Solutions / Engineering guide
Small Wind Project Cost: Build a Complete Comparison
The turbine price is one part of a small wind project budget. Create a cost register that includes installation scope, ongoing responsibilities and the assumptions behind delivered energy, so proposals can be compared on the same basis without relying on an unsupported price-per-kW shortcut.
Compare the project beyond the equipment price.
Keep quotation amounts, uncertain allowances and operating scenarios distinct. The objective is a reviewable budget and sensitivity model, rather than a universal payback claim.
01 / Budget boundary
Specify what the comparison includes.
Choose the supply and delivery boundary before requesting prices.
Choose the supply and delivery boundary before requesting prices. List the turbine, tower, foundation, electrical package, site connection and local works as separate scope lines. Record whether the comparison describes delivered equipment, an installed assembly or an operating project with agreed handover.
The DOE economics overview distinguishes turbine cost from installed project cost. For your register, identify the responsible supplier or contractor and whether each line has a quotation, allowance, exclusion or unresolved scope. A blank row should not silently become zero.
02 / Initial costs
Separate equipment from site-specific work.
Use a checklist for purchase, packing, freight, unloading, tower supply, design work, ground investigation, foundation, erection, cables and connection-related work.
Use a checklist for purchase, packing, freight, unloading, tower supply, design work, ground investigation, foundation, erection, cables and connection-related work. Treat taxes, duties, approvals and professional services according to the actual project location and scope; do not transfer assumptions from another country.
Keep quantity, currency, quotation date, validity and included delivery terms beside every amount. Compare similar revision dates and note provisional items. Use the RFQ guide to collect supplier scope, then obtain the local-work inputs from the parties that would perform that work.
03 / Operating costs
Budget responsibilities without inventing service intervals.
Identify planned inspections, service access, spare-parts provision, monitoring, administration and any backup or storage-related costs.
Identify planned inspections, service access, spare-parts provision, monitoring, administration and any backup or storage-related costs. Use model-specific service requirements and actual contractor proposals where available. This guide sets no universal maintenance frequency, replacement life or service price.
Distinguish regular budget items from contingent repairs or major replacements. State who pays for travel, lifting or downtime-related work in the proposed service arrangement. If an item remains uncertain, model it as a clearly labelled case rather than presenting a generic allowance as a confirmed lifetime cost.
04 / Time & energy
Keep the financial period consistent with the energy basis.
Choose an analysis period as an explicit project assumption, not a claim about turbine lifetime.
Choose an analysis period as an explicit project assumption, not a claim about turbine lifetime. Identify whether amounts are nominal or inflation-adjusted and keep the discount convention consistent. SAM’s levelized-value guidance explains why future annual values require a stated discount basis.
A simplified comparison expresses LCOE as discounted included costs divided by discounted included electricity. State which costs and delivery boundary are included in both sums. A result based on generator energy is not directly comparable to one based on useful load energy. Keep the energy estimate alongside the budget.
05 / Project value
Separate energy cost from avoided expenditure.
For grid supply, distinguish self-consumed energy, exported energy and the relevant charges.
For grid supply, distinguish self-consumed energy, exported energy and the relevant charges. Confirm which charges change when wind generation is added; a fixed charge may remain even when purchased kWh falls. Do not assume export receives the retail purchase price or that permission to connect includes payment terms.
For remote supply, compare the existing and proposed operating cases using actual demand and backup assumptions. Avoid assigning every generated kWh the same avoided-fuel value. LCOE, annual bill change and supply continuity describe different questions and should retain separate results.
06 / Sensitivity
Show which assumption could change the decision.
Create defined cases for uncertain useful energy, local works, access costs and operating provisions.
Create defined cases for uncertain useful energy, local works, access costs and operating provisions. Change one key input at a time when explaining its influence, then use combined cases where the project needs them. List missing inputs that prevent a meaningful comparison.
MARSTON can quote the requested wind-equipment scope for the selected model and configuration. The project team supplies or obtains the remaining installation and commercial inputs. Bring the scope register and unresolved lines to the equipment enquiry; no standard price, saving or payback is promised here.
Continue the review with Wind Turbine Annual Energy: Inputs, Calculation & Uncertainty.
Continue the review with Wind vs Solar for Remote Power: Compare the Project.
Continue the review with Small Wind Grid Connection: Feasibility & Review Inputs.
Further project guides: Wind Power Self-Consumption & Self-Sufficiency Metrics · Electricity Bills: Inputs for a Wind Project Assessment · Wind vs Diesel Power: Compare the Same Remote Service · Wind Power vs Grid Extension for Remote Sites.
Review NPV and payback assumptions, cross-currency budget assumptions and the actual warranty scope alongside the project cost record.
General background: DOE WINDExchange: Economics and Project Cost Boundaries · NLR System Advisor Model: Levelized Values. These references explain industry concepts; they are separate from the applicable MARSTON product and project documents.
Prepare the information for this review.
Use the checklist to organise the project information. Mark unavailable items and retain document references.
| Review item | Information to provide | Purpose |
|---|---|---|
| Scope boundary | Equipment, installed assembly or operating project | Compare quotations for the same deliverable. |
| Initial cost register | Source, currency, date, quantity and exclusions | Trace each budget amount. |
| Operating provisions | Service responsibilities, access and contingent costs | Expose the ongoing project scope. |
| Energy & period | Useful-energy boundary, analysis horizon and conventions | Keep cost and energy cases consistent. |
| Sensitivity cases | Uncertain lines and assumptions that affect the decision | Identify what needs better evidence. |
Engineering questions.
Why is turbine price insufficient?
Tower, civil works, delivery, electrical integration and operating responsibilities may sit outside the equipment quotation. The complete scope determines the project budget.
Does a cost-per-kW figure compare projects fairly?
Only if scope, location, configuration and assumptions match. Use the itemized register before treating a normalized number as comparable.
Does LCOE equal the electricity tariff?
No. It is a modelled cost metric for defined costs and electricity. Purchase tariffs, export terms and fixed charges affect project value separately.
Can I assume a standard turbine lifetime?
Use a stated analysis period and the evidence applicable to the supplied equipment and service arrangement. This page does not prescribe a product lifetime.
How should uncertain repair costs be handled?
Identify their source and model explicit contingent cases. Do not label an unsupported allowance as a confirmed replacement schedule or warranty obligation.
Can MARSTON provide a turnkey project price here?
An equipment quotation requires a defined scope. Local works, installation, integration and commercial responsibilities must be established for the actual project.
Technical enquiry
Bring your project information to the discussion.
The turbine price is one part of a small wind project budget. Share the available information and the equipment scope you want reviewed in a technical quotation.