Home Energy Storage Is Here

New home energy storage systems are fast coming onto the market and some utilities are recognising the opportunities these offer.
Published: Thu 23 Apr 2015

Utilities are beginning to recognize the role of home storage, and several, most recently Duke Energy, are actively investigating it. [Engerati-Duke Energy Puts US$1m Into Energy Storage Research] But with its potential in enabling consumers to maximize their use of home renewable generation and to remain powered during outages, the battery companies are at the forefront with new products fast coming onto the market. [Engerati-Engerati’s Week In Energy – Residential Storage A Gamechanger]

Home energy storage solutions

In the last month both JuiceBox Energy in the US and Kyocera in Germany have launched new storage products for the respective markets.

JuiceBox Energy’s offering is an 8.6kWh lithium-ion battery system that is suitable for both new and existing solar energy installations. Claimed to be maintenance-free with a minimum 10-year life, the battery, system controller and web-interface are housed in a custom designed indoor/outdoor NEMA 3R enclosure designed for rapid wall-mounted installation. Communication to web-based applications is via cellular connection for cloud-based monitor, control and remote firmware update, enabling users to keep up with evolving smart grid standards as well as tariff rate structures managed by utilities. With increasing numbers of systems online in the JuiceBox Energy Network, customers will also have the option to participate in future aggregated demand response markets.

According to JuiceBox Energy, California solar energy provider Cobalt Power has multiple JuiceBox storage installations in progress.

Kyocera is offering two systems in Germany with 4.8kWh and 7.2kWh lithium-ion batteries, enabling customers to select the appropriate size for their power usage. The inverter, which achieves a claimed 97% charging efficiency, and battery box are housed separately to make the system easier to transport and to provide more flexibility in installation. With it is supplied Solare Datensysteme’s Solar-Log monitoring device and software, which provides comprehensive data on the state of electricity usage and will allow users to further optimize the energy use in their homes. Distribution starting in May will be by the German distributor Energetik Solartechnologie-Vertriebs.

Kyocera’s solutions are also available in the US. Last October Kyocera teamed with energy service provider Stem to offer an integrated solar PV and energy storage solution for commercial power users.

The Tesla connection

It should come as no surprise that SolarCity, the largest PV provider in the US, is also moving into energy storage. With the company’s close connection with Tesla it has a natural source of battery supply.

Last month SolarCity announced its “microgrid-as-a-service” including the GridLogic storage system utilizing Tesla batteries aimed at businesses, municipalities and other larger users. [Engerati-Microgrids Now Available As A Service] SolarCity has also introduced a home storage pilot involving more than 400 systems. According to the company’s website, no more sales are being added for the time being but a “new and improved offering” will be available in late Summer 2015. It is an open secret that Tesla is eyeing the home energy storage market and with the “Gigafactory” now under development in Nevada envisages the volumes and volume of scale cost reductions to penetrate it. [Engerati-Tesla’s Gigafactory to Lower Battery Energy Storage Costs] And it is highly likely this solution will be revealed in Tesla CEO Elon Musk’s so far cryptic “Major new Tesla product line -- not a car” announcement on April 30.