Hydrogen vs. Battery Storage Calculator: Cost & Duration Comparison
Hydrogen and lithium-ion batteries are usually framed as competitors, but they aren't really — they win at different storage durations. Batteries dominate short-duration storage measured in hours: round-trip efficiency is 85–90%, and their bundled power-plus-energy cost is low at small scale. But every additional hour of battery duration means buying more cells, so battery cost scales almost linearly with the energy you need to store. Hydrogen inverts that. Its round-trip efficiency is poor — around 35–40% once you account for electrolysis, compression, storage, and reconversion through a fuel cell — and its power-related equipment (electrolyzer plus fuel cell) is expensive. But hydrogen storage tanks are cheap per kilowatt-hour, so once that fixed power-related cost is amortized over a large enough energy volume, hydrogen's cost per kWh delivered keeps falling while the battery's stays flat. That's why hydrogen is discussed for multi-day and seasonal storage, not for evening peak shifting. This tool finds the crossover: the storage duration at which hydrogen's declining cost per kWh delivered drops below the battery's, given your own cost and efficiency assumptions.
Total energy the system must deliver in one full discharge.
Daily cycling ≈ 365. Long-duration and seasonal assets cycle far less (5–50/yr).
All-in installed cost per kWh of usable capacity for a utility-scale system.
Full levelized cost of storage for a 4-hour battery; its charging + O&M share is used as the battery variable cost.
Electrolyzer plus fuel cell, sized to the discharge power. This cost does not grow with duration.
Tank / cavern storage per kWh of stored hydrogen energy — roughly 20× cheaper than battery cells.
Levelized delivered cost implied by hydrogen production economics; its variable share is used as the hydrogen variable cost.
$220/MWh at 88% RTE
$321/MWh at 38% RTE
by 46% per kWh delivered
batteries win below 20 hrs; hydrogen wins above
vs 114 MWh charged into the battery
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
How we calculate this →How the hydrogen vs. battery crossover is calculated
Both technologies are levelized to the same metric: dollars per kilowatt-hour actually delivered back to the grid. Each is built from a capital annuity plus a variable cost.
Capital is annualized with a capital recovery factor (CRF) of 0.10185 — a 20-year life at an 8% cost of capital — and divided by annual delivered energy, which is energy per discharge × 1,000 × cycles per year. That denominator is identical for both technologies, so the comparison is apples to apples.
Battery capital scales with energy. Usable capacity has to cover the full discharge, and charging losses mean you buy slightly more than you deliver: capital = energy delivered (kWh) ÷ round-trip efficiency × $/kWh. There is no cheap way to add hours — more duration means more cells, so the battery's cost per kWh delivered is essentially flat with duration.
Hydrogen capital splits into two very different pieces. The power-related cost — electrolyzer plus fuel cell — is sized to discharge power, which is energy ÷ duration. Stretch the same energy over more hours and the required power falls, so this large fixed cost shrinks per kWh. The energy-related cost is tank storage: stored energy = delivered energy ÷ round-trip efficiency, multiplied by $/kWh of storage. Because tanks cost roughly 20× less per kWh than battery cells, this term grows slowly.
Variable costs come from the two levelized benchmarks you supply — battery LCOS and the hydrogen LCOH-derived delivered cost. Because capital is already modeled explicitly above, only the non-capital share of each benchmark is applied (45%, representing charging electricity, O&M, and degradation-related spending). This avoids double-counting capital while preserving the real cost gap between charging a battery at 88% efficiency and running a hydrogen chain at 38%.
The crossover duration is found by sweeping duration from 1 hour upward and reporting the first hour at which hydrogen's cost per kWh delivered falls to or below the battery's. With the default assumptions the crossover lands in the tens of hours — comfortably above daily energy shifting, and squarely in multi-day territory.