For New Zealand homeowners, the best solar companies are those that design a system around the actual roof, household electricity use and plans for batteries—not simply those that submit the lowest quote. A good proposal explains expected generation, equipment choices, installation work, grid connection and ongoing support in plain language. Compare quotes only after checking that they use similar assumptions and include the same work. If a company cannot show how its design fits your home, or its savings estimate depends on assumptions you cannot verify, ask for a clearer proposal before committing.
There is no single company that is best for every household. A suitable installer should be able to explain why its proposed panel layout and system size make sense for your roof, how much electricity the system may generate, and what affects the savings estimate. It should also be clear about what is included in the price and what could lead to extra work or charges.
That level of detail matters because homes differ. Roof direction, pitch, shading, available space and condition can all affect the design. So can the times your household uses electricity, whether you expect to add an electric vehicle or other large loads, and whether you want a battery now or might consider one later.
Look for a company that treats these as design questions rather than offering the same package to every customer. A lower quote can still be a good deal, but only if the system and installation scope are comparable. A price that leaves out necessary electrical work, monitoring or grid-connection steps may not represent the final cost.
Before choosing between proposals, check that each company is quoting for a similar system and set of services. If one quote includes a battery, switchboard work or backup capability and another does not, their totals are not directly comparable. Ask each company to clarify differences and put any agreed changes in writing.
| What to compare | A clear proposal should explain | Useful question to ask |
|---|---|---|
| System design | Panel layout, system size and any roof constraints considered | Why is this layout suitable for my roof? |
| Generation and savings | Estimated generation and the assumptions behind the savings estimate | How much electricity is expected to be used at home versus exported? |
| Equipment | Panel and inverter models, monitoring and battery compatibility | What are the trade-offs between the proposed equipment and alternatives? |
| Installation scope | Included electrical work, connection steps and any exclusions | What could trigger an extra charge? |
| Warranty and support | Who handles equipment, workmanship and service issues | Whom do I contact if the system stops working? |
| Total cost and finance | Full price, payment terms, fees and financing obligations | What will I pay over the full term, not just upfront? |
Read the assumptions behind any savings estimate closely. The result may depend on how much electricity the household uses during daylight hours, how much solar generation is exported, and what the retailer pays for exported electricity. In New Zealand, export rates and plan terms can vary by retailer, so use the terms available to you rather than treating an estimate as a guaranteed saving.
A useful proposal should show where panels are expected to go and identify any meaningful shading or roof limitations. Ask whether the company has inspected the property or based the design on photographs or remote information. If the roof may need repair or replacement, discuss that before installation: removing and reinstalling panels later can add work and cost.
Ask how the layout changes across the day and year, particularly if the roof has several faces or nearby trees, chimneys or other obstructions. The company should explain the effect of those conditions on its generation estimate rather than relying on a generic figure for a system of that size.
Recent electricity bills can help an installer understand your overall consumption, but timing matters too. A household that uses more electricity during daylight may use more solar generation directly. One that is often empty during the day may export a larger share unless it can shift some use, such as running suitable appliances during sunny hours.
Tell the company about likely changes, including a planned electric vehicle, heat pump or household expansion. These plans may affect system sizing, but they should not be used to justify a larger system without showing the expected benefit. Ask for the design to distinguish current usage from any future scenario.
Panel brand alone does not determine whether a proposal is right for your home. Check the quoted model, the layout and how the equipment is expected to perform under your roof conditions. Ask the installer to explain any difference between the products it proposes and alternatives, including how warranty claims are handled.
The inverter converts the panels’ direct-current electricity into usable household alternating current. A string inverter may suit a relatively straightforward roof layout, while module-level electronics can be worth discussing where panels face different directions or experience uneven shade. The right choice depends on the design; ask the company to explain the benefit, added complexity and cost of its recommendation.
If you may add a battery later, ask whether the proposed inverter supports the battery options you are considering and what additional equipment might be needed. “Battery-ready” can mean different things in practice, so request the specific compatibility details rather than relying on the label alone.
A battery can store some solar electricity for use later, but it changes the system cost and should be assessed against your household’s needs. Ask the company to show how its estimate changes with and without storage, including the assumptions about when the battery charges and discharges. Compare usable capacity and power output as well as the headline capacity, and check what the warranty covers.
Do not assume that a battery will keep the whole home running during a power cut. Backup operation depends on the system design and the circuits selected for backup; some setups may not provide backup at all. If this feature matters to you, ask which circuits will work, what happens when demand is high, and whether the quoted price includes the equipment and installation needed for backup.
For some households, waiting to add a battery may be more suitable than buying one immediately. Ask what would need to change to add storage later, and whether that option affects the inverter choice or installation plan now.
Ask who will carry out the installation and who is responsible for electrical work. In New Zealand, you can ask for the details of the licensed electrical worker responsible for the electrical work and verify their registration through the Electrical Workers Registration Board (EWRB). Also find out whether the company uses its own installation team or subcontractors, and who you contact if an issue arises after handover.
For a grid-connected system, ask who will manage the connection process with the local electricity distribution network and confirm whether any network requirements or export limits affect the design. The installer should explain any relevant approvals for your property and identify anything you need to arrange yourself. Get the expected scope and responsibilities in writing before work begins.
The installation plan should describe how the panels, inverter and cabling will be fitted, what happens to the existing electrical equipment, and whether switchboard work is included. Ask how the crew will protect the property and what inspections, system testing and handover documents you will receive.
Focus on the total cost of owning the system, not just the initial quote. Confirm whether the price includes all listed equipment, installation, electrical upgrades, monitoring setup and connection-related work. Ask the company to identify exclusions, possible variations and the circumstances in which the quoted price could change.
Review the savings estimate as a set of assumptions rather than a promise. It should make clear how expected solar generation, household use and exported electricity contribute to the result. If the estimate includes a payback period, ask which electricity prices, export rates, maintenance costs and system performance assumptions were used. A second scenario with more conservative assumptions can help show how sensitive the outcome is.
If financing is offered, compare the total payments and fees with the cash price. Check the interest rate, term, payment schedule, early-repayment conditions and any obligations that remain if you sell the home. If an incentive or special offer is included in the proposal, verify its eligibility, conditions and availability before counting it as part of the return.
Solar equipment may have separate manufacturer warranties, while installation workmanship and ongoing service may be covered under different terms. Ask for the warranty documents and find out who manages a claim: the installer, the equipment supplier or the manufacturer. A long equipment warranty is less useful if you do not know where to turn when a fault occurs.
Check what monitoring is included and whether the company will explain how to use it. Ask what support is available if the system stops producing as expected, how performance concerns are assessed, and whether a service visit could involve a charge. The answers help you judge the company’s after-installation service, not just its sales process.
Take time to resolve gaps between proposals. If a company makes a strong savings claim but will not show its assumptions, or quotes equipment without explaining why it suits the roof, ask for revised details. The aim is not to collect the most quotes; it is to compare a small set of proposals that are clear enough to evaluate.
Any one concern may have a reasonable explanation, but it should be answered clearly before you sign. A company that can discuss limitations as well as benefits is easier to assess than one that relies on broad promises.
There is no required number, but comparing more than one site-specific proposal can reveal differences in design, equipment and installation scope. Prioritise quotes that explain their assumptions and can be compared on similar terms rather than collecting estimates with different inclusions.
Warranty length is only one part of the decision. Check what is covered, who manages claims, whether installation workmanship is covered separately and what support is available if the installer is no longer providing service.
It may be possible, but compatibility depends on the inverter and system design. Ask the installer to identify suitable battery options and any extra equipment or work that a later installation could require.
Not automatically. Backup depends on whether the system is designed for that function and which circuits are connected to it. Have the company specify exactly what will remain powered and what the quoted installation includes.
A company can estimate savings using stated assumptions, but actual results depend on system generation, household use, electricity prices and export terms. Treat a guaranteed-savings claim cautiously unless the proposal clearly defines what is guaranteed and the conditions that apply.
The best solar companies are those that can explain the design, price and limits of their proposal for your particular home. Compare roof suitability, electricity-use assumptions, inverter and battery options, installation responsibilities and after-sales support alongside the total cost. Before signing, make sure the expected savings and every important inclusion are written down. That gives you a sound basis for choosing a system that fits your needs, rather than paying less upfront for a proposal that leaves key questions unanswered.
