If someone would have told me a few years ago that the price for solar panels would drop to 36 cents by 2017, I might have had some question about the mental health of the one making the assertion. But now, look at what Green Tech Media is reporting. The price per watt of solar PV will keep falling. All of this is well and good for the emerging solar industry, but there is a hitch: the sun doesn’t shine at night.
Green Tech Media covered their report published June 18which projects the price per watt to produce solar panels will fall to 36 cents by the end of 2017. With this cost reduction comes a price – disappearing subsidies for solar PV. The subsidies, which cost billions in taxpayer dollars, are believed to be less and less necessary as the price of solar energy reaches grid parity. Solar PV systems require panels, yes, but also a considerable number of other parts. Inverters, wiring, solar batteries for off grid or backup systems, and a good deal of cash for professional installation account for a large percentage of the startup cost that is so daunting to prospective investors, residential and utility alike. ThAn oft mentioned problem with solar energy is its inability to meet the demands of the grid. At the summer solstice, the sun is out for about 15 hours a day in say Portland, Oregon. During the winter solstice, the sunlit hours in Portland drop drastically to 9. In the hours the sun is just starting to rise or set, as well as the hours it is not shining, the panels are producing little to no electricity. And year round, regardless of when the sun is out, the peak hours of consumption stay approximately the same.
In order to make solar a real answer to our energy needs, it needs to be able to produce energy around the clock, and specifically when it’s needed during peak hours. Price per watt can drop all it wants for panels. To stay competitive, solar energy will need help, and subsidies won’t be coming back to the rescue. The answer is in energy storage.
Chengdu Liang and his team have been working on this at the Oak Ridge National Laboratory. Earth Techling reports “…they say they have designed and successfully tested a new battery that can store four times the energy as conventional lithium-ion versions.” The battery is a new all solid lithium-sulfur battery designed to use sulfur, which is “…a common byproduct of industrial processes…” Liang states that this makes sulfur cheap, and could be a way to recycle waste. The crucial information is in the numbers; “… their new battery translates into four times the gravimetric energy density of lithium-ion technologies.” The work is only just beginning the push out of the research phase, but Liang said that some of the large scale applications included uses in solar and wind farms.
Liang is not the only person recognizing the need for new storage mediums. MIT Professor Donald Sadoway’s recent startup is focused on the future. In his TED talk titled The Missing Link to Renewable Energy Sadoway explains the invention of his liquid metal battery. The battery, based on basic chemical principals, uses antimony and magnesium. He, David Bradwell, and Luis Ortiz founded Ambri (formerly Liquid Metal Battery Corporation) back in 2010, and look to roll out commercial prototypes in 2014. The refrigerator size battery module made up of many smaller ‘hockey puck’ cells will hold up to 2 megawatt hours “…enough to power 70 U.S. homes for a full day” according to MIT Technology Review. Some have questions about whether antimony is a good choice for a battery, as almost all of the world’s supply comes from China.
Back in January, Gigaom.com listed 13 Battery Startups to Watch in 2013. Ambri took the number one spot, and companies doing everything from improving upon existing Lithium Ion battery technology to designing software for grid batteries made the list. The variety of battery startups might indicate scientists’ and engineers’ recognition of renewable energy’s needs. Greater capacity and cheaper batteries are a direct solution to intermittent sources of energy like solar PV. With advancements in battery technology, the sun can become a 24 hour energy source.