Three solar companies. Three quotes. Three different prices.
At first glance, choosing the cheapest option might seem like the easiest way to save money. However, not all solar proposals are designed the same way, even when they offer similar system capacities.
The real question is not simply how much a solar system costs, but whether it is designed to suit your property's energy requirements, current electricity consumption and future needs.
Before making a decision, take the time to understand what each proposal includes and how the recommended system is expected to perform.
Here are 12 important questions to ask before choosing a solar installer.
1. What Is the Expected Annual Energy Production?
Don't look at panel capacity alone. A system with a higher capacity does not automatically guarantee better performance for your property.
Ask the installer how much electricity the proposed system is expected to generate annually, measured in kilowatt-hours (kWh).
Why it matters: Expected energy production helps you understand how much electricity your system could generate and compare the performance estimates of different proposals.
2. What Assumptions Were Used in the Proposal?
Solar performance estimates depend on several factors, including:
Household electricity consumption
Roof orientation and tilt
Shading from trees or nearby buildings
Local weather conditions
Electricity tariffs and feed-in rates
Expected changes in future energy use
Ask the installer to explain the assumptions behind their calculations.
Why it matters: Understanding these assumptions helps you assess whether the estimated savings are realistic for your property rather than based on overly optimistic projections.
3. What Happens to Excess Solar Energy?
Solar panels often generate the most electricity during the middle of the day, when household consumption may be relatively low.
Ask whether excess electricity will be exported to the grid, stored in a battery or potentially curtailed due to system or network limitations.
Why it matters: Your financial benefit depends partly on how much solar electricity you use yourself, how much you export and the applicable electricity rates. A system that generates plenty of electricity may not deliver the expected savings if much of that energy is exported at a low feed-in tariff.
4. Why Was This System Size Recommended?
Ask your installer a straightforward question:
"Why did you recommend this number of panels and this system capacity?"
The answer should relate to your property's electricity consumption, roof space, energy usage patterns and budget.
Why it matters: A larger system is not always the most cost-effective option, while a system that is too small may not meet your energy requirements. The goal is to find a suitable balance between generation, consumption and overall value.
5. What Happens If My Electricity Consumption Increases?
Your energy needs today may not be the same in the next few years.
You might purchase an electric vehicle (EV), install a heat pump, add another air conditioner or start working from home more frequently.
Ask whether the proposed system can accommodate these changes and whether additional equipment or upgrades may be needed.
Why it matters: Considering future electricity demand can help you avoid unnecessary upgrades and make better decisions about system capacity, battery storage and electrical infrastructure.
6. What Happens During a Blackout?
Don't assume that installing a solar battery automatically means your home will have power during a blackout.
Some systems can provide backup power, while others may require additional equipment or specific configurations. Even with backup capability, not every circuit may be supported.
Ask your installer which circuits will remain powered, how much load the backup system can support and how long the battery may last under different conditions.
Why it matters: Understanding backup capability helps you determine whether the system can support essential appliances such as lighting, refrigeration and selected power outlets during an outage.
7. What Australian Standards and Requirements Apply?
Ask whether the proposed installation will comply with the applicable Australian standards, electrical safety requirements, network connection rules and relevant installation requirements.
Your installer should also explain any approvals, inspections or documentation required for your property.
Why it matters: Compliance is essential for electrical safety, reliable operation and a properly documented installation. Requirements can vary depending on the system, location and installation circumstances.
8. What Are the Battery's Usable Capacity and Power Output?
When comparing battery proposals, don't focus on capacity alone. Two batteries with similar capacities may have different power outputs and operating capabilities.
Remember:
kWh ? kW
kWh (kilowatt-hours): Measures the amount of energy a battery can store and deliver.
kW (kilowatts): Measures the rate at which the battery can supply power.
Ask about usable battery capacity, continuous power output, peak power capability and any relevant operating limitations.
Why it matters: Battery capacity influences how much energy is available, while power output affects how many appliances can operate simultaneously.
9. What Maintenance Is Expected?
Ask whether the system requires periodic inspections, performance monitoring, cleaning or other servicing.
You should also understand how to monitor system performance and identify potential issues, such as unexpected drops in solar generation or battery performance.
Why it matters: Understanding maintenance requirements helps you plan for ongoing ownership costs and identify performance issues before they become more significant.
10. What Happens If a Component Fails?
A solar system includes several components, such as panels, inverters, mounting equipment and, where installed, batteries.
Ask about the warranties covering each component, the installation workmanship warranty, the process for reporting faults and who will coordinate repairs.
Why it matters: Warranty coverage, exclusions, claim procedures and responsibility for labour can differ. Knowing these details before installation can help prevent confusion if something goes wrong.
11. Is the System Designed Around My Actual Load Profile?
Your daily energy consumption pattern is just as important as the total amount of electricity you use.
For example, a household that consumes most of its electricity during the day may use more of its solar generation directly. A household that uses most of its electricity in the evening may have different requirements, particularly if battery storage is being considered.
Ask whether the proposal considers your electricity bills, smart meter data or interval consumption data, where available.
Why it matters: Understanding when electricity is consumed helps determine an appropriate system size and whether a battery could provide additional value.
12. What Might My Property Need in Five Years?
Solar system design should consider more than today's electricity consumption.
Over time, you may add EV charging, battery storage, heat pumps, additional air conditioning or other electrical equipment. These changes may affect your future energy demand and electrical infrastructure requirements.
Ask whether the proposed system allows for practical future expansion and what additional costs or technical limitations may apply.
Why it matters: Planning ahead can help you make informed decisions about equipment selection, inverter capacity, switchboard requirements and potential upgrades.
Final Thoughts: Compare the Design, Not Just the Price
When comparing three solar quotes, the cheapest option is not necessarily the best value, and the most expensive option is not automatically the best solution.
A good proposal should clearly explain the expected energy production, system sizing, estimated savings, battery capabilities, applicable compliance requirements and long-term considerations.
Before making your decision, make sure you understand not only what you're buying, but why the system was designed that way.
At RENOSTAIN, understanding a property's energy requirements is an important starting point for evaluating suitable solar and electrical solutions. Asking the right questions can help you make a more informed decision about your property's energy future.
At first glance, choosing the cheapest option might seem like the easiest way to save money. However, not all solar proposals are designed the same way, even when they offer similar system capacities.
The real question is not simply how much a solar system costs, but whether it is designed to suit your property's energy requirements, current electricity consumption and future needs.
Before making a decision, take the time to understand what each proposal includes and how the recommended system is expected to perform.
Here are 12 important questions to ask before choosing a solar installer.
1. What Is the Expected Annual Energy Production?
Don't look at panel capacity alone. A system with a higher capacity does not automatically guarantee better performance for your property.
Ask the installer how much electricity the proposed system is expected to generate annually, measured in kilowatt-hours (kWh).
Why it matters: Expected energy production helps you understand how much electricity your system could generate and compare the performance estimates of different proposals.
2. What Assumptions Were Used in the Proposal?
Solar performance estimates depend on several factors, including:
Household electricity consumption
Roof orientation and tilt
Shading from trees or nearby buildings
Local weather conditions
Electricity tariffs and feed-in rates
Expected changes in future energy use
Ask the installer to explain the assumptions behind their calculations.
Why it matters: Understanding these assumptions helps you assess whether the estimated savings are realistic for your property rather than based on overly optimistic projections.
3. What Happens to Excess Solar Energy?
Solar panels often generate the most electricity during the middle of the day, when household consumption may be relatively low.
Ask whether excess electricity will be exported to the grid, stored in a battery or potentially curtailed due to system or network limitations.
Why it matters: Your financial benefit depends partly on how much solar electricity you use yourself, how much you export and the applicable electricity rates. A system that generates plenty of electricity may not deliver the expected savings if much of that energy is exported at a low feed-in tariff.
4. Why Was This System Size Recommended?
Ask your installer a straightforward question:
"Why did you recommend this number of panels and this system capacity?"
The answer should relate to your property's electricity consumption, roof space, energy usage patterns and budget.
Why it matters: A larger system is not always the most cost-effective option, while a system that is too small may not meet your energy requirements. The goal is to find a suitable balance between generation, consumption and overall value.
5. What Happens If My Electricity Consumption Increases?
Your energy needs today may not be the same in the next few years.
You might purchase an electric vehicle (EV), install a heat pump, add another air conditioner or start working from home more frequently.
Ask whether the proposed system can accommodate these changes and whether additional equipment or upgrades may be needed.
Why it matters: Considering future electricity demand can help you avoid unnecessary upgrades and make better decisions about system capacity, battery storage and electrical infrastructure.
6. What Happens During a Blackout?
Don't assume that installing a solar battery automatically means your home will have power during a blackout.
Some systems can provide backup power, while others may require additional equipment or specific configurations. Even with backup capability, not every circuit may be supported.
Ask your installer which circuits will remain powered, how much load the backup system can support and how long the battery may last under different conditions.
Why it matters: Understanding backup capability helps you determine whether the system can support essential appliances such as lighting, refrigeration and selected power outlets during an outage.
7. What Australian Standards and Requirements Apply?
Ask whether the proposed installation will comply with the applicable Australian standards, electrical safety requirements, network connection rules and relevant installation requirements.
Your installer should also explain any approvals, inspections or documentation required for your property.
Why it matters: Compliance is essential for electrical safety, reliable operation and a properly documented installation. Requirements can vary depending on the system, location and installation circumstances.
8. What Are the Battery's Usable Capacity and Power Output?
When comparing battery proposals, don't focus on capacity alone. Two batteries with similar capacities may have different power outputs and operating capabilities.
Remember:
kWh ? kW
kWh (kilowatt-hours): Measures the amount of energy a battery can store and deliver.
kW (kilowatts): Measures the rate at which the battery can supply power.
Ask about usable battery capacity, continuous power output, peak power capability and any relevant operating limitations.
Why it matters: Battery capacity influences how much energy is available, while power output affects how many appliances can operate simultaneously.
9. What Maintenance Is Expected?
Ask whether the system requires periodic inspections, performance monitoring, cleaning or other servicing.
You should also understand how to monitor system performance and identify potential issues, such as unexpected drops in solar generation or battery performance.
Why it matters: Understanding maintenance requirements helps you plan for ongoing ownership costs and identify performance issues before they become more significant.
10. What Happens If a Component Fails?
A solar system includes several components, such as panels, inverters, mounting equipment and, where installed, batteries.
Ask about the warranties covering each component, the installation workmanship warranty, the process for reporting faults and who will coordinate repairs.
Why it matters: Warranty coverage, exclusions, claim procedures and responsibility for labour can differ. Knowing these details before installation can help prevent confusion if something goes wrong.
11. Is the System Designed Around My Actual Load Profile?
Your daily energy consumption pattern is just as important as the total amount of electricity you use.
For example, a household that consumes most of its electricity during the day may use more of its solar generation directly. A household that uses most of its electricity in the evening may have different requirements, particularly if battery storage is being considered.
Ask whether the proposal considers your electricity bills, smart meter data or interval consumption data, where available.
Why it matters: Understanding when electricity is consumed helps determine an appropriate system size and whether a battery could provide additional value.
12. What Might My Property Need in Five Years?
Solar system design should consider more than today's electricity consumption.
Over time, you may add EV charging, battery storage, heat pumps, additional air conditioning or other electrical equipment. These changes may affect your future energy demand and electrical infrastructure requirements.
Ask whether the proposed system allows for practical future expansion and what additional costs or technical limitations may apply.
Why it matters: Planning ahead can help you make informed decisions about equipment selection, inverter capacity, switchboard requirements and potential upgrades.
Final Thoughts: Compare the Design, Not Just the Price
When comparing three solar quotes, the cheapest option is not necessarily the best value, and the most expensive option is not automatically the best solution.
A good proposal should clearly explain the expected energy production, system sizing, estimated savings, battery capabilities, applicable compliance requirements and long-term considerations.
Before making your decision, make sure you understand not only what you're buying, but why the system was designed that way.
At RENOSTAIN, understanding a property's energy requirements is an important starting point for evaluating suitable solar and electrical solutions. Asking the right questions can help you make a more informed decision about your property's energy future.