“Politician” and “maker” are two words that are rarely used to describe the same person. But, in the case of Thomas Massie, Republican representative for Kentucky’s 4th congressional district and MIT graduate, those are apt descriptions. In a series of tweets yesterday and YouTube videos over the past year, he proved that with a demonstration of a DIY Powerwall he built from a Tesla Model S battery pack.
We don’t endorse Massie’s politics — his views on climate change and education, in particular, are troublesome. But, this is still an interesting build. Massie describes himself as the “Greenest Member of Congress,” and while that’s difficult to verify, this DIY Powerwall designed to run an off-grid house is at least some evidence.
Massie’s off-grid home had been running on lead acid-batteries for years, but they were on their last legs. Even when they were new, they only offered about half the capacity of the lithium-ion batteries in a Tesla Model S. While Massie already owned a Model S, it was in good shape and not worth dismantling just for the batteries. So, he purchased a used battery pack salvaged from a wrecked Model S for about $15,000.
With that battery pack, he was able to setup a fairly standard home battery power system running at 48V. The 85kWh batteries are recharged by nine 315W solar panels, and power is delivered to the home via inverters. A GUI Massie programmed in C runs on a Raspberry Pi to monitor the system. The Raspberry Pi communicates with an Arduino over serial, which in turn monitors the Tesla boards’ CAN bus. It’s a robust system, and is definitely worth replicating if you can afford it.