Storage · the complete global ecosystem

Store energy today. Power the world tomorrow.

Storage balances generation and demand, manages intermittency, steadies the grid and cuts peaks. BARREL covers it all — pumped hydro, batteries, thermal and molten salt, compressed and liquid air, hydrogen, gravity and the long-duration technologies to come — classified by how each one actually stores energy.

Storage families
10
Compared
17
Lifecycle stages
17
Rows of battery storage containers at a grid-scale storage site
01 Pumped Hydro Storage02 Battery Storage (BESS)03 Thermal Storage04 Mechanical Storage05 Chemical Storage06 Electrical Storage

Not everything is a battery. Some technologies store electricity electrochemically; others store it as water at height, pressure, motion, heat, cold or chemical fuel. Output, duration, efficiency and applications differ — so BARREL classifies storage by its actual mechanism.

Technology explorer

Every storage family, its system and its industry.

Storage · 01

Pumped Hydro Storage

Storing electricity through the power of water.

Pumped Storage Hydropower (PSP) pumps water from a lower to an upper reservoir and releases it through turbines when electricity is needed — mature, utility-scale and long-duration.

Viability depends on topography, geology, reservoir design, water availability, environment and transmission access.

Open-loop

  • Existing hydro reservoirs
  • River-connected upper or lower reservoir
  • Integrated with conventional hydro
  • Multipurpose dams

Closed-loop

  • Two off-stream reservoirs
  • Mountain-based
  • Flat-terrain engineered
  • Mine-pit and quarry conversions

Underground & seawater

  • Underground lower reservoir
  • Abandoned mine conversion
  • Underground powerhouse
  • Coastal seawater PSP

Configurations

  • Pure and with natural inflow
  • Reversible or separate pump and turbine
  • Fixed and variable speed
  • High-, medium- and low-head
  • Single- and multi-stage

Civil

  • Upper and lower reservoirs
  • Concrete, earthfill and rockfill dams
  • Intakes and outlets
  • Headrace and tailrace tunnels
  • Penstocks and pressure shafts
  • Surge tanks
  • Underground caverns

Electro-mechanical

  • Reversible Francis pump-turbines
  • Spherical and butterfly inlet valves
  • Governors
  • Motor-generators
  • Static frequency converters
  • Excitation and synchronisation
  • HV switchgear

Applications

  • Renewable time-shifting
  • Peak management
  • Frequency regulation
  • Spinning reserves
  • Black start
  • Seasonal energy management

Lifecycle services

  • Hydrological and geological studies
  • Water balance and hydraulic modelling
  • DPR and financial model
  • Dam safety assessment
  • Turbine and pump overhaul
  • Uprating and modernisation

Technology comparison

Seconds to seasons.

Qualitative classifications, not guaranteed specifications — real performance depends on design, operation and application.

TechnologyTypical roleDuration potentialMaturity
Pumped hydroBulk electricityHours – daysEstablished
Lithium-ion BESSGrid and distributedSeconds – hoursEstablished
Flow batteriesStationaryHours – longCommercial
Sodium-ionStationary and distributedConfiguration-dependentDeveloping
Sodium-sulphurStationaryMulti-hourEstablished niche
Molten saltHigh-temperature heatHours – longerEstablished
Sand / concreteThermalHours – seasonal conceptsDeveloping
PCMHeating and coolingHours – daysCommercial
CAESBulk electricityHours – daysEstablished niche
LAESBulk electricityHours – daysDeveloping
FlywheelHigh power, shortSeconds – minutesEstablished
GravityBulk mechanicalHours – daysEmerging
HydrogenChemical and seasonalDays – seasonalDeveloping
SupercapacitorsRapid power supportSeconds – minutesEstablished
SMESRapid power supportVery shortEstablished niche
Ice / chilled waterCoolingHours – daysEstablished
ThermochemicalHeatPotentially longDeveloping

Applications

The right storage for the job.

Utility-scale grid
PSP, BESS, CAES, LAES
Renewable integration
BESS, PSP, hydrogen, thermal
Long duration
PSP, CAES, flow batteries, thermal, hydrogen
Seasonal
Hydrogen, underground thermal, chemical
Frequency regulation
BESS, flywheel, supercapacitors, PSP
Peak shaving
BESS, PSP, chilled water, thermal
Industrial heat
Molten salt, sand, concrete, PCM
Cooling
Ice, chilled water, cryogenic
Data centre backup
BESS, flywheel, thermal
EV charging
BESS, supercapacitors, hybrid
Remote and off-grid
BESS, hydrogen, pumped hydro
District heating / cooling
Hot water, pits, boreholes · ice, chilled water
Hydrogen economy
Hydrogen, ammonia, synthetic fuels
Emergency power
Batteries, flywheels, fuel cells

Project value chain

Seventeen stages, from resource to recycling.

  1. 01

    Resource assessment

    Demand, resource and site

  2. 02

    Technology assessment

    Battery, hydro, thermal or other

  3. 03

    Feasibility

    Technical and economic

  4. 04

    Engineering

    Conceptual, basic and detailed

  5. 05

    Project development

    Land, permits, approvals, financing

  6. 06

    Manufacturing

    Cells, machinery, equipment

  7. 07

    Procurement

    Equipment and materials

  8. 08

    Construction

    Civil, structural, infrastructure

  9. 09

    Installation

    Mechanical, electrical, controls

  10. 10

    Integration

    Grid, renewable, industrial

  11. 11

    Testing

    FAT and SAT

  12. 12

    Commissioning

    Energisation and verification

  13. 13

    Operation

    Charge, discharge, energy management

  14. 14

    Maintenance

    Preventive and predictive

  15. 15

    Modernisation

    Upgrades and augmentation

  16. 16

    Recycling

    Material recovery and reuse

  17. 17

    Decommissioning

    Dismantling and restoration

Manufacturing ecosystem

Each technology, its own supply chain.

Battery

  • Mineral and chemical processing
  • Cathode and anode materials
  • Cylindrical, prismatic, pouch cells
  • Modules, packs, racks
  • BMS and PCS
  • Cooling plates and HVAC
  • Containers and cabinets
  • Recycling

Pumped hydro

  • Pump-turbines
  • Motors and generators
  • Penstocks
  • Pressure valves
  • Governors
  • Transformers and switchgear
  • Tunnel gates
  • Heavy steel

Thermal

  • Molten salt and oil tanks
  • Sand and concrete storage
  • Ceramic modules
  • PCM and thermochemical materials
  • Heat exchangers
  • Electric boilers
  • Insulation
  • High-temperature pumps and valves

Mechanical

  • Compressors and expanders
  • Turbines
  • Pressure vessels
  • Cryogenic tanks
  • Flywheel rotors
  • Magnetic bearings
  • Hoists and gearboxes

Hydrogen & chemical

  • Electrolysers
  • Fuel cell stacks
  • Compressors
  • Hydrogen and ammonia tanks
  • Reactors
  • Catalysts and membranes
  • Gas detection

BARREL manufactures through OEM partners and works with an OEM / JV partner for batteries.

Raw materials, minerals & chemicals

What storage is made of

Battery minerals
Lithium, nickel, cobalt, manganese
Anode materials
Natural and synthetic graphite, silicon
Cathode materials
Iron phosphate, nickel, manganese, cobalt
Sodium batteries
Sodium compounds, aluminium, carbon
Flow batteries
Vanadium, bromine, zinc, iron
Metal-air
Iron, zinc, aluminium, magnesium
Electrical
Copper, aluminium, electrical steel
Thermal storage
Nitrate and chloride salts, sand, ceramics
PCM
Paraffin, fatty acids, salt hydrates
Hydrogen systems
Platinum, iridium, nickel, zirconium-based
Mechanical
Steel, cast iron, concrete, alloys
Insulation and cryogenic
Mineral wool, ceramic fibre, stainless steel, aluminium

Business ecosystem

One battery maker, many markets.

The same storage manufacturer may supply a solar farm, a substation, a factory, a data centre and an EV charging station — so every company and product is recorded once and linked to each application.

Shared directories

The same masters serve Generation and Storage. Live ones open on BARREL's platforms today.

Read the numbers right

Megawatts are not megawatt-hours.

Power ratingMW
How fast the system can charge or discharge.
Energy capacityMWh
How much it can hold. 100 MW / 400 MWh is a four-hour system.
Discharge durationh
Energy divided by power — seconds for flywheels, days for hydrogen.
Round-trip efficiency%
Energy out against energy in, over a full charge-discharge cycle.
Cycle life & DoDcycles · %
How many cycles at what depth of discharge before capacity fades.
SoC & SoH%
State of charge now; state of health against the new battery.

Reference sources

Where our data comes from

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