- There are always major technological advances to report in solar energy, so this month I turn the spotlight back on this industry. First, let’s look at a series of ideas designed to increase the solar absorption rates of solar panels. One way to increase the amount of energy you capture from the sun is to increase the amount of the solar spectrum absorbed. Silicon-based panels, the vast majority of the panels in use today, only harvest energy from photons in the visible spectrum. 40% of the sunlight’s energy reaching our planet is in the near-infrared (NIR) spectrum and a team at the Massachusetts Institute of Technology has developed an early model of an all-carbon solar cell that can absorb these photons. While the conversion efficiency of the early model is far less than 1%, it is a major advancement in all-carbon solar panels as this version appears to be stable in air. Another MIT researcher has taken a different approach to capturing energy from more of the Sun’s spectrum whereby a thin-film material made of molybdenum disulfide is put under strain by a microscopic needle to create a funnel structure. The strain on the thin sheet changes its molecular structure so that atoms in the funnel are now able to capture energy from different portions of the solar spectrum, not just the visible. Researchers at Northwestern University increase the absorption of sunlight by increasing the amount of time photons stay inside a solar panel. Their idea uses a 100-nanometer thick organic layer designed with the ideal geometry to keep reflected photons in the cells below (which harvest energy) longer. Organic materials are attractive as they may be able to be produced for far less than mineral-based solar panels.
There have also been interesting advances in the ways we use and capture solar energy. For instance, researchers at University of California, San Diego have developed solar panels with vertical, branching nanowires made of abundant natural minerals. The branched structure of these panels let them capture solar energy more efficiently as well as create hydrogen gas on their increased surface area where they split water cells. A scientist at the University of Delaware has taken a different approach to creating hydrogen fuel from sunlight which uses highly concentrated sun to heat up a reactor containing water with zinc oxide sprinkled in it. In this system, the zinc oxide can even be reused after the reaction takes place to form hydrogen gas. Rice University researchers have designed a system that creates steam by concentrating sunlight on containers of water with nanoparticles that capture photons, create heat and vaporize the water. This system could be used to create energy or even to purify water. And finally, there are new locations to harvest the sun’s energy with the advent of floating solar farms in Japan and transparent solar panels for windows.
- Do you like bizarre maps? Well I certainly do! And if you share my love of maps, you need to check out this website. In 2010, San Diego State University (SDSU) sponsored a bizarre maps contest where they selected a first, second and third place map as well as a number of finalists and honorable mentions. Each of the place winners and finalists received cash awards for their awesome maps. Unfortunately, SDSU has not found funding for the past two years to put on another bizarre map contest which is a shame!
- In my continued obsession with complete worthless Google searches involving the word GIS, this month let’s combine it with ‘beer’ and see what we find! Dig into the results and you might uncover this gem of a poster by Ben Barham at the University of Missouri. It is full of fun facts about US beer consumption and production, for instance that Colorado produces far more beer than it consumes, that California has the most breweries and that North Dakota and New Hampshire consume the most beer per capita. Yum, beer!
- From our southwest tour of Phoenix’s online GIS resources, this month we travel to the south and check out what Little Rock, Arkansas, the largest city in the state, has to offer. The Little Rock GIS website can be accessed here. It is a bit clunky and out-dated but works none the less. Most of the links, for instance city parks, census tracts and zip codes, on the main GIS page will take you to a dynamic mapping application with your standard suite of zoom, pan and query tools. If you click on the address layer, then the Information tool and finally over a location address, you can query some basic zoning information. The only downloads I could find were scanned tax maps with little identifying information on them. Overall, this Little Rock website has offered the least amount of functionality in our review of city GIS sites thus far.
Brock Adam McCarty