LDES Technology Comparison Calculator
There is no single "best" long-duration energy storage technology -- the right choice depends almost entirely on how long you need to discharge. This calculator applies the same installed-cost formula to four leading LDES technologies (lithium-ion BESS, vanadium flow batteries, pumped hydro, and compressed air energy storage) using each technology's own representative power-related and energy-related cost figures, then lays the four total installed costs side by side so you can watch the ranking shift as you change duration. It pairs naturally with our Levelized Cost of Storage vs. Duration Calculator for the underlying duration-cost dynamic, our Flow Battery LCOS Calculator and planned Pumped Hydro LCOS Calculator for full levelized-cost treatment of individual technologies, and our CAES Efficiency Calculator for the round-trip efficiency dimension this comparison deliberately sets aside.
The continuous power output all four technologies must deliver.
Try changing this value to see how the relative ranking of technologies shifts -- shorter durations favor lithium-ion, while longer durations favor technologies with cheaper energy-related costs.
(100 MW × 1000 × $150/kW) + (100 MW × 10 h × 1000 × $250/kWh)
(100 MW × 1000 × $300/kW) + (100 MW × 10 h × 1000 × $300/kWh)
(100 MW × 1000 × $1800/kW) + (100 MW × 10 h × 1000 × $50/kWh)
(100 MW × 1000 × $1000/kW) + (100 MW × 10 h × 1000 × $60/kWh)
These power/energy cost splits are representative, illustrative figures for comparison purposes, not precise published benchmarks for every technology -- actual project costs vary significantly by scale, site conditions, and market timing. The relative pattern (how ranking shifts with duration) is the key insight this tool is designed to illustrate.
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
How we calculate this →Duration is the single biggest factor in choosing a long-duration storage technology, more than any fixed 'best' technology. At 100 MW and 10 hours in this example, CAES and pumped hydro come out cheapest thanks to their low energy-related cost per kWh, while lithium-ion's cost -- which scales heavily with energy capacity -- pushes it toward the expensive end at this duration, even though it would likely win decisively at 2-4 hours. This is exactly why there's no single 'winning' storage technology: the right choice depends entirely on how long you need to discharge, not just on headline cost-per-kWh figures.
How the LDES technology comparison is calculated
This calculator applies the same installed-cost formula to four long-duration energy storage technologies -- lithium-ion BESS, vanadium flow batteries, pumped hydro, and compressed air energy storage (CAES) -- using each technology's own representative power-related and energy-related cost figures, so the four results are directly comparable at any power and duration. One formula, applied four times, ties the calculation together.
Total Installed Cost ($) = (Required Power (MW) × 1000 × Power-Related Cost ($/kW)) + (Required Power (MW) × Required Duration (hours) × 1000 × Energy-Related Cost ($/kWh)). The first term is the fixed power cost: converting the required power from megawatts to kilowatts (× 1000) and multiplying by the technology's power-related cost per kW (inverters, controls, stack, turbines, compressors) gives a cost that does not change with how many hours of energy the system stores. The second term is the energy cost: the energy capacity in kWh (required power in MW × 1000 × duration in hours) multiplied by the technology's energy-related cost per kWh (cells, electrolyte, reservoir volume, cavern volume) gives a cost that scales directly with duration. Summing the two gives the all-in installed cost for that technology. The same formula is then repeated for each of the four technologies using its own cost pair, and the four totals are displayed side by side for direct comparison.
The four technologies use these representative, illustrative cost figures: Lithium-Ion BESS -- $150/kW power-related, $250/kWh energy-related; Vanadium Flow Battery -- $300/kW, $300/kWh; Pumped Hydro -- $1,800/kW, $50/kWh; CAES -- $1,000/kW, $60/kWh. At the defaults (100 MW, 10 hours), the four totals are: Lithium-Ion BESS = (100 × 1000 × $150) + (100 × 10 × 1000 × $250) = $15,000,000 + $250,000,000 = $265,000,000; Vanadium Flow Battery = (100 × 1000 × $300) + (100 × 10 × 1000 × $300) = $30,000,000 + $300,000,000 = $330,000,000; Pumped Hydro = (100 × 1000 × $1,800) + (100 × 10 × 1000 × $50) = $180,000,000 + $50,000,000 = $230,000,000; CAES = (100 × 1000 × $1,000) + (100 × 10 × 1000 × $60) = $100,000,000 + $60,000,000 = $160,000,000.
Two notes on the model. First, the power-related and energy-related cost figures are representative, illustrative values for comparison purposes, not precise published benchmarks for every technology -- actual project costs vary significantly by scale, site conditions, and market timing, so the absolute dollar totals should be treated as order-of-magnitude estimates while the relative pattern (how the ranking shifts with duration) is the key insight the tool is designed to illustrate. Second, this calculator isolates the installed-capital-cost dimension and excludes round-trip efficiency, cycle life, operating cost, charging energy cost, site availability, development timeline, permitting, safety, and grid-services capability -- all of which matter for real technology selection, and which each technology's dedicated efficiency or LCOS calculator addresses for that dimension. Data sources: Storage system cost decomposition (power-related vs. energy-related cost) and representative technology cost ranges from DOE (Department of Energy), NREL (National Renewable Energy Laboratory), and IRENA (International Renewable Energy Agency) energy storage technology assessments; lithium-ion, vanadium flow, pumped hydro, and CAES cost structures from industry benchmarks and NREL studies. Verification: with defaults (100 MW, 10 hours), Lithium-Ion BESS = $265,000,000, Vanadium Flow Battery = $330,000,000, Pumped Hydro = $230,000,000, CAES = $160,000,000.