7 New Solar Innovations
In honor of this week's Intersolar North America conference in San Francisco, which was largely focused on "big solar," Sustainable Industries brings you the following piece on new and provocative solar innovation from our friends at Mosaic.
It's a tough time for solar innovation. Heightened global solar PV production, especially in China where production has multiplied 17 times over the last few years, has created such an oversupply of panels that prices have dropped 80% in the last four years. Plummeting prices is exciting news for the distribution of solar energy, but threatens to stymie innovation of new clean energy products. Solar technology startups that are attempting to break into the PV market are finding it challenging to make even the most innovative products cost effective when the cost of traditional solar panels is so low. The disappointing buyout of MiaSole and crash of Solyndra are cacophonous illustrations of the difficulty of this new landscape. But fret not, Mosaic is here to remind you that there are still opportunities for innovative new technologies to transform our clean energy future. Here are seven.
There are 1.2 billion people in the world who live without access to electricity. In order to provide nighttime light, many of households in developing countries use kerosene lamps. Breathing the fumes from kerosene lamps poses numerous health hazards and the lamps cause frequent fatal accidents. Moreover, kerosene lamps add an estimated 200 million tons of GHGs to the atmosphere annually. Bringing even small amounts of light and electricity can have enormous impacts on economic possibilities for workers and scholastic performance for children.
Companies such as D.Light, Greenlight Planet and Angaza Design have developed small, durable, solar charging lamps and appliances that can cheaply replace kerosene lamps. Over the last few years, these companies have begun to distribute their products on wider networks. On a slightly larger scale, companies like OMC, Powerhive, and Mera Gao Power are developing clean energy "microgrids." A few solar panels provide electricity (to power 2-4 LED lights and a cell phone charger) for up to 100 households. These innovative companies face many challenges in distributing their technologies in difficult to access regions of developing countries, but exciting progress has already been demonstrated.
Only about 60 percent of the light that hits the earth's surface is visible light. The rest lies in the infrared (think night vision goggles) and ultraviolet (think sunburn) spectrums. Our traditional silicon-based solar photovoltaics can only convert visible light into energy, leaving huge amounts of potential energy untapped. A group of MIT researchers have pioneered a new carbon-based solar panel that can harness the light in the infrared range. Luckily, the new carbon cells are transparent, meaning they could be transposed on top of silicon-based cells to gather both infrared and visible sunlight. The cells are made of carbon nanotubes which are highly absorptive while needing very little material. So they shouldn't cost much. According to MIT, a peer reviewer of the paper called this discovery “a dream for the field.” The downside is that with many kinks to be worked out, they're nowhere near ready for commercial production.
Building integrated photovoltaics (BIPVs) are thin-film solar panels built smoothly into building materials like roof shingles, curtain walls, facades, or windows (yes, you can spray solar panels onto your windows). BIPVs have actually been around for over 20 years, but have largely been relegated to the realms of R&D and showcase works and currently account for only 1% of global solar PV output. These products are now emerging on the commercial marketplace due to the technological leadership of a number of producers and attractive feed-in tariff programs in numerous European countries. The global overproduction of solar panels means that installation is now taking up an increasingly large percentage of the total cost per watt of solar.
BIPVs are an enticing alternative because they cut out many installation costs (they don't require racking, laborers don't necessarily need to be trained in solar installations) especially on new buildings. A report from the National Renewable Energy Lab demonstrates that BIPVs could economically compete with traditional rack-mounted Solar installations, even in the short term. Moreover, BIPVs are aesthetically appealing for many customers who may not be pleased with a large rack mounted system on their roof.
Daniel Nocera and his research team at MIT have developed the first “artificial leaf.” Made from a thin silicon solar cell, the leaf is dropped into water where it separates hydrogen and oxygen molecules that are collected and connected to fuel cells that produce electricity. The leaves can't collect energy as efficiently as traditional solar PVs, but are incredibly cheap to make. Nocera and his team believe the leaf could bring electricity cost effectively, especially in developing countries, to households that aren't connected to energy grids.
Solar power on mobile gadgets is still in its novelty phase, but expect to see more innovations in the next few years. There are currently over 1 billion smartphones in use around the world. While the energy usage of charging a smartphone is small for each individual, collectively we are contributing 10 trillion pounds of CO2 each year. There are a few innovations that could begin to offset that enormous amount. Solar Focus's new SolarKindle is a Kindle cover integrated with a thin solar panel. With just one hour of sunlight, the SolarKindle gathers enough charge to run your device for three days. This means you can take your Kindle with you on your next trip without having to bring a cable.
Prefer listening to reading? Rukus Solar by Eton is a portable speaker system that streams music via bluetooth. Fully charged in 6 hours, the Rukus can play music for eight more hours out of the sunlight. Eton also sells portable charging stations that can charge phones and tablets using solar energy. SunPartner Group's new Wysip Crystal panels are transparent screens that can be implemented on mobile devices to charge devices and will be available for sale next year.
With the 100 percent solar powered Solar Impulse airplane completing its across the country voyage, new territories are opening in the realm of clean energy transport. While we're far from hopping on commercial solar flights, electric cars are making exciting new strides. A major barrier to electric cars making a dent in the transportation market is their prohibitive upfront costs. However, a recent Greentech Media report demonstrates that many electric car models have reached cost parity with traditional vehicles over their lifetime. In fact, the Nissan Leaf, is 10 percent cheaper than an avearge conventional car over a 60 month lifespan.
The fastest growing electric car company, Tesla Motors, has been making exciting progress recently as they posted their first quarterly profit in 2013 Q1 and repaid their Department of Energy loan nine years early in May. And finally someone made environmentally friendly cars look good. New innovations in solar fueled charging could complete the solar to transportation chain. In 2012, CSU Fullerton flipped the switch on three 1.16 megawatt solar parking canopies that had integrated car charging stations (See our top 15 California solar schools).
While not as flashy as fuel-cell leaves or solar airplanes, new innovations in the manufacturing process of the silicon solar panels that currently permeate the market could have the biggest impact in bringing production costs low enough to compete with fossil fuels. Here's where it gets technical. The conventional process of creating the silicone in a solar panel involves sawing a block of crystalline silicon into what are called “wafers” that are traditionally 180 micrometers thick (your hair is 50-180 micrometers thick). Unfortunately, about half of the original block is wasted as sawdust during this process.
A few companies are working on ways to reduce the amount of waste (and therefore cutting costs) by creating thinner, but equivalently efficient, slices of silicone. Astrowatt is developing a process that involves peeling apart thin sheets of silicone. 1366 Technologies has developed a machine that creates wafers straight from molten silicone, removing some manufactruing processes to cut costs. Crystal Solar developed epitaxial growth methods, used for decades by the chip industry, to deposit silicon films straight from gases, skipping the wafer stage altogether. None of these processes have been proven on an industrial scale and companies need to develop methods to safely handle thinner silicone films (one suggestion is to magnetically float them!), but they provide exciting glimpses of our solar manufacturing future.
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