← Power Stations Guide
Strategy Guide
Peak Shaving: Save Money Without Solar Panels
If your utility charges more during peak hours, a power station can cut your bill significantly — without any solar panels, without any rewiring, and without an electrician. Here is how it works.
What Are Time-of-Use (TOU) Rates?
Most utility companies charge a flat rate per kilowatt-hour (kWh) no matter when you use electricity. But many utilities — particularly in California, Texas, and the Northeast — offer or mandate Time-of-Use (TOU) pricing, where the rate per kWh changes based on the time of day.
Rates are typically structured in two or three tiers:
| Period | Typical Hours | Rate | Why |
|---|
| Off-Peak | 11 PM – 7 AM | Low (e.g., $0.12/kWh) | Low grid demand; excess supply from overnight generation |
| Mid-Peak | 7 AM – 4 PM | Medium (e.g., $0.22/kWh) | Moderate demand; workday hours |
| On-Peak | 4 PM – 9 PM | High (e.g., $0.48/kWh) | Everyone home, AC running, grid under stress |
Check your utility bill or utility company website to find out if you are on a TOU plan, and what your specific rates and hours are. In California, for example, PG&E customers on the E-TOU-C plan see rates that vary by a factor of 4× between off-peak and on-peak periods.
💡
Not on a TOU plan? You may be able to opt in. For households that can shift energy use (via a battery), TOU plans can dramatically lower bills. Contact your utility or check their website for enrollment options.
How Peak Shaving Works
The concept is simple: buy cheap electricity at night, use it during the expensive hours. A power station with a large battery is the tool that makes this possible.
1
Charge the Battery at Night (Off-Peak)
Set the power station to charge from the grid during off-peak hours (typically overnight). You are buying electricity at the cheapest possible rate and storing it in the battery.
2
Discharge During Peak Hours
During the expensive on-peak period (typically afternoon and early evening), the power station powers your loads from the battery. You draw little or nothing from the grid during the expensive hours.
3
Repeat Daily
The cycle repeats every day. The savings accumulate. Add solar panels later and you can also fill the battery for free during the day, making the savings even larger.
🧮 A Concrete Example
Say your on-peak rate is $0.46/kWh and off-peak is $0.12/kWh. You have a 5 kWh battery.
Cost to charge (off-peak): 5 kWh × $0.12 = $0.60
Value of 5 kWh during on-peak: 5 kWh × $0.46 = $2.30
Daily savings: $2.30 − $0.60 = $1.70/day
Annual savings: $1.70 × 365 = ~$620/year
A 5 kWh expansion battery for a home power station costs roughly $1,000–$1,500. Payback period: 2–2.5 years. After that, it is pure savings — for the life of the battery (typically 10+ years on LiFePO4).
What Equipment Do You Need?
A Power Station with Pass-Through Mode
The unit must support pass-through charging — powering loads from the battery while simultaneously charging from the grid. This is what allows seamless transition between modes without interruption.
Most mid-to-large power stations support this. Check the comparison chart’s pass-through row.
Scheduling & TOU Support
For automatic operation, the power station needs to support scheduled charging and discharging. This is typically configured via a smartphone app. Some units have built-in TOU mode where you enter your on-peak and off-peak hours.
Without scheduling, you would have to manually plug/unplug the charging cable. Useful to test the concept, but impractical long-term.
A Large Enough Battery
You want enough battery to cover your on-peak consumption. Check your utility bill for your average daily usage in kWh, then figure out what fraction falls during peak hours. That is the target battery size.
Most households use 1–5 kWh during the on-peak window. Expansion batteries on units like the EcoFlow DELTA Pro Ultra or Anker SOLIX F3800 can scale to 10+ kWh.
Home Integration (Optional but Ideal)
For the power station to power your whole home during peak hours, it needs to feed into your electrical system. Options range from plugging loads directly into the unit, to installing a generator inlet, subpanel, or smart panel. See
Solar Home Strategies for all the options.
Without home integration, you are limited to powering only appliances plugged directly into the unit’s outlets.
What to Look for in the Comparison Chart
Filter the Comparison Chart for these features to find peak-shaving-capable units:
✓
Pass-through mode = Yes
Non-negotiable. The unit must be able to power loads while simultaneously recharging from the grid.
Filter: pass-through = Yes
✓
Large expandable battery
More storage = more savings per day. Look for units with expandable battery options in the 5–15 kWh range for meaningful impact on a home electricity bill.
Filter: expandable = YesFilter: max_batt ≥ 5,000 Wh
✓
WiFi + smart app
For scheduled charging/discharging automation, the unit needs to be connected to your home network and have app-based TOU scheduling. Bluetooth-only units require manual operation.
Filter: WiFi = Yes
✓
Home integration output (14-30 or 14-50)
For whole-home coverage, the unit should have a NEMA 14-30 or 14-50 output so it can feed your home through a generator inlet installation.
Filter: 14-30 or 14-50 = Yes
