Navigating Time-of-Use Rates with Solar Energy

What Are Time-of-Use Rates?

Let’s cut through the utility jargon. Time-of-Use (TOU) rates are simply a pricing structure where the cost of electricity changes based on the time of day. Think of it like surge pricing for Uber, but for your lights and air conditioner.

Instead of paying one flat rate per kilowatt-hour (kWh) all day, your utility charges you more when demand is high and less when demand is low. The logic is straightforward: the grid gets strained during certain hours—usually late afternoons and early evenings when everyone gets home, cranks up the AC, and starts cooking dinner. To discourage you from using power during those stressful moments, utilities jack up the price.

The Three Periods You Need to Know

Every TOU plan breaks the day into three distinct pricing windows. They’re not always labeled the same way, but the concept is universal.

• Peak Hours (The Expensive Zone): This is the golden hour for your utility company, and the enemy of your wallet. Typically, peak hours run from late afternoon to early evening—say, 4:00 PM to 9:00 PM. During this window, you could be paying $0.40 to $0.60 per kWh or more, depending on your region. This is when you want to use as little grid power as humanly possible.

• Off-Peak Hours (The Bargain Bin): These are the rest of the day—late nights, early mornings, and mid-day on weekends. Rates here drop significantly, often to $0.10 to $0.15 per kWh. This is the time to run your dishwasher, charge your electric vehicle, or do laundry. Your solar panels are also pumping out power during the middle of the day, which aligns perfectly with off-peak pricing.

• Super Off-Peak Hours (The Deep Discount): Some utilities offer a third tier, usually between midnight and 6:00 AM. Here, rates can plummet to $0.05 to $0.08 per kWh. This is the absolute cheapest power you’ll ever buy. If you have a smart home system, you can program your water heater, pool pump, and EV charger to run exclusively during these hours.

A Real-World Example: How Your Bill Changes Hour by Hour

Let’s make this concrete. Imagine you live in California and you’re on a standard TOU plan from Pacific Gas & Electric (PG&E). Here’s what a typical weekday rate structure looks like:

Time of Day	Rate per kWh	Period Type
12:00 AM – 6:00 AM	$0.12	Super Off-Peak
6:00 AM – 4:00 PM	$0.18	Off-Peak
4:00 PM – 9:00 PM	$0.52	Peak
9:00 PM – 12:00 AM	$0.18	Off-Peak

Now, let’s run two scenarios for a typical summer day where you use 30 kWh total.

Scenario A: No solar, no awareness. You run your AC all afternoon, do laundry at 5:00 PM, and charge your phone at 8:00 PM. You’re pulling 10 kWh during peak hours. That costs you: 10 kWh × $0.52 = $5.20 just for those five hours. The other 20 kWh at off-peak rates cost $3.60. Your total: $8.80.

Scenario B: Solar + smart timing. You have a 6 kW solar system. During peak sun hours (10:00 AM to 3:00 PM), your panels generate 24 kWh. You run your AC, dishwasher, and pool pump during that time. By 4:00 PM, your home is cool, the dishes are done, and your batteries are full. You use almost zero grid power during peak. Your only grid draw is 5 kWh during super off-peak at $0.12 each. Total bill: $0.60.

That’s a difference of $8.20 per day, or roughly $250 per month in savings during summer. That’s not a rounding error—that’s a car payment.

Why the Goal Is to Avoid Peak Hours at All Costs

Here’s the hard truth: your solar panels generate most of their power between 10:00 AM and 3:00 PM. That’s great—it’s off-peak. But peak hours start at 4:00 PM, right when your solar production is fading. Without a battery, you’re stuck buying expensive power just as the sun goes down.

The entire game of TOU rates is about shifting your energy consumption away from peak hours. You don’t need to be a martyr. You just need to be strategic.

• Run heavy appliances during the day. Wash your clothes at noon, not 6:00 PM. Run the dishwasher right after lunch.
• Pre-cool your home. If peak starts at 4:00 PM, crank the AC at 2:00 PM and let the house coast through the evening.
• Use timers and smart plugs. Set your water heater to heat water at 1:00 PM. Program your EV charger to start at 11:00 PM.

The Hidden Trap: Net Metering and TOU Don’t Mix Well

Here’s where it gets tricky. Under traditional net metering, you get a one-to-one credit for every kWh you send back to the grid. But with TOU rates, the value of that credit depends on when you export.

If you send power back at 2:00 PM (off-peak), you might get credited at $0.18 per kWh. But if you pull power at 6:00 PM (peak), you pay $0.52 per kWh. That’s a massive mismatch. A battery solves this: you store your cheap afternoon solar and use it during expensive peak hours. Without a battery, you’re effectively selling low and buying high.

What Utilities Don’t Tell You

Most utilities won’t volunteer this, but TOU rates are designed to flatten the grid’s demand curve. They want you to shift usage, but they also want you to stay on the grid. That’s why many TOU plans have a fixed monthly charge—often $15 to $30—just to be connected. Solar doesn’t eliminate that.

Also, watch for seasonal rate changes. Summer peak rates are often 30-50% higher than winter rates. And some utilities have “critical peak pricing” events—10 to 15 days a year where rates can spike to $1.00+ per kWh during heat waves. If you’re not prepared, one bad afternoon can wipe out a month of savings.

The Bottom Line

Time-of-Use rates aren’t complicated once you see the pattern. You pay more when the grid is stressed, less when it’s relaxed. Your solar panels are a powerful tool, but they’re not a magic wand. The real financial win comes from pairing solar with smart timing—and ideally, a battery.

If you can shift 80% of your peak-hour usage to off-peak or solar-generated hours, you’ll cut your electric bill by 50-70% before you even factor in solar production. That’s the math that makes TOU rates work for you, not against you.

How Solar Panels Shift the Math

Let’s get straight to the point: Time-of-Use rates are designed to punish the afternoon energy hog and reward the daytime producer. If you’re still pulling all your power from the grid, you’re fighting an uphill battle. But the moment you install solar panels, the entire equation flips. Your roof becomes a mini power plant that cranks out electricity exactly when the utility wants to charge you the most.

The Natural Alignment: Sun Hours = Peak Hours

Here’s the beautiful, almost unfair advantage solar owners have. Peak rate periods—typically 4:00 PM to 9:00 PM in most markets—are when the sun is still high or just starting to dip. Your panels are generating maximum power between 10:00 AM and 4:00 PM. That’s a direct overlap with the shoulder and early peak periods.

Think of it this way:

• Without solar: You pay $0.40 per kWh to run your AC from 5:00 PM to 7:00 PM.
• With solar: Your panels are producing that exact power for free during those hours. You’re not paying the utility a dime for that usage.

But it gets even better. Most solar systems overproduce during the midday hours (11:00 AM to 3:00 PM). That extra power doesn’t disappear—it gets exported to the grid. Under Net Energy Metering (NEM), you earn credits at the retail rate for that exported power. So you’re not just avoiding peak charges; you’re building a bank of credits to offset your nighttime consumption.

The Real World: Before vs. After Solar

Let’s walk through a concrete example. Imagine a typical household in California on a standard TOU-D-4-9 plan. The summer rates look like this:

• Peak (4:00 PM - 9:00 PM): $0.45/kWh
• Off-Peak (all other hours): $0.25/kWh

Here’s how the math changes for a home that uses 30 kWh per day, with heavy AC usage during peak hours.

Scenario A: Home Without Solar You run your AC, cook dinner, and watch TV from 5:00 PM to 9:00 PM. That’s 12 kWh of usage during peak time.

• Peak usage cost: 12 kWh x $0.45 = $5.40
• Off-peak usage cost: 18 kWh x $0.25 = $4.50
• Total daily cost: $9.90

Scenario B: Home With a 6 kW Solar System Your panels produce 28 kWh on a sunny summer day. You use 8 kWh of that directly during the day (running the AC at 1:00 PM). The remaining 20 kWh gets exported to the grid during peak and off-peak hours.

• You export 15 kWh during peak time, earning $6.75 in credits (15 x $0.45).
• You export 5 kWh during off-peak time, earning $1.25 in credits (5 x $0.25).
• You still consume 12 kWh from the grid at night (peak), costing you $5.40.
• Net cost: $5.40 - $6.75 - $1.25 = -$2.60 per day. You’re actually earning money.

Quick Cost Comparison Table

Here’s a clean, side-by-side breakdown of that same 30 kWh day under a standard TOU plan. This assumes a 6 kW system with optimal south-facing orientation.

Cost Category	Home Without Solar	Home With Solar (6 kW)
Peak Usage (12 kWh)	$5.40	$0 (covered by solar credits)
Off-Peak Usage (18 kWh)	$4.50	$4.50 (nighttime usage)
Solar Production (28 kWh)	N/A	-$8.00 (export credits)
Net Daily Cost	$9.90	-$3.50 (negative = credit)
Monthly Cost (30 days)	$297.00	-$105.00 (credit carried forward)

Notice the negative number? That’s real. In many states with 1:1 net metering, a properly sized solar system can completely eliminate your electric bill and start building a credit balance. Even in states with less favorable net metering, you’re still chopping 70-80% off that $297 monthly bill.

The Hidden Trick: Load Shifting

Here’s where you need to be smart. Solar panels produce power during the day, but your peak usage window extends until 9:00 PM. That means you can’t rely on direct solar power for your 7:00 PM dinner cooking. You need to shift your heavy loads into the solar production window.

Practical moves that multiply your savings:

• Run your dishwasher and laundry between 10:00 AM and 2:00 PM. That’s free power from your roof.
• Pre-cool your home. Set the thermostat to 72°F at 2:00 PM. Your solar panels are cranking, so that cooling is essentially free. Then let the house drift to 78°F by 6:00 PM. You’ll use less grid power.
• Charge your electric vehicle during the day. If you have an EV, plug it in at noon. That’s 30-60 kWh of free fuel every day. Charging at night at peak rates would cost you $13.50 to $27.00 per charge.

The Battery Wildcard

If you really want to dominate TOU rates, add a battery. Here’s the killer strategy: your solar panels charge the battery during the day (free power). Then at 4:00 PM, when peak rates kick in, you run your entire house off the battery. You avoid peak rates entirely from 4:00 PM to 9:00 PM.

With a 10 kWh battery, you can cover 100% of your evening peak usage. Your grid draw becomes zero during those expensive hours. The math gets even better:

• Without battery: You still buy some peak power at night.
• With battery: You buy zero peak power. Your only grid costs are the minimum connection fee ($10-$20/month).

The Bottom Line for Your Wallet

The shift isn’t subtle. It’s a total reversal of the cost structure. Without solar, you’re paying a premium for afternoon convenience. With solar, you’re turning that premium into a profit center.

• Typical payback period: 5-8 years for a solar system under TOU rates.
• Annual savings after payback: $1,500 to $3,000 depending on your local rates and system size.
• Net metering cap: Check your state’s rules. Some utilities are phasing out 1:1 net metering, but even at 75% of retail rate, the math still works.

One final number to chew on: A 6 kW system costs roughly $15,000 to $18,000 after the federal tax credit. If it saves you $2,500 per year on a TOU plan, you’re looking at a 6-year payback. After that, you’re generating free electricity—and selling it back at the highest possible rate. That’s the kind of math that makes solar a no-brainer for anyone stuck on a Time-of-Use plan.

Net Metering vs. Batteries: Your Two Options

So you’ve got solar panels on the roof. Great. Now the real question: what happens when the sun goes down? Or when your utility company decides that 5 PM to 9 PM is "peak time" and charges you triple the rate?

You have two distinct paths forward. Each one changes how your solar investment performs. Let's break them down like a financial decision, because that's exactly what this is.

Option 1: Net Metering – The Simple Credit System

Think of net metering as a bank account for electricity. During the day, your panels overproduce. That extra power flows into the grid. Your utility credits your account at the retail rate – usually somewhere between $0.10 and $0.30 per kilowatt-hour (kWh). At night, you pull from those credits. No batteries. No complex software. Just a meter that spins backwards.

When net metering makes sense:

• You live in a state with strong net metering laws (California, New York, Massachusetts, New Jersey, and about 20 others)
• Your utility offers 1:1 credit – meaning you get the same rate for power you send to the grid as you pay to consume it
• You have a predictable, stable grid connection with rare outages
• You want the lowest upfront cost and fastest payback period

The real numbers: A typical 8 kW residential system in a net metering state will save you $1,200 to $2,000 per year. Payback period? Usually 6 to 8 years. No battery needed. Your ROI sits comfortably around 12-15% annually.

But here's the catch: net metering is dying in many states. Utilities hate it. They argue it shifts costs to non-solar customers. In 2023 alone, six states reduced their net metering compensation. California's NEM 3.0 slashed export rates by nearly 75%. If your utility pays you only $0.04 per kWh exported but charges you $0.40 to buy it back at night, net metering becomes a bad deal.

Option 2: Battery Storage – The Independence Play

Batteries flip the model entirely. Instead of selling your excess power to the utility for pennies, you store it in a lithium-ion or LFP (lithium iron phosphate) battery. You use that stored energy when rates spike at 6 PM. You run your house during a blackout. You stop being a price-taker and start being your own power manager.

The key metric: Time-of-use (TOU) rate arbitrage. If your peak rate is $0.45/kWh and your off-peak rate is $0.15/kWh, every kWh you shift from day to evening saves you $0.30. With a 13.5 kWh Tesla Powerwall 3 or similar system, that's roughly $4.05 per full cycle. Do that 250 times a year, and you're looking at $1,012 in annual savings from rate shifting alone.

When batteries make sense:

• Your utility has aggressive TOU rates with a 3x or greater spread between peak and off-peak
• You face frequent power outages (more than 2-3 per year)
• Your state has weak net metering (you get paid wholesale rates for exports)
• You qualify for the 30% federal tax credit (ITC) on battery systems – this is huge
• You live in a state with additional battery incentives (California's SGIP, Massachusetts' SMART, New York's NY-Sun)

The independence factor: A battery paired with solar can power critical loads for 12-24 hours, depending on your usage and panel size. For homeowners in wildfire zones, hurricane regions, or areas with aging grid infrastructure, that peace of mind has real financial value. One extended outage can cost you $500-$2,000 in spoiled food, lost work, and hotel stays.

The Trade-Offs: A Side-by-Side Comparison

Let's get specific. Here's how these options stack up for a typical California homeowner under NEM 3.0 (low export rates, high TOU rates):

Factor	Net Metering Only	Solar + Battery
Upfront cost (8 kW system)	$18,000 - $22,000	$28,000 - $35,000
Annual savings (year 1)	$600 - $900	$1,400 - $2,000
Payback period	12-15 years	8-11 years
Blackout protection	None	12-24 hours critical loads
ROI (10-year)	6-9%	9-13%
Complexity	Low – set and forget	Medium – requires monitoring
Utility dependence	High – you need the grid	Low – you can island

Notice something? In weak net metering states, the battery actually pays back faster. That's counterintuitive but real. The battery lets you avoid peak rates entirely, while net metering forces you to sell low and buy high.

Real-World Scenario: The Suburban Family

Meet the Johnsons. They have a 7.6 kW solar system in Arizona. Their utility charges $0.08/kWh off-peak and $0.38/kWh peak (5 PM - 8 PM). Under net metering, they export 30 kWh per day and get credited $0.08/kWh – that's $2.40. At night, they buy back 20 kWh at $0.38 – that's $7.60. Their net daily cost: $5.20. Ouch.

They install a 10 kWh battery for $12,000 (after tax credits). Now they store 20 kWh during the day and use it at peak. Their export drops to 10 kWh ($0.80 credit). Their peak consumption from the grid drops to zero. Net daily cost: $0.80 saved instead of $5.20 lost. That's a swing of $6 per day, or $2,190 per year. Battery pays for itself in 5.5 years.

Real-World Scenario: The Grid-Tied Retiree

Now meet Maria in Florida. She has full 1:1 net metering. Her utility pays her $0.12/kWh for exports and charges $0.12/kWh for imports. There's no TOU rate. Her system produces exactly what she uses annually. Net metering zeroes out her bill. She pays $0 per year in electricity.

Should she add a battery? Only if she wants backup power. Financially, it makes zero sense. The battery would cost $10,000+ and save her nothing on rates. Her payback period would be infinite. She's better off with net metering and a $500 portable generator for emergencies.

The Middle Ground: Hybrid Strategies

You don't have to choose one or the other. Many homeowners use both. The battery handles peak shaving and backup. Net metering handles seasonal overproduction. In summer, your panels make more than you need. You bank credits. In winter, you use those credits. The battery fills the gap during daily rate spikes.

The rule of thumb: If your utility pays you more than $0.12/kWh for exports, lean toward net metering. If they pay less than $0.08/kWh, you need a battery to make solar work financially. If you're in the middle, run the numbers for your specific usage pattern.

The Bottom Line

Net metering is the path of least resistance. It's simple, cheap, and works great if your utility plays fair. But utilities are changing the rules. Battery storage is the hedge against that uncertainty. It gives you control over when you buy and sell power. It protects you from rate hikes. And in many markets, it's now the more profitable choice.

Your decision comes down to three things: your utility's rate structure, your tolerance for complexity, and whether you want to be a passive participant or an active manager of your energy. Both work. One gives you credits. The other gives you freedom. Choose based on your numbers, not your emotions.

Practical Habits to Maximize Savings

You already have solar panels converting sunlight into free electricity. But here’s the reality check: if you’re running your dishwasher at 5 PM on a hot July afternoon, you’re still paying a premium for power that your panels might not be covering. Time-of-use (TOU) rates punish you for using energy when everyone else is. The fix isn’t complicated—it’s just a shift in timing.

The "Shift and Save" Strategy

Think of your home’s energy consumption like traffic. Peak hours are rush hour—everyone’s on the road, and the tolls are highest. Off-peak hours are the quiet backroads where the ride is cheap. The goal is simple: move as much of your energy use as possible into those low-rate windows.

Here’s where you’ll see the biggest impact:

1. Run major appliances after 9 PM or before 11 AM.

• Your dishwasher, washing machine, and dryer are the biggest hogs. Run them overnight. Most modern dishwashers have a "delay start" button. Use it. Set the washer to start at 10 PM. You’ll never hear it, and you’ll pay half the rate.
• Dryer tip: If you have a heat pump dryer, it uses far less energy. But even a standard electric dryer running from 8 PM to midnight instead of 5 PM to 8 PM can save you $0.15–$0.25 per load. That’s $50–$80 a year just on laundry.

2. Charge your EV like it’s a bank account—only during off-peak hours.

• An electric vehicle is a massive battery on wheels. If you plug in at 6 PM, you’re drawing 7–10 kW at the highest rate. That’s like running five central air conditioners at once.
• Instead, set your car’s charging schedule to start at midnight. Most EVs let you program this in the app. If your off-peak rate is $0.10/kWh and peak is $0.40/kWh, a full charge (60 kWh) costs $6 instead of $24. Over a year of weekly charging, that’s a $936 difference. Yes, nearly $1,000.
• Even if you only charge twice a week, you’re looking at $400–$500 in savings annually.

3. Pre-cool your home before peak hours.

• Your air conditioner is the single largest energy user in summer. During peak hours (often 4 PM–9 PM), rates can triple. The trick? Cool your house down early.
• Set your smart thermostat to drop the temperature to 72°F at 2 PM. Then let it drift up to 78°F by 4 PM. The house stays comfortable because the walls, floors, and furniture have already absorbed the cold. You’re basically using your home as a thermal battery.
• This single habit can cut your peak-hour AC usage by 40–60%. On a 100°F day, that’s saving you $2–$4 per day. Over a 90-day cooling season, that’s $180–$360.

4. Defer pool pumps, water heaters, and dehumidifiers.

• Pool pumps are silent energy vampires. Running them 8 hours during peak can cost $3–$5 a day. Shift to off-peak (say, 11 PM–7 AM) and that drops to $0.80–$1.20. Save $200–$300 per season.
• Electric water heaters: Install a simple timer or use the "smart" mode that heats water only when solar is abundant or rates are low. A standard 50-gallon tank uses about 4.5 kWh per day. Heating it off-peak instead of peak saves $0.50–$1.00 daily. That’s $180–$365 a year.
• Dehumidifiers in basements? Run them at night. They pull the same amount of water regardless of the time of day.

How Small Shifts Add Up to Big Numbers

Let’s do the math for a typical California household on a TOU plan (PG&E E-TOU-C, for example). Off-peak rate: $0.34/kWh. Peak rate: $0.51/kWh.

Habit	Daily Savings	Annual Savings
Shift laundry to off-peak	$0.30	$109
Charge EV at night (2x/week)	$1.80	$468
Pre-cool AC (summer only)	$2.50	$225
Run pool pump at night (6 months)	$1.20	$219
Delay water heater	$0.75	$273
Total	$6.55	$1,294

That’s over $1,200 a year from simply changing when you use power. Even if you only adopt two or three of these habits, you’re looking at $200–$500 annually. No new equipment. No subscription. Just a few changes in routine.

The "Set It and Forget It" Tools

You don’t need to be a control freak. Modern technology does the heavy lifting:

• Smart thermostats (Ecobee, Nest): Program them to pre-cool before peak and hold during peak. Many have "Time-of-Use" settings that automatically adjust based on your utility’s rate schedule.
• Smart plugs (Kasa, Wemo): Put your dishwasher, washing machine, or dehumidifier on a $15 smart plug. Set a schedule to turn on at 11 PM. Done.
• EV chargers (ChargePoint, JuiceBox): These let you set "charging windows" so the car only pulls power during off-peak hours. Some even sync with your solar production.
• Home battery systems (Tesla Powerwall, Enphase): These are the ultimate tool. They charge during off-peak (or from your solar) and discharge during peak. A single Powerwall can save you $500–$800 a year in TOU arbitrage alone.

A Quick Reality Check

You don’t have to be perfect. If you run the dishwasher at 6 PM once a week, you’re not ruining your savings. The key is consistency. Aim for 80% of your heavy loads to shift off-peak. That alone gets you 90% of the savings.

Also, check your utility’s exact TOU schedule. Some have "partial peak" periods where rates are moderate. That’s a good middle ground for things like cooking or vacuuming. Save the peak hours for sitting on the couch and reading a book.

The Bottom Line

Your solar panels already cut your electric bill by 50–70%. Adding these habits pushes that to 80–90% savings. It’s the difference between being a passive solar owner and an active energy manager. And the best part? Once you set the schedules, you never think about it again. The savings just show up in your bank account every month.

Start with one habit this week. Set your dishwasher to run at 10 PM. Then add the thermostat pre-cool next week. Within a month, you’ll have a system that runs itself—and puts $200–$500 back in your pocket every year.

How to Check If Your Utility Plan Fits Solar

You’ve heard the pitch: solar saves you money. But here’s the reality check—your utility’s rate plan determines how much money you actually keep. Not all plans are created equal, and some can turn a smart investment into a frustrating break-even game.

Let’s walk through exactly how to vet your utility plan before you sign a single contract.

Step 1: Find Your Utility’s Rate Schedule

Start by digging up your electricity bill. Look for the small print that lists your “rate schedule,” “tariff name,” or “service classification.” Common names include: “Residential Time-of-Use (TOU),” “Standard Residential,” or “EV Rate.”

If you can’t find it, call your utility and ask: “What is my current rate schedule, and what are the peak and off-peak hours?” Most utilities publish these online in PDFs. Search for “[Your Utility Name] + rate schedule 2025.”

What you’re looking for:

• Peak hours (usually 4 PM – 9 PM in summer)
• Off-peak hours (overnight and midday)
• Super-off-peak hours (if you have an EV plan)
• Any demand charges (a fee based on your highest 15-minute power usage)

Pro tip: If your utility offers multiple TOU plans, ask for a comparison sheet. Some utilities let you switch once per year. Don’t assume your current plan is the best one for solar.

Step 2: Map Your Solar Production Curve

Your solar panels don’t produce power at midnight. They peak between 10 AM and 2 PM, then drop off sharply after 4 PM. This is critical because TOU rates punish you for pulling from the grid during peak hours.

Here’s the mismatch problem:

• Solar produces most: 10 AM – 2 PM (often off-peak or mid-peak)
• You use most energy: 4 PM – 9 PM (peak hours, highest rates)

If your utility credits your solar exports at a low rate (say, $0.08/kWh) but charges you $0.35/kWh during peak, you’re losing money every evening.

Action step: Get a 12-month breakdown of your hourly energy usage. Many utilities provide this in their online portal. Look for a “Green Button” download. If you can’t get it, your solar installer should model your usage using your bill history.

Your production curve checklist:

• Do your panels generate at least 60% of your daily energy between 10 AM and 4 PM?
• Does your utility’s peak window start after 4 PM?
• Are you home during peak hours, or can you shift laundry, dishwashing, and EV charging to off-peak?

Step 3: Calculate Your Break-Even Under TOU

Here’s where the math gets real. You need to compare two numbers:

1. Your solar payback under net metering (where you get full retail credit for exports)
2. Your solar payback under your specific TOU plan

Simple calculation method:

• Average monthly solar production: 1,000 kWh
• Your self-consumption (energy you use directly): 400 kWh
• Your exports to grid: 600 kWh
• Peak rate: $0.35/kWh, Off-peak rate: $0.12/kWh

Under full net metering: You save 1,000 kWh × $0.12 = $120/month (assuming blended rate) Under TOU with low export credit: 400 kWh self-consumed × $0.35 peak = $140 saved + 600 kWh exported × $0.08 credit = $48. Total: $188/month.

Wait—that’s better? Yes, if you use most of your solar during peak hours. But if you’re at work all day, your self-consumption drops to 200 kWh, and your bill looks different.

The real break-even formula:

Monthly Savings = (Self-consumed kWh × Peak Rate) + (Exported kWh × Export Credit) - (Grid purchases during peak × Peak Rate)

Run this for your actual numbers. If your savings are less than 70% of what a standard net metering plan would give you, your utility plan is a bad fit for solar.

Step 4: The Pre-Contract Checklist

Before you sign anything, go through this list with your installer. If they can’t answer every question, walk away.

□ What is my current rate schedule name and number? □ What are the exact peak hours for summer and winter? □ What is the export credit rate for solar (net metering, net billing, or wholesale)? □ Is there a monthly fixed charge or demand charge that applies? □ Can I switch to a better TOU plan after solar is installed? □ Does the installer guarantee my payback period based on my utility plan, not a national average? □ What happens if the utility changes its rate structure in the next 5 years? (Look for a “rate escalation” clause in your contract)

Red flag: If the installer says “don’t worry, solar always works,” they’re not doing their homework.

Step 5: Compare Your Options Visually

Scenario	Peak Rate	Export Credit	Self-Consumption	Monthly Savings	Payback Period
Net metering (full retail)	$0.35	$0.35	40%	$350	7 years
TOU with low credit	$0.35	$0.08	40%	$188	13 years
TOU with high self-use	$0.35	$0.08	70%	$294	9 years

Notice the gap. If you can shift 30% more of your usage to daytime, you cut 4 years off your payback.

Step 6: The “Battery Question”

If your TOU plan has a wide gap between peak and off-peak rates (more than $0.20/kWh), a battery starts to make financial sense. A battery lets you store cheap off-peak solar and use it during expensive peak hours.

Quick math: A 10 kWh battery costs roughly $10,000 installed. If it cycles 300 times per year and saves you $0.20 per kWh each cycle, that’s $600/year. Payback: 16+ years. Not great.

But if your utility offers a “peak demand” charge of $15/kW, that same battery can shave 3 kW off your peak demand, saving $45/month or $540/year. Combined with energy shifting, payback drops to 8–10 years.

Your decision rule: Only add a battery if your utility has a demand charge or peak rates above $0.45/kWh. Otherwise, stick with solar-only.

Final Reality Check

You’re not just buying panels. You’re buying a financial asset that interacts with a constantly changing utility rate structure. The best solar plan in the world fails if your utility’s TOU schedule works against you.

One last number: According to LBNL’s 2024 tracking report, homes on TOU rates with solar save an average of 20% less than homes on standard net metering. But homes that actively shift usage to daytime save 15% more than those that don’t.

Your utility plan is the steering wheel. Solar is the engine. Make sure they’re pointing in the same direction.

Operational checklist before you commit

1. Get a copy of your utility’s TOU rate schedule (peak, off-peak, super-off-peak).
2. Run a solar production estimate for your roof’s orientation and shade.
3. Talk to your installer about battery storage or net metering policies in your area.

Frequently asked questions

Can solar alone save me money on time-of-use rates?

Yes. Solar generates the most power during mid-day—often peak rate hours. That directly offsets expensive grid electricity. Without a battery, you still pull from the grid at night, but daytime savings add up fast.

Do I need a battery to make TOU rates work for me?

Not always. If your utility has 1:1 net metering, you can bank credits during peak hours and use them later. But if net metering is weak or rates spike sharply, a battery gives you control to avoid buying power at 40 cents per kWh.

Final takeaways

Time-of-use rates aren’t a penalty. They’re a puzzle—and solar is the piece that makes it click. By matching your energy habits to when the sun shines, you turn a complex billing structure into a money-saving tool.

Start with your rate sheet and a solar estimate. That’s all you need to see if TOU works for you. And if batteries or smart controls make sense, your installer can walk you through the numbers. No hype, just math.