A large energy project is a single bet on a forecast. A modular one is a sequence of smaller bets, each placed with more information than the last. That difference is usually presented as a cost argument (factory-built units, shorter schedules, less site work). The more important argument is about uncertainty.
The value of being able to change your mind
In decision analysis, the right to make a choice later, once you know more, is called a real option. A standard block of generation, compression or processing that can be added, relocated or shut down gives you several options at once:
- The option to expand when the resource or the market proves better than expected.
- The option to move when a well declines faster than forecast, or a better site appears.
- The option to stop with limited regret, because the remaining units are not stranded.
Discounted cash flow on a single base case gives these options a value of zero. That is one reason modular schemes can look marginal in a standard economic model while still being the better decision. Valuing them properly means modelling the decisions, not just the cash flows.
Flare gas to power, framed correctly
Turning flared associated gas into electricity is one of the clearest modular cases, and one of the most often overstated. Burning the gas in an engine still emits the carbon dioxide that combustion produces; the flare is replaced, not the chemistry. The genuine benefit comes from what the electricity displaces. Where it replaces diesel or oil-fired generation, the avoided emissions are large; where it replaces efficient gas-fired grid power, they are much smaller. Engines also release some unburnt methane, which must be counted in the balance.
The credible claim is "avoided emissions against a stated baseline", never "zero emissions".
Where it fits
Modular thinking applies well beyond gas-to-power: early natural-hydrogen production, small-scale storage, distributed processing for stranded gas, and the reuse of depleted fields. The pattern is the same each time. Start with the smallest block that produces both revenue and information. Write down the evidence that would justify the next block, and the evidence that would stop the programme. Then let the field, not the plan, decide.