Lithium Iron Phosphate (chemical name: LiFePO4) — LFP Battery

Its main advantages: a cycle life of 4,000-6,000 cycles at a depth of discharge of 80-95% (mainstream tier-1 products: Pylontech US3000C/US5000 at 6,000 cycles @ DOD 95%; BYD Battery-Box Premium LVL at 6,000 cycles @ DOD 80%) and higher thermal stability than NMC (Nickel Manganese Cobalt) chemistry, without using cobalt, which often raises ethical-sourcing concerns [IRENA, Electricity Storage and Renewables: Costs and Markets to 2030, 2017 and Global Renewables Outlook, 2020; Pylontech datasheet 2024; BYD Battery-Box datasheet 2023-2024].

LFP has displaced NMC as the mainstream chemistry for stationary storage — batteries installed in a fixed location at a home or commercial building, not in an electric vehicle. The reasons are both technical and economic.

On the technical side, LFP has higher chemical stability because the Fe-P-O bond in the cathode does not release oxygen under excess heat, so the risk of thermal runaway (a chain chemical reaction that can cause fire) is lower than in NMC. The IEC 62619 safety standard — which governs secondary lithium cells and batteries for use in stationary applications — recognizes the difference in thermal characteristics between these chemistries [IEC 62619:2022]. For a factory roof or a server room, this safety margin is material.

On the economic side, the price of LFP per kWh has fallen significantly since 2020. In 2024-2026, an installed residential LFP battery in the Indonesian market is in the Rp 5.5-7.5 million per nominal kWh range [SolarPlanner.id Calculator Data, SECTION 1.3, LFP battery price Q1 2025], with mainstream brands available on the market including BYD Battery-Box, CATL Yilon, Pylontech US series, and Huawei LUNA. A cycle life of 4,000-6,000 cycles at DOD 80-95% (typical residential operating conditions) equates to a service life of 11-16 years at one cycle per day.

A trade-off worth noting: LFP energy density (~120-160 Wh/kg) is lower than NMC (~220-260 Wh/kg). For stationary storage this is not a problem — system weight and volume are not critical parameters as they are in an electric vehicle. For a residential or commercial PLTS system, what matters more is cycle life, safety, and cost per cycle over the service life.

Indonesian PLTS Application Example

On a 5 kWp hybrid PLTS system + 5 kWh LFP battery in Jakarta (PSH 4.8 kWh/m²/day [NASA POWER 1984-2023]), the battery charges ~4.5 kWh usable (DOD 90%) from daytime production and discharges it to night-time loads. With a cycle life of 6,000 cycles (datasheet specification for Pylontech US5000 @ DOD 95%; BYD Battery-Box Premium LVL @ DOD 80%), the battery component does not need replacing for ~16 years of daily use. The battery investment cost is in the Rp 27.5-37.5 million range for 5 kWh of capacity — the component that raises total CapEx ~50-60% above an on-grid system without a battery.

For remote off-grid community systems, an LFP battery with days of autonomy of 1-2 days becomes the dominant cost component, often contributing 40-60% of total system cost [SolarPlanner.id Calculator Data, SECTION 8].