How a Selangor specialist hospital deployed Huawei SUN2000-150K-MG0 microgrid inverter + LUNA2000-215 to protect OT and ICU critical loads while reducing Maximum Demand charges
tCO₂ offset annually
“In a specialist hospital, a 200-millisecond power interruption during a cardiac procedure is not an inconvenience — it is a clinical incident. Our existing UPS covers the OR for 15 minutes, but our anaesthesia team had always been anxious about extended TNB outages. The Huawei LUNA2000 battery now extends that window to over three hours for the surgical block. The Maximum Demand savings are financially material, but the clinical resilience is what got this project approved at Board level. Trexon's team understood both the financial model and the clinical risk language — that combination is rare in solar contractors.”
No commercial building combines the financial motivation for solar with the operational complexity of a specialist hospital. On the financial side, a Tier-1 specialist hospital in Selangor operates 24 hours a day, 365 days a year, with an energy consumption profile dominated by HVAC (operating theatres require ISO Class 5 air purity with 15–25 air changes per hour), medical imaging (CT, MRI, and cardiac catheterisation laboratory equipment drawing 20–50 kW per unit during procedures), and critical-care life-support infrastructure. TNB C2 tariff Maximum Demand charges on a hospital of this size typically account for 35–42% of the total electricity bill.
On the operational side, a hospital's tolerance for power quality degradation is effectively zero. The Joint Commission International (JCI) accreditation standard — which this Shah Alam cardiac specialist hospital holds and renews every three years — requires documented evidence of power resilience planning for essential electrical systems, including a minimum backup duration for operating theatres and intensive care units. Any solar system installed at a JCI-accredited hospital must be designed to enhance, not compromise, that resilience.
This is the context in which Trexon's engagement with the hospital's facilities team began in November 2025. The facilities director's brief was explicit: "Design us a solar system that either improves clinical power resilience or at minimum does not introduce any new failure mode. Financial returns are secondary to clinical safety."
Trexon's energy audit mapped the hospital's load across four functional zones:
Zone A — Surgical Block (OR ×6, sterile processing, anaesthesia workrooms): 280–320 kW continuous during operating hours (07:00–19:00 primary, with emergency procedures 24/7). All OR feeds on a dedicated UPS-backed circuit (Class 1 essential electrical system). Peak demand events occur at 07:30 when all six ORs begin preparation simultaneously.
Zone B — ICU and CCU (24 beds): 80–95 kW continuous, 24/7. Critical-care ventilators, patient monitoring, ECMO equipment, IV pump banks. All on UPS-backed circuits.
Zone C — Imaging and Cardiology Labs: 120–180 kW during operating hours (variable — CT scanner draws 50 kW per scan cycle, cardiac cath lab draws 35 kW during procedures). Not on UPS — brief interruptions are manageable if scheduled in advance.
Zone D — General Hospital (wards, reception, administration, kitchen): 350–420 kW during the day, 220–280 kW at night. Standard grid-tied supply.
The hospital's Monthly Maximum Demand registration averaged 890 kW — driven by the 08:00 surgical preparation and imaging startup coincidence. MD charges were averaging RM 26,700 per month under TNB's C2 tariff at RM 30.00/kW.
The selection of the Huawei SUN2000-150K-MG0 microgrid-capable inverter was the central engineering decision of this project. Unlike a standard grid-tied string inverter, the SUN2000-150K-MG0 is certified for grid-forming operation — it can maintain stable AC voltage and frequency output in the absence of the TNB grid, operating as a voltage source rather than a current source. This means that in the event of a TNB outage, the inverter continues to power the hospital's loads from the PV array and LUNA2000 battery rather than shutting down (as all standard grid-tied inverters must do under anti-islanding regulations).
Two SUN2000-150K-MG0 units (150 kW each, 300 kW total) were installed in a dedicated inverter room adjacent to the main HV distribution panel. The microgrid configuration provides seamless transfer to islanded operation within 20 ms of a TNB supply interruption — below the 100 ms threshold that triggers alarms in the hospital's critical-care monitoring equipment.
557 × Trina Vertex S+ 575W panels were installed across the main hospital block roof (360 panels) and the adjacent specialist clinic wing roof (197 panels), totalling 320 kWp. The Vertex S+ 575W was specified for its Class A fire performance (IEC 61730) and its bifacial factor of 0.70, which provides incremental yield from reflected light off the hospital's white-painted roofing membrane.
Huawei LUNA2000-215 Battery (200 kWh usable): One LUNA2000-215 unit (200 kWh usable, LFP chemistry, IP55 outdoor cabinet) was installed in a ground-floor plant room adjacent to the surgical block's dedicated electrical panel. The battery is wired on a dedicated circuit that prioritises the Zone A (surgical block) and Zone B (ICU/CCU) loads during islanded operation. At 200 kWh and a combined OR+ICU load of approximately 60 kW during reduced-operations mode (3 ORs active plus full ICU), the battery provides approximately 3.3 hours of surgical-block and ICU backup — extending the existing UPS coverage of 15 minutes to a total of approximately 3.5 hours of uninterrupted clinical operations during a TNB outage.
SmartGuard dual-fed configuration: The Huawei SmartGuard module implements a dual-feed logic that simultaneously presents the battery-backed solar supply and the diesel generator supply to the critical-load panel, with automatic priority switching in the event of either supply failure. This eliminated the hospital's previous requirement to manually transfer to generator within 5 minutes of a TNB outage — a procedure that had required a licensed electrician to be on-call 24/7.
Before any works began on-site, Trexon submitted a Clinical Risk Assessment document to the hospital's Patient Safety Committee and the facilities team. The document mapped the proposed system architecture against the JCI Facility Management and Safety (FMS) standard requirements, specifically:
The Clinical Risk Assessment confirmed that the proposed system met JCI FMS.9 requirements for essential electrical system backup duration and demonstrated improved performance over the pre-solar baseline. The hospital's JCI clinical engineer reviewed and approved the document before the Board gave capital expenditure approval.
The installation was completed over nine weeks (January–March 2026) under a protocol reviewed and approved by the hospital's EHS committee:
The hospital's lead biomedical engineer confirmed that no adverse events or near-misses attributable to the solar installation were recorded during the construction period.
Generation performance:
Average monthly generation: 34,700 kWh — a specific yield of 1,303 kWh/kWp/year, above the P50 design estimate of 1,250 kWh/kWp. The hospital's elevated rooftop location in Shah Alam and the double-sided bifacial panel contribution from roof membrane reflection delivered higher-than-modelled yield in the dry season months.
Financial performance:
Average monthly TNB bill reduction: RM 24,100. Of this, approximately RM 14,800 is from energy consumption savings (displaced grid kWh) and RM 9,300 from MD reduction (the 320 kWp array reduces the morning 08:00 peak by approximately 310 kW on clear days, reducing the monthly MD registration from 890 kW to approximately 580 kW on average across the month). Projected annual savings: RM 289,200. Simple payback: 7.2 years.
Clinical resilience:
The system underwent its first real-world backup test in May 2026, when a TNB substation fault caused a 47-minute supply interruption to the hospital's district. The SUN2000-150K-MG0 islanded within 20 ms. All OR and ICU loads continued uninterrupted. The LUNA2000 battery supplied the surgical block and ICU for the full 47-minute outage and ended the event at 87% state-of-charge — confirming the system's 3.3-hour theoretical backup capacity. The facilities director described the event as "the best possible demonstration of system value we could have wished for."
Note: Financial figures represent indicative modelling based on Trexon installation data and TNB C2 tariff schedules. Specific client details are anonymised per B2B confidentiality.
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