The journey from initial enquiry to a generating WindWhisperer 100 Max installation involves seven stages: initial enquiry, site assessment, proposal development, planning and grid connection, detailed engineering and approval, physical installation, and commissioning and handover. The entire process typically takes 4–6 months for most commercial sites in the UK and Scandinavia.
This page explains each stage, what happens, what you need to provide, and what to expect in terms of timeline and cost.
You contact HNordic or visit the website and provide initial information:
HNordic and your prospective certified installer review this information to:
Most sites pass this initial screening. If your location has poor wind resource (mean wind speed below 4.5 m/s) or obvious barriers, you will be advised at this stage.
Typical duration: 1–2 weeks
Your input: Initial enquiry form
Cost to you: None
Once qualified, HNordic connects you with a certified installer in your region. The installer conducts a detailed site assessment covering:
Wind resource evaluation: Desktop analysis using government wind mapping data (UK DESNZ, Swedish SMHI, etc.), local terrain analysis, and obstruction assessment. For rooftop sites, height above ground and surrounding buildings are evaluated. For ground-level sites, height above terrain and wind direction exposure are assessed. This produces a preliminary wind resource estimate.
Structural assessment (rooftop installations): A structural engineer reviews the roof specifications, calculates static loads (turbine weight 650 kg) and dynamic loads (wind forces), and confirms whether the roof can support the installation. For ground-level installations, foundation options (ground screw, concrete pad, rock anchoring) are evaluated against site conditions.
Planning assessment: The installer reviews local planning policy, building designation, heritage constraints, and proximity to sensitive receptors (residences, ecological sites). This identifies likely planning route (permitted development, delegated powers, full application) and estimated timeline.
Grid connection assessment: The installer confirms grid operator, connection capacity, and G99 (or equivalent) application requirements. For rooftop installations, electrical design confirms connection point and inverter sizing.
Electrical site survey: Electrical connections, distribution board assessment, safety compliance check.
The site assessment produces a detailed report confirming feasibility, identifying any constraints, and estimating annual energy output for your specific location, height, and configuration.
Typical duration: 4 weeks (including desk-based analysis, site visit, and report preparation)
Your input: Site access for surveys, information about current electrical systems, confirmation of planning constraints
Cost to you: None (typically covered by the installer as part of pre-contract engagement)
Based on the site assessment, the installer develops a detailed proposal including:
System design: Specification of which WindWhisperer model (50 kW or 100 kW, Max or Ultra), rotor height, rooftop or ground mount, any wind directors.
Financial analysis: Installed cost (turbine, battery, inverter, installation labour, grid connection, planning if required), estimated annual energy output, annual bill displacement, estimated payback period, return on investment over 20 years.
Timeline: Estimated completion date assuming planning approval and grid connection are in parallel.
Commercial terms: Payment schedule (typically: deposit, progress payments during manufacture and installation, final payment at commissioning). Warranty and service contract terms.
You review the proposal, ask questions, and confirm you want to proceed. Once you approve the proposal, the installer orders equipment and begins planning and grid connection processes.
Typical duration: 3–4 weeks
Your input: Decision to proceed, confirmation of financial plan, approval of system design
Cost to you: Proposal development is typically free; you pay for the installation once you commit
Planning permission and grid connection run in parallel.
Planning application (rooftop and ground-mounted installations):
For most commercial rooftop installations, planning permission is granted within 8–12 weeks. Some authorities grant permission under delegated powers (no committee review). Building control approval runs in parallel (typically 4–8 weeks).
Grid connection application (G99 in UK, equivalent standards in Sweden):
Grid connection typically takes 4–8 weeks from application to receipt of connection agreement.
Common barriers and how to address them:
Most installations do not encounter significant barriers at this stage.
Typical duration: 8–12 weeks (planning) + 4–8 weeks (grid connection) running in parallel = 8–12 weeks total
Your input: Approvals and signatures on planning and grid applications; provision of any additional information requested
Cost to you: Covered in installation cost
Once planning permission is granted and grid connection agreement received, detailed engineering proceeds:
Structural design: For rooftop installations, a full structural design including foundation bolts, base frame, and stress analysis. For ground installations, foundation design and structural calculations.
Electrical design: Detailed inverter specification, battery system configuration, switchgear and protection, wiring and cable specification.
Installation method statement: Detailed procedure for how the turbine will be installed, including crane positioning, electrical connection sequence, safety procedures.
These designs are reviewed and approved by building control (for structural elements) and the grid operator (for electrical connection) before installation begins.
Typical duration: 4–8 weeks
Your input: Sign-off on final designs, building access confirmation
Cost to you: Included in installation cost
Installation itself is typically quick — 1–2 weeks on site.
Week 1:
Week 2:
Installation requires appropriate access equipment (ladders, scaffolding, or crane for rooftop installations). The site will be active, with noise and activity, for 5–10 working days. Your building or site remains in use — installation is planned to minimise disruption to operations.
Typical duration: 1–2 weeks
Your input: Site access, utilities marking, traffic management if required
Cost to you: Included in installation cost; typically final payment is due at completion of installation
Once physical installation is complete:
System testing: The electrical system is tested under controlled conditions. Inverter and battery settings are fine-tuned. Grid connection is finalised with the DNO.
Operational testing: Once testing is complete and DNO sign-off received, the turbine is connected and begins generating.
Training and handover: You (or nominated staff) receive training on system monitoring, basic operation, and how to read performance reports. Your installer provides documentation, warranties, service contract terms, and monitoring system access.
Typical duration: 2 weeks
Your input: Attend training, sign final handover documentation
Cost to you: Final payment due (usually against practical completion)
Optimistic scenario (no complications): 4–5 months from initial enquiry to system generating
Typical scenario: 5–6 months
Scenario with planning delay or ecological survey: 6–8 months
Scenario with grid connection complications: 7–9 months
The largest variable is planning permission and any required supporting surveys. If your site requires ecological assessment, add 4–8 weeks. If your local planning authority has a backlog, add 4–8 weeks.
Most commercial rooftop installations in established planning authority areas complete within 5–6 months. Rural and ground-level installations with simpler planning processes can be faster. Sites with environmental sensitivity or in areas with planning delays will extend to 7–9 months.
Along this timeline, you will make several key decisions:
After site assessment: Do you want to proceed with the project?
After proposal: Do you approve the system design and financial plan?
During planning: Do you want to employ a planning consultant to support your application? (Optional, typically £2,000–£5,000, speeds approval if there are objections)
After grid connection: Do you accept the DNO's technical conditions?
Before installation: Do you confirm the installation date and site access?
At commissioning: Do you accept the completed system and commission it?
Ask a question to begin the process and get a timeline for your specific site.
See also: How do I get a quote? · Can vertical axis wind turbines need planning permission in the UK?
Tell us about your site, and we will explain the process and timeline for your specific location.
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