Solar quotations are unusually hard to compare, because what is being sold is a system rather than a product. Two documents can quote five kilowatts of solar with a battery at similar prices and describe installations that will not behave the same way in year one, let alone year ten.
The checks below are ordered by how much they reveal. The first four eliminate most of the difference on their own.
1. Are the exact models named?
Not high-efficiency panels, not lithium battery. A model designation for every panel, inverter and battery. A supplier unwilling to commit to a model in writing has reserved the right to substitute, and the substitution will not be upwards.
2. Is a datasheet attached for every component?
One per model, and a datasheet rather than a brochure. It is where power output, efficiency, temperature coefficients, operating limits, degradation terms and certification actually live. Everything else in the quotation is a summary of it.
3. Do the quoted figures match the datasheets?
Read both. Where a headline claim and a datasheet disagree, the datasheet is the document that will be referred to in a warranty conversation. This check alone is worth the twenty minutes.
4. Is the system size explained, or just stated?
You should be able to follow the reasoning: your consumption, your roof area, your shading, your backup requirement, and how those produce the specified number of panels and the chosen inverter rating. A size with no derivation is a guess, however confident the document sounds.
5. What do the conformity marks actually cover?
CE and UKCA are declarations that a product meets the applicable requirements for its market. They attach to specific products rather than to companies, so the useful question is which of the quoted components carry which marks, and whether the supporting documentation is available on request.
6. Who honours the warranty, and from where?
This is the check that matters most for imported equipment and the one buyers most often skip. A warranty is only as useful as the party standing behind it locally. Ask who you contact if a component fails in year four, whether that party has a registered presence in Ethiopia, whether spare parts are held in country or ordered in, and what the realistic timeline looks like. A generous warranty administered from another continent is worth less than a shorter one serviced from Addis.
7. What is the warranty on each component, separately?
Panels, inverter and battery are three different warranties with three different durations and three different exclusion lists. A single line reading "25 year warranty" on a system quotation is describing one component and implying three.
8. Is the performance warranty stated as a curve?
A meaningful panel performance warranty specifies first-year degradation, annual degradation thereafter, and a guaranteed percentage at the end of term. Written properly it reads something like: no more than 1% reduction in year one, no more than 0.35% annually from years 2 to 30, and at least 88.85% remaining at year 30.
9. Which circuits are on backup?
If the system includes a battery, the quotation should list the circuits that stay live during an outage. "Backup included" is not a specification, and the gap between what a customer assumed and what was actually wired is the most common complaint in residential storage.
10. Is the battery on the inverter's approved compatibility list?
Compatibility depends on battery voltage, BMS communication and system design. It is a documented relationship, not something to be inferred from both items appearing on the same page.
11. What happens after commissioning?
Who maintains the system, at what frequency, with what response target, and is the first year included or sold separately? A quotation that ends at switch-on has described half the ownership. Establish the service area too, particularly outside the main towns.
12. Is there one accountable party?
Where design, supply, installation and maintenance sit with different companies, a fault becomes a conversation between them before it becomes a repair for you. Ask, in writing, who owns the outcome.
Three warning signs
A savings figure produced before anyone visited the property was produced by a spreadsheet with your address in it. Generation depends on your roof, orientation, shading and consumption, none of which can be known from a phone call.
Pressure on the price expiring is the second. Equipment pricing moves slowly, and urgency in a solar quotation is a sales technique rather than a market condition.
The third is reluctance to send datasheets. They exist for every certified product, and the only reason to withhold one is that it does not support the claims in the quotation.
Common questions
What should be in a solar quotation?
Exact model numbers for every panel, inverter and battery, a datasheet for each, the derivation of the system size, separate warranty terms per component, the backup circuit list if storage is included, maintenance arrangements including service area, and a clear exclusions list.
What do CE and UKCA marks mean on solar equipment?
They are declarations that a specific product meets the applicable requirements for its market. They apply to products rather than companies, so ask which quoted components carry which marks and whether supporting documentation is available.
How do I know the warranty will be honoured locally?
Ask who you contact if a component fails in year four, whether that party has a registered presence in Ethiopia, whether spare parts are held in country, and what the realistic replacement timeline is. Get the answer in writing alongside the warranty duration.
How do I compare two solar quotes that cost the same?
Compare the datasheets rather than the totals. Panel efficiency and temperature coefficient, inverter type and backup capability, battery chemistry and capacity, and the three separate warranty terms will usually explain the whole difference.
Should a quote include savings estimates?
Only after a site survey. Generation and savings depend on roof orientation, pitch, shading and your consumption pattern. Any figure produced before those are measured is an assumption presented as a result.
