r/EnergyStorage

https://preview.redd.it/wxmjowssnxsg1.jpg?width=1458&format=pjpg&auto=webp&s=da24627ccb16d17fe1783c9f8b97e0d8ed7b3811

https://www.batterydesign.net/bess-ageing-vs-duty-cycle/ takes a look at the paper: Xu J, Li H, Hua S and Wang H (2025) Experimental investigation of grid storage modes effect on aging of LiFePO4 battery modules. Front. Energy Res. 13:1528691

and how it compares to what we see in the field:

• We see this in the field constantly. Same capacity, wildly different degradation across assets running different grid services. Now there’s a clean paper that confirms it.
• A team from a battery test equipment manufacturer ran 16 months of cycling tests on 220Ah LFP modules using actual peak shaving and frequency regulation profiles from a storage power station.
• Peak shaving degrades 1.8x faster than frequency regulation. Same SOC range, same temperature. Shallow SOC windows (30–80%) age 1.65x slower than deep cycling.
• Most fleet operators still model degradation as a function of cycle count, not service mix. If you’re stacking revenue without modeling what each service does to your asset, you’re optimizing income and ignoring cost.

I have a home battery design that has been turned down by the City inspector for the reason that it lacks a microgrid interconnection device--AKA an ATS to comply with anti-islanding provisions of the NEC code). This device is unnecessary and costly as the inverter I am using (a UL 1741-listed GSL 12Kw smart inverter) incorporate an ATS and recommends a soft switch that disconnects the battery grid from the power grid when the power grid fails. The real reason, I suspect, is that they don't understand how this soft switch works. I am hoping to find a Professional Electrical Engineer to review my design. I expect to pay a fee for this service. Does anyone know of one that can help me? I live in Texas, but Ohm's law still applies in the entire US, so I don't think the PE's state matters.