September 11, 2025

If you’re a homeowner in Ireland considering installing solar PV, you’ll come across reputable installers who do things by the book, and some who don’t.

In this article, we will give you specific questions to ask before you sign, plus the context to recognise solid, evidence-based answers.

Use it to:

• Shortlist two or three reputable installers.
• Ask the same questions to each.
• Compare like-for-like on system size (kWp), components, warranties, and scope of works.

1. A Quick Checklist

Credentials & safety

1. Are you fully insured and certified, and who signs off the electrical work?

2. Will my system comply with current Irish regulations and ESB Networks notification requirements?

Design & components

3. Why this system size (kWp), and what generation (kWh/year) do you expect for my roof?

4. Which panel model and why? Are they Tier One and how long are the product and performance warranties

5. Which inverter (string, hybrid, or microinverters) and why for my roof/groundmount layout/shading?

Battery & backup

6. Do I need a battery? What usable capacity, expected cycles, and warranty terms apply?

7. Will I have backup during grid outages? What can/can’t it power?

Performance & savings

8. What self-consumption rate and bill savings are you assuming? What tariff/export assumptions are you using?

9. Do you have an energy partner that you provide better rates through?

10. What payback range are you projecting, and what could shorten or lengthen it?

Roof & installation

11. How will you fix to my roof type, and what’s your weatherproofing guarantee?

12. Is scaffolding included and who pays for repairs if tiles/slates crack?

Electrics & monitoring

13. What consumer unit changes are needed? Where will the inverter/battery go (ventilation, clearances)?

14. What monitoring app/portal do I get? Who owns the data?

Warranties & aftercare

15. What are the product and workmanship warranties? Who handles warranty claims if a manufacturer exits the market?

16. What’s included in aftercare?

Grants, export & paperwork

17. Will you handle the SEAI grant process guidance and ESB Networks micro-generation notification?

18. What do I need for BER and for my electricity supplier’s export setup?

Price & contract

19. What exactly is included in the price (scaffolding, cabling runs, Wi-Fi extenders, ESB paperwork)?

20. What are payment milestones, cancellation terms and lead times?

Future-proofing

21. How will this design support EV charging, a future heat pump, or an extension?

2. Questions To Ask and “What a Good Answer Looks Like”

1. Credentials, compliance & safety

Ask: Are you insured and certified, and who signs off the electrical work?

Why it matters: You want an installer who adheres to Irish regulations and manufacturer requirements, and who provides proper certification at handover.

What a good answer looks like: Clear evidence of public liability and employer’s liability insurance; named, qualified electrician responsible for the final sign-off; familiarity with ESB Networks micro-generation notification (often referred to as NC6/NC7) and current microgeneration limits; method statements and risk assessments for your specific property. Safe Electric, SEAI, ISEA and MREF registered.

Read this article to learn more about how to choose a reputable solar installer.

Ask: Will my system comply with planning and ESB Networks rules?

Good answer: Confirms that home rooftop PV is generally exempt from planning (with conditions) and commits to checking your layout against the latest legislation and exemptions. Explains the utility notification process and any export-limiting requirements if relevant to your meter/connection.

2. System design & panel selection

Ask: Why this size (kWp) and layout for my roof? What generation (kWh/year) do you expect?

Why this matters: Output depends on orientation, pitch, shading, and local climate.

Good answer: Provides a roof sketch, model or layout plan with module count, kWp, and strings; production estimate. States assumptions for orientation/pitch and shading. Explains seasonal variation.

Ask: Which panel model and why? Are they Tier One and how long are the panel and performance warranties?

Good answer: Names a specific panel (manufacturer and datasheet model), explains efficiency, temperature coefficient, dimensions, and warranties. Explains any black-frame/all-black aesthetic choices, and when bifacial or split-cell designs help (e.g., flat roofs with tilt frames).

Ask: Which inverter, and why?

Good answer: Specifies string, hybrid, or microinverters, brand, model and reason for selection. Matches technology to your roof complexity.

3. Battery & backup

Ask: Do I need a battery, and what size?

Good answer: Recommends a usable capacity sized to your night-time load and shoulder seasons (e.g., 4–10 kWh for typical households, depending on usage). Explains cycle life, round-trip efficiency, warranties, and integration with time-of-use tariffs.

Ask: Will I have backup during outages?

Good answer: Clarifies the difference between standard battery (no backup) and systems with island/backup circuits. Sets realistic expectations: backup circuits typically cover essentials only (lights, fridge, some sockets), not immersion/heavy loads unless specifically designed.

4. Performance estimates (yield, savings, payback)

Ask: What annual generation, self-consumption, and export are you projecting?

Good answer: Provides a range, not a single number, and shows the assumptions: your usage profile, tariff rates, standing charges unaffected, estimated export rate, and degradation (for example between approximately 0.4–0.7% per year).

Ask: Do you have an energy partner that you provide better rates through?

Good answer: Yes or no. If yes, specify the provider and the rate.

Ask: What payback are you quoting and why might it change?

Good answer: Gives a scenario range (conservative/base/optimistic). Explains drivers: energy price changes, export rates, your behaviour (using appliances in daylight), and battery cycling.

Read this article to learn more about payback periods.

5. Roof, structure & installation

Ask: How will you fix panels to my roof type, and how do you prevent leaks?

Good answer: Names the mounting system (manufacturer), fixings appropriate to slate vs tile vs flat roof, use of flashing kits on penetrations, and torque/spec compliance. Provides a weatherproofing guarantee and details who pays if tiles/slates crack.

Ask: Is scaffolding included, and how will you protect gutters and landscaping?

Good answer: Scaffolding is included and installed by certified providers, with protection boards and a plan for access and waste removal.

6. Electrical works & backup during outages

Ask: What changes are needed in my consumer unit? Where will the inverter/battery go?

Good answer: Explains RCD/RCBO provision, spare ways, AC and DC isolators, proper ventilation clearances, and avoidance of bedrooms for noise reasons. Names approximate cable runs and any trunking/conduit.

Ask: If I choose backup, how will you separate critical loads?

Good answer: Proposes a sub-board for essential circuits, discusses changeover devices, and clearly states limitations.

7. Monitoring, data & optimisation

Ask: How will I see generation, consumption, battery state and export?

Good answer: A specific app/portal with per-string or per-module visibility as applicable. Explains data ownership, remote diagnostics, and options for CT clamps or smart meters to measure import/export accurately. Mentions Wi-Fi reliability and offers a hard-wired or Ethernet/Wi-Fi extender option if signal is poor.

8. Warranties, guarantees & aftercare

Ask: What are the product and workmanship warranties, and who handles claims?

Good answer: Distinguishes product vs performance warranty on panels, inverter/battery warranty (years and cycle/throughput limits), mounting warranty, and workmanship warranty. States a clear response time for call-outs and whether remote diagnostics are included. Confirms they’ll act as the first point of contact for manufacturer claims.

9. Grants, export & paperwork

Ask: Will you guide me through the SEAI grant steps and documentation?

Good answer: Explains what you need to qualify in principle, provides guidance on the SEAI application process, and ensures works are completed to grant standards, including the BER requirement post-installation.

Really good answer: The installer completes all grant paperwork for you.

Ask: Will you take care of ESB Networks micro-generation notification and help me set up export with my supplier?

Good answer: Confirms they submit the required micro-gen notification to ESB Networks and provide you with the documentation to enable your supplier’s export tariff (often called Clean Export Guarantee). They outline typical timelines for meter configuration by your supplier.

10. Price, scope & contract terms

Ask: What exactly is included in your price, and what isn’t?

Good answer: A line-item scope: panels, inverter/battery, mounting, scaffolding, DC/AC isolators, surge protection, monitoring hardware, cable runs, penetrations and making good, commissioning, handover pack, grant/ESB guidance, waste removal. Names exclusions (e.g., consumer unit upgrade beyond X, unexpected roof repairs). Provides a drawing showing equipment locations.

Ask: What are the payment milestones and cancellation terms?

Good answer: Transparent deposit, progress, and final payment triggers (e.g., after successful commissioning/handover). Clear cooling-off or cancellation terms, and what happens if timelines slip.

11. Timeline, logistics & site readiness

Ask: What’s the expected schedule and how long is the install?

Good answer: Typical lead time for materials and scaffolding, installation duration, and commissioning/hand-over on the final day. Explains homeowner prep (clearing loft/equipment areas, Wi-Fi access details, parking).

12. Future-proofing (EV, heat pumps, extensions)

Ask: How will this system adapt as my home changes?

Good answer: Designs with spare roof capacity or inverter headroom where sensible; suggests hybrid inverter for future battery; provisions a cable run for a future EV charger; considers heat pump loads and time-of-use strategies. Discusses how adding more panels later interacts with network limits and grant rules.

3. Red flags & how to spot them

Red flags to watch for:

• Pressure.
• Vague or missing calculations for yield and savings, or refusal to show assumptions.
• No mention of ESB Networks notification, BER, or export setup.
• Over-promising on output or whole-house backup without specifying limitations.
• Quote that lacks scope detail (scaffolding, monitoring hardware, aftercare).
• Unwillingness to name exact equipment models and warranty terms.

4. How to compare quotes like-for-like

Create a simple table and standardise on:

• System size (kWp) and module model
• Inverter/battery models and usable kWh
• Projected annual generation (kWh) and self-consumption % (use the same tariff/export assumptions across quotes)
• Inclusions (scaffolding, monitoring, surge protection, aftercare, grant/ESB guidance)
• Workmanship warranty length and response time
• Total price incl. VAT and any allowances for extras

5. Solar Terms Explained

SEAI grant: Government support for eligible home energy upgrades, including solar PV, subject to rules that can change.

BER: Building Energy Rating; you’ll receive/need an updated BER after works.

ESB Networks micro-generation notification: The formal network notification so your system is registered to export; installers typically handle this.

Export tariff / Clean Export Guarantee: Payment/credit for exported electricity from your supplier; rates and terms vary.

kWp vs kWh: kWp = panel “peak” capacity; kWh = actual energy produced/used.

DC-coupled vs AC-coupled battery: DC-coupled ties into the PV side (often higher efficiency); AC-coupled connects on the AC side (flexible for retrofits).

Optimisers/microinverters: Electronics that manage modules individually; helpful for shade/complex roofs.

Self-consumption: The share of your solar you use directly at home.

Round-trip efficiency: Percentage of energy you get back from a battery after charging/discharging.

6. Final Thoughts

Ask each installer to provide a one-page summary with: equipment list (exact models), layout, kWp, expected kWh/year, battery usable kWh (if any), assumptions used, inclusions/exclusions, warranties, timelines and total price. When installers answer clearly and consistently, you can choose with confidence.

Ready to Take the Next Step?

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