The solar panels on the Whitehouse roof were solar hot water units. They were installed on the odd shaped roof and had a problem of causing the roof to leak. Ronald Reagan removed the panels in 1986 and they were donated to a college. I believe they are still used today to make hot water for the campus cafeteria. George 'W' Bush O.K.'d the Parks Department to install solar PV and solar hot water heating on the Carriage house that is on the Whitehouse grounds in 2002. Obama is now enjoying the heated water in the Spa and the offset of electricity provided by the panels.
The solar PV system my wife and I put on the roof of our house doesn't put us "off grid" as it is a grid tied system. But the monthly electric bill savings is an amount one can retire on. At a time when solar PV installations are down in price per installed unit, we are at a point to make the decision as to where our savings should go. If you spend 35K on a solar PV installation a grid tied system could very well eliminate your monthly electric bill (for life). Putting 35K in the bank will net you what, 0.5 to 1.0% interest? What's your monthly electric bill? Putting the 35K in solar PV on your roof will net more return on your investment than putting it in the bank.