You installed solar panels to lower your electricity bill—so it’s understandable to question when your utility bill is higher than expected. In most cases, the explanation comes down to a few interacting factors: home energy consumption, solar production, and utility rates.
Your system was designed around past usage
Your home solar system was likely sized based on your historical electricity usage, along with factors like roof space and budget. If your current usage is higher than what the system was designed to offset, you’ll draw more electricity from the grid and your bill will increase.
Consumption often rises in warmer months or at night (sometimes without noticing)
A high utility bill is often a sign you’re using more electricity than the amount used to design your solar system. Common drivers include:
- Air conditioning changes: Turning the AC down even a degree or two can materially increase usage; you can also check when you last had your AC unit serviced.
- Seasonal activities: Heating a pool; entertaining more guests.
- More people at home: Summer guests, or children home during summer months, can increase overall consumption.
- New or malfunctioning appliances: New appliances may use more energy than before; an appliance that isn't working correctly can also consume more energy.
Keep in mind: once the sun goes down, your panels stop producing power. Unless you have a solar battery to store excess energy for later, you’ll need to draw electricity from the grid at night.
Solar production can drop due to weather or obstructions
Even if your usage hasn’t changed, the amount of energy your home solar system offsets can vary based on:
- Weather: Multiple cloudy or rainy days in a row; hazy summer days due to wildfire smoke and debris in the air.
- Obstructions and buildup: Shade from trees or shrubs; dust or pollen; debris/dirt on the panels.
Utility rates may be higher in summer and at peak times
Your bill can also increase if your utility rate changes seasonally or if you’re on time-of-use (TOU) pricing. Utility prices are often highest in the summer and during peak-demand hours (often in the evenings). Be sure you understand how your utility is billing you, and try to avoid consumption during peak times when possible.
Bottom line: The best way to think about your solar savings is as a balance of production, consumption, and utility rates. Solar is a great tool to limit exposure to rising utility costs, and you’ll get the most benefit by continuing smart energy-saving habits and keeping panels clean and in direct sunlight.