Do Solar Panels Work at Night? California Guide

Short answer: no. Solar panels do not produce electricity at night. Solar photovoltaic (PV) cells need sunlight to generate current, and without sunlight they sit idle. But that's not the end of the story — homes with solar still run electricity through the night, either from a battery that stored the day's solar production, or from the utility grid. Here's exactly how it works in California and how NEM 3.0 changes the calculation.

How Solar Panels Actually Produce Power

A solar panel works by the photovoltaic effect — photons from sunlight knock electrons loose from silicon atoms in the cells, creating an electrical current. No sunlight, no photons, no current. This is why solar production follows the sun's path: zero at sunrise, peak around noon, zero again at sunset. On a cloudless day in California, a typical residential system produces 4-6 hours of "full" output, with partial production for a few hours on either side.

Moonlight produces a tiny amount of measurable current in very sensitive lab conditions, but it's thousands of times weaker than sunlight — not useful for household electricity.

So How Do Solar Homes Run at Night?

Two options: battery storage, or the grid.

Grid-tied solar (no battery). During the day, your panels produce electricity. Your home uses what it needs in real time; excess goes to the grid. At night, your home pulls from the grid like any non-solar house. You pay the utility for that evening grid consumption. Under NEM 2.0 (pre-April 2023), the export credits roughly balanced evening consumption. Under NEM 3.0, exports are credited at a much lower rate, so evening grid consumption is essentially a full-retail charge against a smaller export credit.

Solar + battery. During the day, your panels produce electricity. Your home uses what it needs; excess charges a battery on your wall. At sunset, the battery begins discharging into your home, covering evening use until it runs out. If the battery empties, you fall back to the grid. A properly sized solar + battery system can cover 80-95% of a typical California household's consumption, including the evening, without touching the grid.

Why This Matters More Under NEM 3.0

Under California's Net Billing Tariff, exported solar is credited at approximately 5-8 cents per kWh. Consumed electricity from the grid costs 35-46 cents per kWh depending on your utility. That 5-8x asymmetry means every kWh you self-consume (during the day OR via battery at night) is worth 5-8x a kWh you export.

Translation: a NEM 3.0 solar system without a battery exports most of its production at the low credit rate, then buys electricity back at the high retail rate at night. A NEM 3.0 solar + battery system stores the production and uses it at night, displacing the high-rate grid purchase. That's why battery storage moved from "nice to have" to "essentially required" under NEM 3.0. More detail in our NEM 3.0 worth-it analysis.

What Happens During a Power Outage at Night?

A common misconception: if the grid goes down at night and you have solar, you'll have power. Actually, a grid-tied solar system without a battery shuts off during outages for safety (to prevent backfeeding the grid while utility crews are working on lines). It's the battery that keeps your home running during an outage — day or night.

California homeowners in high-fire-risk areas subject to Public Safety Power Shutoffs (PSPS) lean heavily on battery storage for this reason. When the utility cuts power for wildfire safety, a solar + battery system keeps critical loads running for hours to days, depending on battery capacity and load management.

Does a Battery "Solve" the Nighttime Problem?

Mostly, yes. A typical 13.5 kWh residential battery (Tesla Powerwall, Enphase IQ, FranklinWH) stores enough energy to cover roughly 12-18 hours of typical California household consumption. Properly sized solar with one battery handles nightly cycling and still covers most mid-size outages. Larger homes or all-electric households (EV charging + heat pump + induction cooktop) often need two batteries.

Multi-day outages or winter storms with reduced solar production over consecutive cloudy days will eventually drain even a large battery. In those cases the grid (when it's up) fills the gap — which is why most California residential solar systems are grid-tied with battery backup rather than fully off-grid.

Frequently Asked Questions

Do solar panels work at all at night?

No, they need sunlight to produce electricity. They sit idle from sunset to sunrise.

How do I use solar electricity at night then?

Either via a battery that stored the day's production, or by pulling from the grid at night and letting the daytime solar export offset part of that cost on your bill.

Do solar panels work when there's a power outage at night?

A grid-tied solar system without a battery shuts off during outages. Only a solar + battery system keeps your home powered through a nighttime outage. See our outage-specific guide.

How big does my battery need to be to cover my nights?

For a typical California household, one 13.5 kWh battery (like Tesla Powerwall 3) covers most overnight consumption. Larger homes or all-electric setups usually need two batteries. Our system sizing guide covers the math.

Does moonlight work?

Moonlight is reflected sunlight. It produces a tiny trickle of measurable current in lab conditions but is far too weak for household electricity. Functionally, the answer is no.