Review three solar sizing assumptions

PVSize is asking for technical feedback on three early-planning scenarios. This page is not a quote, design, rebate estimate, or installation recommendation.

What kind of feedback helps?

Are the assumptions clear enough for non-experts?
Should each result show a wider range by default?
Are the formula labels honest and easy to audit?
Which warning should appear before someone uses the result?

For the full public GitHub version, see Solar Sizing Feedback Request.

1,500 kWh/month panel count

A high-usage home wants a first-pass panel count estimate before installer conversations.

Open editable calculator

Load
1,500 kWh/month, about 50 kWh/day

Solar input
4.5 sun hours, 400 W panels

Efficiency
80% simple system efficiency

Simplified approach: panel daily kWh = panel watts / 1000 * sun hours * system efficiency. Under these assumptions, the planning estimate is about 35 panels before roof layout, shading, and local design constraints.

Overnight outage battery sizing

A homeowner wants essential overnight backup, not a whole-home backup design.

Open editable calculator

Load
8 kWh essential overnight load

Backup
1 night planning window

Battery
LiFePO4, 90% DOD, 90% inverter efficiency

Simplified approach: required battery kWh = load kWh / (usable depth of discharge * inverter efficiency). Under these assumptions, the planning estimate is about 10 kWh nominal capacity.

Off-grid cabin, 8 kWh/day

An off-grid cabin needs a rough panel and battery estimate before deeper system design.

Open panel calculator Open battery calculator

Daily use
8 kWh/day

Solar input
4 sun hours, 400 W panels, 75% efficiency

Backup
2 days, 80% usable battery depth

Simplified approach: about 7 panels and about 20 kWh nominal battery capacity before winter sizing, generator backup, temperature derating, and charge controller limits.

Leave lightweight feedback

Please do not include private customer data, addresses, utility bills, or personal contact details. The form is for technical notes on assumptions and wording.

PVSize feedback does not create a quote, partnership promise, engineering review, or installation recommendation.