<http://schema.org/description>
"Philadelphia\u2019s SEPTA subway system sells energy from regenerative braking to balance the grid, a new supercapacitor system could boost efficiency and turn it into a real moneymaker"^^<http://www.w3.org/2001/XMLSchema#string>
<http://spectrum.ieee.org/energywise/energy/the-smarter-grid/supercapacitor-enhanced-hybrid-storage-could-earn-cash-for-subways>