How a Commercial Solar Project Works
From your first enquiry through to commissioned, monitored, and warranted system. A clear, step-by-step explanation of what to expect when you appoint Welsh Solar.
The eight stages of a commercial solar project
Every commercial installation we deliver follows the same disciplined process. We have refined this over hundreds of projects across Wales, and it is designed to give you clarity at every stage and minimise the risk of unwelcome surprises.
1. Initial enquiry and brief
You contact us by phone, email, or web form. A member of our commercial team takes a short brief covering your premises, current energy usage, business goals, and any constraints such as timing or planning concerns. This usually takes 15 to 30 minutes.
2. Desktop feasibility
We carry out a desktop review using satellite imagery, public records, and your last 12 months of energy bills. This tells us whether your site is broadly suitable and gives us an initial size estimate before we invest in a visit. Most enquiries clear this stage within 48 hours.
3. Free site survey
A senior engineer visits the property to inspect the roof or proposed ground-mount area, assess electrical infrastructure, take measurements, and discuss the design in detail with you and any technical staff. The visit typically takes 90 minutes to 3 hours depending on site complexity.
4. Detailed proposal
Within 5 to 10 working days of the survey, you receive a written proposal including system specification, financial model, generation forecast, payback calculation, and fixed total price. We are happy to discuss the proposal in person and to amend it based on your feedback.
5. Contract and DNO application
Once you accept the proposal, we issue a formal contract and submit the application to your distribution network operator. DNO approval typically takes 4 to 8 weeks depending on system size and grid capacity. We handle all correspondence with the DNO on your behalf.
6. Installation
Our installation team mobilises to site on the agreed date with all materials, scaffolding, and equipment. A typical 100 kW system installs in 5 to 10 working days depending on roof access. We coordinate carefully with your facilities team to minimise disruption to your operations.
7. Commissioning and witnessing
Once installed, the system is tested, commissioned, and witnessed by an independent inspector where required. We issue all certificates including MCS, NICEIC, and DNO confirmation. The system is connected to monitoring and producing power on commissioning day.
8. Handover and ongoing support
You receive a complete handover pack including all warranties, certificates, schematic drawings, and operating instructions. We brief your facilities team on monitoring and maintenance, and optionally enter into an ongoing service agreement.
Typical project timeline
For a straightforward rooftop installation between 50 kW and 250 kW on a single building with no grid upgrades, you should budget around 12 to 16 weeks from accepting the proposal to commissioning. Most of that time is DNO approval, which is largely outside our control. The physical installation itself is usually just 1 to 3 weeks.
Larger systems, ground-mount installations, projects requiring grid upgrades, and any work needing planning permission take longer. We always agree a realistic programme at contract stage and update you weekly on progress against milestones.
What we need from you at each stage
To keep things moving smoothly, here is what we typically need from your side at each stage of the project.
- Enquiry stage: a recent electricity bill, address, and basic premises information.
- Survey stage: roof access, electrical drawings if available, and 30 to 90 minutes with a decision-maker on site.
- Proposal stage: any questions or concerns to feed back, and confirmation of your preferred specification.
- Contract stage: signed agreement, agreed payment schedule, and any insurance or landlord consent documents.
- Installation stage: site access, agreed working hours, and a named contact for any operational questions.
- Commissioning stage: someone available to walk through the system and sign the handover documentation.
Frequently asked questions
Do you subcontract any of the installation work?
No. All design, installation, and commissioning is carried out by Welsh Solar employees. We may occasionally subcontract specialist work such as crane operation or asbestos removal, but the primary trades are always our own people.
What payment terms do you offer for commercial projects?
A typical commercial project is paid in three stages: deposit on contract, interim payment on materials delivery, and balance on commissioning. We can discuss alternative structures including leasing, power purchase agreements, and stage payments for larger projects.
Can you work around our operational requirements?
Yes. We routinely work around production schedules, school terms, retail trading hours, and other operational constraints. The earlier you raise specific requirements, the more easily we can accommodate them.
What happens if the system underperforms?
Our proposals include a conservative generation forecast based on PVGIS data adjusted for site conditions. If the system fails to meet that forecast within the first year, we investigate at our cost. Most underperformance is caused by inverter faults under warranty rather than design issues.