Northridge, CA · December 2021 – February 2022 · LADWP / LADBS
Same street, same tile, same module. Different job.
Two houses on one Northridge street went through design and installation in the same month. One storey and 23 modules; two storeys and 26. The differences are the interesting part.
Houses built in the same tract share a roof profile, a rafter spacing and often a service size. What they do not share is how much roof faces the right way, what the household uses, and what the existing panel has left in it. That is why two neighbours end up with different systems.
At a glance
- Array
- 8.51 kW DC — 23 × 370 W
- Modules
- 23 × REC 370 W
- Roof
- S-profile concrete tile
- Structure
- 2×4 rafters at 24 in on centre, single storey
- Busbar
- 225 A, existing
- Request to PTO
- Five weeks
- Neighbour's system
- 26 modules, three weeks later
- Utility / AHJ
- LADWP / LADBS
The story
These two projects were designed and built within three weeks of each other on the same Northridge street. Both houses sit on S-profile concrete tile over 2×4 rafters at twenty-four inches. Both took REC 370 watt modules. From the kerb they are the same job twice.
They are not. This one is a single storey, and it took twenty-three modules onto an existing 225 amp busbar — no service work at all. The house opposite is two storeys and a little larger, took twenty-six modules, and needed a completely new service to carry them.
The other difference is the roof's age. This tile has been on the house a long time, and a fair number of pieces were already cracked. Every one of them was photographed and marked before anything was lifted, so that what was broken beforehand and what broke during the work are two separate lists rather than one argument at the end.
That is worth doing on any old tile roof and it costs nothing but time. Broken tiles were replaced as the rails went down.
The rest ran on the utility's normal clock. The interconnection request went in three days before Christmas, the progress notices arrived through the first two weeks of January, the installation was released on the twentieth, and permission to operate came on the twenty-eighth. The neighbour's permission to operate followed eleven days later.
How it ran
| 21 December 2021 | Plans issued; interconnection request filed |
|---|---|
| 27 December 2021 | Utility fees paid |
| 6 January 2022 | First utility progress notices |
| 11 January 2022 | Solar site evaluation complete |
| 20 January 2022 | Solar service installation released |
| 28 January 2022 | Permission to operate |
The house across the street reached PTO eleven days after this one.
What we did
- Designed twenty-three modules onto the existing 225 amp busbar, with no service work.
- Photographed and marked every cracked tile before lifting anything.
- Replaced broken tile as the rails went down.
- Flashed and sealed each attachment before resetting the tile over it.
- Carried the interconnection from request to permission to operate in five weeks.
System specifications
| Array | 8.51 kW DC on the approved plans |
|---|---|
| Modules | 23 × REC REC370AA, 370 W |
| Microinverters | One per module |
| Roof | S-profile concrete tile, aged |
| Structure | 2×4 rafters at 24 in on centre, single storey |
| Racking | IronRidge |
| Busbar | 225 A, existing — no service work |
| Utility / AHJ | LADWP / LADBS |
Is your project like this one?
- Your neighbour has solar and you want to know why your quote is different.
- Your tile roof is old and you are worried about what breaks during the work.
- You want to know whether your existing panel can take an array without being replaced.
- You live in a tract where every house looks the same from the street.
- You want the roof documented before anyone starts lifting tile.
Cali Energy in Northridge
Northridge is inside City of Los Angeles boundaries: permits run through LADBS, interconnection through LADWP.
Whole blocks of Northridge went up as single tracts, which is why two houses opposite each other can share a roof profile and a rafter spacing and still need different systems.
This installation is on the Northridge projects page alongside the others, and what the work covers is set out on the Northridge service area page.
- License and classifications: CSLB #1032379
- Official reference for this process: LADWP interconnection requirements
- Official reference for this process: LADBS — inspections
Frequently asked questions
Why is my neighbour's system a different size to mine?
Two houses in the same tract can share a roof profile and a rafter spacing and still differ in how much roof faces the right way, what the household uses and what the existing panel has left in it. On this street one house took twenty-three modules with no service work and the other took twenty-six with a new service.
What happens to tiles that are already cracked?
On this roof every cracked tile was photographed and marked before any work started, so the pre-existing damage and anything broken during the work stayed as two separate records. Broken tile was replaced as the rails went down.
Does an array always need a panel upgrade?
No. It depends on what the existing busbar and main breaker will take alongside the house. This house connected to an existing 225 amp busbar with no service work at all.
How long did this take?
Five weeks from the interconnection request to permission to operate, over the Christmas and New Year period.
Do you photograph the roof before you start?
On tile, yes. It takes a few minutes and it means nobody has to argue later about which cracks were there first.
Does Cali Energy work on aged tile roofs?
Yes. Cali Energy holds B, C-10 and C-39 classifications under CSLB #1032379, which covers both the roofing and the electrical work.
What this would look like on your roof
Every number on this page came off a real job in Northridge, CA — not a brochure. Tell us your utility, your roof and what your bill looks like now, and we will model your own version of it before you commit to anything.
Or call +1 (323) 844-7777 · Cali Energy, Northridge · CSLB #1032379 (B, C-10, C-39) — design, permits, install and electrical under one licensed contractor.
Related
This timeline reflects this property and this permitting path. Updated September 2026.