West Adams, CA · September – November 2021 · LADWP / LADBS

West Adams: a second array on the leftover roof.

The south face was taken. What was left pointed east, west and north, and the question was whether that is a system worth building.

Written by the Cali Energy project team · California contractor license 1032379 · Updated September 2026

When a house already has solar, the best roof is usually already occupied, and a second system has to be designed on the faces that were rejected the first time. That is a real design rather than a compromise: module-level electronics mean each panel works independently, so an east, west and north layout does not drag itself down the way a single string would. Cali Energy designed and built the added array on the remaining roof of this West Adams house in Los Angeles, and cleared plan check in about six weeks.

At a glance

Array

340 W modules, black frames, across three roof faces

Inverters

One microinverter per module

Roof used

East, west and north faces

Existing

An older array already on the best face

Design to service release

About ten weeks

Utility / AHJ

LADWP / LADBS

The story

The request was unusual in a way that is becoming ordinary: the house already had solar, and the owner wanted more. Not a replacement — an addition. Use what is left of the roof.

What was left pointed east, west and north. The south face, the one every layout starts from, had been taken by the earlier array years before.

There is a reflex in this industry to treat that as a bad project. It is not, and the reason is the equipment. With a microinverter behind each module, every panel runs on its own — its own conversion, its own tracking of the best operating point. A module on a north face producing modestly does not pull down the modules beside it, because they are not electrically chained to it. On the older string designs they were, which is where the instinct that north roofs are worthless comes from.

East and west are better than their reputation too, and in a useful way. A south array peaks at midday. An east face carries the morning and a west face carries the late afternoon, so a spread layout produces a flatter curve across the day rather than a taller one in the middle. On a house that already has a midday-heavy array, that is not a consolation prize — it is the part of the day the first system does not cover.

So the framing for a second system is not 'the good roof is gone'. It is that the remaining roof does a different job, and the two together cover more of the day than doubling the first one would have.

The site was surveyed within days of the request, the layout went out at the beginning of October, and the full drawing set followed on the fourteenth. The owner approved the design the same day and permitting started immediately.

Plan check ran the way plan check runs. The application was filed on the twenty-second of October and came back incomplete three days later; it was refiled the same day. Fees were paid, the plan was assigned, and corrections were issued the same afternoon. A second round of corrections came in early November, and the plans were approved on the eighth.

Then a gap that catches people out. Approved plans are not a permit. Before one could be issued the department wanted a signed declaration from the contractor, and a city business tax registration number — an entirely administrative item that has nothing to do with the roof and will hold a project for days if nobody has it to hand. It was provided, the permit fees were issued on the twelfth, and the inspection request went in the following week. The building department's service release came through at the end of November.

About ten weeks from the first conversation to a released service, on a house that already had an array on it.

The system was commissioned in December and the house has run two arrays on one service since.

Cali Energy designed, permitted and installed this added array in West Adams, Los Angeles.

How it ran

Ten weeks from the first conversation. Six of them were plan check, and four days of those were an administrative number.

What we did

• Surveyed the roof within days of the request rather than quoting from an image.
• Designed the added array across east, west and north faces.
• Specified module-level electronics so each panel works independently.
• Carried the plan set through two rounds of corrections to approval.
• Supplied the declaration and registration the permit desk was waiting on.
• Commissioned the added array alongside the existing system.

System specifications

Is your project like this one?

• Your house already has solar and you want more of it.
• You have been told your remaining roof faces are not worth using.
• Your plans are approved and the permit has still not issued.
• Your east and west roof faces are the only ones left.

Cali Energy in West Adams

Frequently asked questions

Can I add a second solar system to a house that already has one?

Yes, and it is increasingly common. The design question is different from a first system: the best face is already occupied, so the added array is laid out on the faces that were rejected the first time. Both systems then sit on one service, which is a question the design and the interconnection have to account for together.

Is a north-facing solar panel worth installing?

It depends on the electronics behind it. With one microinverter or optimizer per module, each panel works on its own, so a lower-producing north module does not drag down the panels beside it. On older string designs it did, which is where the reputation comes from. A north face still produces least — it is just no longer a penalty on the rest of the array.

Are east and west roof faces good for solar?

They are better than their reputation, and they do a different job. A south array peaks at midday; an east face carries the morning and a west face the late afternoon. The result is a flatter production curve across the day rather than a taller one in the middle — which on a house that already has a midday-heavy array is exactly the part not yet covered.

Do approved plans mean I have a permit?

No. Approval of the drawings and issuance of the permit are separate steps. Between them the department can ask for a signed contractor declaration and a city business tax registration number — administrative items with nothing to do with the roof that will still hold a project for days if nobody has them to hand.

Does Cali Energy add to existing solar systems in West Adams, Los Angeles?

Yes. This West Adams project added an array to a house that already had one, using the east, west and north faces that remained. Projects here are permitted through LADBS and interconnected through LADWP, and the older housing stock means a good number of these roofs already carry solar from an earlier generation.

What this would look like on your roof

Related

• The azimuth check on a many-sided roof Brentwood, Los Angeles · 19.98 kW · the one number you cannot check by eye Solar
• No south face. The array went west and north instead North Hollywood, CA · 2.67 kW DC · new roof, converted dwelling Solar
• One roof. Four arrays. Two angles Chatsworth, CA · 13.77 kW DC · REC 405 W Solar
• The panel permit was already open. Under someone else's name Glendale, CA · 19 modules · 200 A panel, two spot drawings, one open file Solar
• The ADU was on the main house meter West Adams, Los Angeles · which address the interconnection belongs under Solar

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