Upgrading an existing solar system is more forensic than a new install: legacy inverters, panel matching, warranty continuity and DNSP re-approval all matter. In 2026, many Australian homeowners upgrade to add capacity, replace failing inverters, or unlock batteries under the Cheaper Home Batteries Program (~$372/kWh usable). MrSolar connects you with CEC-accredited upgrade specialists who inspect what you already have before quoting more hardware.
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Indicative 2026 pricing: a typical 6.6kW system often quotes around $5,000–$8,000 after the STC discount (metro installs often $5,000–$7,500; premium/regional can run higher). See our solar cost guide.
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Collect inverter model, panel model, install year, monitoring data and any fault codes. A site assessment should confirm string health and switchboard capacity before you buy more modules. Australian 2026 context still rewards self-consumption over FiT hunting; when reading “Diagnose the current array first”, check whether the advice pushes daytime loads, EV charging, or storage instead of unlimited export assumptions. After install, revisit “Diagnose the current array first” using your app’s import/export charts — that feedback loop is how solar system upgrade stays aligned with real tariffs and DNSP behaviour.
Add panels to spare roof with a new hybrid inverter, replace an aging inverter only, AC-couple a battery, or rebuild toward a modern hybrid ecosystem. Each path has different certificate and network implications. Because solar system upgrade decisions are site-specific, use monitoring or bill interval data where you have it, then ask each CEC-accredited installer to reconcile their design to those facts. If two quotes disagree on “Common upgrade pathways”, ask both to show workings with as-of dates (STC spot and subsidy rules) rather than accepting a verbal reassurance.
Increasing capacity or changing inverters often triggers a new application and possibly tighter export limits than your original approval. Quotes that ignore the distributor are incomplete. If two quotes disagree on “DNSP re-approval is not optional paperwork”, ask both to show workings with as-of dates (STC spot and subsidy rules) rather than accepting a verbal reassurance. On the “DNSP re-approval is not optional paperwork” point for solar system upgrade, write acceptance tests into the quote: product models, STC or battery-subsidy maths, and DNSP/export notes must be explicit for /services/solar-system-upgrade.
Additional eligible solar capacity may create STCs. New eligible batteries may access ~$372/kWh usable federal support. Legacy sections might not earn new certificates — require a clear split on the quote. Because solar system upgrade decisions are site-specific, use monitoring or bill interval data where you have it, then ask each CEC-accredited installer to reconcile their design to those facts. If two quotes disagree on “Incentives on upgrades”, ask both to show workings with as-of dates (STC spot and subsidy rules) rather than accepting a verbal reassurance.
Mixing vastly different currents on one MPPT can waste energy. Installers may isolate new strings or recommend microinverters. Prefer engineering honesty over “just add six panels” optimism. If two quotes disagree on “Matching old and new panels”, ask both to show workings with as-of dates (STC spot and subsidy rules) rather than accepting a verbal reassurance. On the “Matching old and new panels” point for solar system upgrade, write acceptance tests into the quote: product models, STC or battery-subsidy maths, and DNSP/export notes must be explicit for /services/solar-system-upgrade.
Keep serials and CEC accreditation details. Upgrades should not silently void remaining product warranties — ask in writing. On the “Warranty and ownership records” point for solar system upgrade, write acceptance tests into the quote: product models, STC or battery-subsidy maths, and DNSP/export notes must be explicit for /services/solar-system-upgrade. MrSolar’s three-quote flow for solar system upgrade exists so you can reject proposals that skip workmanship warranty length, handover app ownership, or export-limit disclosure.
MrSolar matches CEC-accredited installers comfortable with retrofits. Compare pathway, export assumptions, incentive lines and net price. If two quotes disagree on “Compare three upgrade quotes”, ask both to show workings with as-of dates (STC spot and subsidy rules) rather than accepting a verbal reassurance. On the “Compare three upgrade quotes” point for solar system upgrade, write acceptance tests into the quote: product models, STC or battery-subsidy maths, and DNSP/export notes must be explicit for /services/solar-system-upgrade.
Planning a solar upgrade? Compare up to three CEC-accredited retrofit quotes on MrSolar.
Written and reviewed by Daniel (Marketplace lead, Epic Unicorn Pty Ltd). We build pages from Australian solar datasets and regulatory references, then map you to CEC-accredited installers only.
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