[Battery Series] Enphase vs. “Others”
As energy storage with solar installs becomes more popular and mainstream, we are seeing more companies entering the residential battery storage market. With increased competition, technology will progress more quickly and pricing will improve (spoiler alert, it already has come down drastically in the past two years). For the end consumer, this is a great thing but it can also become confusing to pick a battery and understand the technology with so many choices.
At Solterra, we have installed multiple types of batteries from different manufactures. This includes the older lead-acid style to the latest and greatest lithium batteries. These manufactures include Sonnen, Tesla Powerwall, LG Chem, and Enphase Enpower.
Most of these systems have almost identical space requirements, power output, and can be programmed to work with different utility billing options like time of use billing. We are currently aligned with the Enphase Encharge battery system. Below are some of the reasons why we believe the Enphase system stands above the other options, and why it’s a great solution for your home. Some of the differences we will look at include: Battery Chemistry, Modularity, Inverter technology, and a couple of other nice features.
A good place to start is the actual chemistry of the battery. The Enphase battery uses a Lithium-Ion Phosphate (LiFePo) chemistry. This chemistry may not be as power-dense as something like the Lithium Nickel-Manganese Cobalt (NMC) chemistry that is in the Tesla Powerwall or LG Chem, but it is also much safer chemistry, runs at cooler temperatures (avoiding a fan for cooling which can be an additional failure point) and can cycle more times. The LiFePo battery has no thermal runaway, meaning that if it is punctured, it will heat up and fizzle out. It does not combust. NMC batteries can explode and create a large flame. This link is a great visual representation of what happens when each cell is punctured. When living in areas prone to wildfire or earthquakes, this should be a big consideration when weighing options.
The other issue with cobalt is that it is considered a conflict mineral. Cobalt mining is known to have a high human cost, including in the Democratic Republic of Congo. The Enphase battery offers a conflict-free solution. The solar industry is trying and should be, at the forefront of good labor practices around the world.
Enphase has more modularity to size a system specific to the client’s needs. The batteries start at 3.36kwh units. When three of these are combined, they become a 10.08kwh unit. These units can be mixed and matched all the way up to a 40kwh system to better suit the needs and budget of the homeowner.
Distributed Inverter Technology
An inverter is one of the most important pieces of equipment in a solar energy system. It converts solar energy, which is direct current (DC) electricity, to alternating current (AC) electricity, which the electrical grid uses. Enphase is the world leader in microinverter technology. One key benefit to micro-inverters is that if one micro-inverter fails then only that one solar panel is impacted, and the rest of the system keeps working as normal. On the other hand, when solar is installed with a string inverter, that means there is a single point of failure. If the string inverter fails, then all the panels are off until the inverter gets swapped out.
This same distributed technology is true for the Enphase Encharge battery. Each 10.08kwh battery has twelve micro-inverters inside it. If one micro-inverter happens to fail, the battery will continue to function at 92% capacity. These inverters can be “hot-swapped” without cutting power and the system never needs to be shut down.
Other battery companies have a single inverter inside the battery. If the inverter fails, the battery fails, and you have no backup power. This distributed architecture is a huge benefit when you are relying on the battery for backup power in an emergency. For this reason, the micro-inverters are FEMA recommended because of their reliability. They also come with a 25-year warranty instead of the 10-year warranty that most other manufactures offer.
There are no communication or compatibility issues with the Enphase system since there is only one inverter manufacturer from the roof to the battery. With other battery systems, there is a solar inverter that controls the solar from one manufacturer and another manufacturer for the battery. This means potential compatibility issues over time, especially as companies roll out different firmware updates. With Enphase, all components are from one company and avoid a frustrating experience especially when the power is out and the battery should be working.
In line with the above, there is only one app on your phone to look at. You can easily monitor the solar, home consumption, and battery charge all in the same place. With other solutions, there are multiple apps you need to toggle back and forth between to understand what is happening with the solar versus the battery systems. Enphase has created an ease-of-use solution by combining their monitoring interfaces together.
Additionally, the Enphase system is compatible with a generator to top off the batteries if the solar can’t do it. They are also passively cooled and do not have any moving parts, coolant, or noise-making components that can fail.
If you want to learn more about the differences and similarities in your battery backup options, feel free to give us a call or text us at 206-462-1103 or email [email protected] and we can walk you through everything. You can also get a free quote here.
In the meantime, check out the Enphase website for a free battery sizing tool and more info about their batteries.
Kevin is a Board Certified NABCEP PV Installation Professional and Licensed WA journeyman electrician. He is currently the Sales Manager at Solterra. He is passionate about the outdoors and environmental health, which led him into the solar industry. Skiing and fishing were his main activities before having kids, which now dominate his free time. Through his work at Solterra, he hopes to help do his part so that his kids can continue to grow up in a world with clean air and water.