First a brief history of solar energy. The concept of generating electricity from the sun is not a new idea. In fact the photovoltaic effect was first observed by Alexandre Edmond Becquerel in 1839. He managed a mere 1% efficiency but the idea was not forgotten, many scientists attempted to explain the photoelectric effect, including Albert Einstein. April 1954 marked the birth of the modern solar cell. Bell labs had created the first practical solar cell achieving a staggering 11% efficiency. In the late fifties, the space race catapulted solar to new popularity, even being installed at the White House in the late 70s.
The incremental march of cheaper and more efficient panels continues today, and with the looming threat of climate change solar has never been more popular. The switch to solar is becoming easier thanks mainly to the falling prices in solar panels, solar friendly legislation, and energy storage.
Solar panels work by utilizing two layers of silicon, the top layer with an addition of phosphorous, which creates an abundance of electrons requiring very little energy to knock them free.The second layer is doped with boron, which causes the silicon to accept electrons. Photos from the sun carry enough energy to push electrons from the first layer to the second layer. Thus, the more silicon exposed to the sun the more energy is generated. Silicon is the primary material in Photovoltaic panels, as well as the most expensive.
A new startup out of California has taken advantage of a new, efficient manufacturing process to slice silicon stock. Instead of traditional techniques which use a thin saw to shave off silicon wafers, Raton uses a particle accelerator to inject a layer of ions between silicon atoms. This allows a three-micron thin layer of silicon to be separated, a 67-fold reduction from previous methods. This is significant for two reasons: first, the same amount of silicon stock that would comprise one panel with traditional manufacturing could create 67 panels with Rayton’s technology. The second is that when a cut is made with a saw blade, the width of the blade generates waste material. Even a saw the width of a human hair would waste a 100-micron width with each cut. This new manufacturing process will therefore reduce the amount of waste generated by solar panel production and therefore decreasing the cost.
One of the largest challenges for solar is the fight from utility companies. In 2015, Nevada passed unfavorable legislation all but removing net metering. Net metering is a policy by which the local utility will buy excess energy generated by rooftop solar at a fixed rate. Pre-2015, Nevada utilities would buy excess power dollar for dollar, post legislation utilities would pay twenty-five cents on the dollar. This made solar cost prohibitive for prospective buyers and very expensive for those who just installed new systems. Solar systems which would have paid themselves off in seven years now would take more than twenty years. The shift was so dramatic the entire solar industry froze in Nevada. Hawaii and Utah have also been notorious for poor solar policies.
Not all hope is lost, however, in June of 2017 Nevada reversed its 2015 policy and reinstated net metering, utilities will now buy back power at seventy-five percent the retail rate. As solar becomes increasingly popular and traditional energy jobs become scarce, fair solar policy will become a necessity. Products like the Tesla Power Wall or Aquion Energy’s salt water battery will have a significant impact on the renewable industry as a whole.
Another major argument against solar is that the sun is only present during the day and output may vary during the day. Alternatively, energy storage solutions will provide a way to circumvent utility companies all together. Though multiple storage methods exist batteries are emerging the most promising solution. Lithium ion batteries are now commonplace and only becoming cheaper, they have remarkable energy density, but for large stationary applications energy density becomes less important and cost becomes a significant factor.
Aquion Energy has developed a new type of battery that provides a promising mass storage solution. The batteries use manganese and manganese oxide for the anode and cathode, with a salt water electrolyte, in comparison, car batteries (lead acid) use lead and lead oxide as the anode and cathode with a sulfuric acid electrolyte. Environmentally speaking the composition of the Aquion batteries are far superior as they contain abundant, non-toxic, and highly recyclable materials.
This battery technology is key to energy storage because not only can these batteries be used as a home battery backup but just as easily be combined in utility scale megawatt hour arrays without a complicated battery management system. For communities eager to attain energy independence or for those who prefer to remain tied to the grid, a simple storage option is available, and the energy will only be getting cleaner.
The future is bright for solar… Pun intended.