Enphase enters development and supply agreement with Eliiy Power

Enphase Energy has announced in a SEC filing that it has signed a six-year deal for Japan’s Eliiy Power to exclusively supply its battery cell and battery management units for the Enphase AC Battery.

The development and supply agreement cements the relationship between the two companies, which have collaborated since 2014 on the development of the new Enphase AC Battery.

The AC Battery will be rolled out to the Australian market later this year before being introduced in the U.S. and select markets in Europe in 2016. A modular battery built using Eliiy’s lithium-based technology, a typical system provides 1.2 kWh or energy storage and 275/550 W power output.

Greg Wolfson, Enphase’s director of storage product line, told pv magazine in an interview last month that the battery has been specifically designed to round-out the Enphase Energy Management System.

"We are going squarely after a residential market, where the battery is going to be subjected to harsh thermal environments, which typically are the worst environments for batteries – places like garages where there is a lot of thermal stress," he said.

The SEC filing outlined the terms of the supply agreement, stipulating that Enphase will now purchase "battery module products exclusively from Eliiy until the later of two years from the date the first commercial Eliiy product is sold to Enphase".

Wolfson told pv magazine that Enphase has taken great care in identifying a battery partner, analyzing the benefits of various technologies and suppliers before deciding to choose Eliiy. "We spent a lot of time on the physical design of the battery and emphasizing such aspects as the nature of the technology we are using. The lithium-ion phosphate and the smaller modularity allows us to get away with only passive convective cooling. There is no active cooling, and that makes the O&M very simple."