Sunna Design Outdoor Lighting Specification Guide: 7-Step Checklist for Solar Flood Light Sourcing

When I took over procurement for a facility management company in 2020, I inherited a spreadsheet of lighting vendors and a budget that demanded savings. Four years later—after processing roughly 60-80 lighting orders annually and managing 8 vendor relationships—I can tell you this: most outdoor lighting specification problems aren't technical problems. They're process problems.

This guide is for B2B buyers, distributors, and contractors sourcing solar flood lights, area lights, wall lights, or street lighting systems. Seven steps. Do them in order. Each step has a checkpoint, so you know exactly when you're done.

Step 1: Map the site before you open any spec sheet

Most spec mistakes start before product selection. If you skip the site assessment, every later decision rests on bad assumptions.

• Measure the actual area to be lit—not just the lot dimensions, but the surface that actually needs coverage.
• Confirm mounting heights and pole spacing. Even a 2-meter difference changes photometric outcomes dramatically.
• Note surface reflectance. Asphalt absorbs light. Concrete bounces it. Gravel scatters it. Your lux targets depend on this.

We approved a layout in 2022 based on the manufacturer's "standard assumption" of 8-meter mounting heights. Our poles were 6 meters. The spacing was too wide for the lower mounting height, leaving dark zones between fixtures. Re-purchase. Re-install. Three weeks lost.

Checkpoint: You have dimensional drawings and written notes for mounting heights, pole locations, and surface types.

Step 2: Verify solar resource at the fixture level, not the region level

This is the step everyone skips. Published solar radiation maps are regional averages (meaning: they smooth over local conditions). Your site may have a tree line, an adjacent building, or a utility pole casting shade.

Everything I'd read about solar lighting said, "If the sun map says your region is fine, you're fine." In practice, I found that one shade obstruction can cut a fixture's effective solar harvest by 30-40%. Conventional wisdom ignores real-world obstacles.

Walk the site. Check:

• South-facing exposure (northern hemisphere applications)
• Shade patterns during winter solstice—the worst-case solar day of the year
• Seasonal sun-hour variation, not just annual averages
• Future obstructions: planned construction, tree growth, adjacent developments

Checkpoint: You've documented shade obstacles at winter solstice and know your site's minimum monthly sun hours.

Step 3: Demand photometric data, not wattage

Wattage tells you almost nothing about whether a fixture will light your space. Luminous flux (lumens), beam angle, and lux distribution charts do.

A credible solar flood light manufacturer or wall light OEM should provide:

• Photometric test files (IES or LDT format)
• Lux distribution charts at your specific mounting height—not just at their default
• Beam spread options: narrow, wide, symmetric, or asymmetric
• Color temperature options (typically 3000K, 4000K, 5000K) and their rendering trade-offs

Here's the thing: comparing two fixtures by wattage alone is like comparing two delivery vehicles by engine size alone while ignoring cargo capacity, fuel efficiency, and turning radius. Wattage answers the least interesting question.

Checkpoint: You have IES files or lux charts for every proposed fixture, evaluated at your mounting height.

Step 4: Verify certifications and documentation before you commit

This is where procurement pain hides. In 2023, we ordered 60 wall lights from a new supplier because the unit price was 18% below our incumbent vendor's. The fixtures worked fine. But the vendor couldn't produce proper certification documentation, and our compliance team rejected the batch. I ate $1,300 from the department budget.

Request upfront, in writing:

• UL, DLC, or equivalent certification documents
• IP rating verification (IP65 is common for outdoor fixtures, but confirm for your environment—coastal salt spray is different from desert dust)
• IES file availability for spec submissions
• Warranty terms in writing: what's covered, what's excluded, who handles claims
• Invoicing and documentation capability—this sounds basic, but it's the exact thing that cost me $2,400 in rejected expenses one year

Checkpoint: You have certification documents in hand. Promised doesn't count.

Step 5: Compare total cost of ownership, not unit price

My honest view: in my experience, the lowest quote has cost us more in roughly 60% of projects. Solar lighting changes the cost equation in ways that unit price comparison completely misses.

Here's what belongs in the calculation:

• Fixture cost (unit price × quantity)
• Shipping, customs, and handling fees
• Installation cost—solar fixtures avoid trenching, conduit, and electrical runs, which is often the largest hidden savings
• Battery replacement cycle and cost over the fixture's lifespan
• Maintenance labor: group replacement is cheap; spot replacement is expensive
• Energy savings, year after year, over the service life

We compared a budget solar flood light at $410 per unit against a mid-tier option at $520. The numbers said budget—21% cheaper, similar lumen output. My gut said the spec differences mattered more than the price gap. Went with budget. The battery failed in year three; the mid-tier fixture we'd tested was still holding charge in year five. The $110 per unit savings turned into $260 per unit replacement cost, plus labor. Looking back, I should have done the TCO math properly instead of the unit price comparison.

Checkpoint: You have a written TCO comparison across at least two suppliers, including installation and maintenance—not just fixture price.

Step 6: Evaluate the manufacturer's B2B capabilities

For distributors, dealers, and project buyers, the manufacturer's ability to support your business model matters as much as the product spec. This is where you evaluate the flood light manufacturer or wall light OEM as a business partner, not just a product source.

Ask about:

• OEM/private label support—can they produce under your brand? What are their MOQ requirements?
• Product customization: wattage variants, optics, mounting hardware, color temperature, custom logo placement
• Documentation quality: datasheets, installation guides, compliance files, test reports
• After-sales support: how are warranty claims processed? Who pays return shipping? Typical response time?
• Reference customers you can actually call

Manufacturers like Sunna Design, which focus on solar outdoor lighting and offer OEM/private label programs, typically have these processes in place. But don't take any supplier's word for it—ask for documentation and verify the process yourself.

Checkpoint: You've spoken with at least two current B2B customers and verified OEM and documentation processes.

Step 7: Insist on references and a pilot install

References are only useful if you verify them. Call the contact. Ask:

• Did actual lead times match the quoted lead times?
• What was the defect rate on arrival?
• How did the manufacturer handle warranty claims?
• How does the fixture perform in their climate, not the brochure climate?

If budget allows, install pilot fixtures. In 2021, we spent $800 on pilot units for a parking lot project. That $800 saved us roughly $14,000 when the pilots revealed a beam angle mismatch that would have affected all 40 fixtures.

Checkpoint: References verified, and pilot fixtures (where feasible) running for at least 30 days.

Common mistakes and red flags

Here are the mistakes I see buyers repeat:

• Ignoring IP ratings for the actual environment. Coastal salt spray, industrial dust, and heavy UV exposure kill fixtures not rated for them. IP65 is not a universal answer.
• Treating solar as "free energy, zero maintenance." Batteries degrade. Panels collect dirt. Real maintenance exists and has a cost.
• Assuming "solar" means "install anywhere." Orientation, tilt, and shade matter. A good fixture can't compensate for a bad location.
• Buying on lumen output without checking lux on the ground. Lumen output describes the fixture; lux describes what the surface receives. Only the latter matters to your client.
• Accepting verbal warranty terms. We had a supplier promise a "5-year warranty," but when batteries failed in year four, their written policy covered only the panel. Get it in writing.

That's the checklist. It's not glamorous, and most of it is boring verification work. But every step exists because I've either made the mistake myself or watched a colleague make it. Seven steps take about two weeks to complete properly. The mistakes take years to cost you.