The definition of watt, if I recall correctly, is "work".
Someone - probably the taxpayer - is working and giving a share of what he earns to the school's budget which in turn forwards a share to you.
And by the way, when you buy your bar of gold you pay some guys to dig some gold out of the earth and melt it into a nice bar. However I am not sure how the value and the price of a bar of gold compare.
Or I can buy solar panels for the elementary school down the street and have them pay me 90% of their prior electric bill. The elementary school has a lower electric bill every month and I have a steady income stream and no one does any work.