Customers of Green Mountain Power (GMP) in Vermont will be the first in the US to have Tesla Powerwall stationary batteries installed in their homes, according to the utility. Tesla’s home battery was announced in late April this year and attracted nearly 38,000 reservations in the first week after it was announced.

GMP says it will receive 500 7kWh Powerwalls in early 2016 with shipments starting in January. It will initially install the daily cycling batteries in the homes of 10 pilot customers, and then the utility will open order and installation to all customers.

Back in September, Tesla said that it would start providing Powerwalls for pilot installations, with power company SunEdison beginning installations in Australia in November. Tesla said 7kWh Powerwalls would be shipped first since those batteries have a chemistry that is made for daily cycling (filling up the battery from solar panels and using that power to run your home at night, for example). The 10kWh Powerwalls will not be shipped until later next year—these larger-capacity batteries will have a chemistry suited for backup use in case of a power failure, rather than daily use. Tesla has been clear that third-party installers will be the intermediary getting Powerwalls to individual consumers. Tesla only directly handles the installation and management of so-called “Powerpacks,” which are built for industrial- and utility-grade customers.

GMP said it would install the 7kWh battery on customers’ homes either to use as a supplementary power system to an array of solar panels or as a backup battery in case of power failure (this includes homes without solar panels).

Still, the total price for installation of the battery will be more than twice what Tesla quoted for the 7kWh battery in April. When Tesla first announced its batteries in spring 2015, it drew lots of attention for the price tag—previously, similar lithium-ion batteries went for upwards of $20,000, but Tesla CEO Elon Musk said that batteries would only cost $3,500 for the 10kWh version and $3,000 for the 7kWh version. Now, according to GMP, buying a 7kWh Powerwall outright will cost $6,500, including the inverter and the installation fee.

The inverter, GMP says, is made by SolarEdge and includes communication software that customers can use to check on how the battery is being used and its state of charge. SolarEdge did not respond to Ars’ request for comment.

GMP is also telling its customers that they don’t have to buy the $6,500 battery outright—they can also choose to allow GMP to share access to the battery, which will run customers a mere $37.50 per month with no upfront costs. Or, a GMP customer can buy a Powerwall outright for $6,500 and share access with GMP, receiving a $31.76 monthly credit, which a GMP press release says "represents the value of leveraging the battery to help lower peak energy costs."

In an e-mail to Ars, a GMP spokesperson said that Tesla’s Powerwall is the first stationary storage product that they’ve offered to their customers, but the company is currently talking to other battery companies, too. Many of similar offerings have sprung up since Tesla’s announcement in April. Daimler has been working on building a stationary battery product of its own (as well as a macro-project in which it uses old electric vehicle batteries as stationary storage for utilities). And just last week, German company Sonnenbatterie announced an all-in-one solar-panel-plus-stationary-battery system for €9,999 ( or $10,645). That price includes a 2kWh battery, a solar panel, an inverter, an “intelligent control system,” and 19 percent sales tax. It doesn’t include the price of installation, which varies depending on the installer.

GMP says it’s pushing forward on more experimental grid arrangements with stationary storage playing its part. "We see a future with community microgrid—and have one in Rutland (Stafford Solar Farm) we are building,” the spokesperson told Ars. The Stafford Solar Farm is the first micro-grid in the US to rely solely on solar power and battery backup.

Tesla has also been vocal about its goal to move our current, aging grid infrastructure to a “smart microgrid” system, where energy sources are distributed and include a mix of renewable energy sources, stationary storage, and traditional sources like diesel generators. The advantage of a microgrid is that energy sources can be more flexible, and in the event of a natural disaster, it’s less likely that a single station can leave thousands of homes without power, as in the case of Superstorm Sandy in New York in 2012.