Chatsworth, CA · 2024 · LADWP / LADBS

One roof. Four arrays. Two angles.

A 13.77 kilowatt DC system on a Chatsworth house whose roof is not one surface. Fifteen modules lie flat on a low-slope section. Nineteen more sit at 35 degrees, facing two different directions.

A roof with a flat section and pitched planes does not force a compromise. The array is split into groups, each with its own pitch and heading, and the design accounts for each separately.

At a glance

DC System

13.77 kW

AC System

11.851 kW CEC

Modules

34 × REC 405 W

Inverters

Enphase IQ8M

Sub-arrays

Four

Angles

0° flat and 35°

Est. first-year output

12,986 kWh

Utility / AHJ

LADWP / LADBS

The story

Thirty-four REC 405-watt modules is a large residential array, and this roof would not take them in one block. Part of it is low slope. The rest runs at 35 degrees in two directions.

So the system was designed as four groups rather than one. Fifteen modules lie flush on the low-slope section, facing due south at zero tilt. Nine sit at 35 degrees facing south. Nine more sit at 35 degrees facing east, and a single module completes the east-facing run.

A module lying flat and a module at 35 degrees produce differently through the day and through the year, and an east-facing group peaks hours before a south-facing one. Different orientations call for an electrical design that keeps unlike roof planes from limiting one another. On this project every module has its own Enphase IQ8M microinverter, which gives independent operation and monitoring at each position.

The numbers for the whole thing: 13.77 kilowatts DC, 11.851 kilowatts AC-CEC, an estimated 12,986 kilowatt-hours in the first year. The proposal put that at 76 percent of what the house was using — a large array that still does not cover the whole bill, which is what a house this size with a pool looks like on paper.

Worth saying plainly: four groups is not complexity for its own sake. It is what happens when you use the roof you have rather than only the part of it that faces the right way.

How it ran

What we did

• Designed the array as four groups matched to the roof rather than one block.
• Laid fifteen modules flush on the low-slope section at zero tilt.
• Installed nineteen further modules at 35 degrees across two headings.
• Fitted a microinverter under every module so the groups run independently.
• Set up per-module monitoring across all thirty-four positions.

System specifications

Is your project like this one?

• Your roof has a flat section and pitched planes.
• Part of your roof faces east or west and you have been told to ignore it.
• You want a large array on a house that does not have one big clean roof.
• You have a pool and your bill is larger than the roof can fully cover.
• Your Chatsworth property is served by LADWP, while permits are handled by LADBS.

Cali Energy in Chatsworth

Frequently asked questions

Can solar panels lie flat on a roof?

Yes. On this house fifteen of the thirty-four modules sit flush on a low-slope section at zero tilt, facing south. Flat mounting gives up some winter output compared with a tilted frame, and it keeps the array out of sight from the street and avoids the wind loading a tilted frame brings. Which is right depends on the roof.

Do panels facing different directions work together?

They do when the electrical design accounts for it. Here every module has an Enphase IQ8M microinverter, so the east-facing group and the south-facing group produce on their own schedules and each position is monitored separately. Mixing unlike roof planes is a design question, and this is how it was answered on this roof.

Why would a large system still not cover the whole bill?

Because the roof sets the ceiling. This array is 13.77 kilowatts DC across four groups and was estimated at 76 percent of the household's use. On a house with a pool that is a normal result, and it is better to know the number before signing than to assume a large array means a zero bill.

Does Cali Energy design around awkward roofs in Chatsworth?

It is most of what the design work is. Chatsworth is inside City of Los Angeles boundaries, so permits run through LADBS and interconnection through LADWP, and the sub-array layout with its pitches and azimuths is part of the approved plan set.

What this would look like on your roof

Related

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This timeline reflects this property and this permitting path. Updated September 2026.