Apples-to-Apples Quote Comparison — Solar Street Lights (Stop Hidden Assumptions)
Solar street light quotes often look comparable—until deployment. The difference is usually hidden in assumptions: optics/IES, pole layout inputs, dimming profile (Wavg), battery usable energy, controller type, and worst-month charging. This guide gives strict PASS/FAIL gates and a fair scoring structure so you can evaluate bids defensibly.
Where This Guide Fits
- Start here: Buyer’s Guide Hub
- Related system pages: All-In-Two Solar Street Lights, All-in-One Solar Street Lights
- Evidence centers: Spec Definitions · IES/DIALux · Quality Evidence
TL;DR (The comparison method in 6 rules)
- Rule 1: Lock layout inputs (height/spacing/offset/arm/tilt) and require IES + simulation for every bid.
- Rule 2: Normalize dimming assumptions and compare by Wavg and Wh/night.
- Rule 3: Require worst-month/rainy-season sizing sanity check using the same assumptions.
- Rule 4: Compare batteries by Wh + usable energy policy, not “Ah-only”.
- Rule 5: Controller type (MPPT/PWM) and charging assumptions must be disclosed.
- Rule 6: Warranty must be measurable (SLA + evidence workflow + traceability), or the price is not real.
Step 0: Define the “common basis” (lock before bidding)
- Application: road type, environment, vandal risk
- Layout basis: arrangement + mounting geometry
- Lighting intent: local authority/spec target (avoid “looks bright”)
- Operating intent: runtime hours and control mode
Lock your inputs using:
PASS/FAIL Gate #1 — Photometrics (IES + simulation or FAIL)
PASS requires:
- IES file for the quoted optic
- Simulation PDF using your locked layout inputs
- Declared CCT/CRI basis and delivered lumens for the configuration
FAIL triggers: “no IES”, “generic IES”, or simulation built on different heights/spacing/inputs than your basis.
PASS/FAIL Gate #2 — Energy model (Wavg + Wh/night or FAIL)
To compare bids fairly, you must normalize energy use at night:
- Declared dimming profile (time/PIR/hybrid + steps)
- One-page energy sheet showing Wavg, runtime hours, and Wh/night
Reference:
PASS/FAIL Gate #3 — Worst-month / rainy-season sanity check
Quotes that pass in summer can fail in rainy season. Require each bidder to provide a worst-month sizing check consistent with the same Wavg/Wh-night assumptions.
Reference:
PASS/FAIL Gate #4 — Battery comparability (Wh + usable policy)
- Battery specified in Wh (nominal voltage + Ah or direct Wh)
- Usable energy policy disclosed (usable factor + cutoffs)
- BMS protections list disclosed
Reference:
PASS/FAIL Gate #5 — Controller and charging assumptions
- Controller type disclosed (MPPT or PWM)
- Charging assumptions disclosed and aligned with the rainy-season check
Reference:
PASS/FAIL Gate #6 — Durability & environment (IP/IK + configuration lock)
- Assembled-product IP/IK declared for the delivered configuration
- Sealing-critical parts disclosed (gaskets/vents/connectors) + no silent substitutions
Reference:
Scoring (only after PASS/FAIL gates)
Only score price after the bid passes the gates above. Then score on:
- Serviceability: replacement difficulty, access, downtime risk
- Traceability: serial mapping and QC record availability
- Warranty reality: SLA, spares plan, claim workflow
- O&M readiness: commissioning records and maintenance templates
Operations and warranty references:
Comparison Table Template (copy/paste)
| Comparison Item | Bid A | Bid B | Bid C | Notes / Pass-Fail |
|---|---|---|---|---|
| IES file provided | FAIL if missing | |||
| Simulation uses locked layout inputs | FAIL if different inputs | |||
| Dimming profile disclosed | Required for Wavg | |||
| Wavg and Wh/night sheet provided | FAIL if missing | |||
| Worst-month sizing sanity check | FAIL if missing | |||
| Battery in Wh + usable policy | FAIL if Ah-only | |||
| Controller type (MPPT/PWM) declared | FAIL if unclear | |||
| IP/IK assembled-product declared | FAIL if parts-only | |||
| Warranty SLA + evidence workflow | Price not real if missing |
Internal Link Map (recommended cross-links)
- Photometrics section: CCT/CRI/Beam Angle, Pole Height & Spacing
- Energy model section: PIR vs Time Dimming, Autonomy Days
- Worst-month gate: Rainy Season Sizing
- Battery gate: LiFePO4 Battery Lifespan
- Controller gate: MPPT vs PWM, Mono vs Poly
- Durability gate: IP & IK Selection, Failure Modes
- After scoring: Warranty Terms, Maintenance Plan, Commissioning Checklist
Want a quick engineering sanity check? Share your road class, pole height, target lux/uniformity, and worst-month PSH assumptions.
Quote Comparison Pack
Use this pack to evaluate bids consistently and defend your award decision:
- PASS/FAIL gate checklist
- Comparison table template
- Clarification question list (to force missing assumptions)
- Warranty SLA & evidence checklist
Want a quick engineering sanity check?
Share your road class, pole height, target lux/uniformity, and worst-month PSH assumptions.
Next Steps (Keep Your Project Tender-Ready)
Ensure your solar street light project meets all procurement and engineering standards.
Templates & Evidence
- 📑 Buyer’s Guide Hub — Pick a scenario & follow evidence-first path.
- 📊 Resources Library — Specs, QC evidence, & IES workflows.
- 🔍 Spec Definitions Hub — Normalize Wavg, Wh, & IP/IK evidence.
- 💡 IES & DIALux Center — Spacing & uniformity validation.
- 🛡️ Quality Testing — Verified proof vs marketing claims.
- 📋 RFQ & BOQ Kit — Templates, clauses & scoring rubrics.
Shortlist a System Type
- 🚀 All-in-One Solar Street Lights
- 🌓 All-in-Two Solar Street Lights
- 🛠️ Split Type Solar Street Lights
- 📏 Solar Pole Lights
- ✨ Decorative Solar Street Lights
- ⚠️ Specific Solutions (Explosion-proof/Hybrid)
FAQ
Why do low-price bids fail after installation?
Because they rely on hidden assumptions: optimistic dimming/charging, no worst-month check, Ah-only batteries, or weak warranty obligations. The PASS/FAIL gates expose these issues before award.
What should I do if a bidder refuses IES or simulation?
Treat it as non-comparable. Without photometric evidence under your layout inputs, performance claims cannot be verified or fairly compared.
What is the fastest way to normalize energy assumptions?
Force a declared dimming profile and require a one-page energy budget sheet showing Wavg, runtime hours, and Wh/night, aligned with worst-month sizing.