Renewable Energy is America's Next Frontier
Renewable Energy is America's Next Frontier
In spite of all the advances in renewable energy technologies, the most elusive prize remains unclaimed. Whether it is wind, solar, water or any derivative of these core renewable energy sources, they each have the same limitation – the inability to store generated power effectively and efficiently. For the most part, energy storage has relied on batteries, albeit more and more advanced types of battery storage.
But we are poised for a breakthrough on the energy storage front, with a number of unique approaches to stockpiling energy. It is these processes and technologies that will capture the most interest from investors. A sophisticated, effective storage process may well cross the various renewable energy sectors, offering the holy grail to each of the core renewable energy sources.
First, innovative work by Saft Energy on a nickel-based battery technology to serve the world’s largest hybrid diesel/wind project on the island of Bonaire, in the Caribbean will see a storage system with a capacity of 3MW for over 2 minutes. While seemingly small, the battery provides emergency power in case of system failure, whereas systems without that backup will experience blackout conditions.
Isentropic Energy is developing a truly creative, yet deceptively simple power storage concept: Using one storage container of hot (500C) gravel, one of cold (-150C) gravel, Isentropic relies on basic heat exchange between the two to generate power. With a round trip efficiency of 72-80% and a projected cost of as little as $8/Kwh, this process potentially crush the cost efficiency of any existing battery storage.
Bloom Energy recently announced its solid oxide fuel cell, producing electricity from natural gas or hydrocarbons on demand. While current prices are in the range of $7,500 per kilowatt, or $700,000 per system, Bloom hopes to bring those costs down for home generation systems that cost around $3,000 for 2-3 kilowatts output.
Other technologies and processes for storing energy include both compressed air and compressed nitrogen, as well as pumped hydro.
Pumped hydro is the least innovative, using the same principle as current hydro turbines. Water is simply pumped to a high level, then allowed to fall through the generation turbines. Most of the larger hydro systems in use rely on lagoon or artificial lake storage to hold pack water power. The major innovation in this process is to store the water in underground caverns, pump it up to ground level when not needed, and then let it fall down to the caverns again when power is needed.
Compressed air technologies come in several variations. One will see air compressed and stored in large caverns, for later use. Because the air does not have to be compressed by natural gas, costs are significantly decreased. General Compression recently announced a $17 million share issue led by US Renewables Group.
A variation on this process is to compress air, generated by wind turbines, into large bags that are stored at depth in the ocean, compressed by the weight of the water.
While each of these systems and technologies has a distance to go to be cost-effective, there is sufficient promise in each to warrant significant interest by potential investors.
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