Here is a fact about most home solar systems that almost nobody tells you when they sell you one: cut the utility line, and the panels on your roof go dark too.
This is one of those quietly absurd facts about the energy business. You spend tens of thousands of dollars to put a power plant on your roof, and then, during exactly the moment you most want power - a storm, an outage, a wildfire shutoff - the system politely switches itself off, because the grid it's tied to went down and it doesn't know how to run alone. The panels are fine. The sun is out. And you are sitting in the dark, holding a flashlight, next to your very expensive solar array.
Arnold Leitner has spent a good chunk of his life annoyed by this. He is a physicist - University of Colorado at Boulder, doctorate, the whole thing - who as a teenager helped his family build one of Germany's first super-efficient "passive" houses, back in 1991. He later authored a U.S. Department of Energy study called "Fuel from the Sky," founded a concentrating-solar company called SkyFuel, and won an R&D 100 Award with a national lab. So when he asks the question that anchors his current company - "if the sun shines everywhere, why is solar power still dependent on the grid?" - it is not a marketing slogan so much as a decades-old irritation finally turned into a product.
That product is the PowerBloc, and the company, founded as YouSolar in 2010 and recently rebranded to Leitnium, is essentially one long argument for a single engineering decision: build the whole thing on constant direct current, at 400 volts, and let the box - not the utility - be the grid.
