The Hospital Solar Process, Step by Step
NHS solar projects typically run 18–36 months from conception to commissioning — most of it governance and funding, not construction. Knowing where the time goes is how estates teams keep projects on programme.
Where the time actually goes
The physical installation of a 300 kW–2 MW hospital array takes 6–20 weeks. Everything else is process: a PSDS application cycle of 4–6 months, framework procurement of 8–16 weeks, G99 grid approval that can run 6–18 months in parallel (though hospital sites are usually less constrained because they hold large existing connections with spare capacity), and the Trust's own governance calendar. None of these steps can be skipped, but they can be overlapped — and overlapping them well is most of what a specialist contractor contributes before anyone touches the roof.
Five stages from data to generation
- 01Weeks 1–2
Desk feasibility
You send 12 months of half-hourly data and roof drawings. We model the array in PVSyst against your real load profile, screen the roof from drawings and aerial survey, and return system size, installed cost, savings, CO2 impact, and recommended funding route. Free, and no site visit needed.
- 02Months 1–6
Funding & business case
For NHS sites we write the PSDS Phase 4 or Salix application with auditable SBEM and PVSyst evidence, and assemble the Full Business Case with HMT Green Book treatment for Trust Board sign-off. Private groups get capital, finance, and PPA options modelled side by side instead.
- 03Months 4–9
Design & approvals
Structural engineer verifies roof loading. HTM 06-01 electrical design goes through AE(E) review. G99 application lodged with the DNO. Planning checked — most hospital solar proceeds under permitted development, with listed buildings and conservation areas the exceptions. Infection control methodology agreed with the IPC team.
- 046–20 weeks
Installation
Mobilisation with Estates and IPC induction, DBS verification, segregated work zones. Roof installation proceeds above live clinical operations — wards, theatres, and ITU run normally throughout. Weekly programme reviews with the Estates team; crane lifts and deliveries scheduled around clinical activity and helipad operations.
- 05Final month
Connection & handover
The single operational touchpoint: a planned 4–8 hour window for grid connection, agreed with Estates and theatre management weeks in advance. Then commissioning, EN 50549 compliance verification, monitoring setup feeding your BMS, O&M documentation, and operator training.
What never gets interrupted
Clinical operations. Roof work happens above functioning wards under HTM 03-01 infection control protocols — contractor induction by Estates and IPC, segregated construction zones, negative-pressure areas maintained where applicable, and PPE protocols throughout. We have delivered installations above immunocompromised patient zones with zero infection control incidents. The grid connection window is the only planned outage event, and it is scheduled like any other piece of estates maintenance: agreed weeks ahead, with theatre lists protected.
After commissioning
A 25-year asset needs more than a handover pack. Monitoring runs from day one with fault alerts to your helpdesk and ours; generation data feeds ERIC returns and Green Plan reporting for NHS sites, and ESG disclosures for private groups. Panel cleaning and inverter maintenance follow a published O&M schedule, and performance is reviewed against the PVSyst model annually — if the array underperforms the model, we investigate rather than hope you will not notice. The yield file is yours, shared at proposal stage, and verifiable by any third party.
Ready to start the clock?
Stage one needs nothing from your estate but data. Send half-hourly consumption and roof drawings through the quote form and the feasibility lands within two weeks. If your project depends on grant funding, check PSDS timing early — application windows drive the whole programme, and our guide to application timing explains why early submissions win.