Wisconsin-based storage developer EnSync Energy Systems is working on a system that could allow your residential battery to sell energy to your neighbor’s electric vehicle.

The device-to-device transaction system is designed to operate behind the meter, using DC links, and could be up and running within a year, according to Jim Koeppe, product manager for EnSync’s distributed energy resources Flex Internet of Energy platform. 

The first iteration of the system, called DER Flex, will monitor exchanges on DC meters and send the data to a cloud computing center where payments will be calculated and settled. 

However, said Koeppe: “As we move forward, we intend to not only use a centralized model in the cloud, but to push that down to the device level, where, then, units can be aware and potentially transact with other units.”

The platform would enable energy devices to communicate privately with each other and carry out transactions at pre-established prices, he said. 

Around 20 DER Flex units will be sent out for alpha testing, he confirmed, with some going to strategic partners for use in residences in Hawaii, where EnSync has a large customer base. DER Flex will also be demo'd at the Solar Power International industry show this month. 

The first generation of DER Flex will not allow neighboring battery systems to talk to each other.

But EnSync hopes it will be enough to open up small-scale energy trading for residential customers who might live in homes too small to warrant a PV installation or an independent power-purchase agreement (PPA).

Specifically, the company has designed the system so that it can help distribute C&I-scale PV and storage across residential communities, such as blocks of apartments.

“If we put this sort of distributed network inside of our PPA, we’re able to be distributed on a home level,” Koeppe explained. “Then we’re really able to optimize the economics of our PPAs and be able to service all the individual residences efficiently.”

There were “huge financial benefits” in being able to distribute energy across a community in this way, he said. EnSync is currently working on the cybersecurity and other network elements required to create such behind-the-meter energy trading networks, said Koeppe. 

Numerous other companies are developing energy trading platforms, mostly based on blockchain. And energy storage vendors such as sonnen have developed aggregation platforms to create virtual power plants and residential trading systems.

But these all rely on energy passing over the utility AC grid, said Koeppe. Only a few vendors are focusing on DC bus-based systems, he noted. And “when it comes to creating a physical network of power behind the meter, I have not seen that,” he said.

Colleen Metelitsa, a grid edge analyst with Wood Mackenzie Power & Renewables, said EnSync is looking to achieve something akin to blockchain-based energy trading, but without blockchain.

“They are building a platform, but on different network and data protocols than blockchain companies,” she said.

EnSync launched a home energy system in May with a press release claiming a “sizable order backlog” from customers, including the approximately 150-unit Keahumoa Place property in Oahu, Hawaii.

“EnSync will initially target the multi-residential property market for its solution, then broaden its market presence,” said the company.

EnSync’s residential modular battery offering has been in development for two years, starting at 9 kilowatt-hours of capacity and expanding in 9 kilowatt-hour increments up to 27 kilowatt-hours.

It comes with a 10-year system-level warranty and a battery guarantee of 10 years or 30 megawatt-hours of discharge, whichever comes first.

In May, EnSync was hoping to grow its residential 2018 order book from $5.5 million to $15 million with the launch of the residential system, according to reports.

This month it announced a stock selloff to raise $2.9 million “to fund the development of distributed energy resource projects and for working capital and general corporate purposes.”