8 Specifications Every Municipal Solar Lighting RFP Must Include

Picture this: your city issues an RFP for solar street lighting. Three vendors respond. The proposals are wildly different: different wattages, different battery types, different warranty terms, prices that range from $800 to $8,000 per unit. There's no clear way to compare them fairly.

You award to the lowest bidder. Eighteen months later, half the lights are dim or dark. The vendor is difficult to reach. The council is asking questions. And you're facing the very situation you were trying to avoid.

This scenario plays out in municipalities across the country every year; not because solar lighting doesn't work, but because the RFP didn't require the specifications that separate a 25-year commercial system from a product designed to survive just past its warranty expiration.

Writing a solar lighting RFP without the right technical specifications doesn't just risk a bad vendor selection. It creates comparison chaos, opens the city to bid protests from losing vendors, and can invalidate the entire procurement process if a grievance reveals the evaluation criteria were too vague to defend.

This guide exists to prevent all of that.

Below are the 8 specifications that every municipal solar lighting RFP must include, in plain English, with explanations of what each means, why it matters legally and technically, and exactly what happens when it's left out. At the end, we'll show you how SEPCO's cooperative purchasing contracts let eligible agencies skip the RFP process entirely while maintaining full procurement compliance.

Why Most Solar Lighting RFPs Fail Before the Bids Come In

The most common RFP failure in municipal lighting procurement follows a predictable pattern: the document specifies hardware categories without defining measurable performance thresholds. When evaluation criteria are vague, bidders struggle to understand how their proposals will be assessed, creating inconsistencies in responses that make it nearly impossible to compare bids effectively or defend an award decision.

Real-world experience confirms this. In Milwaukee's solar procurement program, "Milwaukee Shines," city staff initially wrote an RFP that was either too restrictive or too vague, producing bids that came in at double the budgeted cost, or proposals that couldn't be meaningfully evaluated against each other. The program ultimately had to rewrite their RFP to be outcome-based, specifying desired levels of system output rather than prescribed equipment requirements.

The lesson is not that RFPs are inherently flawed; it's that solar lighting RFPs require a specific set of technical performance thresholds that general procurement templates simply don't include.

A poorly written lighting RFP invites bids from hardware-only vendors who can't deliver the operational outcomes your city needs, drives procurement decisions based on the lowest upfront cost rather than total value, and leaves significant long-term savings benefits on the table. The most common failure pattern: specifying hardware rather than outcomes. When you treat lighting as a commodity purchase rather than as infrastructure with measurable financial returns, the lowest-cost hardware vendor wins, and the city gets exactly what it paid for.

The 8 specifications below fix that. Each one is a measurable, defensible threshold that gives you a clear basis for vendor comparison, protects the city from a bid protest, and ensures the system you purchase will still be performing 25 years from now.

SPECIFICATION #1: Site-Specific Solar Resource Analysis Using NREL Data

What to Require:

"Vendor shall provide a solar resource analysis for each installation location using National Renewable Energy Laboratory (NREL) National Solar Radiation Database (NSRDB) data. The analysis shall use December (worst-case month) peak sun hours for the project location and shall document the design insolation value used for system sizing."

What It Means:

This requires every vendor to prove their system was sized for your specific location's actual solar conditions, not a generic template, not summer averages, not a number that makes the proposal look favorable. December NREL data represents the minimum energy available for the entire year, making it the correct engineering baseline for an off-grid system that must operate reliably every night.

What Happens Without It:

Vendors can size systems using favorable assumptions; annual averages, best-case seasonal data, or standardized templates, producing systems that perform well in spring and summer but fail to charge fully through winter months. Without a documented NREL baseline, you have no defensible technical basis for rejecting a proposal on performance grounds.

Where to Access NREL Data:

The NREL National Solar Radiation Database (NSRDB) provides time-series data at 30-minute resolution for every location in the United States, updated annually through 2023. Access it at: nsrdb.nrel.gov and through NREL's solar resource mapping tools at nrel.gov/gis/solar.

SPECIFICATION #2: Battery Autonomy & Minimum Days of Independent Operation

What to Require:

"Battery storage shall provide a minimum of [3-5+] consecutive days of full design-load operation without solar recharge, depending on battery technology being used, under worst-case winter conditions at the installation location. Vendor shall provide the autonomy calculation as part of the proposal, documenting nightly energy demand, usable battery capacity, and depth of discharge assumptions."

Recommended Minimums by Climate Zone:

• Florida, Gulf Coast, Southwest: 3-5 days minimum
• Mid-Atlantic, Southeast, Midwest: 4-6 days minimum
• Pacific Northwest, Upper Midwest, Northern New England: 7+ days minimum

What It Means:

Autonomy days determine how long your lights stay on during an extended stretch of bad weather; the most-asked question in solar lighting procurement. Infrastructure guidelines published by the World Bank Framework for Street Lighting underscore that a 3-to-5-day autonomy minimum is mandatory to ensure uninterrupted public safety during extreme climate anomalies. Requiring the vendor to show their calculation, not just assert a number, prevents inflated autonomy claims that don't hold up in winter.

What Happens Without It:

If the designed battery capacity is too low, poles will drop below target illuminance before dawn, especially after several cloudy days. Without a documented autonomy requirement and supporting calculation, there is no basis for disqualifying an undersized system, and you may not discover the problem until the first prolonged overcast period after installation.

SPECIFICATION #3: Battery Chemistry, Cycle Life, and Temperature Range

What to Require:

"Vendor shall specify battery chemistry, rated cycle life at documented depth of discharge, and operating temperature range. Battery systems shall be rated for a minimum of [2,000] charge cycles at the specified depth of discharge. Operating temperature range shall be appropriate for [your location's climate record], and vendor shall provide temperature derating documentation for installations in climates where winter temperatures fall below 32°F (0°C)."

What It Means:

Not all batteries perform equally in outdoor temperature extremes, and battery chemistry is the single most impactful component-level decision in a solar lighting system's long-term reliability. Most modern commercial solar street lights use three main battery families; sealed lead-acid, lithium-ion, and LiFePO4, with LiFePO4 now leading new projects because it can deliver roughly 2–5× more cycles than gel packs and more stable output across real-world temperatures.

The practical differences are significant:

• Lead-acid: Cycle life is limited to 300–800 cycles at 50% depth of discharge, with an actual operational lifespan of only 3–5 years. SEPCO provides a system with 20% depth of discharge for an operational lifespan of 5-7 years.
• LiFePO4 (Lithium Iron Phosphate): 2,000–5,000+ cycles; 80–100% usable depth of discharge; stable performance across wide temperature ranges; 8–15 year service life. These batteries are typically used with systems that provide little to no autonomy to reduce costs.
• NiMH (Nickel-Metal Hydride): NiMH batteries can last more than 5,000 charge cycles, with a 90% depth of discharge; and compared to lead-acid, have a much deeper usable capacity daily. NiMH batteries are rated for extreme temperature ranges, making them well-suited for northern-climate applications.

What Happens Without It:

A vendor can win the bid with a system that short-changes the battery storage capacity, technically functional at the time of purchase, but requires full battery replacement sooner than expected. Without a specified minimum cycle life, you have no basis to reject that proposal, and the city will bear unexpected maintenance and replacement costs within the system's first operational phase.

SPECIFICATION #4: LED Fixture Performance: Lumens, Efficacy, Color Temperature, and IES Distribution

What to Require:

"LED fixture shall deliver a minimum of [specify lumens appropriate for application; see IES standards below] lumens of delivered light output, with a minimum luminous efficacy of 150 lumens per watt. Color temperature shall be between 3000K and 5000K for roadway and parking applications, or 2700K–4000K for parks and pedestrian areas or 3000K or less where DarkSky compliance is required. Vendor shall provide IES-format photometric test files and a photometric layout demonstrating compliance with applicable IES illumination standards for the project application."

IES Minimum Illumination Standards by Application (Reference):

• Local roadways: 0.6 fc average horizontal illuminance (IES RP-8)
• Collector roadways: 0.9 fc average (IES RP-8)
• Parking facilities: 0.5 fc average minimum (IES RP-20)
• Pedestrian pathways: 0.5 fc average (IES RP-22)
• Parks and recreation areas: 0.5–2.0 fc depending on activity type (IES RP-6)

What It Means:

Optical distribution type determines how light is patterned across the target area: Type II suits narrow roadways and walkways, Type III is standard for general street lighting, and Type IV and V is appropriate for area lighting like parking lots. Understanding these patterns is essential for specifying appropriate fixtures for specific applications. IES photometric files (.ies format) allow your engineering team to run a photometric layout in DIALux or AGi32 software, producing a visual map of light levels across your project area before a single pole is installed.

What Happens Without It:

Vendors can win a bid with a fixture that produces adequate total lumens but distributes them in a pattern that leaves dark spots, creates glare, or fails to meet IES standards for the specific application. A light that looks bright at the pole but fails 30 feet away is not a compliant lighting system, and without photometric documentation in the RFP, you have no contractual basis to reject it after installation.

SPECIFICATION #5: Ingress Protection (IP) Rating and Structural Certifications

What to Require:

"All luminaire components shall carry a minimum IP65 rating per IEC 60529. For coastal applications, flood-prone areas, or installations within 1 mile of salt water, a minimum IP66 rating shall be required. All luminaires shall meet IK08 or higher impact resistance rating. Pole and mounting hardware shall be rated for local wind load requirements per applicable building code [specify: Florida Building Code, ASCE 7-22, or local AHJ standard]."

What the IP Ratings Mean:

The IP (Ingress Protection) code is defined by international standard IEC 60529 and uses two digits to rate protection against solid particles and liquids:

• IP65: Dust-tight; protected against water jets from any direction. The global minimum for any outdoor solar lighting installation.
• IP66: Dust-tight; protected against powerful water jets. Required for coastal installations, high-rainfall areas, or fixtures subject to direct storm exposure.
• IP67: Dust-tight; protected against temporary immersion. Appropriate for low-level pathway lighting near drainage areas or flooding risk zones.

For coastal or high-spray environments, specify at least IP66 for luminaires and corrosion-resistant finishes; marine-grade aluminum or powder coat finishes with stainless steel hardware and fasteners. Include salt-spray (neutral salt spray) testing in procurement requirements for coastal exposure.

What Happens Without It:

IP65 is the global minimum for any outdoor solar street light; any supplier shipping IP54 or lower for outdoor use is cutting corners that will result in field failures. Without a specified IP rating in the RFP, vendors can submit fixtures with inadequate weatherproofing that will admit moisture, corrode internally, and fail within 2–3 years. In coastal or storm-prone municipalities, this is not a theoretical risk; it is a predictable outcome of under-specified procurement.

SPECIFICATION #6: Manufacturer Track Record and Municipal Reference Requirements

What to Require:

"Vendor shall demonstrate a minimum of [5] years of commercial solar lighting manufacturing experience. Vendor shall provide a minimum of [3] references from comparable municipal or government solar lighting installations completed within the last [5] years, including project owner contact information, number of fixtures installed, installation date, and geographic location. References shall be from installations in climates comparable to [your city/region]."

Why This Matters:

Your RFP should demand customer references and a track record of similar public projects. Bid evaluation should be based on cost, technical compliance, delivery schedule, and post-installation support, not cost alone.

The solar lighting market includes manufacturers with 30+ years of proven field installations, regional distributors with limited manufacturing experience, and import-and-resell operations with no engineering capability. From a proposal document, these can look identical. References from comparable public sector installations are the primary tool for distinguishing them.

What to Ask References:

1. Has the system operated as specified through winter months?
2. Have there been any warranty service requests, and how were they handled?
3. Did the vendor provide complete documentation for the project?
4. Would you work with this vendor again on a future project?

What Happens Without It:

A vendor with no municipal installation history, or with installations exclusively in warm-weather states applying to a northern-climate project, can submit an equally compliant proposal against a 30-year manufacturer. Without reference requirements, you have no procurement-defensible basis for giving weight to proven track record in the award decision.

SPECIFICATION #7: Buy American and BABA Compliance Documentation

What to Require:

"For projects utilizing federal grant funding (including but not limited to SS4A, FEMA BRIC, CDBG, EECBG, or other federal financial assistance), vendor shall provide Build America, Buy America Act (BABA) compliance documentation for all iron, steel, manufactured products, and construction materials. Vendor shall provide a written self-attestation of domestic content compliance consistent with U.S. Department of Energy BABA attestation requirements. For direct federal procurement projects (military, federal facilities, national parks), vendor shall provide Buy American Act (BAA) compliance documentation demonstrating that the end product is manufactured in the U.S. with greater than 65% domestic content by cost."

Understanding BAA vs. BABA – They Are Not the Same:

The Buy American Act (BAA) applies to direct federal procurement; when a federal agency buys a product with appropriated funds. The Build America, Buy America Act (BABA) applies to federal financial assistance recipients; grants, loans, and cooperative agreements used for infrastructure projects by non-federal entities. Both require domestically produced materials, but BABA reaches a broader set of project types. A city receiving a federal transit grant for a lighting upgrade project, for example, must source BABA-compliant materials, even though the city itself is not a federal agency.

BABA is now tied to federally funded money for most projects utilizing materials for various USA infrastructure; steel, solar, and yes, lighting. In most cases, without BABA-approved products, the funding from Washington, D.C., will not flow to states and local municipalities.

What Happens Without It:

A city that receives a federal grant, awards a solar lighting contract to a foreign manufacturer without BABA documentation, and begins purchasing product may be required to return the grant funding or halt the project mid-execution when the compliance gap is discovered. BABA compliance is not a nice-to-have for federally funded projects; it is a legal prerequisite for drawing down grant funds.

Note on SEPCO: SEPCO is a Made-in-America manufacturer that provides BAA and BABA compliance documentation as a standard deliverable for all projects involving federal funding. This documentation is available immediately upon request as part of the project consultation process.

SPECIFICATION #8: Post-Installation Documentation and Maintenance Plan

What to Require:

"Vendor shall provide the following documentation upon project completion: as-built drawings, locations for each installed fixture, photometric verification report documenting achieved light levels, battery commissioning data, and a written maintenance schedule for the first 5 years of operation. Vendor shall specify the expected maintenance intervals, what each maintenance activity entails, and the expected replacement schedule for battery systems over the system's designed operational life."

What It Means:

One of the most common procurement failures is including no requirements for system operations and maintenance (O&M) in the RFP, incorrectly assuming that city staff will assume these responsibilities. Commercial solar lighting systems designed for a 25-year life with a 5-year maintenance schedule have very specific, predictable maintenance requirements. Requiring the vendor to document those requirements at the time of procurement establishes contractual accountability for long-term performance, and protects the city from inheriting an undocumented maintenance burden.

What the Maintenance Schedule Should Include:

• Battery system inspection interval and replacement timeline
• Panel cleaning schedule (especially in high-particulate or salt-air environments)
• Photocell and controller inspection schedule
• Structural inspection requirements for poles and foundations
• Firmware update protocol for any smart/IoT-enabled components

What Happens Without It:

The city receives a system with no documentation of what maintenance is needed, when, or at what cost. The vendor's obligation ends at installation. When the battery begins degrading in Year 4 or the controller fails in Year 6, there is no contractual baseline to determine whether this represents a failure of the vendor's responsibility or expected end-of-life behavior.

The Fastest Alternative to Writing an RFP: Cooperative Purchasing

Writing a technically sound solar lighting RFP; with all 8 specifications above; takes significant time, engineering expertise, and procurement staff capacity. For many municipalities, particularly smaller cities and counties, that capacity doesn't exist in-house.

There is a faster, legally compliant path: cooperative purchasing contracts.

By leveraging pre-competed, legally compliant cooperative contracts, your organization can bypass time-consuming RFPs, bid evaluations, and lengthy negotiations, shortening project timelines from months to weeks.

Cooperative contracts have already undergone competitive solicitation processes that meet or exceed most public procurement requirements. These contracts are specifically designed to satisfy legal procurement standards, enabling your organization to leverage pre-negotiated pricing without conducting individual RFPs, which can take 6–12 months.

SEPCO holds active cooperative purchasing contracts through over six national programs:

Using a cooperative contract does not mean skipping competitive procurement. HGACBuy awards contracts after either a competitive bid (IFB) or competitive proposal (RFP) process compliant with state statutes. When a city purchases SEPCO systems through HGACBuy, BuyBoard, or any of SEPCO's other cooperative contracts, that purchase satisfies competitive procurement requirements, including the requirements of SS4A, FEMA BRIC, CDBG, and other federal grant programs that mandate competitive purchasing.

This means: you can apply for a federal grant, receive the funding, and purchase SEPCO systems through a cooperative contract, without writing a separate RFP, running a bid period, or evaluating competitive proposals. The cooperative contract is your competitive procurement documentation.

Your Complete RFP Specification Checklist – At a Glance

Print this checklist before your next solar lighting procurement. If any box cannot be checked, the corresponding specification is missing from your RFP:

Specification 1 - Solar Resource Analysis

• Vendor required to use NREL NSRDB December data for the specific project location
• Design insolation value documented in the proposal

Specification 2 - Battery Autonomy

• Minimum autonomy days specified (3 / 5 / 7 based on climate zone)
• Autonomy calculation required as part of proposal documentation

Specification 3 - Battery Chemistry and Cycle Life

• Battery chemistry specified or minimum cycle life required
• Operating temperature range documented and appropriate for local climate

Specification 4 - LED Performance and Photometrics

• Minimum lumen output or foot-candle level specified per IES standards
• IES photometric files (.ies format) required
• Photometric layout demonstrating compliance required

Specification 5 - IP Rating and Structural Certifications

• Minimum IP65 (IP66 for coastal/storm-prone) required for luminaire
• Wind load compliance with local building code required
• Salt-spray testing required for coastal installations

Specification 6 - Manufacturer Track Record

• Minimum years of manufacturing experience required
• Minimum number of municipal references required
• References in comparable climate required

Specification 7 - BABA/BAA Compliance

• Required for all federally grant-funded project components
• Written self-attestation required per DOE BABA template
• BAA compliance documentation required for direct federal projects

Specification 8 - Post-Installation Documentation and Maintenance

• As-built documentation package required
• Photometric verification report required
• Written 5-year maintenance schedule required

How SEPCO Responds to Every Specification By Default

Every item in the checklist above is addressed in SEPCO's standard project documentation. When you engage SEPCO, whether through a competitive RFP, a cooperative purchasing contract, or a direct project consultation, you receive:

Engineering Documentation:

• Site-specific NREL solar resource analysis for your project location
• Complete autonomy calculations for your climate zone
• Photometric layout with IES files demonstrating compliance with applicable standards

Product Certifications:

• LM-79 and LM-80 tested LED fixtures
• Wind load calculations for your location's building code requirements

Compliance Documentation:

• Made-in-America manufacturing certification
• BABA/BAA compliance documentation for federally funded projects
• Cooperative purchasing contract references for grant-compliant procurement

Warranty and Maintenance:

• 25-year system design life documentation
• 5-year maintenance schedule with specific maintenance activities and intervals

This documentation package is not an upsell. It is the standard deliverable for every SEPCO project; because we believe the city deserves to know exactly what they're getting before they commit, and exactly how to maintain it for the life of the system.