What installed cost would a wind project need to meet my payback target?

The short answer

For a simple, undiscounted screening calculation, multiply the target payback period by the expected annual net cash benefit. This gives the up-front cost the project could recover within that period under those assumptions. It is a cost ceiling for the chosen scenario, not a market price, budget recommendation or prediction that the project will achieve the required energy and savings.

Define the annual benefit correctly

Start with the value of useful generation and permitted exports. Subtract the operating costs included in the screening model, such as the assumed annual service and insurance costs. Keep financing, taxes, replacement events and incentives explicit; a simple calculation may exclude them, but they do not disappear from the real project.

If annual benefits vary substantially, use a year-by-year cash-flow model rather than dividing by one favorable annual figure. State whether the cost ceiling represents total installed cost or the owner’s net initial cash outlay.

Work backward from a target

Illustrative assumptions: annual electricity value is 3,000 currency units, annual operating cost is 700, and the buyer wants a simple eight-year payback. The annual net benefit is 2,300. The corresponding initial-cost ceiling is 8 × 2,300 = 18,400.

If assessed generation or tariffs reduce the annual net benefit to 1,700, the same eight-year ceiling falls to 13,600. The 4,800 difference comes from the operating assumptions, not a change in supplier pricing. None of these values describes a MARSTON offer.

Use the ceiling to test feasibility

Compare complete, compatible proposals with the calculated ceiling. If unavoidable site works alone consume much of the allowance, changing the turbine price may not be enough. Revisit the site, useful-energy share, project scope or required return.

Then check discounted value over the intended analysis period. A project can pass a simple-payback screen yet have unattractive later expenses or an unacceptable risk profile. Use the reverse calculation to organize decisions, rather than turning a target payback into a guaranteed supplier outcome.