Introduction
Installing a commercial solar PV system is a significant investment, so it’s important to understand exactly what happens during the installation process.
From the initial site survey through to commissioning and ongoing monitoring, every stage is carefully planned to ensure the system is safe, compliant and designed to deliver maximum long-term performance.
At Energy Gain, every project is managed by experienced engineers and project managers, ensuring disruption to your business is kept to a minimum while maintaining the highest standards of quality and safety.
Step 1 - Initial Consultation
Every project begins with understanding your business rather than your roof.
During the initial consultation we discuss:
- Your business objectives
- Current electricity costs
- Future expansion plans
- Sustainability targets
- Building ownership
- Existing electrical infrastructure
We also request:
- Electricity bills
- Half-hourly electricity data (where available)
- Site drawings – if available
- Existing roof information
This information allows us to begin assessing the project’s technical and financial viability.
Energy Gain Insight
What questions do you always ask customers?
We always start by understanding how your business uses electricity. We also discuss your objectives, future growth plans and any planned changes to the site.
What are the common misconceptions at this stage?
Many businesses think the biggest system will deliver the best return. In reality, the best system is the one designed around your energy demand.
Why is understanding energy usage more important than roof size?
Your energy consumption determines the financial return, not the size of your roof. Analysing how and when you use electricity allows us to design a system that maximises savings and return on investment.
Step 2 - Site Survey
The site survey provides the information needed to design the system.
Typical surveys include:
- Roof measurements
- Roof condition
- Structural assessment
- Electrical survey
- Shading analysis
- Drone survey (where appropriate)
- Cable routes
- Inverter locations
No two buildings are the same, so every survey is tailored to the individual site.
Step 3 - System Design
Using the survey information, our design team develops a bespoke solar PV system.
The design considers:
- Energy demand
- Roof orientation
- Panel layout
- Inverter selection
- Structural loading
- Cable routing
- Future expansion
- Fire safety
- Maintenance access
The objective is to maximise long-term performance rather than simply install the largest possible system.
Energy Gain Expert Insight
Why does Energy Gain design to RC62 guidance?
Designing to RC62 guidance helps improve fire safety, maintenance access and long-term system reliability. It ensures key safety considerations are incorporated from the outset of the project. Download RC62 Guide
Why is maintenance access important?
Safe access allows inspections, servicing and future repairs to be carried out efficiently throughout the life of the system. Good access also helps minimise maintenance costs and downtime.
Why does cable management matter?
Well-managed cabling protects the electrical installation, reduces the risk of damage and makes future maintenance easier. It also contributes to a safer, more professional installation.
Step 4 - Grid Connection
Every commercial installation must comply with Distribution Network Operator (DNO) requirements.
Depending on system size, this may involve:
- G98 notification
- G99 application
- G100 application
- Export limitation Scheme
- On site assessments
- Transformer assessment
- Network upgrades
Energy Gain manages this process on behalf of the customer.
Step 5 - Procurement
Once approvals are complete, equipment is ordered.
This typically includes:
- Solar panels
- Inverters
- Mounting system
- Cabling
- Monitoring equipment
- Access & Plant
- Safety equipment
Only products meeting the project specification are installed.
Step 6 - Installation
Installation is carefully planned to minimise disruption.
Typical activities include:
- Deliveries
- Scaffold or access equipment
- Mounting installation
- Panel installation
- DC cabling
- Inverter installation
- AC connections
- Monitoring equipment
- Testing
Where businesses remain operational during installation, work is coordinated around production schedules wherever possible.
Energy Gain Expert Insight
How long does a typical commercial solar installation take?
All figures are indicative and based on a typical commercial rooftop installation using 450W solar panels. Actual installation programmes and panel quantities will vary depending on site conditions, system design, roof type, access requirements and electrical infrastructure.
System Size | Approximate Number of 450W Panels | Typical Installation Duration | Typical Team Size | Approximate Roof Area Required |
50 kWp | 112 panels | 3–5 working days | 4–6 | 250–300 m² |
100 kWp | 223 panels | 1–2 weeks | 5–7 | 500–600 m² |
200 kWp | 445 panels | 2–3 weeks | 6–8 | 1,000–1,200 m² |
400 kWp | 889 panels | 3–5 weeks | 8–10 | 2,000–2,400 m² |
600 kWp | 1,334 panels | 5–7 weeks | 8–12 | 3,000–3,600 m² |
800 kWp | 1,778 panels | 6–8 weeks | 10–12 | 4,000–4,800 m² |
1 MWp | 2,223 panels | 8–10 weeks | 10–14 | 5,000–6,000 m² |
How do you work on live manufacturing facilities?
We plan installations around your operations to minimise disruption. Where possible, work is phased to allow production to continue safely.
Do you work at weekends?
Yes. Weekend working can be arranged where it helps reduce disruption to your business or production schedule.
Can installation be carried out out of hours?
Yes. We regularly undertake out-of-hours work where access is limited or electrical shutdowns need to be completed outside normal operating hours.
How do you communicate with facilities teams?
A dedicated project manager provides regular updates throughout the project, ensuring facilities teams are informed of progress, planned activities and any operational requirements.
Health & Safety
Safety is fundamental to every commercial solar installation. Before work begins, Energy Gain prepares comprehensive site-specific documentation to ensure every project is planned and delivered safely.
Every project is supported by detailed risk assessments, method statements and a Construction Phase Plan (CPP), produced in accordance with the Construction (Design and Management) Regulations 2015 (CDM 2015). The Construction Phase Plan sets out how health, safety and welfare will be managed throughout the project, ensuring all parties understand their roles and responsibilities before work commences.
Areas considered include, but are not limited too:
- Working at height
- Electrical safety
- Lifting operations
- Public protection
- Fire safety
- Emergency procedures
- Site access and security
- Welfare facilities
- Traffic and delivery management
- Environmental considerations
All work is completed in accordance with current legislation, recognised industry guidance and Energy Gain’s own health and safety procedures, helping to ensure every installation is delivered safely and with minimal disruption to the client’s operations.
Energy Gain Expert Insight
Every project begins with careful planning through a through pre construction process. A detailed Construction Phase Plan (CPP) is completed before work starts, identifying potential risks, safe working methods and coordination of activities with the client to minimise disruption while maintaining the highest standards of health and safety.
On site activities begin with a site-specific induction to ensure everyone understands the site rules, hazards and emergency procedures before work starts. Daily briefings and toolbox talks are carried out to review planned activities, identify potential risks and reinforce safe working practices.
Where required, we work within the client’s permit-to-work system, ensuring all activities are properly authorised and coordinated with site operations. This structured approach helps maintain a safe working environment while minimising disruption to your business.
Step 7 - Testing & Commissioning
Before handover every system undergoes comprehensive testing.
This includes:
- Electrical testing
- String testing
- Inverter commissioning
- Monitoring setup
- Protection testing
- Grid compliance
- Performance verification
Only once testing is complete is the system handed over.
Project Insight
MIPD – Manufacturing 1 MWp
Following the installation at MIPD, the commissioning process included comprehensive electrical testing, verification of all protection systems and confirmation that the installation was performing in line with the design specification before being energised. Once the system was successfully commissioned, the Energy Gain team configured the remote monitoring platform and demonstrated how to monitor live generation, review performance data and identify any system alerts. A full project handover was then completed, including all certification, operation and maintenance documentation, ensuring the client had everything needed to maximise the long-term performance of their investment.
Step 8 - Handover
The customer receives:
- Operation manuals
- Warranties
- Test certificates
- Maintenance recommendations
- Monitoring access
- Emergency contacts
Training is also provided where required.
Step 9 - Monitoring & maintenance
Installation is only the beginning.
Ongoing monitoring allows:
- Live performance monitoring
- Fault alerts
- Performance analysis
- Preventative maintenance
- Warranty support
This helps ensure the system continues operating efficiently throughout its lifetime.
Annual Maintenance & support
Energy Gain offers both preventative and reactive maintenance services to help protect your investment. Planned annual maintenance visits include system inspections, electrical testing and performance checks to identify potential issues before they affect generation. If a fault is detected through remote monitoring or reported by the customer, our reactive maintenance service enables problems to be investigated and resolved quickly, helping to minimise downtime and maintain system performance.
Energy Gain Expert Insight
- Remote Monitoring
Our systems are continuously monitored remotely to track performance, identify potential issues, and ensure optimal operation. This proactive approach allows many faults to be detected and addressed before they impact system performance.
- Annual Servicing
We recommend and provide annual servicing to maintain system efficiency, reliability, and compliance with manufacturer warranty requirements. Routine maintenance includes inspections, testing, cleaning, and any necessary adjustments to ensure continued performance.
- Fault Response
In the event of a fault, our support team will respond in accordance with the agreed service level arrangements. Initial diagnosis can often be carried out remotely, with site attendance arranged when required to restore the system as quickly as possible.
- Performance Guarantees
Performance guarantees are available subject to the specific system design, operating conditions, and maintenance requirements. These guarantees provide assurance that the system will achieve agreed performance levels, with remedial action taken if targets are not met.
- Additional Support
We also offer ongoing technical support, system reporting, software updates, and operational guidance to help maximise system efficiency and longevity.
How long does installation take?
Every project is different.
Smaller commercial systems may be completed within a few days, while larger industrial installations may take several weeks depending on complexity.
The programme is agreed before work begins and is coordinated to minimise disruption.
Will installation disrupt my business?
Most commercial installations are completed while businesses remain fully operational.
Careful planning, phased working and regular communication help minimise disruption.
Where necessary, electrical shutdowns are planned around business operations.
Common Mistakes
Businesses sometimes:
- Delay roof surveys.
- Ignore structural advice.
- Forget future expansion.
- Underestimate grid connection times.
- Choose installers with limited commercial experience.
FAQs
Do I need to close my business during installation?
No. Most commercial installations are completed while businesses continue to operate.
How long does installation take?
This depends on system size and complexity. Your project programme will be agreed before work begins.
Will my roof need strengthening?
Not always. Structural assessments determine whether any additional work is required before installation.
Do I need planning permission?
Many commercial rooftop solar installations can proceed without planning permission, although every site should be assessed individually.
Who manages the DNO application?
Energy Gain manages the grid connection process, including applications where required.
What happens after installation?
Your system is tested, commissioned and handed over with monitoring access, documentation and maintenance recommendations.
How will I know the system is working?
Your system is tested, commissioned and handed over with monitoring access, documentation and maintenance recommendations.
Key Takeaways
A successful commercial solar installation relies on careful planning, detailed engineering and experienced project management.
From the first consultation to long-term monitoring, every stage contributes to the performance, safety and reliability of the system.
By combining technical expertise with proven project delivery, Energy Gain ensures every installation is designed to provide maximum value with minimal disruption to your business.
Lesson Summaries:
- Lesson 1: How commercial solar works
- Lesson 2: Understanding commercial solar costs
- Lesson 3: Understanding return on investment (ROI)
- Lesson 4: Funding commercial solar
- Lesson 5: The commercial solar installation process
Related Services:
Energy Gain solar rooftop service
Commercial solar cost and savings calculator
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