesthetic of a building could significantly increase the market for solar. And because Tesla would be marketing these right alongside its Powerwall energy storage systems and fancy electric cars, the knock-on effects for carbon emissions could be dramatic indeed.
What else is out there?
There's plenty of reason to hope that solar will continue to advance and, once it becomes widespread and truly competitive with fossil fuels, it could usher in a radical shift in how we think about our energy systems. That said, as anyone who remembers the Solyndra "scandal" knows, we'd be foolish to hold out for any one single technology to save us. From other companies working on good-looking building integrated solar roofs to much-hyped but outlandish concepts like solar roadways, there are many people working on pieces of this puzzle all over the world. Some will fail, some will succeed, but collectively — we can hope — there's a good chance that we will continue to move forward.