Project guide / Wind resource & siting
Small Wind Turbine Site Assessment Guide
Is your site suitable for a small wind turbine? Review the wind information, proposed hub height, surrounding obstacles and electrical demand before choosing equipment. This guide sets out the information to prepare for a 5–50 kW MARSTON turbine enquiry.
Understand the site before choosing the turbine.
A site assessment connects the available wind resource with a practical installation and a defined electricity requirement. Record where the data come from, what they represent and which questions remain open.
01 / Wind data
Start with the source of your wind information.
Regional screening and a site-specific assessment answer different questions.
Wind resource maps help identify locations worth investigating. Keep the coordinates, map source, reference height and data period with any result. The Global Wind Atlas is intended to support exploration and preliminary resource assessment before on-site measurements.
A weather forecast describes expected conditions over a forecast period. A nearby weather station provides observations at its own location and measurement height. Record the distance, exposure and differences between that station and the proposed turbine site before using those observations in a project review.
If site measurements are available, send the original records with sensor location, height, recording interval and measurement dates. Preserve notes on missing or invalid records. The need for further measurement should be established from the project’s uncertainty and decision requirements.
Screening information
Use maps to frame an investigation and retain their height and source.
Site information
Provide measurement metadata and records alongside a summary.
02 / Hub height
Assess the wind at the proposed rotor height.
A reading near the ground does not automatically represent the wind at the turbine hub.
Wind conditions vary with height and exposure. State the proposed hub height above ground and the height associated with every wind-data source. A conversion between heights requires assumptions appropriate to the terrain and surroundings; one fixed correction factor should not be applied to every site.
Review the tower position together with nearby buildings, trees and changes in ground elevation. Confirm the available installation space, access route and constraints affecting tower height. Tower and foundation requirements must be established for the selected equipment and site.
Include a simple plan with a north arrow and photographs showing the proposed position from several directions. Label approximate dimensions as estimates until they have been surveyed.
Height reference
Distinguish hub height, sensor height and map reference height.
Installation context
Document the tower position, surroundings and access constraints.
03 / Wind quality
Look beyond a single average wind speed.
Direction, variability and obstruction exposure help explain the quality of the available wind.
A mean wind speed does not show how long different speeds occur. As a mathematical illustration, equal periods at 3 and 7 m/s have the same 5 m/s mean as equal periods at 4 and 6 m/s. The two distributions differ. Neither example predicts turbine output; an energy assessment needs the applicable power curve and operating assumptions.
Record the wind directions associated with nearby obstacles. Trees, buildings and terrain can influence local airflow and turbulence. A direction summary or wind rose is useful when supplied with the location, height and time period it represents.
Electric yaw controls nacelle orientation. It cannot supply energy during calm conditions or make an obstructed wind resource equivalent to an open site. See the electric yaw system guide for its mechanical and control roles.
Wind distribution
Identify occurrence by speed range and changes across the available period.
Direction & exposure
Relate the wind information to obstacles around the tower.
04 / Start-up & energy
Separate rotor start-up from useful energy output.
Starting to rotate, supplying electrical power and producing useful annual energy are separate questions.
Rotor start-up wind speed describes the onset of rotation. Electrical cut-in refers to the operating point at which the configured system begins supplying electrical output at a defined measurement boundary. A visible rotating rotor alone does not establish useful output to a load or grid.
For the current FD14-50KW documentation, 2.5 m/s is a rotor start-up value. It should not be used as a verified electrical cut-in value or as evidence that a site with a 2.5 m/s annual mean is suitable.
Rated power is expressed in kW; energy over a period is expressed in kWh. An annual energy estimate must identify the wind dataset, applicable turbine configuration, power-curve boundary and assumptions for losses and availability. Multiplying rated power by the hours in a year does not account for variable wind and operating conditions.
A defined operating value
Ask what the stated wind speed measures and which configuration it covers.
A defined energy estimate
Request the data, curve and assumptions behind any projected kWh.
05 / Demand & connection
Match the wind project to the electrical demand.
A site can have wind potential while still needing a different equipment or system arrangement.
Provide your electricity use in kWh and, where available, the load profile showing when it is needed. Include peak demand, operating hours and the loads that need continuity. This makes it possible to discuss turbine size and the intended electrical package.
For a grid-tied project, identify the existing connection and obtain the local utility requirements. For an off-grid project, describe backup arrangements and any existing generation or third-party storage. Compatibility and system responsibilities need confirmation for the equipment being combined.
State the country, site environment and local installation constraints in the enquiry. Ask the responsible local authorities or project professionals about permissions and construction requirements. Agree the assessment, installation and equipment supply scope before procurement.
Demand information
Energy use, timing, peak loads and continuity requirements.
Project interfaces
Electrical connection, existing equipment and local installation constraints.
06 / Next steps
Prepare the evidence for the next decision.
A useful assessment identifies both the available information and the remaining uncertainty.
Bring together the site coordinates, wind sources, proposed hub height, obstacle record, photographs and electrical demand. Identify which information is measured, modelled or estimated. Keep the source files so the assumptions can be checked during a technical review.
The next step may be further measurement, a different tower location, a revised system scope or an equipment discussion. Record the reasons for that step instead of treating a single map value as an approval to install.
Further project guides: Small Wind Turbine Noise: Evidence & Site Assessment · Rooftop vs Ground-Mounted Small Wind: Project Review · Small Wind Turbines at High Altitude: Project Assessment · Small Wind Turbines in Cold Weather & Icing Conditions.
General background is available in the DOE Small Wind Guidebook, the DOE Small Community Wind Handbook, the Small Wind Site Assessment Guidelines publication record and the Global Wind Atlas purpose statement. These explain assessment concepts; they are not MARSTON site surveys or turbine performance validation.
Evidence record
Identify sources, reference heights, dates and assumptions.
Project decision
Establish what needs checking before a technical quotation or installation.
Prepare your site information pack.
Send available information and mark missing items clearly. A map screenshot is useful when its source, location and reference height are included.
| Information | What to provide | Why it helps |
|---|---|---|
| Site location | Country, coordinates and proposed tower position | Establish the location for wind screening and project discussion. |
| Wind information | Source files, dates, location, height and recording interval | Understand what each wind value represents. |
| Proposed hub height | Height above ground and any tower-height constraints | Compare the installation with the height represented by the wind data. |
| Surrounding obstacles | Plan and photos; approximate heights, distances and directions | Identify potential obstruction exposure and questions for the site review. |
| Wind variability | Available speed distribution, direction summary and seasonal records | Look beyond a single mean or a short weather observation. |
| Electrical demand | Energy use, load timing, peak demand and continuity needs | Discuss the turbine output class and system requirements. |
| Connection & equipment | Grid information or existing off-grid generation, backup and storage | Identify electrical interfaces requiring confirmation. |
| Installation conditions | Access, environment, land constraints and local requirements | Define practical installation questions and the project scope. |
Questions before installing a small wind turbine.
What is the minimum wind speed for a small wind turbine?
Distinguish rotor start-up, electrical cut-in and project suitability. Operating thresholds are model- and configuration-specific; site suitability needs wind-resource, installation and demand information. There is no single wind-speed value that establishes every project’s viability.
Can I use a weather app to decide whether to install a wind turbine?
A forecast can provide context, but its period and location do not establish the long-term resource at the proposed hub height. Retain the source and compare it with appropriate site information before an installation decision.
Is a wind resource map enough to predict annual output?
A map supports initial screening. A project energy estimate also needs wind information appropriate to the site and height, an applicable turbine power curve and stated loss and availability assumptions.
Does the FD14-50KW generate useful electricity at 2.5 m/s?
The documented 2.5 m/s value refers to rotor start-up. A verified electrical cut-in value at a defined output boundary has not been established in the information published here.
Can electric yaw solve turbulence from nearby buildings?
Electric yaw controls orientation. The tower location and obstruction exposure still need a site assessment. Yaw type alone does not establish the suitability of a turbulent site.
What should I send with my site enquiry?
Send coordinates, available wind data with its source and height, site photographs, proposed hub height, surrounding-obstacle information and electricity requirements. Include the intended connection and any existing equipment; mark missing information clearly.
Project enquiry
Tell us about your site and electricity needs.
Share the location, available wind data, site photographs and intended grid or off-grid connection. Include your load information and preferred equipment scope so the turbine and electrical configuration can be discussed together.