The Solar Installer Checklist: 10 Questions to Ask Before You Pay a Kobo

You have done your research. You know what you want. You have saved the money.

Now comes the hardest part: finding someone who will install it correctly.

The solar industry in Nigeria is flooded with self-taught electricians who watched a few YouTube videos and decided they were engineers. They will underbid the professionals, cut every corner possible, and disappear when something goes wrong.

Do not let price be your only guide.

A bad installation is worse than no installation. It can destroy expensive batteries, start electrical fires, and leave you stranded without power while you chase a ghost who has blocked your number.

Ask these ten questions before you pay a single kobo.

1. "Can I speak to three previous customers?"

Professional installers have happy customers. Amateurs have excuses.

"People don't like to be disturbed." Red flag.

"I just started my business." Proceed with caution.

"Here are their numbers, feel free to call." Green light.

Any reputable installer should have at least three recent projects they can refer you to. Call those customers. Ask if the installer showed up on time. Ask if the system still works perfectly. Ask if they would hire them again.

If the installer cannot produce references, walk away.

2. "What happens if something breaks next month?"

Solar equipment fails sometimes. Panels can be defective. Batteries can underperform. Inverters can develop faults.

The question is not whether failures can happen. The question is who takes responsibility when they do.

A professional installer offers a clear warranty:

Minimum 1 year on installation labour

5 years on inverter

2 years on batteries (or manufacturer's warranty, whichever is longer)

10 to 25 years on solar panels

Get the warranty in writing before installation begins. Verbal promises are worthless when the installer stops answering your calls.

3. "Are you certified by any manufacturer?"

The best installers have formal training from the brands they sell.

Victron certified. Sunsynk approved. Growatt trained. These certifications mean the installer has attended factory training, passed exams, and demonstrated competence.

Uncertified installers can still be excellent. Many old-school electricians learned through years of experience and are exceptionally skilled. But certification provides an extra layer of accountability. If a certified installer messes up, you can report them to the manufacturer and threaten their certification status.

That leverage matters.

4. "Show me your cable management on a recent job"

This sounds like a small thing. It is not.

Look at how an installer routes cables. Are they bundled neatly with cable ties? Are positive and negative cables clearly distinguished by colour? Are cables protected from sharp edges and heat sources? Is everything labelled?

Sloppy cable management reveals sloppy thinking. An installer who cannot be bothered to make wires look neat will cut corners on more important things like fuse sizing and torque specifications.

Ask for photos of recent installations. If everything looks like a rat's nest, find someone else.

5. "What size DC cable do you use for battery connections?"

This is a technical question that exposes amateurs immediately.

Between your batteries and inverter, the DC cable must be thick enough to handle the maximum current without overheating.

Here is the correct answer for a typical 3KVA to 5KVA system: "We use 25mm² or 35mm² copper cable depending on the distance."

Here is a wrong answer: "The same cable we use for house wiring."

House wiring handles 5 to 15 amps. Battery cables can carry 100 to 200 amps. Putting thin cable on a battery system is a fire waiting to happen.

Ask this question. Watch their face. You will learn everything you need to know.

6. "Do you perform load testing before commissioning?"

Any installer can connect wires and turn on an inverter. Professional installers prove the system works before they leave.

Load testing means:

Running all connected appliances simultaneously

Measuring actual power draw against design specifications

Verifying battery capacity under realistic load

Checking inverter response to sudden load changes

Amateurs skip this because it takes time. They declare the system "working" because the lights turn on. Then you discover the inverter trips every time the freezer compressor kicks in.

Do not accept delivery until you have seen a load test.

7. "Where do you mount the charge controller?"

This sounds like a trick question. It is.

The answer should never be "inside the battery compartment" or "directly above the batteries."

Charge controllers generate heat. Batteries, especially lead-acid, can emit corrosive gases when charging. Putting a heat-generating electronic device directly above a gas-emitting, heat-sensitive battery bank is poor design.

The correct answer: "We mount charge controllers in a ventilated space separate from the batteries, preferably on a fire-resistant backboard."

If your installer does not understand why battery placement matters, they do not understand thermal management. Find someone who does.

8. "What is your policy on roof penetrations?"

Solar panels need to be mounted on your roof. Mounting requires drilling holes. Drilling holes requires waterproofing those holes properly.

Any installer who says "We don't waterproof, that's the roofer's job" should be escorted off your property immediately.

Professional installers use proper flashing kits, sealant, and techniques that prevent leaks for the life of the installation. They guarantee their roof work in writing.

Ask to see how they sealed previous installations. If they cannot explain their waterproofing method clearly, they have not thought about it. That is a problem.

9. "Will you provide as-built drawings after installation?"

Most residential solar systems are small enough that detailed engineering drawings seem excessive.

But you should still receive a simple diagram showing:

Panel configuration (series vs parallel)

Cable routing and lengths

Fuse and breaker locations and ratings

Battery bank wiring diagram

This document becomes invaluable if you need to troubleshoot issues later or expand the system. Without it, every future electrician will waste hours tracing your cables and guessing your configuration.

Professional installers provide documentation. Amateurs disappear with the knowledge in their heads.

10. "What ongoing support do you offer?"

Solar systems are not appliances. They need occasional monitoring, software updates, and periodic maintenance.

Ask specifically:

Do you offer remote monitoring access?

Who do I call on a Sunday evening when the inverter shows an error code?

Do you stock spare parts for the equipment you sell?

What is your typical response time for service calls?

The right answers vary depending on your budget and expectations. But the wrong answer is always the same: "You will not need support, our systems never fail."

Everything fails eventually. The question is whether someone will be there to help when it does.

The One Question You Should Actually Ask Yourself

After you ask all ten questions, after you compare quotes, after you check references, ask yourself one final question:

Does this person seem to care about the quality of their work?

A skilled but arrogant installer who rushes through jobs will leave you with technically correct but user-hostile systems. A less skilled but meticulous installer who takes pride in their craft will build something that serves you well for years.

Given the choice between the two, hire the careful one. Skill can be learned. Attention to detail is a personality trait.

Your solar system will outlast your installer's business card. Choose someone who builds things that last.