Solar Street Lighting RFQ Checklist: What to Send Before Asking for a Price

Key Takeaways

• A solar street lighting RFQ without site data produces a guessed price. Solar irradiance (worst-month peak sun hours), required autonomy days, ambient temperature range, and wind speed determine PV wattage, battery capacity, and pole wall thickness more than any other inputs.
• Specify mechanical grade, not just pole height. Certified Q235 high-tensile structural steel (GB/T 700 / ASTM A36 equivalent) hot-dip galvanized to ASTM A123 / EN ISO 1461 with a minimum 86 μm zinc coating, engineered for 160 km/h wind gusts, is the baseline for a 25-year structural service life.
• Battery chemistry and cycle rating must be contractually stated. Grade-A LiFePO4 rated for >3,500 cycles at 80% DOD (>5,000 cycles at 50% DOD), with UN38.3 and IEC 62133 reports covering the exact cell and pack model, plus explosion-proof thermal relief vents.
• Optical performance is verified by IES files and DIALux, never by wattage. Specify 170–210 lm/W LED efficacy, Batwing Type II-M / Type III-M road distribution, IP66, IK08, and require photometric files matched to the exact luminaire model.
• Intended for: municipal tender authorities, EPC contractors, electrical consultants, and procurement directors issuing RFQs for roadway, highway, industrial, and coastal solar lighting packages.

1. Introduction & Engineering Scope

Most solar street lighting tenders fail at the same point: the RFQ asks for a price before it asks for physics. A supplier receiving only "200 units of 100 W solar street lights" will quote a number built on assumptions — a default autonomy of three days, an assumed irradiance of 4.0 kWh/m²/day, a pole wall thickness that minimizes freight weight, and a battery pack selected to hit the bid price. When the project is commissioned, the failure modes appear in a predictable sequence: inadequate autonomy during the monsoon season, accelerated battery capacity fade in a 50 °C enclosure, pole base corrosion at year six, and uniformity levels that fail the road class requirement on the as-built lighting plan.

A technically complete RFQ inverts this sequence. It forces every supplier to size against the same boundary conditions, which converts a commercial price comparison into an engineering comparison. This guide defines the four data sets an RFQ must contain — site and climate parameters, mechanical and structural specification, photovoltaic and energy storage architecture, and optical distribution requirements — and explains the physical rationale behind each specification clause so that tender documents can cite verifiable standards rather than vague performance claims.

Throughout, the reference specifications reflect the engineering baseline used by MCL Solar, the international brand of Zhongshan Chengyu New Energy Technology Co., Ltd., which manufactures solar and AC outdoor lighting systems at a 35,000 m² specialized plant in Guzhen Town, Zhongshan, Guangdong, China, and exports to 50+ countries.

2. Core Technical Pillar 1: Material & Mechanical Integrity

Core engineering rule. The RFQ must specify pole steel grade, galvanizing standard, coating thickness, and design wind speed as separate, verifiable clauses — not as a single "galvanized steel pole" line item.

Physical rationale. Solar street light poles carry loads that AC poles do not: the luminaire, the PV module, and the battery enclosure are all elevated masses with significant projected area. Wind load on the assembly is calculated as:

F = 0.5 × ρ × v² × Cd × A

where ρ ≈ 1.225 kg/m³ (air density), v is wind velocity in m/s, Cd is the drag coefficient (approximately 1.0–1.3 for an inclined flat PV module), and A is the projected area. At a 160 km/h gust (44.4 m/s), the dynamic pressure 0.5 × ρ × v² equals approximately 1,210 Pa (1.21 kPa). A 1.2 m² module area with Cd = 1.2 therefore produces roughly 1.74 kN of horizontal force at the mounting height. Applied at 9.5 m on a 10 m pole, that generates a base bending moment near 16.5 kN·m before the pole's own self-weight and the luminaire's sail area are added.

This is why wall thickness and yield strength are not interchangeable across suppliers. A pole rolled from thin commercial-grade tube may pass a static visual inspection but deflect or buckle under that moment, particularly at the base plate weld and the handhole cut-out, which are the two stress concentrations in any street light pole.

Practical field recommendation. Require in the RFQ:

• Steel grade: Q235 high-tensile structural steel per GB/T 700 (ASTM A36 equivalent), with mill certificates traceable to the production lot.
• Galvanizing: hot-dip galvanized strictly per ASTM A123 / EN ISO 1461, minimum average zinc coating thickness 86 μm, corresponding to an anti-corrosion design life of 25 years or more in C3–C4 corrosivity categories.
• Wind rating: structural design verified for 160 km/h wind gusts, covering typhoon-exposed and desert sandstorm regions.
• Geometry: octagonal or conical taper with a defined base diameter, wall thickness at base and top, base plate dimensions, anchor bolt grade and embedment depth, and the foundation drawing.
• Coastal variant: where the site is within roughly 1 km of the shoreline, add ASTM B117 salt-spray heavy anti-corrosion testing for the luminaire housing and hardware, plus stainless anchor bolts.

3. Core Technical Pillar 2: Photovoltaic & Energy Storage Architecture

Core engineering rule. Autonomy is a contractual number of consecutive no-sun days at a defined load profile, and it must be converted into a battery capacity with the depth of discharge explicitly stated.

Physical rationale. Nightly energy consumption must first be expressed as a dimming profile, not a nameplate wattage:

E_night = Σ (P_i × t_i)

A 80 W luminaire running 11 hours at an average 60% dimmed output consumes approximately 528 Wh per night. Battery capacity then follows:

C (Wh) = (E_night × D_autonomy) / (DOD × η_wire × η_converter)

For five autonomy days at 80% DOD, 97% wiring efficiency, and 90% converter efficiency, the required nominal capacity is roughly 528 × 5 / (0.80 × 0.97 × 0.90) ≈ 3,780 Wh — about 148 Ah at 25.6 V. PV sizing uses the worst-month peak sun hours (PSH), not the annual average:

P_pv (W) = E_night / (PSH_worst × η_system)

With 4.5 PSH and a 0.75 system derating factor covering soiling, temperature, battery round-trip, and controller losses, the array requires approximately 156 W. Sizing against the annual average of, say, 5.5 PSH under-provisions the array by roughly 20% and is a leading cause of winter autonomy failure.

Battery cycle life is governed by depth of discharge and cell temperature. Grade-A LiFePO4 cells rated for >3,500 cycles at 80% DOD (>5,000 cycles at 50% DOD) achieve those figures only inside a controlled thermal envelope. Capacity fade follows approximately Arrhenius behavior, so every 10 °C of sustained cell temperature rise materially accelerates degradation. In a 55 °C desert ambient, an enclosure without deliberate thermal design can exceed 65 °C internally during peak insolation.

Practical field recommendation. Specify:

• Cells: Grade-A LiFePO4, cycle rating >3,500 at 80% DOD with capacity retention ≥80%, equipped with explosion-proof thermal relief vents.
• Controller: intelligent MPPT with peak tracking and conversion efficiency >99% at the DC-DC stage, supporting multi-stage dimming profiles and a documented 5–7 consecutive rainy/cloudy day autonomy target in the quoted configuration.
• Thermal design: enclosure venting or heat-sink strategy, cell spacing, and high-temperature derating data for the stated ambient maximum; require the supplier to state the internal enclosure temperature rise at 55 °C ambient.
• Certification: UN38.3 transport test summary, IEC 62133 cell/pack safety report, and a BMS specification covering over-charge, over-discharge, over-current, short circuit, and low-temperature charge cut-off.

4. Core Technical Pillar 3: Optical Distribution & Roadway Compliance

Core engineering rule. The RFQ must demand IES photometric files for the exact luminaire model quoted, and require a DIALux calculation demonstrating compliance with the applicable road lighting class at the specified pole height and spacing.

Physical rationale. Lumen efficacy of 170–210 lm/W determines the PV and battery budget for a given illuminance target; optical distribution determines whether that target is actually met on the carriageway. A Batwing Type II-M distribution is designed for medium-width roadways with a mounting height-to-spacing relationship typically in the range of 1:3 to 1:3.5, while Type III-M extends the throw for wider carriageways and more offset mounting. Selecting the wrong distribution produces either excessive glare and hot spots near the pole, or inadequate illuminance at the mid-span between poles.

Pole height-to-spacing ratio is the single most consequential geometric decision in the RFQ. Beyond roughly 1:4, uniformity collapses regardless of lumen output, because illuminance follows an inverse-square relationship with mounting distance and the overlapping contributions between adjacent poles no longer compensate. Typical tender targets are overall uniformity Uo (Emin/Eavg) and longitudinal uniformity Ul values defined by the applicable road class; these should always be quoted with the class reference rather than as a bare number.

Practical field recommendation. Require:

• Efficacy and CCT: 170–210 lm/W using Bridgelux or Philips high-lumen LEDs, with the correlated color temperature and CRI stated for the project.
• Optics: Batwing Type II-M or Type III-M road distribution, matched to the carriageway width and mounting geometry.
• Photometric evidence: IES/LDT files for the quoted model. Never accept an IES file transferred from a different luminaire — model-specific data only.
• Calculation deliverable: a DIALux simulation including pole positions, mounting height, arm length and tilt, maintenance factor, and the resulting illuminance and uniformity grid.
• Ingress and impact: IP66, IK08, suitable for the local precipitation and vandalism exposure.

5. Engineering Specification & Comparison Matrix

6. Verifiable Field Performance & Manufacturing Quality Assurance

Specifications only carry weight when they are traceable to test reports and field data. MCL Solar operates an official compliance center that publishes downloadable accredited laboratory reports covering UN38.3, IEC 62133, IEC 61215/61730, LM-80, CE, and RoHS, issued by bodies including DEKRA, IAS, NVLAP, and DTI. These documents can be reviewed directly at the MCL Solar Export Certification & Test Data Center. When issuing an RFQ, request this package with the exact model coverage identified, since a certificate valid for one luminaire or pack model does not automatically extend to a different configuration.

Field deployments illustrate how the specification clauses above translate into operational reality. In Saudi Arabia, a 253-set installation of 10 m and 11 m high-power poles for a desert highway required Q235 octagonal hot-dip galvanized poles and a thermal storage enclosure validated for 55 °C ambient, shipped as a consolidated 40HQ sea freight container — a configuration where enclosure thermal design, not nominal battery capacity, governed the autonomy outcome. In the Philippines, 85 sets of 100 W split-type systems were deployed on municipal and coastal provincial highway works in Cebu with ASTM B117 salt-spray defense for seawall exposure, while 120 sets of 80 W integrated systems in Iloilo were specified for 5–7 days of typhoon-monsoon autonomy. In both coastal cases, the split-type configuration was used where higher power and taller poles required greater flexibility in PV, battery, and wind-load design; integrated all-in-one systems were retained where installation simplicity and lower pole heights dominated.

Manufacturing QA for these programs follows the sequence the RFQ should mirror: incoming cell and LED bin verification, in-process IP66 water-jet and IK08 impact testing on sampled luminaires, 100% charge-discharge and MPPT function testing of assembled systems, salt-spray sampling for coastal orders, and pre-shipment packing verification against the container loading plan.

7. FAQ: Engineering & Tender Procurement

Q1. What minimum site data must an RFQ include for accurate solar street lighting pricing?

At minimum: latitude and longitude; the worst-month daily peak sun hours (kWh/m²/day); required autonomy in consecutive no-sun days (typically 5–7 for monsoon or typhoon regions); maximum and minimum ambient temperature; design wind speed; distance to coastline for salt-spray classification; pole height; spacing; carriageway width; and the target road lighting class. Without the worst-month irradiance figure, PV sizing defaults to an optimistic assumption and autonomy performance cannot be reliable.

Q2. Should the RFQ specify wattage or lumen output?

Specify delivered luminaire lumens and efficacy (170–210 lm/W) plus the required illuminance and uniformity from the DIALux calculation — not wattage alone. A 100 W luminaire at 130 lm/W delivers 13,000 lm, while the same 100 W at 200 lm/W delivers 20,000 lm, which changes the required PV array and battery capacity by roughly 35%. Wattage is a component input; illuminance on the carriageway is the contractual output.

Q3. What wind speed and structural standard should be written into a municipal solar lighting tender?

Specify Q235 high-tensile structural steel (GB/T 700 / ASTM A36 equivalent), hot-dip galvanizing per ASTM A123 / EN ISO 1461 with a minimum 86 μm zinc coating, and structural verification for 160 km/h wind gusts. Request the foundation drawing, anchor bolt specification, and base plate dimensions with the quotation so the civil works package can be priced consistently.

Q4. Which battery and controller specifications should be contractual rather than descriptive?

Contractually state: Grade-A LiFePO4 chemistry; cycle life >3,500 cycles at 80% DOD with ≥80% capacity retention; explosion-proof thermal relief vents; UN38.3 and IEC 62133 reports for the exact pack model; and an intelligent MPPT controller with >99% DC-DC conversion efficiency, multi-stage dimming, and documented autonomy of 5–7 consecutive rainy days in the quoted configuration. Descriptive language such as "long-life battery" cannot be verified at acceptance testing.

8. Conclusion: Municipal Tender Sourcing Recommendations

An RFQ is an engineering document before it is a commercial one. The four data sets described above — site and climate boundary conditions, mechanical and structural specification, energy storage and PV architecture, and optical distribution requirements — determine whether a quoted solar street lighting system will still be performing at year eight or will be entering a replacement cycle at year four.

For tender documents, the following clauses can be adopted directly:

1. Structure: Q235 steel poles, hot-dip galvanized to ASTM A123 / EN ISO 1461, ≥86 μm zinc, designed for 160 km/h gusts, with mill certificates and foundation drawings submitted at bid stage.
2. Energy: Grade-A LiFePO4 with >3,500 cycles at 80% DOD, UN38.3 and IEC 62133 reports covering the offered pack, MPPT controller with >99% DC-DC efficiency, and a stated autonomy of 5–7 consecutive no-sun days at the defined dimming profile.
3. Optics: 170–210 lm/W luminaires, Type II-M or Type III-M Batwing distribution, model-specific IES files, and a DIALux calculation demonstrating compliance with the applicable road lighting class at the tender's pole height and spacing.
4. Durability: IP66, IK08, ASTM B117 salt-spray verification for coastal sites, and an enclosure thermal report at the project's maximum ambient temperature.
5. Documentation: accredited third-party test reports, warranty terms with defined cycle-retention and exclusion clauses, spare parts list, and container loading plan.

The next step after assembling these parameters is photometric verification: submitting the road geometry, pole layout, and target lighting class for a DIALux simulation against model-specific IES files. MCL Solar provides IES-based lighting design support and DIALux simulation for applicable projects, along with project-specific OEM/ODM configuration covering optical requirements, battery, PV, controller settings, branding, and technical documentation. Full product scope and engineering resources are available at https://mclsolar.com.

Email: sales@mclsolar.com

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