Welcome to the May Tech Buzz! This month, we’ll check out some of the latest news affecting solar panels, from angle-adjustment and roof-top solar to how waste bottle glass help improve LiPo batteries, and then all the way down to 3,000 feet in the ocean where the sun doesn’t shine at all.
What’s Your Angle?
As most solar panel or PV (photovoltaic) owners know, solar panels need to be oriented in the correct direction and tilted at the proper angle in order for the panel to catch the sun’s rays as directly as possible. The optimal tilt angle depends on the panel’s latitude. Home owners in lower latitudes, such as Texas and the southwestern states, get high amounts of insolation with less tilt, while northern states get less direct sunshine and so their panels need to tilt more.
Many PV owners have long known that seasonal adjustments to the tilt of their solar arrays can increase their production, usually by adding 15 degrees in winter or subtracting 15 degrees in summer. Fixed roof top mounting system must settle for the average between summer and winter extremes.
However, analysis from researchers at Binghamton University in New York have found that PV owners in the US can enjoy higher energy output if they adjust their panels’ tilt 4 to 5 times a year —even if they do it manually.
According to the paper Study of Sufficient Number of Optimal Tilt Angle Adjustment to Maximize Residential Solar Panels Yield , modifying a solar panel’s tilt angle 4 times during the year at optimally divided intervals can provide around 25 kW/m2 more power versus adjusting the tilt angle four times a year based on the seasons. Because latitude affects insolation and therefore electrical output, the times for optimal adjustment don’t depend solely on dates on the calendar. The intervals and angles of the changes depend upon the geographic location of the panel.
So how do you know just when to tweak your tilt? Check out NREL’s Solar Radiation Data Manual for Flat-Plate and Concentrating Collectors which lists averages of solar radiation per state/city by month.
Use a Light Touch
Engineers at the University of Minnesota created a new nano-scale thin film material that not only may reduce the cost of touch displays but also may lead to smaller, faster electronics and transparent solar cells.
Most touch screen devices now available rely on highly conductive thin film coatings based on indium, which in 2014 sold for $705/kg. Though it’s price is falling, indium is being replaced by a host of cheaper substances. The new material from Minnesota is a transparent thin-film that is highly conductive at room temperature —which is unusual because it’s transparent. What makes it even more groundbreaking is that it is based on a combination of barium, tin, and oxygen that instead uses a precursor of tin — all of which are abundant and much less expensive than indium.
This formulation also allows for better control over thickness and composition of coatings. Plus, the production process is scaleable, which means it will likely find its way into new touchscreen gadgets and solar panels as soon as the few remaining defects are fixed.
Lightning in a Bottle?
When researchers at the University of California, Riverside considered the number of glass bottles ending up in landfills, they asked themselves an interesting question: Could waste beverage bottles contain enough high purity silicon nanoparticles for lithium-ion batteries?
All batteries have a cathode (negative) pole and an anode (positive pole). Today’s lithium ion batteries, which are used to power nearly everything from phones to laptops to even electric cars, use graphite for their anode poles. Silicon anodes had a 10-fold capacity but limited lifespan. Ultimately, silicon dioxide nanoparticles succeeded at producing stable cycling but processing the pure silicon into the silicon dioxide added to the expense.
What the UCR researchers realized was that glass bottles were already mostly through that process. By crushing and grinding glass bottles to a fine powder, they were able to create a silicon nanoparticle coating with carbon that improved stability and storage for a fraction of the cost. They made coin cell batteries that outperformed regular batteries and cycle 400 times. One glass bottle provides enough nanosilicon for hundreds of coin cell batteries.
A Sea of Troubles?
Roughly 300 miles from the Canary Islands lies the Tropic Seamount, an underwater mountain about 9,000 feet tall. It’s also 3,000 feet down. Robot submarines from the UK’s National Oceanography Centre showed researchers that they had stumbled onto a rich concentration of tellurium estimated to be one-twelfth of the world’s total supply. And it’s all over the mountain in a layer of dirt about 2.5 inches (4cm) thick.
Tellurium is used to make thin film solar cells. And it’s estimated that if the full deposit could be mined and brought to the surface, enough inexpensive thin-film solar panels could be made to cover 65% of the UK’s electricity demand.
Just two little problems…
Nobody has ever engaged in that kind of seriously deep sea mining…yet. In 2019, Canadian firm Nautilus Minerals Inc. will begin the very first deep sea operation on the floor of the Bismarck Sea (general depth of 6,600 feet) off the coast of Papua New Guinea in search of copper and gold. Digging will be done by huge robot excavators.
The environmental impact could be huge. The plume of mud churned up by mining robots would affect local species near the mine site. It could also spread for miles in the ocean, affecting sea life and ultimately coastal areas that rely on fishing and recreation. While undersea mining might uncover enormous mineral wealth that might benefit us on shore, most involved in the as-yet dry-footed industry think that it could dredge up all sorts of serious environmental harm.
The question is, will all this untold wealth be worth the price?