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Published on July 31st, 2012 | by Jake Richardson


Alactraz Island Now a Shining Solar Example

July 31st, 2012 by  

Previously on CleanTechnica, the plan to transition Alcatraz Island to some degree of solar power, and off of diesel generators, was discussed. That was about two years ago, and now that plan has come to fruition. Previously, about two thousand gallons of diesel fuel were being used per week to generate electricity on the small island.

Now, they have a 307-kW photovoltaic solar system, and their own microgrid. What used to be the main cellhouse building, containing dangerous criminals, is now the site of many solar panels. Next to the new solar power plant is a two-megawatt-per-hour lead-acid battery for storing surplus energy. (The development of a solar system on the island coincided with declining solar technology costs and rising diesel prices.) All of the island’s electricity demand can be met by the solar system, but diesel generators are used to fill in when needed.

Before the solar power microgrid was completed, the island’s electricity cost the National Park Service about $0.76 per kWh. Now that cost is about $0.71 per kWh, including the cost of the solar plant’s construction.

While a 307-kW solar system on a small island in the San Francisco Bay may seem like ‘small potatoes’ to some, consider the fact that over one million visitors are there each year. Of course, a big part of the Alcatraz experience is the educational aspect focused on the history of the prison and who the inmates were. Now, a portion of what visitors learn about is clean energy, and that educational component will be in place for many years to come.

Image Credit: BLuP1, Wiki Commons

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Hello, I have been writing online for some time, and enjoy the outdoors. If you like, you can follow me on Google Plus.

  • mds

    $0.71 kWh is really steep for solar.  Not really what I’d call a “shining example”, althought they are reducing oil use and saving a few pennies per kWh.  I’d like to see a better explanation of why it’s so high, maybe the cloudy conditions seen in the picture.  Maybe the battery storage.  Maybe this is a gold platted instal.
    The solar panel part of this installation should be less than a third of that cost.

    • RobS

      It’s pretty good for what is actually an off grid battery backed up system, as you say it is quite likely the solar panels represent one third of that cost and the batteries two thirds. In the end though all that matters if solar is to move from a source for those who care more about environmental factors then financial ones to one for those who care about the bottom line is that solar needs to reach parity with your current power source, in this case diesel generation, and it has here. Similarly grid retail parity is being reached in a few places now, over the next 5 years the number of places where that is true will swell dramatically and with it so will installations.

      • mds

        Thanks for the response.  I should have realized the batteries were a large part of the cost here.  Maybe a hybrid system with fewer batteries for change-over and diesel for night power would have saved more per kWh.
        the end though all that matters if solar is to move from a source for
        those who care more about environmental factors then financial ones to
        one for those who care about the bottom line is that solar needs to
        reach parity with your current power source, in this case diesel
        generation, and it has here.”Your heart is in the right place.  Unfortunately, most humans are short term rationalizers of our own needs and virtually all of us do this when economically pressed.  What is really important is for solar to reach end-of-grid parity and you are doing that here, but for an over-priced system that is not typical of other areas.  Electricity costs in other areas using diesel power, like Hawaii, the Caribbean, remote areas in India, are more typically closer to $0.50/kWh.  Solar certainly saves a great deal of money in these areas when the sun shines.  It is only a matter of time till solar and battery prices together get cheap enough to take over for deisel in these areas 24/7 at a significant savings in cost.  I read the island of Hawaii is already seeing a boom in solar with battery installations.  As far as the future of battery costs: search and read about Aquion for one.This is a poor example of how going solar is making more and more sense.  Keep your examples realistic if you want to win converts.  Get the price competitive if you want large scale adoption.  It is happening though!  The cost will continue to go down.  Add in EREVs and oil is not as essential as it was even a few years ago.  Coal is next and NG in the end.  Solar and storage is the answer.  We agree on that.

    • Your contention is unsupported. I’d like to see some documentation on why you claim it’s so high.

      • mds

         According to, before they unfortunately removed that free information, USA residential solar in sunning areas was averaging $0.29/kWh, commercial $0.20/kWh, and utility $0.15/kWh.
        Electricity cost in Hawaii (mostly generated using imported deisel) went up to $0.44/kWh to (I think) $0.50/kWh last September.
        $0.71/kWh is high, just compare it to your own electrical bill.  Your comment is unsupported.
        For the record I’m very pro-solar.  Having said that it should be cheaper in this application.  I suspect special site considerations are at fault… or…

        • Bob_Wallace

          Alcatraz is a very foggy location.  They must have really installed a lot of panels and batteries to run 100% solar.
          They should drop a turbine in the water.  Pretty decent tidal flow through there.  Around 3 knots, IIRC.

          It’s a shame that SolarBuzz dropped their info page.  I emailed them and complained a couple weeks back, perhaps others should as well.

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