Techno‑Economic Analysis of Li‑ion vs. Lead‑Acid Batteries in Energy Storage

This summary is based on the academic work “Techno‑economic analysis of lithium‑ion and lead‑acid batteries in stationary energy storage applications” (Kebede et al., 2021).

Why Compare These Batteries?

When we talk about renewable energy — solar, wind, and other sources — one of the biggest challenges is their inconsistency. The sun doesn’t always shine, and the wind doesn’t always blow. Batteries step in to smooth out those ups and downs, keeping the grid stable and managing energy loads.

Both lead‑acid and lithium‑ion (Li‑ion) batteries are used for this purpose, but they bring very different strengths and weaknesses to the table.

The Trade‑offs

  • Lead‑acid batteries
    • Affordable upfront.
    • Easy to charge.
    • Widely used for smoothing renewable power.
  • Lithium‑ion batteries
    • Much higher energy and power density.
    • Require little maintenance.
    • Last far longer in terms of cycle life.

The debate often centers on cost: Li‑ion batteries are more expensive at the start, but their longer lifespan (beyond five years) makes them economically competitive in the long run.

The Numbers Tell the Story

  • Specific Energy: Li‑ion ~151 Wh/kg vs. Lead‑acid ~30 Wh/kg.
  • Efficiency: Li‑ion ~87% vs. Lead‑acid ~76%.
  • Service Life: Li‑ion ~12.7 years vs. Lead‑acid ~8.8 years.

In short, Li‑ion batteries outperform lead‑acid across almost every technical measure.

How the Study Was Done

The researchers used two main models:

  • Equivalent Circuit Model (ECM): Simulated how batteries charge, discharge, and degrade over time, factoring in things like discharge rates, depth of discharge, and temperature.
  • HOMER Optimization Model: Analyzed the economics of micro‑grid systems, focusing on Net Present Cost (NPC) and Cost of Energy (COE).

What They Found

  • Technical Performance: Li‑ion batteries are clearly superior for long‑term stationary energy storage.
  • Economic Feasibility: Despite higher upfront costs, Li‑ion becomes the better investment after about five years.
  • Cycling Impact: Li‑ion batteries hold up better under heavy use, losing less capacity and voltage compared to lead‑acid.
  • Overall Conclusion: Li‑ion batteries offer both technical and economic advantages, especially when paired with renewable systems like solar PV. Optimized with tools like HOMER, they deliver the lowest cost of energy and total system cost.

In plain terms: Lead‑acid batteries are the budget option, but Li‑ion batteries are the smarter long‑term choice. If you’re building a renewable energy system that needs to last, Li‑ion wins on efficiency, durability, and overall value.

Title: Techno-economic analysis of lithium-ion and lead-acid batteries in stationary energy storage application
Authors: Abraham Alem Kebede, Thierry Coosemans, Maarten Messagie, Henok Ayele Behabtu, Joeri Van Mierlo, Maitane Berecibar
Journal: Journal of Energy Storage
Volume: 40
Article Number: 102748
Publication Date: August 18, 2021
DOI: 10.1016/j.est.2021.102748

SOURCE: https://www.sciencedirect.com/science/article/pii/S2352152X21004783