Comparing Solar and Battery Quotes on O‘ahu: Look Beyond the Total Price

Before comparing the total price of two solar-and-battery proposals, check whether they are designed to do the same job. Put the equipment, expected production, backed-up circuits, included work, and payment terms side by side.

For an O‘ahu home, ask each installer to identify the HECO program and assumptions behind the proposal, especially if you already have solar. HECO encourages customers to compare multiple rooftop solar bids and makes clear that it does not endorse or recommend solar contractors. HECO’s guidance

Give Each Installer the Same Starting Point

Share the same usage history and priorities with each company. Include roof information, an existing solar agreement if you have one, and any household changes you are planning.

Be specific about the job you want the system to do. Reducing grid purchases, keeping selected appliances available during an outage, and preparing for future EV charging are different goals. Ask each proposal to distinguish your current needs from assumptions about future use.

For an existing NEM home, ask how the proposed work fits the current agreement. Do not assume every addition requires moving to a different program—or that every design preserves the same arrangement. HECO provides separate pathways for existing NEM customers and reviews equipment amendments. HECO’s application and amendment guidance

Compare Equipment and Expected Output

Record the exact panel and inverter models, quantities, and system ratings. Ask for expected annual energy production and the assumptions behind it, including the proposed layout and shading. Panel count alone does not describe the complete design.

Keep the units clear: kilowatts (kW) describe power, while kilowatt-hours (kWh) describe energy over time. Ask installers to label array and inverter ratings consistently so you can compare the same measurement. An annual production estimate in kWh is not the same as an equipment rating in kW. Tesla’s explanation of power and energy

If estimates differ, ask why. The goal is to understand the assumptions, not automatically choose the largest number or treat an estimate as a guarantee.

Ask What the Battery Will Actually Back Up

Ask each proposal to identify the battery model, usable stored energy, output power, and the circuits included in backup. Find out which appliances are excluded or need to be managed during an outage.

A battery count or “whole-home” label is not enough to understand the proposed operation. Ask what the runtime estimate assumes about appliance use, starting charge, reserve settings, and solar recharge. Manufacturer backup guidance illustrates why the equipment and household loads matter; the actual design must establish what works for your home. Tesla’s backup guidance

Our home battery planning guide can help you prepare a priority-load list before comparing proposals.

Read the Included Work and Exclusions

Ask who is responsible for the roof review, electrical work, applicable permits, HECO coordination, inspections, and system start-up. Have each installer identify what is included and what could require a separate price or change order.

If reroofing may be needed, bring it into the conversation before comparing installation schedules. Our solar and reroofing guide covers the handoffs to clarify with both contractors.

Look beyond installation day as well. Ask who provides monitoring access, explains the system, supplies final documentation, and handles later service questions. These are scope questions to resolve in writing, not services you should assume are included in every quote.

Separate Price from Payment Assumptions

Record the full project price before conditional incentives. If the proposal shows an estimated net cost, ask which assumptions produce that number and what happens if an anticipated benefit does not apply. Verify any tax treatment separately for your circumstances.

A cash purchase, financed purchase, lease, and power purchase agreement create different payment and ownership arrangements. Ask for the full terms rather than comparing only an advertised monthly payment: payment schedule, term, any escalation, fees, ownership, and applicable transfer or end-of-term provisions.

The Federal Trade Commission recommends taking time to read solar agreements and reviewing warranties, payment schedules, cancellation policies, and fees. This article is a comparison checklist, not a recommendation of a particular financing arrangement. FTC’s consumer guidance

Your Quote Comparison Checklist

Use this list to compare each proposal, and ask the installer to clarify any missing details in writing.

• Household goals and usage period used
• Panel and inverter models and quantities
• Expected annual production and assumptions
• Battery models, usable energy, and output power
• Backed-up circuits and excluded loads
• HECO agreement and export assumptions
• Included roof and electrical work; exclusions
• Approval, inspection, and start-up responsibilities
• Gross price and conditional incentives
• Ownership and full payment terms
• Equipment warranty, workmanship, and labor coverage
• Service contact, monitoring access, and final records

A missing answer is a reason to ask for clarification, not automatic proof of a poor installer. For warranties, request the actual documents and ask who handles a claim, what labor is covered, and which exclusions apply. A long warranty term alone does not answer those questions.

Get Unclear Answers in Writing

Send each installer the questions that remain and compare the updated proposals. You should be able to explain what each system is intended to do, what work is included, and which assumptions affect the price and expected outcome.

That makes the final decision more useful than choosing by the lowest headline price—or the most optimistic estimate—alone.