Tesla’s Powerwall ‘Hum’ Drives Customers Crazy

Tesla’s Powerwall home battery system appears to suffer from a number of issues, including a loud electronic hum that is driving many customers crazy.

Genentech Media has been a huge supporter of Tesla’s Powerwall. But it is now reporting that the noise level from early residential installations of Tesla’s battery storage system suffer from a disturbingly higher-than-expected sound due to electronic hum.

GTM reported that a German customer measured a noise level from a Powerwall installed in his garage in February at more than 80 decibels. That is equivalent to of a garbage disposal or city traffic noise.

The customer was supposedly told the noise would only last for the first day or two, but it did not vanish. The customer emailed GTM: “It was a continuous noise that was [audible] in the whole house.”

The customer wrote that when Tesla sent one of its “ranger” technicians to address the issue, “I was told that the power consumption of the ventilation or cooling system was reduced to 15 percent of its original value,” said the customer. “After this update, the noise was not there anymore.”

But since Tesla’s Powerwalls use a radiator liquid cooling system, slashing the cooling capacity to cut the noise issue would seem to risk damage to the equipment and limit Powerwall’s performance capability.

Logan Goldie-Scot, head of energy storage analysis at Bloomberg New Energy Finance told GTM, “I’ve heard they’re loud enough to want to relegate to a garage or outside. Not for communal areas, certainly. I haven’t been able to substantiate this, though.”

Mathias Bloch, a spokesperson for Sonnen, a rival of Tesla’s that makes traditional power generators, said that in addition to noise and location, installation times are in excess of the five hours allotted to an installer, “because it is very complex.” He argues that this “can make the overall system more expensive” than the $3,000 retail price advertised by Tesla.

In addition, true cost of a Powerwall in Europe could be $9,600 to $10,150 with the addition of the necessary StorEdge inverter interface, gateway, installation fee and sales tax. GTM found that Powerwall pricing by SolarQuotes was $6,175 — about double the original estimates.

GTM is also concerned that the Powerwall manufacturer’s warranty guarantee only covers 85 percent of the battery capacity for the first two years, 70 percent for the next three years, and only 35 percent for the final 5 years.

GTM’s senior storage analyst head of research Ravi Manghani warned:

“Capacity fading and degradation are known challenges within energy storage community. Most analytical models (including ours) account for it. Of course, the fact that Tesla has kept most important warranty terms out of the main product press/specs is not unusual. I would be surprised if warranty terms from other vendors looked much different from Tesla’s.”