Alcatraz is Now One of The Largest Microgrids in the United States.

James Radford | Solar IndustryFebruary 10, 20173737


Alcatraz is Now One of The Largest Microgrids in the United States.

Old meets new for Aging National Landmark

Once known as home of the nation's most dangerous criminals,  Alcatraz has changed its billing to now be known as the nation's largest microgrid.  Since 1972 more than 1 million tourists annually visit the famed bay area island.

Stepping off the boat, and onto the island, gives you a feel of what people for over 180 years felt like as they stepped onto the grounds of this aging military fortress turned prison facility for the very first time, only to see what fate awaited them. Today guest are welcomed to a place where history and technology colid, the crazy part is most of them don’t even know it. This 22 acre site is now the home to the nation's largest microgrid powered by a solar - diesel hybrid power system.  The $7.1million dollar project was funded by the American. Recovery and Reinvestment Act has reduced the islands need for fuel by 45% since installed in 2012 saving more than 25000 gallons of fuel annually.

The biggest problem this island prison has always had is how to keep the lights on for this global attraction. This isn’t a new issue at all but one that caused Alcatraz to close as a maximum security  prison after 29 years of operation back in 1963. The answer to the issue was to ferry up to 2000 gallons of diesel fuel each week to Alcatraz weekly. A solution that led to high operation cost, and pollution  risk to the bay. In 2008 a greenhouse gas inventory found that the Aging Prison was producing more that 632 metric tons of carbon dioxide which is almost half  of the total electricity generated for the entire park system.

After extensive research it was time to act and the answer came in the form of a massive 959 solar pv panel system, 8 power inverters, 480 batteries, 2 diesel generators and 1 controller device to coordinate the generator operations. Issues continued for the National Park Service after the first 2 years of operations when they realized that this massive solar system was not living up to its designed potential. The solar side of the hybrid system was only producing about 45% of the expected energy for the island which was about 15% lower than expected.  After review of the issues it was found that the overcharging of the  batteries was causing a major storage issue resulting in significant curtailment of excess solar power.  The NPS is now working on resolving these issues in order to allow for the system to meet its maximum efficiency. As with everything else that has to do with the parks service funding is now being sought out to add additional microgrid controllers, capable of better optimization and advanced features such as demand management and forecasting.

As solar continues to become more affordable and efficient I think it will only be a matter of time before we see all solar and no diesel at this loved tourist attraction.



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