Energy storage is the Holy Grail for renewable energy producers. In an ideal world, they would be able to capture that burst of wind at two in the morning and use it to power your coffee maker when you wake up at seven. A solar project in Arizona called Solana is using an innovative solution for energy storage: molten salt.
Imagine pure salt so hot it looks, and moves, like liquid water. This molten salt is the substance inside large insulated tanks that allows the Solana project to store heat for up to six hours. Most of the solar thermal energy is channeled directly to the steam generator that produces electricity, but some of the heat is diverted into heating up these molten salt tanks whose energy can be harnessed long after the sun has set from the sky.
These molten salt tanks make Solana the largest solar thermal project with energy storage in the world. Using heat to store energy is fairly new; some other solar power plants use expensive batteries to store electricity. While storing energy as heat is not mechanically efficient, the economic benefits of producing energy at peak demand may make the molten salt storage worthwhile.
Solar energy typically does a fairly good job of matching peak demands for electricity during the daylight hours, but can fall short in the early morning when people are getting ready for work or in the evenings after the sun goes down. Energy storage capabilities would allow renewable energies like solar to be harnessed around the clock, making them a more formidable competitor to fossil fuels.
(Photo: Solena Project by Abengoa Solar. Article via: New York Times, “Arizona Utility Tries Storing Solar Energy for Use in the Dark”)
Solar power is a growing energy source on Staten Island. Freshkills Park, already an alternative energy source from the methane harvested at the site, will be using solar power for many of its structures in the future. But the future is here at an office building on Edward Curry Avenue in Bloomfield in the form of solar panels that provide shade for your parked car. No more searching for the only tree in the parking lot, now shady parking spots are created by solar panels that are working double duty: producing energy and providing shade.
The solar panels, installed by American Solar Partners, shelter 25 cars and provide roughly 5% of the power for the 80,000 square foot office building. The office building has other energy saving and resource conserving systems that earned it an Energy Star Rating, such as occupancy sensors, LED lighting and motorized solar shades that move with the position of the sun throughout the day.
The permitting process has begun for a North Park Photovoltaic Shade Structure which will provide shade for visitors sitting on benches while also generating energy for the overhead lights throughout the parking lot.
Links to similar stories:
City requires portion of energy to come from solar: http://www.greentechmedia.com/articles/read/Lancaster-CA-Becomes-First-US-City-to-Require-Solar\
More on solar parking lots: http://cleantechnica.com/2010/08/03/solar-power-transforms-parking-lots-into-green-job-generators/
A closed landfill in Canton, Massachusetts plans to implement solar power infrastructure that will generate $16.3 million for the city. The landfill sat unused for over 20 years when city officials decided to build a solar array on the site that will include 19,844 solar panels, citing the relatively low investment and significant return. Additionally, this system involves a ‘non-invasive’ mounting system that was developed to prevent landfill cap disturbance. City officials reported the solar generation won out over other options because of the return on investment and relatively short timeframe – one year from construction to operation.