Earlier this year, SolarEdge Technologies announced its StorEdge solution would be available for international distribution after completing a number of installs toward the end of 2015. With energy storage becoming more and more important, we reached out to Lior Handelsman, VP of marketing and product strategy at SolarEdge, to learn a little bit more about the brains of this system and how it will operate.
SB: Where does StorEdge fit within a system?
Handelsman: For homeowners, the typical energy usage of a homeowner does not match the daytime energy generation of a PV system. So, when the market transitions away from FiT and net metering, there is a financial incentive to store energy produced by residential PV systems. Unused PV power is stored in a battery and utilized when needed. By coupling energy storage with a PV system, homeowners can continue to reduce their electric bills and increase their energy independence.
Compatible with Tesla’s home battery, the Powerwall, StorEdge is a DC-coupled storage solution that manages and monitors PV production, consumption and storage and allows home owners to reduce electric bills and gain energy independence. With StorEdge, unused solar energy is stored in a battery and used when needed to maximize self-consumption and for power backup during power outages. StorEdge also supports charge/discharge management, which promotes energy consumption when electric demand from the grid is low (off-peak rates) and lower consumption when demand is high (peak rates). The backup function allows homeowners to store solar energy and use it during electric outages for selected loads.
Acting as the brain of the entire system, the inverter is a key component in any storage system. Since the inverter manages production, consumption and storage, it plays a central role in energy efficiency of the system. The charge/discharge user profiles are programmed into the inverter. Different profiles can be created based on usage, needs, and electricity costs. The inverter also provides insight into system status. With StorEdge, homeowners receive full visibility into battery status, PV production, and self-consumption data through the SolarEdge monitoring platform. Just as important, the inverter is also responsible for grid interaction, which has an increasing amount of requirements.
SB: How does its time of use management work?
Handelsman: For profile programming, the StorEdge system can be programmed to operate according to different charge/discharge profiles, also referred to as Time of Use (TOU) arbitrage. This allows homeowners to increase energy consumption when electric demand from the grid is low (off-peak tariffs) and lower consumption when demand is high (peak tariffs). Profiles can be created for the following applications:
• Charge the battery from the grid when electricity prices are low;
discharge to supply house consumption when they are high;
• Charge the battery from PV when electricity prices are low; discharge it when they are high;
• These two applications can be used simultaneously with one profile.
Every profile is a yearly calendar divided into 15 min segments. During each segment the system operates according to one of seven charge/discharge modes. The yearly profile is repeated for 20 years as long as no profile changes are made.
It is important to note, that a profile program can also be set for when there is no PV, which allows charging the battery from the grid when electricity prices are low, and discharge to supply house consumption when they are high. These charge/discharge user profiles are programmed into the inverter.
The StorEdge inverter is programmed to discharge the battery in an optimal manner to meet its programmed goal, such as electric bill reduction, TOU gain, or maximizing backup. StorEdge is designed to use discharge patterns that do not shorten the battery’s lifetime.
SB: What is installation like? Is it complex?
Handelsman: The SolarEdge StorEdge solution has a number of installation benefits. Since it requires only one inverter for PV and storage, it allows for easy installation. Using standard PV cables, no special wires are required. Having no high voltage or current during installation and maintenance, further improves safety and ease of installation. Lastly, the StorEdge inverter can be installed outdoors which offers easy access to the inverter during maintenance.
SB: What is the battery profile?
Handelsman: SolarEdge’s StorEdge solution is compatible with Tesla’s home battery, the Powerwall. The battery published specs are 6.4 kWh of energy, with continuous and peak power of 3.3 kW. It is a lithium ion battery with liquid thermal control.
SB: What is the warranty?
Handelsman: The warranty on the StorEdge solution is 25 years for power optimizers, 12-25 years for inverters, 10 years for interface, and 3 for the Modbus Meter.