The hard part of an LPG power plant is not the turbines but the fuel chain. In a concept proposal for a 50 MW plant serving an inland region of South-East Asia, the largest load the river could carry was about 1,000 tonnes of LPG, which would run the plant for almost four days. That single number shaped the storage, the contract and the feasibility study that the proposal asked for.
The document was clear that it was a concept, not an offer. It was not based on a feasibility study or due diligence, and it said so up front.
The challenge: power for a region without fuel infrastructure
The region needed more electricity quickly. LPG could be imported by sea, but the plant would be inland. The fuel would have to move in four steps: ocean tanker to a coastal landing point, bulk storage at the coast, river barge to the plant, and bulk storage at the plant.
Why LPG, and why it is easier than LNG
LPG is a by-product of natural gas processing. Compared with the alternatives it is easier to handle:
| LPG | LNG | Compressed natural gas | |
|---|---|---|---|
| Liquefies at | about -42°C | about -260°C | Not liquefied |
| Storage pressure | about 100 to 150 psi | Cryogenic | about 3,000 psi |
The proposal also states that LPG costs about a third of diesel on a thermal energy basis, subject to contract. Generation on LPG gives slightly lower output and efficiency than on natural gas, but turbines can run it in simple cycle, combined cycle or cogeneration. It is cleaner than diesel and, unlike solar or wind, it is dispatchable.
The approach: fuel-flexible turbines and a staged commitment
Fuel flexibility
The plant was specified as gas turbines running primarily on LPG, but able to switch to diesel or natural gas. That protects the operator if one fuel is unavailable and leaves open a later switch to natural gas if it becomes available to the state.
The commercial shape
The proposal envisaged a fixed seven-year period on LPG so that the import facilities could pay for themselves, followed by shorter renewals. If natural gas became available, LPG supply could be curtailed with notice, and the plant would then operate under a service contract paid for operation and maintenance only. The fuel charge was variable and linked to the cost of supply, while the service charge was fixed and adjusted for inflation. A 25-year build-own-operate-transfer arrangement was proposed, subject to a feasibility study and negotiation.
Three ways to build it
- Fast track: mobile aero-derivative gas turbines in 25 MW units, suited to emergency capacity of up to around 250 MW, with light fuel oil as back-up.
- Long term: heavy-duty open-cycle turbines, with the option to add a steam turbine and heat recovery to form a combined cycle. A configuration of up to about 810 MW at roughly 60% efficiency was described.
- Phased build-up: 25 MW modules added as demand grows. Standard modules shorten procurement, while larger non-standard units take longer.
For a 50 MW requirement the proposal pointed to the phased approach as potentially the best.
What the feasibility study had to answer
- Can an ocean tanker berth, or is an offshore single-point mooring needed?
- How far is the landing point from bulk storage?
- Can the river carry fuel barges all year, or is there a dry-season problem?
- Is there existing LPG storage that could be bought or rented?
- Who provides the land?
The last two matter commercially. Existing storage would reduce the cost, while a river that cannot carry barges for part of the year would increase it. The proposal flagged both as possible swing factors in the power price.
What to consider for your own project
- Map the fuel chain before the power plant. Every transfer point needs storage, and storage is a major cost.
- Size storage by days of operation. One barge load gave almost four days here.
- Keep fuel options open. A turbine that can burn LPG, natural gas or diesel avoids lock-in.
- Separate fuel and service charges. It makes the contract transparent if the fuel source changes.
- Do the feasibility study first. Berths, navigation and land are unknowns until investigated.
For UK readers, safety and storage rules for flammable gases are covered by the Health and Safety Executive.
FAQ
Why use LPG instead of diesel?
The proposal states LPG costs roughly a third as much as diesel per unit of thermal energy and is cleaner to burn.
Can gas turbines run on both LPG and natural gas?
Yes. The proposed turbines could run on LPG, natural gas or diesel.
How much fuel does a 50 MW plant need?
A 1,000 tonne LPG load would last for almost four days at 50 MW.
What is a BOOT arrangement?
Build, own, operate, transfer: the developer builds and runs the plant for a set period, then hands it to the host.
Exploring fuel-flexible power?
Talk to us about your fuel options and load.