Energtek Tank calculator
Composite natural gas cylinders mounted on the roof frame of a bus at dusk (AI-generated image) AI
AI-generated image
storage · transport · fuel

Natural gas storage & hydrogen guide: gas, held under pressure.

How methane and hydrogen are squeezed, chilled and adsorbed into tanks, trucks and vehicles: natural gas storage methods, hydrogen hardware and the trade-offs behind every gaseous fuel.

Four ways to think about a tank

Each section starts from one question and follows it down to the hardware: cylinders, adsorbents, cryogenic tanks and the trucks that move them.

Gas held per tank volume, DOE target for ANG180V/V

From the glossary

Type IV: a polymer liner fully wrapped in carbon fiber, the lightest class of pressure vessel.

the route

From well to wheel, in five steps

Every gaseous fuel takes the same route: it is gathered, made dense, moved, stored again and finally burned or converted. Each guide on the site sits at one of these steps.

Source, densify, move, dispense, use Sourcewell · digester Densifysqueeze · chill Movepipe · trailer Dispensefast · slow fill Useengine · cell
  1. SourceWells, digesters and electrolysers
  2. DensifyCompress, adsorb or liquefy
  3. MovePipelines or tube trailers
  4. DispenseFast-fill or time-fill stations
  5. UseEngines and fuel cells

Natural gas storage methods, one tank compared

The energy a 100-liter tank holds with each method, as a share of the energy in 100 liters of diesel.

CNG, 200 bar

~23% of diesel

ANG, 35 bar

~14% of diesel

LNG, −162 °C

~59% of diesel

H₂, 700 bar

~13% of diesel

Energy of the stored fuel only, lower heating value, 15 °C; tank walls, valves and insulation not counted. Diesel taken as 35.8 MJ/L; ANG at 150 V/V. See the full comparison

Truck with a cryogenic LNG fuel tank on a desert highway (AI-generated image) AI
AI-generated image
tool

Tank capacity calculator

Pick a gas, set the water volume and pressure. Densities come from reference equations of state, not the ideal-gas shortcut.

13.4 kggas stored
5.0usable GGE
≈ 200 kmlight van

Open the full calculator

Why natural gas storage is a hardware problem

Methane carries about 50 megajoules per kilogram, more than diesel, yet at room temperature and atmospheric pressure a kilogram of it fills almost one and a half cubic meters. Every form of natural gas storage is a way around that volume: compression to 200–250 bar in steel or composite cylinders, cooling to −162 °C until the gas becomes a liquid, or packing the molecules onto the inner surface of a porous solid so that a tank at 35–50 bar holds far more than its empty volume would.

Each route moves the cost somewhere else. Compression needs heavy vessels and multi-stage compressors. Liquefaction needs insulated tanks and accepts slow boil-off. Adsorption needs a material that stays stable through thousands of fill cycles and a way to remove the heat released while it fills. The natural gas storage section compares the three natural gas storage methods side by side, and the guide to natural gas storage tanks covers the vessel classes from all-steel Type I to full-composite Type IV.

Hydrogen: the same question, a smaller molecule

Hydrogen holds about 120 megajoules per kilogram but weighs so little that a kilogram at 700 bar still needs roughly 25 liters of tank. Hydrogen storage borrows the same toolkit as methane, high-pressure composite cylinders, cryogenic liquid and porous or metallic materials, at harder conditions. The hydrogen storage guide sets the methods against each other by weight and volume, and the comparison with natural gas shows what changes in pipes, seals and safety rules.

Whichever fuel a reader starts with, the calculator turns a cylinder size and a pressure into kilograms, gasoline gallon equivalents and range, and the glossary explains terms such as V/V, GGE and boil-off.

Gas storage questions, answered briefly

The questions readers ask before they open a long guide.

What are the main natural gas storage methods?

There are three: compression to about 200–250 bar in steel or composite cylinders, liquefaction at about −162 °C in insulated tanks, and adsorption onto a porous solid at 35–50 bar. Large volumes are also held underground in depleted fields, aquifers and salt caverns.

How much methane fits in a CNG cylinder?

At 200 bar and 15 °C methane has a density of about 168 grams per liter, so an 80-liter cylinder holds roughly 13 kg, a little over 5 gasoline gallon equivalents.

Why is hydrogen storage harder than natural gas storage?

Hydrogen is about eight times lighter than methane. Even at 700 bar a liter holds only about 40 grams, which is why hydrogen storage needs larger carbon-fiber tanks, very low temperatures or chemical carriers.

What is adsorbed natural gas?

Adsorbed natural gas is methane held on the inner surface of a porous material such as activated carbon. It lets a tank at 35–50 bar hold several times more gas than the empty vessel would at that pressure.

Is LNG or CNG better for trucks?

LNG carries about twice the energy per liter of tank of CNG at 250 bar, so it suits long-haul trucks. CNG is simpler and cheaper to store and suits buses and delivery fleets that refuel at a depot.

Start reading: three long guides

Three long reads that answer the questions asked most often.

Macro view of porous activated carbon granules in cool side light (AI-generated image) AI
AI-generated image
Natural gas storage

Adsorbed Natural Gas (ANG): How It Works, Storage Capacity and Limits

Adsorbed natural gas storage puts a porous solid inside the tank, which then holds four to five times more methane at 35 bar than the empty vessel would. The heat, the leftover gas and the packing density are where the engineering gets hard.