Comparing Sonnen Eco’s and Enphase Encharge (2024)

by Jeff Mathias | Feb 21, 2020 | Battery Storage Systems | 0 comments

Sonnen Eco Storage System compared to Enphase Encharge Storage System.

Synergy has been installing the Sonnen Eco storage system pared with solar for more than 3 years with great success. With the release of Enphase’s Ensemble energy storage system with roof inverter integration, we will be picking up a second offering. Both of these products meet our fundamental requirements in the area of safety, reliability and longevity, and offer two very different approaches to energy storage.

Let’s first look at the similarities.

1. The first criteria we use in selecting a battery storage system is safety. The number one area we look at is lithium technology and whether it is cobalt free. Many of the leading battery suppliers use cobalt to increase power at the expense of safety. Cobalt is a combustive element and there is clear evidence of these batteries going into thermal runaway and catching fire. Both Sonnen and Enphase use Lithium Iron-Phosphate batteries, which do not contain cobalt and thus are not susceptible to the same spontaneous combustion problem. Also, while Lithium Iron Phosphate produces less 0-60 MPH power, it produces more energy and cycles better than batteries with cobalt (more longevity) making it the perfect choice for home storage.
2. Both systems offer a 200-amp transferswitch allowing for easily configurations to most homes electrical systems. Transfer switches are required in home battery backup systems to allow them to disconnect from PG&E in an outage. This prevents back feed to the grid and protects utility line-workers. When these transfer switches “feel” that there is no power coming from the grid, they disconnect from the grid and create what we call a microgrid so the home can continue to have power in an outage. When the transfer switches “feel” the power return, they reconnect to the grid.
3. Both systems can be setup as whole house or use a protected loads panel (PLP). Whole house has the advantage of allowing the whole house to be onbackup, and the disadvantage of heavy loads that can shut down the system, or quickly drain the battery, requiring homeowner involvement. This can be an issue when the homeowner is away. Using a PLP’s allows a homeowner to have a smaller subset of the home’s electrical needs that they want to keep powered when the grid is out. Having both options offers a greater flexibility of design.
4. Both products are AC coupled This means the storage and the solar are connected via AC, and enter the electrical panel as AC, not DC. AC coupling offers some advantages. They allow roof top inverters that are tied to the grid to bypass the storage system. It is also usually easier to retro-fit AC coupled systems to existing solar systems.
5. Both systems come with a 10-year limited warranty, allowing for <70% of battery life after 10 years, with Encharge offering up to 4,000 cycles and Sonnen 10,000 cycles.

The differences of Sonnen and Enphase.

There are differences between these two products. The key to remember is that the benefit depends upon your application. In many cases, it will be obvious which of the solutions will be needed for a homeowner, while in other cases, either solution will meet the homeowner’s need.

1. Probably the biggest difference between the two is that even though both systems are AC coupled, the Enphase system requires the Enphase IQ or M on the solar system to work with the Encharge system. Even older Enphase S series products will not work with the new Enphase Encharge system. New storage installations and customers who currently have Enphase’s newer IQ or M series inverters will be Synergy’s primary market for Enphase Encharge. Customers who have other inverters or Enphase’s older S series inverters may favor Sonnen.
2. At Synergy, we see the Enphase product as perfect for most city users who do not need as much power or storage as their county counterparts. An Enphase 10 KWH or 13 KWH system will work well for a customer who wants to backup a refrigerator, a few lights, receptacles, and gas igniters for water heating, stove and furnace at a lower price point than Sonnen. At Synergy, we start selling the Sonnen at the Eco 10 (10 kWh) size and it scales in the box to an Eco 20 (20 kWh) so it can have a higher cost than Enphase on the small size. Sonnen can be less expense for larger city or country properties where it can more easily handle larger loads.
3. One of the biggest differences between Sonnen and Enphase is in the inverter size and surge capability. Heavy electrical surges occur with wells, booster and septic pumps, refrigerators, blower fans, etc. The Sonnen Eco 10 has an 8,000-watt inverter that can handle surges of over 17,000 watts. The similarly sized Enphase Encharge 10 has an equivalent of 3.8kW of inverters and can handle a surge of 5.7 kW for 10 seconds. On properties with pumps and motors, Sonnen’s ability to handle the surges of these devices gives it a strong competitive advantage.
4. Enphase allows us to stack inverters, while Sonnen systems are not stackable, needing to be installed in parallel. With Enphase we can stack two Encharge 10’s to increase the power from 3.8 kW to 7.6 kW, the surge from 5.7 kW to 11.4 kW and the battery from 10 kWh to 20 kWh. Enphase allows us to stack up to 4 Encharge 10’s. This can add flexibility and it is important to note that while an Encharge 10 costs about 15% – 20% less than a Sonnen Eco 10, two Encharge batteries stacked costs about the same asa single Sonnen Eco 20. Installing multiple Sonnen systems can cost more than stacking multiple Enphase Encharge systems, it really depends on the need.
5. Sonnen allows for a generator control to charge batteries when there is minimal solar access (storms, clouds or fog) or during high usage times. This is a future option for the Encharge system.
6. And then there is the personal options – I have a Sonnen, and like that it is more mechanical and has less software controlled (options) (I like simple) while my business partner Mike who has the Enphase Encharge system, likes the software controls (from his phone or computer) with many more software options.

We are excited to add the Enphase Encharge product line. It allows us a lower entry level cost point and can be easily configured with new systems. We will continue to install the Sonnen systems, especially where a large inverter is needed to meet the needs of homeowners who have more motors and pumps. Both systems are well designed, safe, and provide the longevity you would expect from these two leading storage providers.