The White House is trimming its utility bills by undergoing an "energy retrofit to improve the overall energy efficiency" of the first family's residence, according to White House officials. 

The installation of solar panels on the White House's roof began last week. It's part of President Barack Obama’s pledge in 2010 to show commitment to renewable energy. 

The solar panels "will help demonstrate that historic buildings can incorporate solar energy and energy efficiency upgrades," according to a statement from the White House. "[The solar panels] are estimated to pay for itself in energy savings over the next eight years."

Solar panels have been added to the White House before. In the late 1970s, President Jimmy Carter had 32 solar panels installed to provide hot water. The panels were removed by President Ronald Reagan in 1986. In 2003, President George W. Bush installed a photovoltaic system on a maintenance building and two solar thermal units, which heated the White House swimming pool, The Washington Post reports. 

The solar industry has undergone big growth in recent years as the price of solar panels becomes more affordable. The solar industry now generates enough electricity to power more than 1.3 million American homes, according to the Solar Energy Industries Association. 

Source: The Washington Post