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Where do home batteries make the most financial sense? We analyzed SAIDI/SAIFI reliability data for 16 utilities across 9 states to answer the question with real numbers — not marketing claims.
Quick Answer
Batteries make the most financial sense in utility territories with high SAIDI (outage duration) scores: CMP in Maine (300-500 min/yr, battery value 9/10), Eversource CT (200-280 min/yr, 8/10), and CenterPoint TX (150-300 min/yr, 7/10 with rising trend). In these areas, combined backup protection + TOU arbitrage + VPP revenue yields 7-9 year payback. In low-outage territories like PPL or Oncor (80-160 min/yr), batteries are better understood as power insurance — payback is 12-15+ years, but a single avoided flood or pipe freeze pays for the system.
Before we compare utilities, you need to understand the two metrics that define grid reliability. These are not marketing numbers — they are federally mandated performance metrics reported to the Energy Information Administration (EIA) by every investor-owned utility in the country.
What it measures: The total number of minutes per year that the average customer is without power. A SAIDI of 200 means the average customer on that utility experienced 200 minutes (3 hours 20 minutes) of total outage time over the year.
Why it matters for batteries: Higher SAIDI means more total hours per year that your battery is actively protecting your home. A battery in CMP territory (SAIDI 300-500) provides 2-3x more annual backup hours than one in Oncor territory (SAIDI 80-140).
What it measures: How many times per year the average customer experiences a power interruption. A SAIFI of 1.5 means the average customer lost power 1.5 times that year.
Why it matters for batteries: Higher SAIFI means more frequent discharge events, which increases the annualized backup protection value. It also means more disruption to daily life — food spoilage, lost work, resetting clocks and electronics. A battery eliminates every one of those micro-events.
Important context: SAIDI and SAIFI values can be reported with or without Major Event Days (MEDs) — catastrophic storms that skew the average. The data in this analysis includes MEDs because those are exactly the events where battery backup matters most. A utility with a “clean” SAIDI of 90 but a MED-inclusive SAIDI of 280 is masking the storms that cause real damage. We include the storms.
This table compares SAIDI and SAIFI data for every major utility in NuWatt's service area. Sort by Battery Value Score to see where batteries deliver the most total value (backup + TOU + VPP combined).
| State | Utility | SAIDI (min/yr) | SAIFI (events/yr) | Avg Outage | Trend | Battery Value |
|---|---|---|---|---|---|---|
| MA | Eversource | 180-240 | 1.2-1.5 | 2-3 hrs | ↑ Rising | 7/10 |
| MA | National Grid | 120-180 | 0.9-1.2 | 1.5-2.5 hrs | Stable | 6/10 |
| CT | Eversource CT | 200-280 | 1.3-1.8 | 2-4 hrs | ↑ Rising | 8/10 |
| CT | United Illuminating | 90-150 | 0.7-1.0 | 1.5-2 hrs | Stable | 5/10 |
| ME | CMP | 300-500 | 2.0-3.5 | 3-6 hrs | ↑ Rising | 9/10 |
| ME | Versant | 200-350 | 1.5-2.5 | 2-4 hrs | Stable | 8/10 |
| NH | Eversource NH | 200-300 | 1.5-2.0 | 2-4 hrs | Stable | 7/10 |
| NH | Liberty | 150-250 | 1.2-1.8 | 2-3 hrs | Stable | 7/10 |
| RI | RI Energy | 150-220 | 1.0-1.5 | 2-3 hrs | Stable | 7/10 |
| VT | GMP | 180-280 | 1.3-2.0 | 2-4 hrs | Stable | 7/10 |
| NJ | PSE&G | 100-160 | 0.8-1.2 | 1.5-2 hrs | Stable | 5/10 |
| NJ | JCP&L | 150-250 | 1.2-1.8 | 2-3 hrs | ↑ Rising | 7/10 |
| PA | PECO | 120-180 | 0.9-1.3 | 1.5-2.5 hrs | Stable | 5/10 |
| PA | PPL | 100-160 | 0.8-1.2 | 1.5-2 hrs | Stable | 4/10 |
| TX | Oncor | 80-140 | 0.7-1.0 | 1-2 hrs | Stable | 4/10 |
| TX | CenterPoint | 150-300 | 1.2-2.0 | 2-4 hrs | ↑ Rising | 7/10 |
SAIDI/SAIFI data sourced from EIA Form 861 filings (2023-2025), utility reliability reports, and state public utility commission records. Ranges reflect year-to-year variation and include Major Event Days. Battery Value Score is a composite of outage exposure, TOU potential, VPP eligibility, and local electricity rates.
Most battery payback calculators consider only one dimension of value. A home battery actually earns its keep through three independent channels — and outage frequency amplifies the most important one.
The cost of outage damage you avoid. Food spoilage ($200-$500 per event), sump pump failure ($5,000-$25,000 in flooding), frozen pipes ($3,000-$15,000), lost remote work productivity ($200-$500/day), and medical equipment disruption.
Value scales directly with SAIDI/SAIFI: more outages = more damage avoided = higher backup value.
Time-of-use rate plans charge different prices per kWh depending on the time of day. A battery charges during cheap off-peak hours (often 11 PM–7 AM) and discharges during expensive peak hours (2–7 PM), saving $30-$80/month.
Value depends on rate differential. Texas (deregulated) and MA/CT (high rates) offer the strongest TOU arbitrage.
Virtual Power Plant programs pay battery owners for dispatching stored energy during grid peak demand. ConnectedSolutions (MA, CT, RI) pays $225-$275/kW, generating $1,000-$1,500/year per battery. Green Mountain Power (VT) offers a similar program.
Only available in select utility territories. Where available, it can cut payback period by 3-5 years.
When all three pillars stack, payback accelerates dramatically. A battery in Eversource CT territory earns $1,000-$1,200/yr from ConnectedSolutions, saves $420-$780/yr in TOU arbitrage, and avoids $500-$2,000/yr in outage damage (based on SAIDI 200-280 min/yr with rising trend). Total annual value: $1,920-$3,980. At an installed cost of $13,500, payback is 3.5-7 years — well within the battery's 15-year lifespan. Compare that to PPL territory in Pennsylvania: $0 VPP, $180-$420/yr TOU, and $100-$400/yr backup value. Total: $280-$820/yr with 16-48 year payback. Same product, completely different economics.
These three utility territories combine high outage risk with additional revenue streams, creating the strongest battery investment case in NuWatt's service area.
Maine • Battery Value: 9/10
300-500
SAIDI (min/yr)
2.0-3.5
SAIFI (events/yr)
3-6 hrs
Avg outage duration
CMP serves 650,000+ customers across Maine's most rural and forested territory. Long transmission lines through dense tree cover are extremely vulnerable to ice storms and nor'easters. Average restoration times are the longest in NuWatt's service area because crews must travel long distances through damaged infrastructure. Battery backup here is not a luxury — it is a practical necessity for homes with well pumps, heating systems, and medical equipment. The rising SAIDI trend reflects worsening storm severity, not improving infrastructure.
Connecticut • Battery Value: 8/10
200-280
SAIDI (min/yr)
1.3-1.8
SAIFI (events/yr)
2-4 hrs
Avg outage duration
Eversource CT has the best combination of high outage risk AND VPP revenue in NuWatt's service area. SAIDI of 200-280 creates substantial backup value, and ConnectedSolutions adds $1,000-$1,200/year in grid services revenue. Connecticut's high electricity rates ($0.30+/kWh) also amplify TOU arbitrage savings. The rising outage trend is driven by aging infrastructure in tree-dense suburban corridors. Tropical storms like Isaias (2020, 700,000+ without power for up to 8 days) demonstrated that Connecticut's grid is fragile under severe weather stress.
Texas • Battery Value: 7/10
150-300
SAIDI (min/yr)
1.2-2.0
SAIFI (events/yr)
2-4 hrs
Avg outage duration
CenterPoint serves the greater Houston metro area, one of the most hurricane-exposed population centers in the country. The Winter Storm Uri (2021) event — where millions lost power for days in freezing temperatures — demonstrated that ERCOT's isolated grid has unique vulnerability. Battery value here is amplified by Texas's deregulated electricity market, where TOU arbitrage savings of $45-$85/month are among the highest in NuWatt's service area. REP buyback programs offer a modest VPP-like revenue stream of $300-$600/year. The rising SAIDI trend reflects rapid population growth outpacing infrastructure investment.
In low-outage utility territories, the financial payback is longer because backup events are infrequent. This does not mean batteries are a bad idea — it means the value proposition is different. Think of it as power insurance, not a financial investment.
SAIDI 100-160 • Battery Value: 4/10 • Stable trend
PPL has one of the most reliable grids in NuWatt's service area with low outage frequency and short restoration times. No VPP program, moderate electricity rates ($0.14/kWh), and limited TOU differential. Battery payback here is 15+ years based on financial metrics alone. The value case is pure insurance: protecting a finished basement from sump pump failure or keeping a home office online during the 1-2 outages per year.
SAIDI 90-150 • Battery Value: 5/10 • Stable trend
UI serves a compact, urbanized territory along Connecticut's coast with a significantly better outage profile than Eversource CT. The saving grace is ConnectedSolutions VPP access ($1,000-$1,200/yr) and Connecticut's high electricity rates, which provide meaningful TOU value. With VPP enrolled, payback drops to 8-10 years. Without VPP, it stretches to 13-15 years.
SAIDI 80-140 • Battery Value: 4/10 • Stable trend
Oncor serves the DFW metro with generally reliable service. The low SAIDI/SAIFI means backup events are infrequent. However, Texas's deregulated market creates strong TOU arbitrage opportunity ($40-$80/month), and REP buyback programs add $300-$600/year. The value case improves if you experienced Winter Storm Uri — where backup power was literally a survival need, not a convenience.
SAIDI 100-160 • Battery Value: 5/10 • Stable trend
PSE&G has invested heavily in grid hardening after Superstorm Sandy (2012) and delivers relatively reliable service. No active VPP program limits the revenue upside. However, NJ's Storage Incentive Program and moderate electricity rates help the financial case. Battery value here is primarily disaster preparedness — the next major hurricane or nor'easter will remind PSE&G customers why backup power matters.
The financial damage from a single extended outage can exceed the cost of a battery system. These are not hypothetical scenarios — they are insurance claims and repair bills that homeowners pay every storm season.
$3,000-$15,000
Loss of heating during a winter outage can freeze water pipes within 4-6 hours in an uninsulated basement. A burst pipe causes flooding, drywall damage, and mold remediation costs that homeowner insurance may not fully cover. Northeast homes with heat pumps are especially vulnerable because the heat pump requires electricity.
$5,000-$25,000
Power outages during storms are exactly when sump pumps are needed most. Without power, water enters basements within minutes during heavy rain. Finished basements with carpet, furniture, electronics, and stored items face catastrophic damage. A battery activates in <200ms — faster than water can rise.
$200-$500
A full refrigerator stays safe for 4 hours and a full freezer for 48 hours — if the door stays closed. An extended outage means throwing away everything. For families who buy in bulk or stock chest freezers, a single spoilage event costs $300-$500. Two outages per year, and you are losing $600-$1,000 annually.
$200-$500/day
Remote workers lose income or PTO days during outages. A lost internet connection means missed meetings, delayed deliverables, and damaged professional reputation. For households with two remote workers, a single-day outage can cost $400-$1,000 in lost productivity.
Priceless
CPAP machines, oxygen concentrators, medication refrigeration, and other medical equipment require uninterrupted power. A battery with <200ms switchover keeps these devices running seamlessly. For medically dependent households, a battery is not a financial decision — it is a safety decision.
$13K-$15K
A 13.5 kWh battery costs $13,000-$15,000 installed and lasts 15 years. That is $900-$1,000/year for guaranteed power during every outage. One avoided basement flood ($10,000+) pays for the battery. Unlike traditional insurance, a battery also generates TOU savings and VPP revenue — it is insurance that pays you back.
For a detailed comparison of batteries vs generators as backup solutions, see our Battery vs Generator 2026 guide, or calculate your specific backup needs with the Battery Sizer tool.
Virtual Power Plant (VPP) programs are the single largest factor in battery payback outside of outage protection. Where available, they cut payback periods by 3-5 years. Unfortunately, availability is limited to certain utility territories.
MA — ConnectedSolutions
$1,300-$1,500/yr via Eversource & National Grid. $275/kW summer season.
CT — ConnectedSolutions
$1,000-$1,200/yr via Eversource CT. $225/kW summer season.
RI — ConnectedSolutions
$1,100-$1,350/yr via RI Energy. $250/kW summer season.
VT — GMP Battery Program
$900-$1,100/yr via Green Mountain Power. Unique utility-owned lease model available.
TX — REP Buyback Programs
$300-$600/yr through retail electricity provider export credits. Not a true VPP, but provides modest revenue.
ME — No program
Despite having the highest outage rates, Maine lacks a VPP program. Battery value is entirely backup + TOU.
NH — No program
Neither Eversource NH nor Liberty offers VPP enrollment. Battery value is backup + moderate TOU.
NJ — No active program
NJ's Storage Incentive Program provides upfront rebates but no ongoing VPP revenue.
PA — No program
Neither PECO nor PPL offers VPP enrollment. Battery value is limited to backup + modest TOU.
Learn more about VPP economics in our Virtual Power Plants 2026 guide.
Select your state and utility to see outage data, your utility's battery value ranking, and a personalized breakdown of backup protection value, TOU savings, and VPP revenue. Then select your critical loads to calculate payback period and recommended battery size.
Choose your location to see outage risk data and battery value analysis
Select a state and utility above to see your outage risk analysis
Data covers 16 utilities across NuWatt's 9 service states
We pay for homeowner insurance hoping to never file a claim. A battery works the same way — except it also earns money while it waits.
You pay $1,200-$2,500/year for homeowner insurance. It sits idle until you need it. When a storm causes $20,000 in damage, insurance covers it (minus deductible). You never complain about “wasted” premiums in quiet years — that is how insurance works.
You pay $900-$1,000/year (amortized over 15 years) for a battery. Unlike traditional insurance, it actively earns money through TOU savings ($360-$960/yr) and VPP revenue ($0-$1,500/yr) while you wait. When a storm knocks out power, it prevents $200-$25,000 in damage. It is insurance that pays you back in quiet years.
The key insight: in high-value territories (CMP, Eversource CT, CenterPoint TX), the battery insurance effectively costs $0 or less after TOU and VPP revenue — you are being paid to have backup power. In low-value territories (PPL, Oncor), the net insurance cost is $300-$600/year after TOU savings — still cheaper than the annual maintenance on a standby generator ($300-$500/yr) which provides no revenue at all. Read our full battery storage guide and battery cost breakdown for complete pricing details.
SAIDI/SAIFI data: Compiled from EIA Form 861 annual filings (2021-2025), state public utility commission reliability reports, and utility-published reliability scorecards. Ranges represent the min-max of the most recent 3-year reporting period including Major Event Days.
Battery Value Score: A weighted composite index (1-10) factoring SAIDI (30%), SAIFI (20%), outage trend (15%), VPP eligibility and revenue (20%), TOU arbitrage potential (10%), and local electricity rates (5%). Scores are relative within NuWatt's 9-state service area.
Backup protection value: Estimated from average insurance claim data for water damage, food spoilage reports, and Bureau of Labor Statistics productivity data. Annualized using utility-specific SAIDI/SAIFI to approximate outage frequency and duration exposure.
TOU and VPP values: TOU savings based on published rate differentials from each utility's time-of-use tariff. VPP revenue based on ConnectedSolutions published incentive rates ($225-$275/kW) and GMP program published terms. REP buyback values from published Texas retail electricity provider export rates.
Battery cost basis: $13,500 average installed cost for a single 13.5 kWh LFP battery system (Tesla Powerwall 3 or equivalent). Actual costs range from $6,000 (Enphase IQ 5P, 5 kWh) to $16,000 (Franklin WH aPower2, 13.6 kWh). No federal tax credit assumed (Section 25D expired December 31, 2025).
SAIDI (System Average Interruption Duration Index) measures the total minutes per year that the average customer is without power. SAIFI (System Average Interruption Frequency Index) measures how many times per year the average customer experiences an outage. Together, they quantify grid reliability for a specific utility territory. Higher SAIDI and SAIFI values mean more outages, which increases the backup protection value of a home battery. CMP in Maine (SAIDI 300-500 min/yr) has dramatically higher outage exposure than Oncor in Texas (80-140 min/yr), making batteries far more valuable as backup in Maine.
Central Maine Power (CMP) has the highest SAIDI at 300-500 minutes per year, with 2.0-3.5 outage events annually (SAIFI). Eversource CT is second with SAIDI of 200-280 minutes and a rising trend. CenterPoint Energy in Texas has SAIDI of 150-300 minutes with a rising trend driven by hurricane exposure and rapid growth outpacing infrastructure investment. Versant Power in Maine and Eversource NH round out the top five. These utilities all score 7-9 out of 10 on battery value because the frequency and duration of outages dramatically increase backup protection value.
In high-outage territories like CMP (Maine), batteries can pay back in 7-9 years through combined backup protection value, TOU savings, and avoiding outage damage costs. In low-outage territories like PPL (Pennsylvania) or Oncor (Texas), payback extends to 12-15+ years because backup value is minimal. However, the financial picture changes dramatically if TOU rates are high (Texas) or if VPP programs are available (MA, CT, RI, VT). A battery in PSE&G territory (low outages) with ConnectedSolutions enrollment in nearby MA would have a completely different payback than a battery in PPL territory with no VPP access.
Battery value comes from three sources. Pillar 1 is backup protection: avoiding the cost of outage damage including food spoilage ($200-$500), sump pump failure ($5,000-$25,000), pipe freeze ($3,000-$15,000), and lost work productivity ($200-$500/day). Pillar 2 is TOU (time-of-use) arbitrage: charging the battery with cheap off-peak electricity and discharging during expensive peak hours, saving $30-$80/month depending on your utility rate structure. Pillar 3 is VPP (virtual power plant) revenue: earning $900-$1,500/year by dispatching stored energy during grid peak demand events through programs like ConnectedSolutions. Most payback calculators only count one pillar, undervaluing batteries significantly.
The top three territories for battery value are: (1) CMP in Maine — highest SAIDI in our service area (300-500 min/yr) with a rising trend; rural areas face 3-6 hour average outages and long restoration times. (2) Eversource CT — SAIDI of 200-280 min/yr with a rising trend, plus ConnectedSolutions VPP revenue of $1,000-$1,200/year. (3) CenterPoint Energy in Texas — SAIDI of 150-300 min/yr with a rising trend, plus high TOU arbitrage value from deregulated rates. In all three cases, the combination of high outage risk and additional revenue/savings creates payback periods under 9 years.
PPL Electric in Pennsylvania (SAIDI 100-160, battery value score 4/10) and Oncor in Texas (SAIDI 80-140, score 4/10) have the lowest battery value scores. These utilities have relatively reliable grids, no VPP programs, and moderate electricity rates, so the financial return is limited. United Illuminating in Connecticut (SAIDI 90-150, score 5/10) is similar, though it benefits from ConnectedSolutions VPP access. In these territories, a battery is best understood as power insurance rather than an investment — the value is real when you need it, but the math does not produce a quick payback.
The cost varies dramatically by what fails. Food spoilage from a refrigerator and freezer runs $200-$500 per extended outage. Sump pump failure during a storm can cause $5,000-$25,000 in basement flooding damage. Frozen pipes from loss of heating in winter cost $3,000-$15,000 to repair. Lost productivity for remote workers runs $200-$500 per day. Medical equipment disruption is harder to quantify but potentially life-threatening. A single major damage event (flooded basement or burst pipes) can exceed the entire cost of a battery system, which is why the insurance analogy is so powerful.
Yes. Utilities with rising SAIDI/SAIFI trends — CMP (Maine), Eversource CT, JCP&L (New Jersey), and CenterPoint (Texas) — are getting worse, not better. This means the backup value of a battery increases each year. For these utilities, delaying a battery purchase means accepting higher outage risk with each passing year. Climate change, aging infrastructure, and growing demand are the primary drivers. Utilities with stable trends may improve through grid hardening investments, but historical data shows most utilities are flat at best. Early battery investment in rising-trend territories locks in protection before the next major weather event.
VPP programs dramatically accelerate payback. ConnectedSolutions (available in MA, CT, RI through Eversource, National Grid, and RI Energy) pays battery owners $225-$275/kW of discharge capacity during summer peak demand events. A single 13.5 kWh battery with 5 kW continuous output earns $1,000-$1,500/year. Over 10 years, that is $10,000-$15,000 in revenue — nearly covering the installed cost of the battery from VPP revenue alone, before counting backup value or TOU savings. Green Mountain Power in Vermont offers a similar program. Territories without VPP programs have significantly longer payback periods.
Both. In high-value territories (CMP, Eversource CT, CenterPoint TX, any utility with VPP access), a battery is a genuine financial investment with 7-10 year payback and 15-year lifespan. In low-value territories (PPL, Oncor, UI), it is better understood as power insurance: you pay $13,000-$15,000 installed for the guarantee that your critical loads stay on during every outage for the next 15 years. Like homeowner insurance, you hope you never need it, but when you do, the value is immediate and outsized. A single avoided basement flood ($10,000-$25,000) pays for the battery. The right framing depends on your utility territory and personal risk tolerance.
NuWatt installs Tesla Powerwall, Enphase IQ, and Franklin WH batteries across 9 states. Get a free assessment that includes your utility's outage data, VPP eligibility, and a personalized payback analysis.