By Matthew Hirsch
In a room full of energy storage products, the first thing you notice about the Enphase Storage System is its size. Many of the devices on the market are as big as a refrigerator. The Enphase solution could fit underneath a Christmas tree. On an exhibition table at Greentech Media’s US Energy Storage Summit, it takes up no more space than the flat-screen monitor giving a first look at Enphase’s Home Energy Solution in action.
The next thing you notice is the simplicity of the Home Energy Solution itself, a platform that delivers generation, storage, control and management all in one. As visitors at the Energy Storage Summit question how the nascent market for grid-tied batteries will evolve, Enphase presents a clean and intuitive finished product demonstrating how homeowners can immediately maximize the value of their electric system.
The top of the display interface is divided neatly into three sections showing energy imports from rooftop solar and the grid on the left, household energy consumption in the middle, and Storage System performance on the right. The bottom of the screen tracks changes in production, consumption and storage in real time.
Greg Wolfson, Enphase’s senior director of the storage product line, calls the demonstration “A day in the life of the Storage System.” To simulate a morning sunrise, Wolfson turns the dial on a solar simulator, a device that enables controlled testing of solar panels in the Enphase lab. The monitor reports how much energy the home’s solar system is producing and how the available energy in the Storage System is going up.
As people start waking up, the simulated home begins consuming energy. Wolfson switches on two desktop lamps with energy-eating incandescent light bulbs. Now the Storage System reverses the flow of energy, discharging to supply the load in the house. Throughout the day, as solar production and home energy consumption change, Enphase’s upgraded networking hub, the Envoy-S, performs a balancing act to store up energy when the solar production is at its peak and minimize imports from the grid when electricity rates are high.
The simulation also shows how the Home Energy Solution can meet stringent utility requirements that limit power exports to the grid regardless of the available solar power on the roof or energy consumption levels in the home. This is important because it means the system complies with Hawaii’s new self-supply tariff and similar programs that may be introduced in the future.
“This is not a solar generation solution or an inverter solution. It’s a home energy solution. Now you have the range of capabilities to control how you generate and consume energy in your home,” Wolfson says.
In mid-2016, Enphase will roll out the Home Energy Solution first in Australia and New Zealand, and then in Hawaii. These markets are ripe for residential storage because they have high energy costs, a large penetration of solar on the grid, and declining utility incentives for solar energy. Residential solar system owners can easily retrofit their homes by adding the Storage System to keep excess energy in reserve and use it later instead of selling at a reduced price.
As utility rates and solar incentives continue to evolve, so will the energy storage market. That’s why Enphase likes the small size and modular design of its Storage System. With 1.2 kilowatt-hours of storage capacity, the product delivers a low up-front cost without a great deal of excess capacity that might go unused. For more storage capacity in the future, simply install additional units next to the first one and connect them using standard AC wiring.
Solar installers who don’t want to transport and install refrigerator-sized batteries will appreciate the manageable size of the Storage System. Once the final demonstration at Greentech Media’s Energy Storage Summit was over, a product engineer powered off the device, disconnected the cabling, and lowered it onto a pushcart, all in a matter of minutes.
Matthew Hirsch runs Hirsch Media Services, a B2B content marketing agency with deep roots in the energy industry. He occasionally writes on behalf of Enphase.