In April 2016, President Street in Brooklyn witnessed a historic first: one resident sold the excess energy from his rooftop solar installation to a neighbour across the street, all paid for and recorded through blockchain. This was the world’s first small-scale power grid to use a consumer blockchain transaction. The houses aren’t connected directly to each other, of course, but rather to TransActive grid, a local microgrid, so the sale was a transaction of renewable energy ‘attributes’ only, rather than a transfer of electrons.
