Did NEM 3.0 Turn Solar Panels West? No: 111,000 SCE-Area Roofs in LA County, 2020–2026
No. Among home solar systems connected in Southern California Edison’s part of Los Angeles County from 2020 to March 2026, about 29% faced west in every year — 29.5% in 2020, 28.4% in 2025 — and systems on the new net billing tariff faced west as often as those on NEM 2.0 (29.6% against 29.3%). South stayed the main direction at about 54%. What did change was the tilt: the share of arrays at 10° or less doubled, from 10% of systems in 2020 to about 20% in 2024–2025.
When California replaced NEM 2.0 with the Net Billing Tariff for new applications from April 15, 2023, exported solar became worth far more in the late afternoon and evening than at noon. West-facing panels make more of their power late in the day, so a common expectation was that new systems would turn west. The state’s interconnection records show whether that happened: every system that connects to SCE’s grid is listed in the CPUC’s DG Stats with the azimuth and tilt its installer reported, and the tariff it was approved under.
Direction by year
Residential rooftop systems in SCE territory, Los Angeles County, by the year SCE approved the connection.
| Year approved | Systems | Listed as 180° / 18°* | South | West | East | North | Tilt 10° or less |
|---|---|---|---|---|---|---|---|
| 2020 | 9,484 | 16% | 54.3% | 29.5% | 13.6% | 2.7% | 10.4% |
| 2021 | 13,880 | 14% | 53.2% | 30.0% | 14.7% | 2.1% | 10.6% |
| 2022 | 22,118 | 15% | 54.0% | 29.6% | 14.0% | 2.4% | 13.0% |
| 2023 | 28,035 | 14% | 54.4% | 29.2% | 13.6% | 2.8% | 15.2% |
| 2024 | 16,884 | 16% | 54.9% | 29.5% | 12.9% | 2.7% | 19.6% |
| 2025 | 16,165 | 14% | 55.2% | 28.4% | 12.5% | 4.0% | 19.5% |
| 2026 | 4,839 | 14% | 52.5% | 31.1% | 13.3% | 3.0% | 18.1% |
| *Records listed at exactly 180° and 18° look like a form default rather than a measured roof; they are left out of the direction and tilt shares (15% of all records). 2026 covers January–March. | |||||||
https://cali-energy.com/research/solar-panel-orientation-west-nem-3-los-angeles. Aggregated data are free to use under CC BY 4.0 with a link to this page.By tariff and battery
The tariff is the one recorded by SCE, not inferred from the date.
| Group | Systems | South | West | East | North |
|---|---|---|---|---|---|
| NEM 2.0, all | 66,994 | 54.6% | 29.3% | 13.6% | 2.5% |
| Net billing (NEM 3.0), all | 27,627 | 53.3% | 29.6% | 13.5% | 3.6% |
| With battery, NEM 2.0 | 9,137 | 59.2% | 26.2% | 11.7% | 3.0% |
| With battery, net billing | 20,755 | 52.6% | 29.4% | 13.9% | 4.1% |
| No battery, NEM 2.0 | 57,857 | 53.9% | 29.8% | 13.9% | 2.4% |
| No battery, net billing | 6,872 | 55.5% | 30.3% | 12.1% | 2.1% |
The tariff split is clean: 29.6% of net billing systems faced west against 29.3% under NEM 2.0. The one group that moved was battery systems: 29.4% faced west under net billing against 26.2% of battery systems under NEM 2.0. Under net billing most new systems carry a battery (75% here), and a battery, not the panel direction, is what moves midday solar into the evening. Why the tariff rewards evening power: NEM 3.0 export credits explained.
Where the panels point, and what each direction gives
| Direction | Share of arrays | Energy against due south* |
|---|---|---|
| South | 42.5% | 100% |
| Southwest | 12.2% | 97% |
| West | 22.4% | 87% |
| Southeast | 9.1% | 95% |
| East | 9.3% | 85% |
| Northwest | 2.5% | — |
| North | 1.9% | 69% |
| Northeast | 0.1% | — |
| *NLR (formerly NREL) PVWatts v8, a 20° roof in Northridge, from our runs published in east-west versus south-facing solar. | ||
Two in five arrays point roughly due south (within 22° either way), and about one in five roughly due west. A due-west array makes about 87% of what the same roof would make facing south, a southwest one 97%, an east one 85%. That trade is small next to the cost of leaving a roof face empty, which is one reason installers fill whatever face has room and sun. The direction your own panels face, and what it is worth on your rate, is covered in east-west versus south-facing solar; how panels on two faces of one roof compare in practice is measured in panel-by-panel data.
Tilt and roof pitch
| Tilt | Share of arrays |
|---|---|
| 10° or less (flat or low-slope) | 15.2% |
| 11–15° | 10.8% |
| 16–20° | 39.4% |
| 21–25° | 25.7% |
| 26–30° | 6.7% |
| over 30° | 2.1% |
| Pitch (rise over 12) | Share of arrays |
|---|---|
| 4/12 | 37.0% |
| 5/12 | 23.6% |
| 3/12 | 12.7% |
| 6/12 | 7.7% |
| 0/12 | 7.6% |
| 2/12 | 5.8% |
| Pitch converted from the reported tilt: rise = tan(tilt) × 12, rounded. 4/12 is about 18–19°. | |
Most arrays sit on ordinary sloped roofs: 4/12 and 5/12 together account for about 61% of systems. The change is at the flat end. Arrays at 10° or less made up 10% of systems approved in 2020 and 20% in 2025 — flat and low-slope roofs, and panels laid nearly flat on them. The records do not say why; more flat-roof homes going solar and fewer tilt racks are both possible. A flat array gives up some winter output and sheds dust less readily; see solar on flat and low-slope roofs.
City by city, and Ventura County
| City | Systems | South | West |
|---|---|---|---|
| Lancaster | 8,322 | 54.2% | 30.4% |
| Palmdale | 7,257 | 51.8% | 30.0% |
| Long Beach | 5,157 | 57.2% | 27.0% |
| Santa Clarita | 4,609 | 56.0% | 28.8% |
| Whittier | 3,439 | 55.3% | 25.5% |
| Valencia | 3,415 | 56.1% | 30.8% |
| Pomona | 2,520 | 49.2% | 33.9% |
| West Covina | 2,269 | 54.5% | 26.3% |
| City as recorded in DG Stats. Only cities served by SCE appear; most of the City of Los Angeles is LADWP territory and not in this dataset. | |||
Ventura County shows the same picture: 30% of arrays faced west over 2020–2026 (21,000 systems with usable data), and the share did not rise under net billing (25.2% in 2025). Its low-tilt share rose even faster, from 6% in 2020 to 23% in 2025.
Methodology
- Data
- CPUC California Distributed Generation Statistics, Interconnected Project Sites for SCE, January 2020 – March 2026: residential systems in Los Angeles and Ventura counties, rooftop-mounted, with the year SCE approved the interconnection.
- Direction
- One azimuth per system, as the installer reported it. Systems on several roof faces carry a single value, usually the main face. South 135–225°, west 225–315°, east 45–135°, north otherwise; compass points by 45° sectors.
- Defaults
- 16,369 Los Angeles County records (15%) list exactly 180° and 18°, the pattern of a form default. They are excluded from direction and tilt shares; with them, south would look larger.
- Tariff
- The NEM tariff recorded for each system (NEM 2.0 or Net Billing Tariff), not the approval date. Many systems approved after April 2023 applied earlier and kept NEM 2.0.
- Energy by direction
- NLR (formerly NREL) PVWatts v8, 20° tilt, Northridge typical-year weather, from our published runs.
- Limits
- Installer-reported values, not measured on site. LADWP territory, including most of the City of Los Angeles, is not in this dataset.
Sources: CPUC, California Distributed Generation Statistics (californiadgstats.ca.gov), SCE Interconnected Project Sites, data through March 2026; PVWatts v8, National Laboratory of the Rockies.
Frequently asked questions
Did NEM 3.0 make installers face solar panels west?
Not in SCE’s part of Los Angeles County. About 29% of home arrays faced west every year from 2020 to 2025, and net billing systems faced west 29.6% of the time against 29.3% for NEM 2.0 systems.
Which direction do most solar panels face in Los Angeles?
South. About 54% of arrays face south (135–225°), 29% west, 14% east and 3% north.
How much less do west-facing solar panels produce?
In PVWatts runs for a 20° roof in Northridge, a due-west array makes about 87% of a south-facing one over a year, and more of it in the late afternoon.
What roof pitch do most LA solar systems have?
4/12 is the most common, at about 37% of arrays, followed by 5/12 at 24%.
Are more solar panels being installed flat?
Yes. Arrays at 10° or less rose from 10% of systems approved in 2020 to 20% in 2025.
More research
Next steps
Deciding which roof faces to use?
Prepared by Cali Energy, October 15, 2026. Figures describe public interconnection records and are not a guarantee of what any specific roof will produce; orientation, tilt, shade, equipment and weather change results. Not engineering, financial or utility advice. See our Content Disclaimer.