Saudi Solar Developers' YB Series Substations: 11kV Riyadh PV Collector MOQ 5

Saudi Arabia's solar energy sector has entered a phase of aggressive capacity addition. With the Kingdom targeting 50% renewable energy by 2030 and the National Renewable Energy Program (NREP) driving a competitive auction pipeline exceeding 30 GW by2030, the engineering and procurement decisions being made today will determine how reliably Saudi solar farms perform for the next 25 years. At the critical interface between the PV array and the grid—where power is collected from thousands of inverters and stepped up to transmission voltage—the package substation is not an afterthought. It is foundational infrastructure. Ningbo Tianan's YB series package substation, with its 11kV rating and Saudi grid compatibility, is purpose-built for this role.

Saudi Arabia's Solar PV Collection Infrastructure: The Context

A utility-scale Saudi solar farm—say, a 300 MWp installation in the Riyadh region—generates power across hundreds of strings of PV modules. Each string terminates in a string inverter that converts DC to AC at 0.69kV (690V). These inverters are grouped into clusters, and the AC output from each cluster is collected at a medium voltage (MV) collection point, typically at 11kV or 33kV depending on the project's scale and grid operator requirements. From that MV collection point, a feeder cable runs to the Saudi Electricity Company (SEC) substation yard or directly to the point of grid interconnection.

The package substation—also called a Prefabricated Substation, compact substation, or MV/HV substation—is the equipment installed at that MV collection point. It houses the step-up transformer, the MV switchgear, the LV auxiliary supply, protection and control equipment, and sometimes the monitoring and communication systems. In the Saudi context, where large solar farms are often in remote inland desert locations with extreme temperatures, the package substation must meet demanding environmental, electrical, and operational standards.

The YB Series Package Substation: Design Overview

Tianan's YB series represents the manufacturer's standard commercial range of prefabricated substations, designed for outdoor deployment in utility and industrial Power Distribution applications. The YB series uses a three-compartment enclosure structure:

• HV Compartment: Houses the high voltage switchgear (ring main unit or RMU) operating at 11kV. The RMU typically includes a load break switch and fuse/circuit breaker combination for transformer protection.
• Transformer Compartment: Houses the cast resin or oil-immersed distribution transformer that steps up from 0.69kV to 11kV (or 0.4kV to 11kV depending on configuration). The transformer is the largest single component and is vibration-isolated from the enclosure structure.
• LV Compartment: Houses the low voltage switchgear, protection relays, SCADA communication equipment, auxiliary power supply, lighting, and ventilation controls.

YB Series Standard Specifications

Saudi Grid Interconnection Requirements and SASO Compliance

The Saudi Electricity Company (SEC) and the Saudi Standards, Metrology and Quality Organization (SASO) impose specific technical requirements on all equipment connected to the Saudi grid. For solar farm package substations, the key compliance requirements include:

• SASO Quality Mark: Equipment must carry the SASO Quality Mark or be certified by an accredited conformity assessment body. Tianan's export team manages the SASO certification process for Saudi buyers, including test reports from SASO-approved laboratories.
• IEC 62271 Compliance: High voltage switchgear must comply with IEC 62271 (high-voltage switchgear and control gear standards), specifically the relevant parts for switchgear, circuit breakers, and control gear.
• Grid Code Interconnection Requirements: The substation's protection and control systems must be configurable to Saudi grid code requirements, which include specific fault ride-through (FRT) characteristics, anti-islanding protection, and active/reactive power control setpoints communicated via SCADA.
• Environmental Conditions: SASO and SEC require equipment to operate without degradation at ambient temperatures up to 55°C, with solar radiation loading of up to 1,000 W/m² on enclosure surfaces. Tianan's high-temperature option for the YB series is specifically validated for these conditions.

Transformer Design for Saudi Desert Solar Applications

The distribution transformer is the core component of the package substation, and its performance underpins the reliability of the entire PV collection system. For Saudi solar applications, Tianan offers two transformer technologies:

Cast Resin (Dry-Type) Transformer

Cast resin transformers use epoxy resin encapsulation of the windings, eliminating the need for insulating oil. Key advantages for Saudi solar deployments:

• Fire safety: No combustible insulating oil means no fire risk—a critical consideration in a desert environment with high ambient temperatures and dust.
• Maintenance-free: No oil level monitoring, no oil sampling, no oil leak risk. Suitable for remote solar sites where maintenance visits are infrequent.
• Class H insulation: Tianan's dry-type transformers use Class H insulation (180°C maximum winding temperature), allowing operation at elevated ambient temperatures with acceptable thermal derating.
• Outdoor installation: Cast resin transformers are designed for outdoor installation without a separate housing, and the encapsulation provides protection against humidity and contamination.

Oil-Immersed Transformer

For applications where transformer efficiency and thermal performance are prioritized over fire safety, Tianan supplies oil-immersed transformers with mineral oil or biodegradable ester fluid. Oil-immersed transformers offer 5–8% lower no-load losses and10–15% lower load losses compared to equivalent cast resin designs, which translates to operational cost savings over the transformer's 25-year lifespan.

For Saudi coastal solar installations where fire safety codes may permit oil-immersed transformers (and where the higher efficiency is economically attractive), Tianan offers oil-immersed transformers with corrugated tank design for enhanced heat dissipation and high-retention oil spill containment basins as standard.

Package Substation Sizing for Solar PV Collector Systems

Correctly sizing the package substation is one of the most consequential decisions in solar farm design. The substation must be sized to handle the aggregate AC output of the PV inverters it collects, with appropriate headroom for future capacity expansion and without excessive over-sizing that inflates capital cost.

For a Saudi Riyadh region solar project of approximately 300 MWp capacity, the typical configuration involves 10–12 YB series package substations rated at 2500 kVA, distributed across the PV field at collection point locations approximately 1.5–2 km apart. The 11kV output from each substation feeds into an 11kV ring main or radial feeder network that converges at the project substation yard, which then steps up to 132kV for grid interconnection.

Why MOQ 5 Units? The Economics of Project-Scale Procurement

The5-unit MOQ for Tianan's YB series package substation reflects the economics of project-scale electrical equipment manufacturing. Package substations of this size and complexity are configured to buyer specifications at the time of order—transformer rating, HV voltage class, protection relay settings, SCADA communication protocol, and enclosure finish are all defined per project. This bespoke configuration process requires a minimum production run to justify the engineering and tooling setup cost.

For Saudi solar developers, a 300 MWp project with 10 substations places the order in a single-batch production run, which improves unit pricing and ensures consistent quality across all substations in the project. The MOQ of 5 units effectively gates smaller project developers (sub-50 MWp solar farms) from accessing this equipment, but positions the product for the large-scale solar farms that represent the dominant market in Saudi Arabia's NREP pipeline.

Turnkey Project Services: From Equipment Supply to Commissioning

Tianan has developed a comprehensive international project service model for solar substation exports. Their 15+ years of power equipment export experience across Asia, Africa, the Middle East, and South America has built a repeatable process for managing cross-border equipment supply to project sites:

Pre-Sale Engineering Support

• Technical feasibility study based on buyer's project load profile and grid interconnection requirements
• Substation sizing and configuration recommendation
• Single-line diagram development and review with buyer's engineering consultant
• SASO certification pathway and timeline confirmation

Equipment Supply

• Manufacturing with buyer-witness inspections (WIT) at key stages: transformer test, switchgear test, assembly inspection
• Third-party factory acceptance testing (FAT) at an accredited laboratory if required by the buyer
• Packing for sea freight export: export-grade timber crating with desiccant, shock watch indicators, and humidity barrier

Installation and Commissioning Support

• Installation supervision by Tianan-certified field engineer (travel and accommodation at buyer's cost)
• Commissioning procedure review and execution assistance
• Protection relay setting coordination with the Saudi grid operator (SEC)
• On-site acceptance testing (SAT) support

Post-Commissioning Support

• Spare parts supply via air freight from Ningbo or from regional stock held in Dubai
• Remote technical support via video call or remote SCADA access
• Warranty: 24 months from commissioning date or 30 months from shipment date, whichever is earlier

Desert Environmental Considerations for Package Substations

Saudi Arabia's solar deployment environment presents distinct challenges that differ from typical temperate-climate substation installations. Tianan's engineering team has developed specific adaptations for the Saudi market:

Thermal Management

Ambient temperatures in the Riyadh region regularly exceed 45°C during summer months (May–September), with direct solar radiation loading adding the equivalent of 10–15°C thermal stress to enclosure surfaces. Tianan's high-temperature YB series addresses this through:

• Enclosure surfaces with high-albedo powder coating (solar reflective index >0.7) to reduce solar heat absorption
• Forced ventilation fans with temperature-controlled operation (activating above 35°C ambient)
• Thermal derating of transformer and switchgear to IEC 60076-7 standards for operation at +55°C
• UV-resistant external coatings tested to ASTM D4799 (accelerated UV weathering)

Sand and Dust Ingress Protection

Desert sand infiltration can compromise switchgear, protection relays, and ventilation systems. Tianan's IP55-rated YB substations use:

• Double-gasket door seals on all enclosure openings
• Filtrated air intake with replaceable G4-grade panel filters
• Sealed cable entries with compression glands on all LV and HV cable penetrations
• Stainless steel hardware throughout for UV and salt corrosion resistance

Competitive Landscape: How Tianan Compares

The global market for solar package substations includes European manufacturers (ABB/S Hitachi Energy, Siemens Energy), Korean manufacturers (Hyundai Electric, LS Electric), and Chinese manufacturers (Tianan, TBEA, XD Electric). Tianan occupies a competitive position in the mid-to-premium tier of Chinese manufacturers:

Tianan's advantage lies in the combination of SASO-compliant product design, competitive pricing relative to European and Korean alternatives, and a turnkey project service model that reduces the buyer's procurement and logistics complexity. Their 10–14 week delivery timeline (from order confirmation to ready-to-ship at Ningbo port) compares favorably to the 16–20 week timelines common for European manufacturers.

Procurement Process for Saudi Solar Developers

The typical procurement process for Tianan's YB series package substation in a Saudi solar project follows this timeline:

• Week 1–2: Technical specification review, substation sizing confirmation, commercial quotation
• Week 3–4: Commercial negotiation, order confirmation, 30% deposit payment
• Week 5–14: Manufacturing and factory acceptance testing (FAT)
• Week 15: Packing and shipping from Ningbo port
• Week 16–20: Sea freight to Jeddah Islamic Port or King Abdullah Economic City (10–15 days transit)
• Week 21–24: Customs clearance, inland transport to project site
• Week 25–30: Installation, commissioning, and grid connection testing