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We serve MA, NH, CT, RI, ME, VT, NJ, PA, and TX
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Time-of-use electricity rates create an opportunity to save money with a home battery. Charge when power is cheap, discharge when it is expensive. Stack ConnectedSolutions revenue on top for maximum returns.
$300-700/yr
TOU Savings
$1.6-2K/yr
DR Revenue
4-9 PM
Peak Hours
$0.20/kWh
Best Spread
Charge your battery during midday with solar (free) or overnight with cheap off-peak grid power. Discharge during evening peak hours (4-9 PM) when electricity costs the most. TOU arbitrage saves $300-$700/year. In ConnectedSolutions states (MA, CT, RI, VT), stack $1,650-$1,950/year in demand response revenue on top for total annual value of $2,000-$2,600.
Most residential electricity customers pay a flat rate per kilowatt-hour regardless of when they use power. Time-of-use (TOU) pricing charges different rates depending on the time of day.
$0.30-$0.38/kWh
Typically 1-9 PM weekdays. Highest demand on the grid, highest prices for you. This is when AC units, home cooking, and EV charging all hit simultaneously.
$0.10-$0.18/kWh
Typically 9 PM - 1 PM. Grid demand is low, and electricity is cheap. This is when you should charge your battery from the grid.
$0.00/kWh
When your solar panels produce power, charging is free. Midday solar is the cheapest way to fill your battery for evening peak discharge.
The "spread" between peak and off-peak rates determines how much money TOU arbitrage can save. A $0.20/kWh spread means each kWh you shift from peak to off-peak saves you $0.20. A 13.5 kWh Powerwall cycling once daily with 97.5% efficiency and a $0.20 spread saves roughly $0.20 x 13.5 x 0.975 = $2.63/day, or about $960/year (assuming daily cycling, which is optimistic; real-world savings are $300-$700/yr).
Not every utility in NuWatt's service area offers residential TOU rates. Here is the current status across our key utilities.
Spread: $0.20/kWh
Peak Hours
1-9 PM weekdays
Off-Peak
9 PM - 1 PM
Peak Rate
$0.38/kWh
Off-Peak Rate
$0.18/kWh
TOU available only for EV charging rate (Rate 7). Standard residential rates are flat. Battery TOU optimization is limited to EV rate customers.
Spread: $0.00/kWh
National Grid does not offer residential TOU rates in Massachusetts. Battery value comes entirely from ConnectedSolutions DR revenue and solar self-consumption, not TOU arbitrage.
Spread: $0.19/kWh
Peak Hours
12-8 PM weekdays
Off-Peak
8 PM - 12 PM
Peak Rate
$0.35/kWh
Off-Peak Rate
$0.16/kWh
CT Eversource offers an optional residential TOU rate. Good spread for battery optimization. Available to all residential customers who request it.
Spread: $0.18/kWh
Peak Hours
12-8 PM weekdays
Off-Peak
8 PM - 12 PM
Peak Rate
$0.33/kWh
Off-Peak Rate
$0.15/kWh
UI offers the same TOU structure as Eversource CT. Slightly lower rates but similar spread. Solid candidate for battery optimization.
Spread: $0.18/kWh
Peak Hours
2-7 PM weekdays (summer)
Off-Peak
7 PM - 2 PM
Peak Rate
$0.32/kWh
Off-Peak Rate
$0.14/kWh
PSE&G offers a TOU pilot program in New Jersey. Summer-weighted peak hours. Good spread for battery optimization during summer months.
Spread: $0.10-$0.20/kWh
Peak Hours
2-8 PM weekdays (summer)
Off-Peak
8 PM - 2 PM
Peak Rate
$0.18-$0.30/kWh
Off-Peak Rate
$0.05-$0.10/kWh
Deregulated Texas market offers dozens of TOU plans through retail electricity providers. Spread varies widely. Some free-nights-and-weekends plans offer extreme spreads for battery optimization.
For homeowners with solar + battery on a TOU rate, here is the ideal daily cycle. Most battery management systems (Tesla app, Enphase app) can be programmed to follow this schedule automatically.
Grid charges battery (if TOU available)
If you are on a TOU rate, the grid charges your battery at the cheapest overnight rate. With no TOU, the battery stays at whatever charge level it reached the previous day.
Solar begins charging battery
As solar production ramps up, excess energy charges the battery instead of going to the grid. Net metering credits are less valuable than stored energy you use during peak hours.
Solar powers home + battery full charge
Peak solar production. Your system powers the home directly, charges the battery to full, and exports any remaining excess to the grid. Battery should reach 100% by early afternoon.
Battery discharges to power home
This is the money period. Solar production drops, but your battery supplies the home instead of drawing expensive peak-rate grid power. This is where TOU arbitrage generates savings.
Grid supplies remaining needs
Battery is depleted from evening peak discharge. Grid supplies power at cheap off-peak rates. Battery stays at low charge, ready for overnight grid charging or next-day solar charging.
The real power of a home battery comes from stacking multiple revenue streams. TOU arbitrage is just one piece. Here is how the economics add up for a single Tesla Powerwall 3 (13.5 kWh) in a ConnectedSolutions state.
$300 - $700
per year
Savings from charging at off-peak rates and discharging during peak hours. Depends on TOU spread and daily cycling.
$1,650 - $1,950
per year
Utility demand response payments for dispatching battery during peak grid demand events. Eversource $275/kW, National Grid $225/kW.
$200 - $500
per year
Value of using stored solar energy during evening instead of exporting at net metering rates (which may be less than retail).
$100 - $300
per year
Avoided cost of spoiled food, hotel stays, and generator fuel during power outages. Varies by outage frequency.
For a homeowner in Massachusetts with Eversource, a TOU rate, solar panels, and ConnectedSolutions enrollment, a single Powerwall 3 can generate $2,250-$3,450 in combined annual value. Over 10 years, that is $22,500-$34,500 against an installed cost of $8,500-$12,000.
Payback period: 3-5 years in the best-case scenario (Eversource MA, TOU rate, full ConnectedSolutions participation). This is one of the fastest battery payback timelines in the country.
Here is a realistic annual calculation for a single Tesla Powerwall 3 (13.5 kWh, 6 kW dispatchable) paired with an 8 kW solar system in Eversource MA territory.
| Revenue Stream | Calculation | Annual Value |
|---|---|---|
| ConnectedSolutions (Summer) | 6 kW x $275/kW = $1,650 | $1,650 |
| ConnectedSolutions (Winter) | 6 kW x $50/kW = $300 | $300 |
| TOU Arbitrage | ~250 cycling days x $0.20 spread x 13 kWh usable | $650 |
| Solar Self-Consumption | Evening solar use vs net metering credit gap | $350 |
| Avoided Outage Costs | ~2 outages/year x avoided spoilage/hotel | $200 |
| Total Annual Value | Sum of all streams | $3,150 |
Assumes Eversource MA EV TOU rate, daily battery cycling during appropriate months, full ConnectedSolutions participation. Actual results vary based on weather, usage patterns, and dispatch frequency. TOU arbitrage figure is optimistic and assumes consistent daily cycling.
A battery is not always a good financial investment. The economics depend heavily on your utility, rate structure, and whether demand response programs are available.
Stacking ConnectedSolutions revenue ($1,650-$1,950/yr) with TOU arbitrage ($300-$700/yr) yields $2,000-$2,600 per year. A Powerwall pays for itself in 4-6 years.
No TOU arbitrage, but ConnectedSolutions alone provides $1,350-$1,950/yr. Combined with solar self-consumption savings, payback is 6-8 years.
TOU arbitrage alone yields $300-$700/yr. At $8,500-$12,000 for a Powerwall, payback exceeds 12-15 years. Only makes sense if you also need backup power.
Without TOU or demand response, a battery saves only $200-$500/yr from solar self-consumption. Payback exceeds 20 years. Buy a battery only if backup power is your primary goal.
If you are outside a ConnectedSolutions state and your utility does not offer TOU rates, a home battery is primarily a backup power investment, not a financial one. We will never oversell a battery to a customer whose utility rates do not support it. Backup power has real value, but the payback math should be honest.
NuWatt helps you maximize battery ROI with TOU optimization, ConnectedSolutions enrollment, and smart energy management. We analyze your utility rate, usage patterns, and available programs. Serving MA, CT, RI, NH, ME, VT, NJ, PA, and TX.