Why Is My SMUD Bill So High in Summer? The AC Math for Folsom Homes
A high summer SMUD bill in Folsom is almost never a mystery. It is one appliance — the air conditioner — running its longest hours during the three most expensive hours of the day. The math below uses SMUD’s published 2026 rates, so you can see exactly where the money goes and which of the three fixes pays back first.
Fast answer: On SMUD’s Time-of-Day rate, weekday electricity from 5–8 p.m. (June 1 – September 30) costs $0.3765 per kWh — nearly 3× the $0.1285 off-peak rate. An AC that runs through that window costs roughly $4 per day for those three hours alone. Pre-cool before 5 p.m., keep the system tuned, and replace it when it passes 15 years.
What the SMUD summer rate actually charges
SMUD charges Time-of-Day pricing between June 1 and September 30: $0.3765 per kWh on weekdays from 5 to 8 p.m., and $0.1285 per kWh the rest of the day, per SMUD’s 2026 residential rate schedule. That 2.9× spread is the entire story of a painful August bill — the rate is designed to move load out of the early-evening window, and an AC left on its normal schedule does the opposite.
How much the peak window costs a Folsom AC owner
The peak window costs a typical Folsom home about $4 per weekday in compressor time. A 3-ton central system draws roughly 3.5 kW while running. If it runs through the full 5–8 p.m. window — normal on a 100°F day — that is 10.5 kWh × $0.3765 ≈ $3.95 per day. Across a 90-day summer with weekends at off-peak pricing, the peak window alone adds roughly $250–$350 to the season. An older 10-SEER unit, which wastes 25–40% of its energy compared to a modern system, pushes that number higher still.
How to cut the bill without touching the equipment
Cutting the bill starts with moving run-time, not replacing hardware. Pre-cool the house to 72°F between 2 and 5 p.m. at the $0.1285 off-peak rate, then set the thermostat to 78°F and let the house coast through the peak window. The compressor does the same total work but bills most of it at one-third the price. Ceiling fans, closed west-facing blinds, and delaying the dishwasher and dryer past 8 p.m. all push load in the same cheap direction.
When the equipment itself is the problem
The equipment is the problem when the run-times themselves are too long. Two thresholds matter. First, maintenance: a well-maintained system runs 15–25% more efficiently than a neglected one — a dirty condenser coil alone can increase energy use by 25%. A $189 spring AC tune-up is the cheapest kilowatt-hours you will ever buy. Second, age: switching from a 10 SEER to a 17–20 SEER system saves the average Folsom household $300–$700 per year on the SMUD bill. If your system is 15+ years old, the AC replacement math now includes SMUD’s 2026 rebates — up to $3,000 for a gas-to-electric heat pump conversion — though the federal 25C tax credit expired December 31, 2025 and no longer applies.
A system that suddenly runs constantly without cooling is a different problem — low refrigerant, a failing capacitor, or restricted airflow — and shows up on the bill before it shows up as a breakdown. Current price ranges for those fixes are in the AC repair cost in Folsom guide.
Frequently asked questions
Why is my SMUD bill so high in summer?
SMUD bills spike in summer because air conditioning is the largest load in the house and it runs hardest during the most expensive hours. Weekday electricity from 5 to 8 p.m. costs $0.3765 per kWh from June through September — nearly three times the off-peak rate.
How much does it cost to run an AC during SMUD peak hours?
A 3-ton system drawing about 3.5 kW that runs the full 5–8 p.m. window uses roughly 10.5 kWh — about $3.95 per weekday at the 2026 peak rate, or roughly $250–$350 across the summer for that window alone.
Can pre-cooling lower a SMUD summer bill?
Pre-cooling can lower the bill because it shifts compressor run-time to off-peak pricing. Cool to 72°F before 5 p.m., then let the house drift to 78°F through the peak window.
Should I tune up or replace my AC to lower the bill?
You should start with a tune-up — 15–25% efficiency recovery for $189 — and consider replacement once the system passes 15 years, where a high-SEER upgrade saves $300–$700 per year and SMUD’s 2026 rebates apply.