In April 2015, Tesla announced that they were producing a rechargeable lithium-ion battery called the Powerwall. The news was met with a frenzied response from solar enthusiasts who had been waiting for years to see a notable advancement in battery technology.
However, a month later, an article in Forbes magazine doused the solar excitement when they suggested the Powerwall would not make economic sense. The writer calculated that using a Tesla Powerwall combined with grid-tied solar panels in your home would cost 30 cents/kWh—nearly twice the cost US consumers normally pay for grid power (the article did acknowledge that the Tesla battery could make economic sense if used in off-grid solar applications).
Tesla initially planned to produce two Powerwall models: a 7 kWh capacity for daily-cycle applications, and a 10 kWh capacity intended to provide backup power during power outages, virtually eliminating the need for an emergency generator.
Each Powerwall has a 6.4 kWh energy storage capacity, sufficient to power most homes during the evening using electricity generated by solar panels during the day. Multiple batteries may be installed together for homes with greater energy needs.” —From Tesla Website
Tesla overestimated the backup power market and concluded that given the unpredictable, infrequent nature of power outages (what, they haven’t heard about the hurricanes and blizzards that plunge the East Coast’s into darkness every year?), the realistic use cases and resulting payback for a battery backup Powerwall are not attractive.
Citing low demand for battery backup applications, Tesla has quietly dumped the 10kWh model. The company will move forward with production of the 7kWh model.
However, due to what Elon Musk called “crazy, off the hook” demand, the 7kWh model Powerwall is currently “sold out until mid-2016.” Will the availability date continued to get pushed back as mid-year approaches? Only time will tell, so stay tuned.
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Unbound Solar sells 18 Powerwall-Compatible SolarEdge solar systems. To learn which SolarEdge solar system is right for your needs, call a Unbound Solar sales tech at 1-800-472-1142.
As of early 2016, SolarEdge has indicated that systems running on the SE7600A-US inverter can be upgraded with the StorEdge system and made Powerwall-compatible.