Technology Comparison
| Technology | Round-Trip Efficiency | Lifespan (Cycles) | Cost ($/kWh) |
|---|---|---|---|
| Lithium-ion (NMC) | 85-95% | 3,000-5,000 | $150-300 |
| Lithium-ion (LFP) | 90-95% | 5,000-10,000 | $180-320 |
| Flow Batteries | 65-75% | 10,000-20,000+ | $300-500 |
| Pumped Hydro | 70-85% | 50+ years | $50-150 |
Round-trip efficiency measures energy out divided by energy in. If you store 100 kWh and retrieve 90 kWh, that's 90% efficiency. The "lost" 10% converts to heat through chemical reactions and electrical resistance.
Grid Services Revenue
Battery storage generates revenue from multiple grid services:
- Frequency Regulation: $5-15/MW/hour for maintaining 60Hz grid frequency within ±0.02Hz
- Capacity Payments: $50-150/kW/year for being available during peak demand
- Energy Arbitrage: Buy electricity at $0.02/kWh at night, sell at $0.15/kWh during peaks
- Voltage Support: $3-8/MWh for maintaining voltage stability
- Black Start: Premium payments for ability to restart grid after blackout
These economics explain the explosive growth in battery deployment—from 1 GWh globally in 2015 to over 60 GWh in 2024, with projections of 1,000+ GWh by 2030.
Why this matters on this site
Storage changes two numbers you meet everywhere else here. It lifts the useful capacity factor of a solar or wind project by moving output into the hours when power is worth most, and it adds a cost line that lands in the project's LCOE. That is the trade Race to Zero prices in: once wind and solar pass roughly 60 % of a country's mix, each further point costs more, because it has to be firmed rather than simply built.