Top 10 Questions to Ask Prospective Solar and Battery Installation Companies

Buyer’s guide for homeowners comparing solar.

Investing in solar—and especially solar plus battery storage—is a big decision. The right solar installer will design a safe, code‑compliant system that meets your goals and stands behind the work for years. The wrong choice can lead to delays, surprise costs, or a system that underperforms.

If you’re comparing proposals from a solar company, use these 10 questions to separate polished sales pitches from proven expertise. The answers will also help you compare, for example, “solar in New Jersey” quotes on an apples‑to‑apples basis.

1) Are you licensed, insured, and certified for solar + storage?

Why it matters: Solar plus batteries involves high‑voltage DC and whole‑home backup wiring. You need a contractor authorized to do the work and insured to protect you.

Ask for:

• Current state electrical or home improvement license numbers.
• Proof of general liability and workers’ compensation insurance.
• Relevant certifications (for example, NABCEP PV Installation Professional) and manufacturer trainings for the battery you’re buying.

Look for: Clear, current documents. A simple yes/no isn’t enough—request the actual numbers and coverage limits.

Red flags: Licenses “in process,” expired insurance, or reluctance to share documentation.

2) Who designs my system and stamps the plans?

Why it matters: A strong design aligns equipment, your roof and main service panel, and your goals. For storage, it also aligns critical loads and backup expectations.

Ask:

• Is the design done in‑house or outsourced?
• Will a professional engineer review structural and electrical plans when required?
• How do you model shading, tilt, azimuth, and degradation?
• How will the system meet the latest electrical code and local AHJ requirements?

Look for: A single point of contact who can explain the one‑line diagram in plain English.

3) Which equipment are you proposing, and why?

Why it matters: Panel, inverter, and battery choices affect reliability, warranties, monitoring, and backup behavior.

Ask:

• Panel brand and model, inverter type (string with optimizers vs. microinverters), and battery brand/model.
• AC‑coupled vs. hybrid/“DC‑coupled” storage and why that architecture fits your home.
• Warranties (product and performance for panels; parts/labor for inverters and batteries; throughput/cycle limits for batteries).
• What happens if a listed component is unavailable—what’s the approved substitute and how will it change performance or price?

Look for: Clear reasoning tied to your roof layout, shading, and backup priorities—not just a favorite brand.

4) How will you size my battery and choose the backed‑up loads?

Why it matters: Storage works best when sized to a goal. Is it whole‑home backup, essential‑loads backup, bill savings, or a mix?

Ask:

• What is the primary objective of the battery in my case?
• Which circuits go on the backup loads panel (fridge, lights, outlets, heating controls, well pump, medical devices)?
• Estimated runtime for a typical outage—based on my historical usage—not a generic brochure number.
• Can the system support large loads (HVAC, electric range, EV charger) during an outage? If not, what’s the plan?

Pro tip: Share a recent electric bill and mention any future changes (EV, heat pump, home office). It’s far easier to size storage before installation than after.

5) What production, savings, and backup expectations should I have - and what assumptions are you using?

Why it matters: A projection is only as good as its assumptions. Knowing them lets you compare proposals fairly.

Ask:

• Annual production estimate and the modeling inputs (tilt, azimuth, shading losses, system losses, panel degradation).
• Utility rate plan assumptions and any escalation used in the savings model.
• Monitoring access: Will I see real‑time production and battery state of charge?
• Do you offer performance guarantees or production assurances?

Look for: A plain‑language summary with the key inputs. Beware of aggressive rate escalations or “too perfect” shading losses.

6) What warranties cover parts, labor, and my roof?

Why it matters: Solar and battery warranties vary widely. You need to know who pays for what—and for how long.

Ask:

• Panel warranty (product years and performance guarantee).
• Inverter warranty and process for replacements.
• Battery warranty: term, cycle/throughput limits, and what voids coverage.
• Workmanship warranty on the installation itself.
• Roof penetration warranty and what happens if a leak is suspected under the array.

Look for: Written terms that include labor, not just parts. Ask how warranty claims are handled and typical turnaround times.

7) Who handles permits, interconnection, and incentives?

Why it matters: Great installs can stall at paperwork. An experienced <Location> solar company will anticipate local requirements.

Ask:

• Do you manage permits, utility interconnection/net metering, and any applicable incentives or RECs?
• What do you need from me, and when?
• Typical timelines in my jurisdiction from signed contract to Permission to Operate (PTO).
• How will you notify me about each milestone?

Look for: A clear process map and realistic timeline ranges. Delays happen; transparency should be standard.

8) What does your installation process look like, start to finish?

Why it matters: You’re inviting a crew to your home and roof. You deserve to know exactly what will happen.

Ask:

• Will you use your own crew or subcontractors? If subcontractors, who oversees quality?
• Who is my day‑to‑day project manager?
• Expected installation duration and how you protect landscaping and property.
• What does commissioning day look like and who teaches me the monitoring app?

Look for: Daily start/finish times, cleanup standards, and a punch‑list process before final payment.

9) How do you monitor and service the system after install?

Why it matters: Solar should be “set and forget,” but good service keeps it that way—especially with batteries and firmware updates.

Ask:

• Do you offer proactive monitoring and alerts?
• Standard response times for support tickets and on‑site service.
• Costs for out‑of‑warranty visits or diagnostic calls.
• How you handle emergency support during a grid outage.
• Annual inspection or health‑check options.

Look for: Clear SLAs, not vague promises. Verify you’ll have full access to the monitoring portal.

10) What are my payment options and project protections?

Why it matters: Terms and protections should be as solid as the hardware.

Ask:

• Purchase, loan, or other financing options—and total costs over time.
• Progress payments tied to milestones, not vague dates.
• Detailed change‑order process if conditions differ from the initial site survey.
• Lien releases from the contractor and any subcontractors upon payment.
• Cancellation and refund terms where applicable.
• Whether the warranties transfer if you sell the home.

Important: Solar tax credits and incentives can be valuable, but they depend on your situation. This article isn’t tax advice; consult your tax professional.

How to compare bids “apples to apples”

Use this quick checklist when you’re weighing solar energy:

• Total system size (kWdc/kWac) and module count.
• Shading losses and degradation assumption used in the model.
• Inverter type and battery architecture (AC‑ or DC‑coupled).
• Backup scope: whole‑home vs. essential loads; list of backed‑up circuits.
• Warranties: parts and labor durations; roof penetration coverage.
• Timeline: permit, install, inspection, PTO.
• Service: monitoring access and response times.
• All‑in price and payment milestones: what’s included, what’s optional.

If two proposals differ by price, find the line items that explain why—equipment quality, battery capacity, labor scope, or warranty coverage are common drivers.

A quick hypothetical comparison

Hypothetical example for illustration only.
Proposal A uses string inverters with optimizers and a 10 kWh battery. Proposal B uses microinverters and a 15 kWh battery. A is $X cheaper but estimates lower production on your partially shaded roof. B costs more but isolates module‑level shade impacts and offers longer labor warranty.

In this scenario, if your priority is reliable backup for essential loads, Proposal B’s larger battery may fit better. If your priority is fast payback, Proposal A may win—as long as the shading assumptions are honest and the smaller battery still covers your critical circuits. The “right” answer follows your goals, not the lowest number on the page.

Why these questions protect your project

Asking pointed, practical questions saves time and money. It also sets clear expectations for design, scheduling, and long‑term support. At PowerLutions Solar, we welcome informed conversations—we find that educated homeowners end up happier, whether the goal is resilience, savings, or both.

If you’re exploring solar in <Location>, bring this list to your consultations. You’ll quickly see which installer is prepared to deliver a safe, durable system—and which one is just selling.

Summary checklist (print or save)

• Licenses, insurance, certifications verified
• In‑house design and code‑compliant plans
• Equipment list with reasons and warranties
• Battery sizing tied to your goals and loads
• Transparent production and savings assumptions
• Workmanship and roof warranties in writing
• Permitting, interconnection, incentives handled
• Clear installation process and project manager
• Monitoring access and service SLAs
• Fair payment terms, change‑order and lien protections

PowerLutions Solar - helping homeowners make confident, long‑term energy decisions with custom solar energy in New Jersey and New York.