Commercial solar system takeover
Previous installer gone. Current O&M provider not performing. Inherited a building with solar and no documentation. We conduct a baseline audit, get monitoring online, remediate existing faults, and transition the system onto an independent O&M contract — with a clear record of exactly what condition it is in.
System takeover
Transitions into ongoing O&M contract
No obligation · no lock-in
When is a commercial solar system takeover needed?
Commercial solar systems across the UK change hands more often than people expect. Installers go out of business, O&M contracts lapse, buildings are sold, and tenants inherit systems they know nothing about. In each case, the priority is the same: establish what condition the system is in and get proper maintenance in place.
Installer no longer trading
The company that installed the system has closed, been acquired, or stopped responding. Documentation is missing, monitoring has lapsed, and warranty claims have no clear route. We step in, assess the system independently, and establish a new maintenance relationship.
Switching O&M provider
Your current provider is not delivering — missed inspections, slow fault response, poor reporting, or a loss of confidence in their recommendations. We conduct a baseline audit to assess the true condition of the system and transition maintenance to an STS contract with clear SLA terms.
Building acquisition or lease
You have acquired or leased a building with an existing rooftop solar installation. You need to know what condition it is in, whether it is generating correctly, what maintenance history exists, and whether any faults need addressing. The baseline audit provides that clarity before you commit to ongoing maintenance.
No existing maintenance
The system was installed years ago and has never been formally maintained. No inspections, no monitoring, no performance records. Faults may have developed unnoticed and generation may be well below expected levels. We establish a baseline and bring the system under professional management.
Compliance or insurance requirement
Your insurer, landlord, or facilities management team requires evidence of ongoing professional maintenance. A takeover with baseline audit provides the documented starting point, and the ongoing O&M contract delivers the regular inspection reports and compliance records they need.
Poor performance, unclear cause
Generation figures do not match expectations and the current provider cannot explain why. Our baseline audit benchmarks actual output against expected yield, identifies the cause of underperformance, and provides a clear remediation plan with fixed pricing — before any ongoing contract begins.
How a commercial solar system takeover works
The takeover process is structured to give you a complete picture of your system before any ongoing commitment. Every step produces a documented output that you can share with stakeholders, use independently, or carry into an O&M contract.
Initial conversation
Tell us about the system — location, approximate size, brand (if known), current maintenance arrangement, and why you are looking to change. We confirm the scope of the baseline audit and provide a fixed-price proposal. No obligation to proceed beyond this point.
Baseline audit
A full on-site inspection covering all inverters, panels, cabling, isolators, battery storage (if present), mounting systems, and electrical connections. We test string-level performance, check for faults, verify safety compliance, and document the current condition of every major component. This is the same thorough inspection used in our independent audit service.
Documentation recovery
We gather any existing documentation — commissioning records, DNO connection agreements, MCS certificates, warranty paperwork, and previous maintenance logs. Where records are missing, our engineers reconstruct a working system file from the on-site assessment. This documentation forms the foundation of your ongoing O&M record.
Monitoring setup
Where the installed equipment supports remote connectivity — most modern commercial inverters do — we configure real-time fault monitoring with automated alerts to the STS engineering team. If monitoring hardware is not currently online, we assess what is needed and quote for the setup. Monitoring status is confirmed before the system enters ongoing O&M.
Remediation plan
If the baseline audit identifies faults, underperformance, or safety issues, we provide a clear remediation plan with fixed pricing for each item. You choose what to address and when. There is no obligation to carry out remediation through STS — you can use the audit report independently. Remediation typically includes inverter replacements, string repairs, isolator upgrades, and monitoring reconfiguration.
Transition to O&M contract
Once the baseline is established and any agreed remediation is complete, the system transitions onto a standard STS O&M contract. This includes scheduled annual inspections, real-time monitoring, written performance reporting, and priority emergency response. No lock-in, no automatic renewal — contract terms are confirmed in writing before you commit.
What the baseline audit covers
The baseline audit is a thorough, independent assessment of your commercial solar system. It establishes a documented starting point for ongoing maintenance and identifies anything that needs attention.
Inverter inspection
Visual and electrical inspection of all inverters. Error code history, firmware version, fan condition, heat damage assessment, and performance benchmarking against expected output. All major brands — SMA, Huawei, Solis, SolarEdge, GoodWe, and others.
Panel and string testing
String-level voltage and current measurements to identify failed panels, bypass diode faults, or wiring issues. Visual inspection for hotspots, microcracks, snail trails, delamination, and physical damage. Shading assessment where applicable.
Electrical safety
DC isolator condition, cable routing and integrity, earth continuity, insulation resistance testing, and verification of protective device settings. Safety compliance assessed against current regulations and any issues flagged for immediate attention.
Battery storage assessment
Where battery storage is present — state of health, charge/discharge cycle history, BMS configuration, cell balancing status, and thermal management. Warranty status verified where manufacturer records are available.
Monitoring and communications
Current monitoring status assessed — is data flowing, are there gaps, is the platform configured correctly? If monitoring is offline, we identify what is needed to restore it and quote for setup. CT clamp calibration verified where applicable.
Documentation and compliance
DNO connection agreement reviewed (G98/G99 compliance verified), MCS certificate located where possible, commissioning records gathered, and any previous maintenance history compiled. Missing documentation reconstructed from the on-site assessment.
System takeover — frequently asked questions
A system takeover begins with a baseline audit — a full on-site inspection of your commercial solar system to assess current condition, identify faults, verify monitoring status, and recover or reconstruct documentation. We then remediate any immediate issues, configure monitoring, and transition the system onto an STS O&M contract with clear scope, SLA terms, and a documented baseline to measure future performance against.
Yes. This is one of the most common reasons commercial clients contact us for a system takeover. When the original installer is no longer trading, documentation is often missing, monitoring may have lapsed, and warranty claims become more difficult to pursue. We assess the system independently, recover what documentation we can, and establish a new maintenance baseline. We are not tied to any installer network — we work with all major brands and can take over any commercial solar system regardless of who installed it.
That depends on your existing contract terms. We recommend reviewing your current agreement for notice periods, termination clauses, and any handover obligations. STS can conduct the baseline audit while your existing contract is still active — so there is no gap in coverage — and we can coordinate the transition to minimise disruption.
Missing documentation is common, particularly for older installations or where the original installer is no longer trading. Our engineers can assess the system on site, identify all components, verify wiring configurations, check DNO connection agreements, and reconstruct a working system record. This baseline documentation becomes part of your ongoing O&M file.
The baseline audit is typically completed in a single site visit. Monitoring setup, documentation recovery, and any immediate fault remediation may take one to two weeks depending on system complexity and the availability of existing records. Once the baseline is established, the system transitions onto a standard O&M contract and ongoing maintenance begins immediately.
Yes. The baseline audit identifies all existing faults and underperformance. We provide a clear remediation plan with fixed pricing for any repair work needed before the system enters ongoing O&M. This ensures you know exactly what condition the system is in and what it will cost to bring it up to standard. There is no obligation to carry out remediation through STS — you can use the audit report independently.
Related commercial services
Annual O&M contracts
Scheduled inspections, real-time monitoring, performance reporting, and priority emergency response. £795/year.
EmergencyEmergency repair
Same-day remote triage, next-business-day on-site for contract holders. Inverter replacement, fault diagnosis, and safety isolation.
AuditIndependent audit
Objective performance assessment for acquisition due diligence, insurance compliance, or benchmarking. No commercial agenda.
Discuss a system takeover
Tell us about the system — location, approximate size, brand (if known), and why you are looking to change provider. We will confirm scope and pricing for the baseline audit, usually within one business day. No obligation to proceed.