If you have solar in Sacramento, there is a good chance you have noticed the same pattern every year: production looks great through spring and summer, then starts falling as the days get shorter.

That does not necessarily mean anything is wrong with your system.

Winter solar production in Sacramento is naturally lower than summer production. The bigger question is how much of a drop is normal—and what that lower production means for your PG&E bill.

Why Does Solar Production Drop During a Sacramento Winter?

The biggest factor is not cold weather. It is available sunlight.

During winter, Sacramento has shorter days and a lower sun angle. Your panels simply have fewer hours each day to produce energy, and the sunlight reaching them is less direct than it is during late spring and summer.

Cloud cover and storms can reduce production further.

PG&E specifically notes that solar systems may produce less energy during winter because days are shorter and cloudier. You can read more in PG&E’s information on solar billing.

Cold Temperatures Are Not Necessarily Bad for Solar Panels

This surprises a lot of homeowners.

Solar panels do not need hot weather to work well. In fact, photovoltaic modules generally operate more efficiently at cooler temperatures.

The problem with winter is that the efficiency benefit from cooler panels usually cannot make up for the shorter days, lower sun angle, clouds, and seasonal shading.

So a bright, cool Sacramento winter afternoon can actually produce very good instantaneous power. There just are not as many productive solar hours in the day.

How Much Should Winter Solar Production in Sacramento Drop?

There is no single percentage that applies to every solar system.

A system’s winter production depends on several factors, including:

• Roof orientation
• Panel tilt
• System size
• Tree and structure shading
• Weather
• Panel condition and soiling
• Inverter or microinverter performance

A south-facing array with relatively steep panels may hold up better in winter than an east/west system with a shallow roof pitch.

Seasonal shading can also become much more noticeable. The lower winter sun can place trees, chimneys, neighboring homes, and other obstructions in the path of sunlight that did not affect the array during summer.

For that reason, comparing December production directly against June production usually does not tell you whether a system is performing correctly.

Will My PG&E Bill Go Up During Winter Even With Solar?

Possibly—and that can be completely normal.

During winter, your solar system is generally producing fewer kilowatt-hours while your home may simultaneously be consuming more electricity.

That combination can increase the amount of power you import from PG&E.

Common winter loads include:

• Electric space heating or heat pumps
• More indoor lighting
• Longer periods spent at home
• Electric water heating
• Holiday cooking and appliance use
• EV charging

If production falls while consumption increases, grid imports naturally go up.

That does not automatically indicate a solar problem.

Your PG&E Solar Plan Also Matters

How that winter energy usage affects your actual bill depends heavily on which solar billing program and rate plan you have.

For customers on older Net Energy Metering programs, energy charges and credits may accumulate throughout the billing year before being reconciled at True-Up.

Customers under the newer Solar Billing Plan have a different relationship between the value of exported solar energy and the cost of electricity imported later.

If you are not sure which program you have, see NEM 2.0 vs. NEM 3.0: How Can I Tell Which Plan I Have?

PG&E also began replacing the residential Minimum Electric Charge with a Base Services Charge in March 2026. That charge cannot generally be offset by solar generation credits, so homeowners should not assume that every dollar appearing on a solar bill is related to system performance.

Winter Production Can Make Your PG&E True-Up Look Worse

If you are on a NEM billing structure, winter often represents the portion of the year when you begin using credits that may have accumulated during stronger production months.

That means your running True-Up balance can move in the wrong direction during winter even while the solar system is operating normally.

The important number is not necessarily one individual month.

You need to look at production, consumption, grid imports and exports, and billing over a longer period.

For a deeper explanation, see my guide to PG&E Solar True-Up bills for Sacramento homeowners.

When Is Low Winter Solar Production Actually a Problem?

Seasonal production loss is normal. A sudden or unexplained drop is different.

I would take a closer look if:

• Production is dramatically lower than the same month last year
• One section of the array is producing much less than the others
• Your inverter or monitoring platform shows errors
• One or more microinverters or optimizers stop reporting
• Production suddenly drops instead of gradually declining with the season
• Your PG&E bill increases substantially without a corresponding increase in household usage

Year-over-year comparisons are especially useful.

Comparing January to July tells you very little. Comparing January of this year with January of last year under similar conditions can tell you much more.

How to Tell Whether the Problem Is Winter or Your Solar System

Start by looking at your solar monitoring history.

Compare monthly production against the same months in previous years. Then compare that information with your PG&E usage and billing data.

PG&E allows customers to review electric usage by month, day, and even shorter intervals through its online account tools. That data can be extremely helpful when trying to separate a production problem from increased household consumption.

There are really three separate questions:

1. How much electricity did the solar system produce?
2. How much electricity did the house consume?
3. How much electricity moved between the house and PG&E?

Those numbers are related, but they are not the same.

If the bills still do not make sense after comparing them, a more detailed solar performance and utility bill analysis can determine whether the issue is production, consumption, system configuration, rate structure, or simply normal seasonal variation.

The Bottom Line on Sacramento Solar Production in Winter

Lower solar production during a Sacramento winter is normal.

Shorter days, a lower sun angle, cloud cover, and seasonal shading all reduce the amount of solar energy available to your system. At the same time, household electricity consumption may increase.

As a result, you may import more electricity from PG&E and see your bill or running True-Up balance increase during winter.

The key is determining whether the change follows a normal seasonal pattern.

If production gradually falls going into winter and remains reasonably consistent with previous years, the system may be doing exactly what it should. If production suddenly drops, individual panels disappear from monitoring, or the numbers are significantly different from prior winters, that is when it makes sense to investigate further.