How to Compare Solar Quotes Like a Pro

Step one: normalise before you compare

You cannot compare two quotes until they describe the same thing. Before anything else, line up the fundamentals so you are comparing like-for-like.

Match the system size

Look at three numbers on each quote: inverter size (in kW), battery capacity (in kWh) and panel count. A quote with a 3.6kW inverter and a 3.6kWh battery is a different product from one with a 5kW inverter and a 5.3kWh battery, and it should cost less. Being cheaper is not a virtue if the system is simply smaller. If the two differ, you're not comparing prices, you're comparing sizes, and the headline gap tells you nothing until you adjust for it.

Match the payment model

A subscription, a rent-to-own and an outright purchase produce wildly different-looking numbers for the same hardware. A subscription might read from around R1,299/month, a rent-to-own from around R1,911/month, and a cash price around R47,000 and up, all potentially for comparable systems. Make sure you're comparing the same model, or at least understand which model each quote represents, before you react to the figures.

1299Subscription (per month)

1911 | unit=R | caption=Same hardware can read very differently by payment modelRent-to-own (per month)

Step two: interrogate what is inside

Once the systems are on the same footing, dig into the components and the fine print. This is where good and bad quotes really separate.

The battery is where corners get cut

Batteries are expensive, so an undersized battery is the easiest way to make a quote look cheap. Ask how many hours of backup the capacity actually gives your home, not in theory but for your real load. A 3.6kWh battery gives a modest household roughly three hours of cover; a busy family running more appliances will burn through it far faster. If a suspiciously cheap quote achieves its price with a small battery, that is the trick exposed.

Check the brands, not just the specs

A spec sheet does not tell you whether the equipment is well supported locally. Look for mainstream, well-backed brands: inverters like Sunsynk, Solis, AlphaESS or Huawei; established lithium batteries; reputable panels such as Trina or Jinko. An obscure brand at a lower price can mean slow service and scarce parts when something fails years later, which is a false economy.

Warranty and what actually backs it

A warranty is only as good as the company standing behind it. Check the length on the inverter, battery and panels, and, more importantly, who honours it and how call-outs work. A five-year backing from a company with a real local footprint beats a longer paper warranty from one that may not answer the phone.

The inclusions that quietly matter

Read what the price covers. Does it include SSEG registration with your municipality, which is legally required for grid-tied systems in most areas? Monitoring? Maintenance and repairs? For a subscription or rent-to-own, does the monthly fee cover call-outs and component failures, or will those be billed to you? These inclusions are where two similar-looking quotes diverge in real-world cost.

Step three: pressure-test the sizing against your life

Even a well-specified system is wrong if it does not fit your usage. The best quote is the one sized to how you actually live, so sanity-check it.

Think about what you run at once during load-shedding. If your quote assumes a modest load but you regularly run a pool pump, tumble dryer and multiple air-cons together, the system will keep leaning on Eskom and your savings will disappoint. Conversely, do not let anyone oversell you a system far bigger than you need. A good quote is preceded by someone asking about your consumption, your roof and your peak usage. If nobody asked, the sizing is a guess.

Running your own numbers first puts you in a stronger position. You walk into the conversation already knowing roughly what size system your home needs and what savings are realistic. Then a quote either matches that reality or it doesn't.

Step four: judge the honesty

The most underrated signal in a quote is candour. A provider who tells you where their offering does not fit (that a subscription costs more over a long stay, that a small battery won't carry a heavy load) is being straight with you. One that claims to be perfect for every home is selling, not advising. Trustworthy quoting shows up as clear breakdowns, named components, transparent inclusions and honest trade-offs, not glossy round numbers with no detail.

For a typical home wanting a straightforward, well-supported system on a path to ownership, a package like Alumo's Silver "The Eishkom Ex" (a Sunsynk 3.6kW inverter, 3.8kWh battery and four panels from around R2,035/month) is the kind of clearly specified offer you can actually evaluate against the checklist above, rather than a vague number.

Putting it all together

Comparing solar quotes like a pro comes down to a simple discipline: normalise first, interrogate the components and inclusions, pressure-test the sizing against your real usage, and reward honesty. Do that and the "cheaper" quote often reveals itself as the smaller or thinner one, while the genuinely good deal stands out clearly.

The cleanest way to compare is to get at least one detailed, transparent quote to benchmark the rest against. Get a free Alumo quote → and you will have a properly specified system (size, components, inclusions and monthly figure) to hold every other quote up against.

Frequently asked questions

Why is one solar quote so much cheaper than another?

Almost always because it is a smaller or thinner system: a smaller battery, fewer panels, a lower-spec inverter, an obscure brand, or fewer inclusions like warranty and SSEG registration. Once you normalise the quotes to the same size and inclusions, the gap usually shrinks or disappears. Cheaper rarely means better value in solar.

What should every solar quote include?

Inverter size, battery capacity, panel count and brands; the warranty terms and who backs them; whether SSEG registration, monitoring and maintenance are included; and, for subscription or rent-to-own, exactly what the monthly fee covers. A quote missing these details is hard to evaluate and should raise questions.

How do I know if a system is the right size for my home?

Estimate what you run during load-shedding and your overall consumption, then check the quoted inverter and battery against that. A good provider asks about your usage, roof and peak loads before quoting. If nobody assessed your actual needs, the sizing is guesswork and worth challenging.

Should I always choose the cheapest quote?

No. The cheapest quote is often the smallest system or the one with the weakest support and warranty, which costs more over the system's life. Choose the quote that best matches your actual usage, uses well-supported equipment and is transparent about inclusions and trade-offs.

How does SolarGuide help me compare?

SolarGuide is an independent comparison site. We help you understand your options and currently arrange quotes through our install partner, Alumo, who supplies, installs, finances and warrants the systems. Pricing is indicative and subject to a site assessment and credit approval. Get a free Alumo quote →