They could make the same claim if they installed massive generators for their buildings too. All they would have to do is not claim what the fuel cost for making their electricity. They could claim they saved tons of money in electricity bill costs from the grid.
Right now the Air Force is installing hundreds of solar panel installations on all of the quarters they are building. They are tearing down all of the housing from the 50's and putting up new quarters including multi story family houses. They are also putting solar panels on all of them. Some are pointed South, some East and others West. All are fixed in place and do NOT track the sun. Even the long solar farm on the South side of Golf Links RD for almost the length of the base there is fixed. They are spending millions upon millions of dollars for solar farms and roof installations to save hundreds in electricity. Those solar panels will never ever recoup the cost of putting them up or maintaining them given the installation plan they are using.