What is a kilowatt-hour? kW vs kWh explained simply (2026)

One kilowatt-hour is simply 1,000 watts of power running for one full hour — it is the fundamental unit on every electric bill in Southern California. At SCE's current average of roughly 34–35¢ per kWh, a single kWh costs about as much as a gumball; the problem is that an average SoCal home burns through 600–700 of them every month.

Last verified: August 2026 by Helios Energy Global.

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kW vs kWh: the one analogy that makes it click

Think of electricity like water flowing through a hose:

• Kilowatt (kW) = the flow rate — how fast water is gushing out right now.
• Kilowatt-hour (kWh) = the total volume that flowed — how many gallons ended up in the bucket.

Your utility does not charge you for how fast you draw power at any given second. It charges you for the total energy you consumed over the billing period. That total is measured in kWh.

A 1,000-watt (1 kW) hair dryer running for one hour uses 1 kWh. The same hair dryer running for 30 minutes uses 0.5 kWh. A 100-watt bulb left on for 10 hours also uses 1 kWh. Same unit, very different appliances — because kWh multiplies power by time.

Why "kilo"?

"Kilo" means 1,000. So:

• 1 kilowatt = 1,000 watts
• 1 kilowatt-hour = 1,000 watt-hours

Your solar system's output is rated in kilowatts (kW) of capacity, but what it actually produces — and what offsets your bill — is measured in kilowatt-hours (kWh). That distinction matters enormously when you're comparing quotes. See how solar production is estimated →

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How your electric bill counts kWh

Your meter records every kWh that flows into your home from the grid. At the end of the billing cycle, your utility multiplies that number by its rate schedule to produce your bill. Simple in theory — but Southern California has three very different utilities with very different rates.

Utility	Avg. residential rate (2026 est.)	Peak hours (TOU)	Net metering structure
SCE (investor-owned)	~34–35¢/kWh blended	4–9 PM daily	NEM 3.0 (Net Billing Tariff)
LADWP (municipal)	~22¢/kWh blended	Varies by plan	Retail-rate net metering
SDG&E (investor-owned)	~50–55¢/kWh blended	4–9 PM daily	NEM 3.0 (Net Billing Tariff)
Pasadena PWP (municipal)	~18–22¢/kWh est.	Varies by plan	Own net metering program
Burbank / Glendale / Anaheim (municipal)	~18–24¢/kWh est.	Varies by plan	Own net metering program

Rates are approximate blended averages from utility filings and EIA data. Your actual rate depends on tier, TOU period, and baseline allocation.

Why does this matter for solar? At SDG&E, every kWh your panels produce is worth roughly 2× more in avoided costs than the same kWh at LADWP. That difference drives payback periods — and it's exactly why a custom design and savings estimate beats any generic online calculator.

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Typical kWh usage anchors for SoCal homes

Knowing what things actually consume helps you understand your bill and size a solar system correctly.

Common appliances (approximate kWh per use or per day)

• Central air conditioner (3-ton): ~3–4 kWh per hour of runtime
• Electric vehicle charger (Level 2, 7.2 kW): ~7–8 kWh per hour of charging
• Electric water heater: ~3–4 kWh per day
• Refrigerator (modern, full-size): ~1–2 kWh per day
• LED lighting (whole house, 8 hrs): ~1–2 kWh per day
• Pool pump (1.5 HP, 8 hrs): ~6–8 kWh per day
• Dishwasher (one cycle): ~1–2 kWh per cycle
• Clothes dryer (one load): ~3–5 kWh per load

Monthly household totals

A small condo or apartment in Los Angeles might use 300–450 kWh/month. A typical 3-bedroom house in the San Fernando Valley or South Bay lands around 600–800 kWh/month. A larger home with a pool, EV, and electric appliances can easily hit 1,200–1,800 kWh/month in summer.

Climate matters too: Inland areas like the San Gabriel Valley and Inland Empire run air conditioning far more than coastal Santa Monica, so usage can be 30–50% higher for similar-sized homes.

For a deeper dive on daily and monthly consumption, see our guides on how many kWh per day a home uses and how that maps to a solar system size on our solar page.

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How solar production is measured in kWh

A solar panel system's nameplate capacity is rated in kilowatts (kW). A 8 kW system means it can produce up to 8,000 watts at peak sunlight. But what you actually generate — and what offsets your bill — is measured in kilowatt-hours (kWh).

In Southern California, a well-oriented rooftop system produces roughly 4–5 kWh per day per installed kW of panels (per NREL PVWatts data for the LA basin). So:

• 6 kW system → approximately 24–30 kWh/day → ~720–900 kWh/month
• 8 kW system → approximately 32–40 kWh/day → ~960–1,200 kWh/month
• 10 kW system → approximately 40–50 kWh/day → ~1,200–1,500 kWh/month

These are estimates — actual production depends on roof pitch, shading, panel orientation, and local weather. Coastal homes get slightly less peak sun than inland ones.

How kWh interacts with net metering

If you're on SCE or SDG&E, you're under NEM 3.0 (the CPUC Net Billing Tariff). Excess kWh you export to the grid are credited at a low wholesale-ish rate — not the full retail rate you pay to import. That's why pairing solar with a home battery is increasingly important under NEM 3.0: you store kWh you'd otherwise export cheaply and use them during the expensive 4–9 PM peak instead.

LADWP customers have it differently. LADWP is a municipal utility and is not on NEM 3.0. LADWP still credits exported solar kWh at the full retail rate (~22¢/kWh), making the economics of solar-only systems more straightforward there. Other municipal utilities — Pasadena PWP, Burbank, Glendale, Anaheim — also run their own net metering programs separate from NEM 3.0. Read the full NEM 3.0 explainer →

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What a kWh costs you: the real math

At SCE's ~34–35¢/kWh blended average, a home using 700 kWh/month pays roughly $238–$245/month before fixed charges. At SDG&E's ~50–55¢/kWh, the same 700 kWh costs $350–$385/month. At LADWP's ~22¢/kWh, it's closer to $154/month.

Those differences explain why solar payback periods vary so dramatically by utility — and why a Santa Monica homeowner on SCE and a Pasadena homeowner on PWP need completely different system designs and financial analyses.

For a full breakdown of what solar panels cost before and after sizing for your specific kWh usage, visit our solar panel cost guide.

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Batteries store kWh for later

A home battery is rated in two ways:

• Power (kW): how fast it can discharge (e.g., 5 kW continuous output)
• Capacity (kWh): how much total energy it holds (e.g., 13.5 kWh)

A 13.5 kWh battery running at 5 kW output would last about 2.7 hours at full draw — enough to power most of a home through the SCE peak window. Installed cost for a single battery unit runs roughly $10,000–$16,000 in 2026.

Note on SGIP: California's Self-Generation Incentive Program (SGIP) offered rebates for home batteries, but residential SGIP funds are waitlisted in 2026 — not currently available for new applicants. Check our batteries page for the latest status.

Learn more about home batteries →

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Frequently asked questions about kilowatt-hours and kW vs kWh

What's the difference between kW and kWh in plain English?

A kilowatt (kW) is a measure of power — how much electricity something uses at a given instant. A kilowatt-hour (kWh) is a measure of energy — the total amount consumed over time. Your bill charges you for kWh; your appliances are labeled in watts or kW.

How many kWh does a typical house use per day in Southern California?

Most SoCal homes use roughly 20–30 kWh per day, though that range swings widely. A small coastal apartment might use 10–15 kWh/day, while a large inland home with a pool and EV can exceed 50 kWh/day in summer. See our solar page for usage-to-system-size charts.

How much does one kWh cost in Los Angeles?

It depends on your utility. LADWP customers pay roughly ~22¢/kWh on average. SCE customers in the greater LA area pay roughly 34–35¢/kWh on average. SDG&E customers in San Diego pay ~50–55¢/kWh on average. All figures are blended averages from utility rate filings — your actual rate depends on your tier and time-of-use plan.

How many kWh does a solar panel produce per day?

A single residential solar panel rated at 400 watts produces roughly 1.6–2.0 kWh per day in Southern California (assuming 4–5 peak sun hours). A full 20-panel, 8 kW system produces approximately 32–40 kWh per day on average — enough to cover most or all of a typical home's usage. Get a custom production estimate →

Does my utility charge more per kWh at certain times of day?

Yes, if you're on a time-of-use (TOU) plan — and most SCE and SDG&E residential customers are. SCE's TOU-D rate peaks at 4–9 PM daily, when rates are significantly higher than off-peak hours. LADWP also offers TOU plans, though its base rates are lower. This is why solar + battery systems that shift stored kWh into peak hours save more money under SCE and SDG&E than a solar-only system.

Is a bigger solar system always better if I use more kWh?

Not necessarily — the right system size depends on your actual kWh usage, roof space, utility net metering rules, and whether you're adding an EV or battery. Under NEM 3.0 (SCE, SDG&E), oversizing a system produces excess kWh that are credited at low rates, reducing your return. A custom design matches your system to your real consumption. You can also explore roof types and solar compatibility.

What happened to the federal solar tax credit in 2026?

The 30% federal residential solar tax credit expired on December 31, 2025. There is no federal tax credit available for a residential solar system installed in 2026. Always verify current incentives with a licensed tax professional — we can point you toward what's still available at the state and utility level during your consultation.

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Next steps

• Book a free consultation and custom design — we'll pull your actual kWh usage from your utility bill and show you exactly what a system would produce and save.
• See what solar costs in Southern California →
• Explore home battery storage →
• Understand NEM 3.0 and how it affects your kWh credits →
• Solar vs. battery under NEM 3.0: which makes more sense? →
• Learn about our Southern California service locations →
• Get a custom savings and production design →