The right local solar company should be able to explain, in writing, how its proposed system fits your roof, electricity use and budget—and what support it will provide after installation. A low panel price is only one part of the comparison. System size, inverter choice, installation work, warranty terms and the assumptions behind projected savings can all change the value of a quote. Before choosing a provider, give each the same information about your home and compare complete proposals side by side. That makes it easier to spot missing costs, understand trade-offs and choose a system you can confidently own over the long term.
Solar companies can only make useful recommendations if they understand how your household uses electricity. Gather recent electricity bills and note any expected changes, such as a planned electric vehicle, heat pump, home extension or change in who is usually home during the day. These details can affect the best system size and whether battery storage deserves consideration.
Think about your priorities, too. You may want to lower electricity purchases, make better use of daytime solar generation, or have backup power during an outage. Those aims are not interchangeable. A standard grid-connected solar system may not provide electricity during a grid outage, and backup capability depends on the system design. If backup matters, ask the company to specify which circuits or appliances could be supplied and under what conditions.
Share basic information about your roof, including its age if known, any planned repairs, visible shading, and the roof areas you are willing to use. A company may need a site visit or further checks before confirming a design. If the roof needs work, clarify whether it should be completed before panels are installed and who is responsible for coordinating it.
Ask each company for a complete written proposal, not just a panel specification or an estimated monthly saving. The table below highlights the details that make quotes meaningfully comparable.
| What to compare | What a useful proposal explains | What to ask |
|---|---|---|
| System design | Proposed system size, panel layout, estimated generation and design assumptions | How does the design reflect my roof, shading and electricity use? |
| Equipment | Panel, inverter and, if included, battery make and model | Why were these components selected, and how do they work together? |
| Installation | Included electrical and roof work, project responsibilities and any exclusions | Who will do the work, and what preparation is required from me? |
| Warranties and service | Separate terms for equipment and installation, plus the contact for support | Who handles a fault, and what labour or call-out costs might apply? |
| Cost and savings | Itemised total, optional extras, financing terms and calculation assumptions | Which costs or electricity charges are excluded from the estimate? |
Use the same comparison basis for every proposal. Check that each quote covers similar system capacity, equipment, installation work and monitoring. A lower figure may reflect a smaller system, different components or work left out of the price, rather than a more efficient offer.
A suitable design starts with the roof, not a standard package. Roof orientation, pitch, shading and available space can affect how much electricity the panels generate and when they generate it. Ask the company to show the proposed panel layout and explain any areas it has avoided. If the estimate assumes trees will be trimmed or roof repairs completed, those assumptions should be written down.
Ask how the estimated generation was calculated and what conditions it assumes. The estimate is a planning tool, not a guarantee that your panels will produce a fixed amount in every year. Compare the projected generation with your household’s electricity use, but also consider when that use happens. Electricity generated while the household is using power may have a different financial value from electricity exported to the grid.
System size should reflect your likely use and the way your electricity plan treats exported power. A larger system is not automatically better if a substantial share of its output would be exported on terms that make the extra capacity less valuable to you. Ask for the reasoning behind the proposed size and, where practical, request an explanation of a smaller or larger alternative.
The inverter converts the panels’ output into electricity that can be used in the home or sent to the grid. The right type and configuration depend on the panel layout, shading, system design and any plans to add a battery. Ask the installer to explain the choice in plain language, including what monitoring is provided and what happens if the inverter needs attention.
A battery adds another decision and another cost. It may help a household use more of its solar electricity at a later time, but the value depends on the household’s usage pattern, electricity plan, battery settings and purchase cost. Ask for a separate battery price and a separate estimate of its expected effect on bills. If the company presents a combined solar-and-battery saving, request the assumptions behind it and compare the figures with a solar-only option.
“Local” can describe a company’s sales office without telling you who will carry out the installation or handle a service call. Ask whether the company uses its own installation team or subcontractors, who will supervise the project, and whom you should contact if something goes wrong. Find out whether a site assessment is included and what conditions could change the design after that visit.
In New Zealand, ask who is responsible for the electrical work and how you can verify the relevant registration or authorisation. The Electrical Workers Registration Board (EWRB) provides a way to check electrical workers’ registration. Also ask what documentation you will receive when the work is complete. A clear answer should identify responsibilities rather than leave you to coordinate different trades yourself.
Ask the company whether any network approval, export limit, retailer arrangement, consent or other project requirement may apply to your home. Confirm who will handle each relevant step and whether it is included in the proposal. Requirements can depend on the property and local network, so do not assume that a general sales estimate accounts for every connection detail.
Installation quality matters beyond the panels themselves. Clarify how the company will manage roof penetrations, cable routes, equipment placement and any work around existing electrical equipment. Ask what access the crew will need, whether you need to be home, and how the work area will be left. The proposal or contract should make clear which repairs or alterations are outside the quoted scope.
A proposal may mention warranties without explaining what each one covers. Panel, inverter, battery and installation terms are different; do not treat a single warranty headline as protection for the whole project. Ask for the written documents and check who provides each warranty, how to make a claim, and whether labour, travel or removal and refitting costs are included.
Pay particular attention to the installer’s workmanship terms. If a roof leak or wiring issue appears after installation, you need to know whether to contact the installer, an equipment manufacturer or another party. Ask how service requests are handled and what happens if the original installer is no longer operating. Warranty coverage can depend on conditions and exclusions, so read the actual terms rather than relying on a verbal summary.
Also ask what monitoring is included and whether the company will help you interpret an alert or investigate a drop in output. Monitoring can show system performance, but it does not itself resolve a fault. Find out whether support continues after installation and whether any ongoing service is optional or carries a charge.
Compare the total installed cost and its itemised components, not a headline price per panel. Check whether the proposal includes the inverter, mounting equipment, electrical work, monitoring, connection-related tasks and any required switchboard or roof work. The company should identify optional items and likely exclusions so you can distinguish the quoted system from possible additions.
Projected savings deserve the same scrutiny. Ask what electricity tariff, export rate and household usage pattern the estimate assumes. Confirm whether it accounts for the times you are likely to use solar power, and whether it assumes a battery. If your electricity plan or export arrangement changes, the financial result could change too. Treat payback estimates as scenarios based on stated assumptions, not promises.
If financing is offered, compare the total amount you would pay over the agreement, not just the regular repayment. Check fees, interest, payment timing, ownership of the equipment and what happens if you sell the home or want to repay early. For incentives or other financial support, ask which specific programme the quote assumes applies to your home and verify its current eligibility and terms before including it in your budget.
A low price is not a reason by itself to reject a company, but pressure or missing detail should slow your decision. Be cautious if a representative promises a particular bill outcome without explaining the assumptions, avoids identifying the equipment, or asks you to sign before you have had time to review the contract.
Ask for missing information in writing. If a company cannot explain its design or responsibilities clearly before installation, it may be difficult to resolve questions afterwards.
Keep the final proposal, contract, equipment details, warranty documents and handover information together. These records make it easier to understand the system and contact the right party if you need maintenance or support.
There is no required number, but comparing more than one complete proposal can reveal differences in design, scope and assumptions. Focus on whether each quote is based on the same information rather than collecting estimates that cannot be compared fairly.
Location alone does not establish installation quality or after-sales support. Ask any provider, local or not, who will do the work, how service requests are handled and whether its team covers your area. A nearby contact may be convenient, but clear responsibilities and written terms matter more.
That figure can help compare panel capacity, but it does not show the full installed cost or whether the system fits your roof and usage. Use it only alongside system design, inverter and battery choices, installation scope, warranties and savings assumptions.
Not necessarily. A battery may suit households that can use stored electricity at times when panels are not generating, but its value depends on costs, usage and electricity arrangements. Ask for separate solar-only and solar-with-battery proposals so you can judge the difference.
Ask both companies to show the assumptions behind their estimates, including household usage, solar generation, electricity tariffs, export rates and battery settings. Differences may come from the model inputs or system design; do not compare headline savings until you understand those differences.
Keep the signed contract, final system design, equipment details, warranty terms, electrical documentation and any handover or monitoring instructions provided. Ask the installer to confirm which records apply to your project and how to contact the relevant support team.
When comparing local solar companies, favour the proposal that clearly connects the system design to your roof and electricity use, accounts for the full project cost, and explains who will support you after installation. If a quote leaves important assumptions or responsibilities unclear, ask for a written answer before committing.
