Selection guide / MARSTON 5–50 kW
How to Choose a Small Wind Turbine: 5–50 kW
Choose a small wind turbine by bringing together your electricity demand, site wind information and intended electrical connection. Compare the five MARSTON electric-yaw models, identify the equipment scope and prepare the information needed for a technical quotation.
From project requirements to a model shortlist.
A useful shortlist explains why a model is being considered and which specifications still need review. Start with the energy requirement and wind resource, then compare the turbine configuration and the complete installation scope.
01 / Electricity demand
Define how much energy you need and when.
Energy use, peak demand and supply continuity describe different project requirements.
Record electricity consumption in kWh over the relevant day, month or year. Add the load profile where available: operating hours, simultaneous loads and periods when demand changes. State whether the wind project is intended to offset consumption or contribute to an independent supply system.
Peak demand is expressed in kW. As a load example, equipment drawing a steady 20 kW for three hours consumes 60 kWh. This is a consumption calculation, not a prediction of output from a 20 kW wind turbine.
Identify loads that need continuity and describe the existing grid or backup supply. Wind generation varies with conditions; the proposed electrical system must address the actual load and continuity requirements.
Energy requirement
kWh identifies the electricity needed over a defined period.
Demand profile
kW, timing and continuity identify the operating requirement.
02 / Wind resource
Use wind information for the intended installation.
The turbine and the site need to be evaluated together.
Provide the coordinates, wind-data source, measurement or reference height, recording period and proposed hub height. Include photographs and the main obstacles around the tower position. Use the small wind turbine site assessment guide to prepare this information.
Ask how the wind dataset will be matched to the turbine performance information. Record assumptions about installation exposure, data quality and operating availability. An estimate should identify its inputs so alternative models can be compared on a consistent basis.
A rotor start-up value describes the onset of rotation. It should not be used by itself to establish the electrical output or suitability of a low-wind site. For the current FD14-50KW, the documented 2.5 m/s value is rotor start-up, rather than a verified electrical cut-in value.
Defined wind inputs
Location, height, period and source accompany the wind data.
Defined assumptions
Record the data and operating conditions used for a model comparison.
03 / Model shortlist
Compare the configuration behind each model.
Rated power and rotor diameter provide a starting point for reviewing the five-model range.
MARSTON offers FD5-5KW, FD7.5-10KW, FD10-20KW, FD12-30KW and FD14-50KW with rotor diameters of 5, 7.5, 10, 12 and 14 m respectively. All five use electric yaw. The comparison table links to each product page for the model-specific information.
If you are comparing 20 kW and 30 kW, use the same site wind information and installation assumptions for both. Request the applicable performance information, electrical package and installation requirements for each proposal. A difference in rated power alone does not define the difference in annual energy.
Confirm the generator, braking and control configuration for the selected model. The current FD14-50KW has a brushless permanent-magnet direct-drive generator and hydraulic disc braking; those details should not be assumed for every model. The electric yaw system overview explains orientation and braking roles.
Model identity
Use the complete model code alongside rated power and rotor diameter.
Technical comparison
Compare performance information and the proposed package under common project assumptions.
04 / Electrical application
Define the grid or off-grid connection.
The turbine assembly, controller and conversion equipment need an agreed relationship.
For a grid-tied wind project, identify the connection voltage, frequency and utility requirements relevant to the site. Establish the equipment needed to connect the selected turbine and the scope covered by the technical proposal.
For an off-grid project, provide the load details and existing generation, backup or third-party storage equipment. Record which devices are expected to supply the loads under changing conditions. Equipment compatibility and operating responsibilities must be confirmed for the system being proposed.
MARSTON can discuss turbine assemblies, controllers and power-conversion equipment as separate supply items. Define the control interfaces before combining equipment. A turbine power class alone does not establish compatibility with a particular converter, battery or grid connection.
Grid connection
Project voltage, frequency, utility requirements and proposed equipment scope.
Independent supply
Load behaviour, backup arrangements, existing equipment and confirmed interfaces.
05 / Technical evidence
Compare the performance information and supply scope.
A complete proposal identifies both the turbine configuration and the supporting equipment.
Request the specification and performance information applicable to the configuration being quoted. For a power curve, identify where output is measured and which equipment is included. For an energy estimate, request the wind inputs and assumptions. Keep historical operating records identified by the configuration they represent.
Compare quotations with the same scope: turbine assembly, controller, converter, tower or tower-supplier coordination, installation documents and agreed support. Record project items such as foundations, lifting, cabling and local installation work separately when they are outside the equipment quotation.
Establish the documentation, project compliance requirements, warranty terms and service responsibilities in the proposal. Availability and applicability need confirmation; specifications from one configuration should not be treated as evidence for another. For a yaw integration review, use the yaw drive selection guide.
Performance boundary
Identify the turbine version, output measurement point and estimate assumptions.
Quotation boundary
Identify supplied equipment, excluded project items and agreed responsibilities.
06 / RFQ information
Prepare an enquiry that can support a model comparison.
Send the available information and identify what remains unknown.
Include the following in a turbine enquiry:
- Country, coordinates and site photographs.
- Wind information with its source, height and dates.
- Electricity use, peak demand and operating schedule.
- Intended grid connection or independent-supply arrangement.
- Existing controllers, converters, backup generation or third-party storage.
- Proposed hub height, tower constraints and installation access.
- Models to compare, if you have a shortlist.
- Required equipment, documents and project schedule.
A useful request is: “Please compare the FD10-20KW and FD12-30KW using the attached site and load information, and identify the electrical package and documents included in each proposal.” This is an enquiry example, not a model recommendation for a particular site.
For general sizing and project-planning concepts, see the DOE Small Wind Guidebook and DOE Small Community Wind Handbook. MARSTON product facts and supply scope must be confirmed against the applicable proposal.
Further project guides: 5 kW vs 10 kW Wind Turbines: Small-Load Expansion Review · 10 kW vs 20 kW Wind Turbines: Electrical Package Review · 20 kW vs 30 kW Wind Turbines: Staged Expansion Review · 30 kW vs 50 kW Wind Turbines: Configuration Evidence Review.
Project information
Wind, loads, connection, tower requirements and existing equipment.
Comparison request
Name the candidate models and the scope you want reviewed.
Compare the five MARSTON models.
The current five-model range uses electric yaw. Rated power and rotor diameter identify the models; annual energy and electrical suitability require a project-specific review.
| Modèle d’éolienne | Puissance nominale | Diamètre du rotor |
|---|---|---|
| FD5-5KW | 5 kW | 5 m |
| FD7.5-10KW | 10 kW | 7.5 m |
| FD10-20KW | 20 kW | 10 m |
| FD12-30KW | 30 kW | 12 m |
| FD14-50KW | 50 kW | 14 m |
Questions when choosing a small wind turbine.
What size small wind turbine do I need?
Begin with electricity use, peak demand, the site wind information and the intended connection. Compare model-specific performance and the complete equipment scope using the same project assumptions. A power class alone is insufficient to establish the best fit.
Does a 20 kW wind turbine continuously supply a 20 kW load?
Rated power is an output rating, while generation changes with wind and operating conditions. Continuous loads require an electrical-system review that includes the grid or appropriate backup and any confirmed storage arrangement.
How should I compare a 20 kW and a 30 kW turbine?
Use the same site wind dataset and installation assumptions. Compare the applicable performance information, electrical configuration, tower requirements and quotation scope. State which energy or operating requirement each proposal is intended to address.
Is rotor diameter the same as blade length?
No. Rotor diameter describes the complete swept circle. Use the confirmed rotor diameter and model-specific blade and hub drawings when reviewing dimensions.
Are the controller, converter and tower always included?
The supply scope is defined in the quotation. MARSTON can discuss separate supply of turbine assemblies, controllers and conversion equipment, with tower-supplier coordination where required. Confirm all included and excluded items.
Can I choose an off-grid turbine from its rated power alone?
An off-grid proposal also needs the load profile, continuity requirement and the roles of backup generation or third-party storage. The equipment interfaces and system behaviour require confirmation for the proposed package.
Technical quotation
Ask us to compare models for your project.
Send your site wind information, electricity requirement and intended connection. If you have a shortlist, identify the models you want to compare and the equipment or documents needed in the quotation.