EcoMotion is currently working on several exciting energy resilience projects in the LA area and the Bay area. Specifically, we are “hardening” municipal buildings with solar plus storage. The goal is to deliver energy resilience for critical loads during power outages. We’re designing for a four-hour duration minimum, but this can be managed to be much longer as our systems are replenished with solar power.

Here’s a new wrinkle: What happens over time as the batteries that anchor the systems lose their capacity? Like normal household batteries and car batteries, they degrade. They lose their punch! Does this mean we will not be able to serve all the critical loads identified over time?

This brief and non-technical investigation delves into the state of battery degradation in two modes: First, and most common, is normal cycling mode. State of California battery incentives currently requires 104 cycles a year. Cycling is used to trim peak demands, which is super important for the grid. Batteries can also charge during off-peak, and discharge during peak periods. That’s called energy arbitrage. These financial plays are largely the name of the game in the battery energy storage world.

This brief, however, looks a bit deeper… and into batteries whose primary mission is to be in reserve for energy resilience. These batteries are not cycled daily. They are on standby for an emergency. They are at the ready, but batteries held in reserve are degrading. Just how fast are they degrading? What is their rate of “self-discharge” as it is called in the industry?

Click here to read the full white paper.