How Can I Compare Two Solar Installation Quotes in Nigeria?

Last reviewed: September 25, 2026

Do not compare two solar installation quotes by the final naira total alone. First make the quotes comparable: the same backup appliances, similar battery energy, similar solar-panel capacity, the same inverter output, proper protection, clear installation work and a written warranty. Only after that should you decide which quote offers better value.

A quote that is cheaper may simply contain less battery, fewer panels, weaker protection, shorter cable runs, less installation work or no after-sales support. A more expensive quote may be justified if it includes a larger usable battery, better equipment, difficult roof work, longer cable routes or proper commissioning. The method below helps you compare the real system rather than two attractive totals.

1. Start with the same job, not the same inverter size

Before comparing installers, write down what you actually want the system to do. For example:

Keep lights, fans, television, decoder, router and a refrigerator running during outages.
Run a POS shop, salon or office for a defined number of hours.
Reduce generator use but leave heavy appliances on public power.
Power a larger part of the house, including pumps or air conditioners.

Two installers can both write “5kVA solar system” while offering very different systems. One may quote a 5kVA inverter with a small lithium battery and a few panels. Another may quote the same inverter rating with twice the battery storage, more panels and a larger protection board. Those are not equivalent offers.

Write down four items before requesting or comparing quotes:

The appliances that must run together.
The appliances that can remain on grid or generator.
How many hours of backup you want.
Whether you want occasional backup or solar energy every day.

If you are still unsure what size your loads require, use SolarPriceNG’s guide on how much solar power a house may need in Nigeria before judging the equipment in a quotation.

2. Put both quotes into the same comparison table

A Nigerian homeowner comparing two solar installation quotations line by line — Compare the equipment, protection and installation scope line by line before comparing the final price.

Ask each installer to identify the make, model, quantity, rating and included work. Do not accept vague descriptions such as “premium panel”, “strong battery”, “complete protection” or “5kVA package” without the details.

Line item	Quote A	Quote B	What to compare
Inverter	Brand, model, output	Brand, model, output	Continuous output, surge rating, battery voltage, PV input and warranty
Battery	Chemistry, voltage, kWh or Ah	Chemistry, voltage, kWh or Ah	Usable energy, quantity, BMS features and expected operating limits
Solar panels	Quantity × watts	Quantity × watts	Total array watts, panel model, roof layout and shading
Protection	Devices and ratings	Devices and ratings	DC/AC breakers, fuses, isolators, surge protection and earthing
Mounting and cables	Included or excluded	Included or excluded	Structure, cable sizes, cable length and weatherproofing
Installation	Labour scope	Labour scope	Roof work, changeover, distribution board, testing and commissioning
Support	Warranty and response	Warranty and response	Who handles faults and what the warranty excludes

Use the total price only after every important row has a clear answer. A blank row is not automatically included just because the installer says the quote is “turnkey”.

3. Compare battery capacity correctly

The battery often creates the biggest difference between two apparently similar quotes. Compare energy and usable backup, not only the number of batteries.

For a lithium battery, use the verified kWh rating as the main comparison. For tubular, GEL, AGM and other lead-acid batteries, compare the voltage and Ah together. For example, “two 12V 200Ah batteries” does not tell you the same thing as “one 5kWh lithium battery”, and Ah alone cannot be used to rank different battery chemistries.

For a simple estimate, nominal battery energy is:

Voltage × Ah ÷ 1,000 = nominal kWh

But the energy available to your appliances is lower after allowing for the battery’s recommended depth of discharge and inverter losses. A quote should state, or at least allow you to calculate, the practical usable energy.

Example: Suppose Quote A offers a 5kWh lithium battery and Quote B offers 10kWh. If the two quotes are for the same appliances, Quote B may provide more backup, but it will normally cost more. If Quote A promises the same runtime without explaining the assumption, ask the installer to show the load and runtime calculation.

Also check whether the quoted battery can deliver the required power. A battery may have enough stored energy but still be unsuitable if its continuous discharge limit is too low for the inverter and the appliances.

For a deeper check, read SolarPriceNG’s guide on checking the battery capacity on a solar quote.

4. Compare the solar panels by total watts and system limits

Do not compare panels by quantity alone. Six 450W panels provide a different array from six 600W panels. Calculate the total panel capacity:

Number of panels × panel wattage = total array watts

Then check whether the proposed inverter or charge controller can safely accept that array. The important limits include maximum PV power, maximum PV voltage, MPPT operating range and maximum input current. The installer should also explain how the panels will be arranged in series and parallel.

A larger panel array can help recharge the battery faster after a long outage, but the result depends on sunlight, roof direction, shading, dust, heat, rain and the equipment’s input limits. In Nigeria, Harmattan dust and heavy rain can change daily production, so a quote that promises the same output in every season deserves questions.

Ask both installers:

What is the total panel wattage?
What panel model is being supplied?
How many strings will be used?
What are the expected voltage and current at the inverter?
What happens if one roof section is shaded?
Is the mounting structure included?

5. Check whether the inverter ratings are genuinely comparable

“5kVA” is not enough information. Ask for the inverter model and check its continuous real-power output, battery voltage, surge capability, solar input limits, charging current and warranty.

Two inverters with the same headline kVA rating may have different limits. One may be more suitable for a refrigerator, freezer or pump because of its surge performance. Another may accept more solar panels but require a different battery voltage. The quoted system should match both your running load and the starting demand of motor-driven appliances.

Ask the installer to separate:

Running load: the power appliances use during normal operation.
Starting or surge load: the short burst needed by compressors, pumps and some motors.
Backed-up load: the appliances connected to the inverter output.
Non-backed-up load: appliances deliberately left on grid or generator supply.

A quote that claims the system will run every appliance in the house should show how the installer will prevent overload. A sensible design may place air conditioners, electric irons, kettles, water heaters or pumping equipment on a separate circuit.

6. Compare protection, earthing and wiring—not just the main equipment

Protection equipment is easy to hide in a cheap quote because it may represent a smaller line item than the inverter or battery. It is still essential. Ask for an itemised list of the proposed DC and AC protection, including the ratings and locations.

Depending on the design, the quote may need to address:

DC isolators and appropriately rated fuses or breakers.
AC breakers and a suitable changeover or bypass arrangement.
Surge protection on the relevant DC and AC sides.
Battery isolation and correctly sized battery cables.
Earthing and bonding of the equipment and mounting structure.
Labels, enclosures and protection from accidental contact.
Safe cable routing and weatherproof connections on the roof.

Do not accept a proposal to remove protection devices to reduce the price, and do not choose cable sizes by appearance. The correct design depends on current, voltage, cable length, installation method and equipment instructions. Electrical installation work should be handled by a qualified professional.

For larger or more formal projects, you can also ask how the installer handles inspection and certification. NEMSA’s published mandate covers technical inspection, testing and certification of electrical installations, and its solar inspection guidance stresses correct design, specification, installation, inspection and certification. See the NEMSA website for official information and contractor or inspection services.

7. Separate equipment cost from installation scope

One installer may include only labour while another includes mounting, long cable runs, a new distribution board, changeover wiring, wall drilling, transport and commissioning. Comparing their totals without separating these items can make the wrong quote look cheaper.

Ask whether the price includes:

Delivery and movement of equipment to your location.
Roof access, mounting rails or a ground structure.
Extra cable length between the roof, inverter and battery.
Wall drilling, trunking, conduits and cable protection.
Changeover installation and connection to selected circuits.
Distribution-board modifications.
Earthing work and surge protection.
Testing, commissioning, user training and handover documents.
Removal of old batteries, inverter or generator wiring, if required.

SolarPriceNG’s installation services price section separates installation-related services from equipment prices. It is useful for planning, but the final labour amount still depends on system size, location and the actual work at the property.

8. Compare warranties and after-sales support in writing

A warranty is not useful if nobody can explain who will honour it. Compare the warranty period for the inverter, battery and panels separately. Then ask what is excluded, who pays transport, how faults are diagnosed and how quickly the installer normally responds.

Clarify whether the installer or the manufacturer handles each claim. Also ask what happens if the installer stops trading or if the equipment is supplied through a different distributor. Keep the invoice, serial numbers, manuals, commissioning report and warranty terms.

Be careful with promises such as “lifetime support” or “the battery will last ten years”. Battery life depends on chemistry, temperature, charge and discharge settings, cycling, installation quality and usage. Ask what the promise means in measurable terms.

9. A worked comparison example

Imagine you receive these two offers for a home that wants to run lights, fans, a television, router and refrigerator:

Quote A: 5kVA inverter, 5kWh lithium battery, 3.3kW of panels, basic installation and a short warranty.
Quote B: 5kVA inverter, 10kWh lithium battery, 4.4kW of panels, full protection board, longer cable runs, commissioning and a clearer warranty.

Quote B may be more expensive, but it is not automatically overpriced. It contains twice the stated battery energy and more solar capacity, so it may provide longer backup and faster recovery after an outage. The correct question is whether your appliances need that extra capacity and whether the battery and panels are genuine, compatible and properly installed.

Now imagine Quote C costs more than both but uses the same battery and panel capacity as Quote A. Its extra price could still be justified by a difficult roof, a long cable route, a new distribution board or better protection. Ask for those differences to be itemised rather than guessing.

10. Warning signs in a solar quotation

Pause before paying if the quote:

Names no inverter or battery model.
Uses “5kVA system” without listing battery energy and panel watts.
Promises to run heavy appliances without a load or surge check.
Lists “complete installation” but does not describe the work.
Has no protection, earthing or cable information.
Pressures you to pay immediately because the price is “today only”.
Cannot explain who will provide warranty support.
Refuses to show serial numbers, manuals or evidence of the equipment supplied.

A low price is not proof of fraud, and a high price is not proof of quality. The missing information is what matters.

Final checklist before choosing

Before accepting either quote, confirm that both proposals clearly state:

Your backed-up appliances and expected usage.
Inverter brand, model, continuous output and surge rating.
Battery chemistry, voltage, quantity, capacity and usable-energy assumption.
Panel brand or model, quantity and total wattage.
PV voltage/current arrangement and inverter input limits.
Protection, earthing, cable sizes and mounting method.
Exactly which circuits will be connected to the backup output.
Installation, testing, commissioning and handover scope.
Warranty terms, exclusions and after-sales contact.
Total price, payment stages and what can change the final amount.

If one installer will not provide these details, you are not comparing two complete quotations yet. Ask for a revised, itemised quote or obtain another proposal. And before accepting the work, use SolarPriceNG’s guide on what an installer should test before handover.

Conclusion

The best solar quote is not necessarily the cheapest or the one with the biggest inverter. It is the quote that matches your actual loads and backup target, states the equipment clearly, includes safe protection and installation work, and gives you realistic warranty support.

Make the two offers comparable line by line. Compare usable battery energy, total panel watts, inverter limits, protection, cable and mounting work, commissioning and after-sales support. Once those items are equal, the price difference becomes much easier to understand—and you are less likely to pay for a system that cannot deliver what you were promised.