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NH ice storms are not hypothetical. A 12-factor comparison of home batteries vs. generators — including the honest winter solar recharging limitation that most salespeople do not mention.
Eversource ConnectedSolutions: ~$225/kW/yr. December solar production: ~2.5 peak hours/day.
New Hampshire's grid is vulnerable. Aging overhead lines through heavily forested terrain, combined with nor'easters and ice storms, make extended outages a recurring reality — not an edge case.
2008
critical
Deadliest NH storm in decades. National Guard deployed. Hundreds of NH residents relied on emergency shelters.
2017
major
Downed trees across southern NH. Eversource criticized for restoration times.
2020
major
Southern NH worst affected. Power out during early cold snap.
2024
moderate
Freezing rain coated lines. Eversource mobilized mutual aid crews from neighboring states.
8
Battery Wins
of 12 factors
Winner depends on your specific situation
4
Generator Wins
The right choice depends on your outage duration expectations, budget, and whether you have solar.
Battery
$8,000–$18,000 (Tesla Powerwall 3, Enphase 5P)
Generator
$3,000–$15,000 (portable to whole-home standby)
Portable generators start at $500–$800 but require manual operation and produce carbon monoxide. Whole-home standby generators (Generac, Kohler) run $5,000–$15,000 installed.
Battery
$0 (charges from grid or solar; minor inverter maintenance)
Generator
$200–$800/yr (propane/gas fuel + annual service + oil changes)
Generators need annual servicing ($100–$200), fuel storage, and load-testing. Batteries have essentially zero ongoing cost if paired with solar.
Battery
Excellent. 1–3 batteries cover most NH homes for 1–2 days.
Generator
Good. Runs indefinitely on propane/gas supply.
For typical 1–3 day NH outages (summer thunderstorms, brief winter events), a battery system is ideal. It activates instantly, silently, and automatically.
Battery
Challenging. Battery depletes in 1–2 days without solar recharge.
Generator
Superior. Can run indefinitely if you can get fuel.
The December 2008 storm lasted 16 days for some NH customers. A single battery cannot sustain a home that long without recharge. This is the generator's strongest argument.
Battery
Severely limited Dec–Feb. See detailed analysis below.
Generator
Not dependent on sun.
A December ice storm — exactly when NH historically loses power — may bring 0 usable solar production for 3–7 days. Batteries cannot recharge without sun or grid power.
Battery
Yes. Seamless switchover in milliseconds. Clocks, computers, sump pumps unaffected.
Generator
Standby: ~10 seconds. Portable: manual start required.
Batteries like the Tesla Powerwall 3 and Enphase IQ Battery 5P switch to backup mode within milliseconds. Portable generators require someone to start them in a storm.
Battery
Silent. Zero noise during backup operation.
Generator
60–80 dB (portable). 62–70 dB (standby, outdoor unit).
Generator noise is significant — roughly equivalent to a lawn mower running 24/7. NH towns may have generator noise ordinances. Batteries are completely silent.
Battery
Critical loads only: refrigerator, lights, phone charging, sump pump. Heat pump possible with multiple units.
Generator
Whole-home standby can power everything: furnace, well pump, EV charger.
A whole-home standby generator (22 kW Generac) can run your entire home. A single Tesla Powerwall 3 (13.5 kWh) powers critical loads 12–24 hours. Two to three batteries extend that significantly.
Battery
No fuel needed. Can recharge from grid when power returns, or from solar.
Generator
Depends on propane/gas supply chain — during 2008, fuel was scarce.
During the 2008 storm, propane deliveries were delayed across NH for 7–10 days. Homeowners with partial tanks ran out. Batteries eliminate fuel dependency entirely.
Battery
Zero. No combustion.
Generator
Significant. Portable generators kill ~400 Americans/year from CO poisoning.
Portable generators are dangerous if operated indoors or in garages. Even standby generators carry exhaust risks if improperly installed. Batteries produce zero CO.
Battery
Yes — earn ~$225/kW/yr via Eversource ConnectedSolutions demand response.
Generator
No. Generators cannot participate in demand response programs.
Eversource ConnectedSolutions pays battery owners approximately $225/kW per summer season for demand response dispatch. A 13.5 kWh / 11 kW battery earns ~$330–$400/yr, meaningfully improving ROI.
Battery
Adds home value. Modern buyers increasingly request solar+battery.
Generator
Modest value add. Generators are often viewed as a liability (maintenance) by buyers.
As grid reliability becomes a growing concern in NH, solar+battery systems increasingly add measurable resale value. Generators are often seen as a maintenance obligation.
This is the section most battery salespeople skip. Read it before committing to a battery-only system.
The December 2008 ice storm hit during the shortest, darkest days of the year. NH averages just 2.5 peak sun hours per day in December under clear skies. During a multi-day ice storm, panels may produce near zero for days.
December NH Solar Production
~2.5 hrs/day
vs 5.5 hrs/day in June
Production During Ice Storm
~0 hrs
Ice-coated panels: essentially zero
Battery Depletion Rate
12–24 hrs
Critical loads only, single Powerwall 3
Recharge Time (after outage)
4–6 hrs
From grid once power restores
Oversized battery bank (3–4 units) extends coverage without recharge
Manually load-manage (power only critical loads: fridge, sump pump, lights)
Keep battery at 100% before predicted storm events
Pair with a small propane generator for extended winter events as backup to the backup
For NH homeowners who want maximum resilience, the hybrid approach combines the best of both technologies.
Handles 90%+ of outages automatically, silently, instantly
$9,000–$18,000
Combined for maximum resilience
Covers extended winter events (1–2 weeks) when battery depletes
$8,000–$14,000
Battery handles it silently and automatically. 100% of daily outages covered.
Battery depletes, generator auto-starts. Recharges battery. Generator cycles on/off as needed.
Generator runs on propane supply. Battery acts as buffer, reducing generator runtime and noise.
Battery charges from solar or grid. Earns ConnectedSolutions revenue. Generator on standby.
Hybrid total investment: $17,000–$32,000. This is a significant investment. For many NH homeowners, the right answer is a battery-only system (handles 90%+ of outages) paired with a carefully stocked propane supply for a small portable generator — total cost $10,000–$15,000 — rather than a full whole-home standby plus battery system.
Capacity
13.5 kWh
Power Output
11.5 kW continuous
NH Backup Coverage
~1.0–1.5 days critical loads
ConnectedSolutions
~$330–$400/yr (Eversource)
NH Strengths
All-in-one solar inverter + battery. Seamless automatic backup. High power output.
NH Limitations
One unit insufficient for whole-home for extended outages.
Capacity
5.0 kWh per unit (stack up to 4)
Power Output
3.84 kW per unit
NH Backup Coverage
0.5–2 days critical loads (1–4 units)
ConnectedSolutions
~$100–$400/yr depending on units
NH Strengths
Modular — add capacity over time. Integrates with Enphase microinverter solar systems.
NH Limitations
Lower per-unit power output; may need 2+ units for heat pump or well pump backup.
Capacity
13.6 kWh
Power Output
10 kW continuous
NH Backup Coverage
~1.0–1.5 days critical loads
ConnectedSolutions
Compatible with Eversource ConnectedSolutions
NH Strengths
Competitive pricing. Strong backup power.
NH Limitations
Less brand recognition than Tesla/Enphase; verify installer support in NH.
Capacity
Whole-home (22 kW)
Runtime
Unlimited (fuel-dependent)
Most popular whole-home standby in NH. Automatic start within 10 seconds. Annual service required.
Capacity
Whole-home (20 kW)
Runtime
Unlimited
Premium build quality. Excellent in NH cold temperatures.
Capacity
Critical loads (7 kW)
Runtime
5–7 hrs per tank
Quieter than conventional generators (52–60 dB). Safe for sensitive electronics. Manual start required.
Eversource dispatches your battery during summer peak demand events
Battery discharges to reduce grid stress during hot afternoons (typically 3–7 PM)
You earn approximately $225 per kilowatt of enrolled capacity per summer season
A Tesla Powerwall 3 (11 kW) earns ~$330–$400 per year
Your home comfort is protected — Eversource cannot override your backup settings
Generators cannot participate — battery-only program
Annual ConnectedSolutions Revenue
~$330–$400/yr
(Tesla Powerwall 3 · Eversource territory)
10-Year Revenue
~$3,300–$4,000
Meaningfully improves battery ROI
Effective Battery Cost (after revenue)
~$5,000–$9,000
vs $9,200–$12,000 installed
A single Tesla Powerwall 3 (13.5 kWh) or similar battery powers critical loads — refrigerator, LED lights, phone charging, sump pump — for approximately 12 to 24 hours. If you add a heat pump, Wi-Fi router, and medical equipment, that drops to 8 to 12 hours. Two batteries extend coverage to 24 to 36 hours. During a December ice storm with no solar production, the battery will not recharge until power returns or the sun comes out. This is why extended winter outages favor generators or a hybrid approach.
Realistically, very little. New Hampshire averages about 2.5 peak sun hours per day in December under normal conditions. During an ice storm, panels may be covered in ice and producing near zero for days at a time. An ice-coated panel produces essentially nothing until it clears. The honest reality is that a December ice storm — exactly when NH historically loses power — is the worst possible scenario for solar battery recharging. This is why the hybrid approach (battery for short outages, generator for extended winter events) is so popular in NH.
The December 2008 ice storm is the benchmark for NH backup power planning. It knocked out power for over 400,000 customers across New Hampshire — roughly half the state. Restoration took up to 16 days for the most affected areas. National Guard was deployed. Hundreds of residents relocated to emergency shelters. Fuel deliveries were delayed. The storm established that NH is genuinely at risk for extended multi-week winter outages and that backup power planning must account for 7 to 14+ day scenarios, not just 24 to 48 hours.
Eversource ConnectedSolutions pays residential battery owners approximately $225 per kilowatt of usable capacity per summer season for demand response participation. For a Tesla Powerwall 3 with 11 kW of power, that translates to roughly $330 to $400 per year. The program dispatches batteries to reduce grid load during summer peak events. This revenue improves battery ROI meaningfully over a 10 to 15 year ownership horizon. Generators cannot participate in demand response programs.
For a typical NH home (2,000 to 3,000 sq ft), a 18 to 22 kW standby generator can power everything — well pump, furnace, lights, refrigerator, and basic appliances. The Generac Guardian 22 kW is the most popular whole-home option in NH. For homes with electric vehicles, high-power heat pumps, or large well pumps, consider 24 to 26 kW. For critical loads only (refrigerator, sump pump, lights, furnace), a 7 to 10 kW unit is sufficient and significantly less expensive.
Portable generators can be used safely in NH winters if operated outdoors at a safe distance from windows, doors, and vents. Carbon monoxide poisoning kills approximately 400 Americans per year from generator misuse — primarily from indoor or garage operation. Never run a generator inside your home, garage, or partially enclosed space, regardless of the weather outside. In winter storms, position the generator under a covered outdoor area (not enclosed) with proper ventilation. Standby generators are permanently installed outdoors with proper exhaust routing and are significantly safer.
The hybrid approach pairs a home battery (for short, automatic, silent backup for 90% of outages) with a propane standby generator (for extended winter events like the 2008 ice storm). The battery handles typical outages under 24 to 48 hours automatically and silently. The generator exists as a backup to the backup for multi-week winter events. Cost: approximately $12,000 to $22,000 for battery plus $8,000 to $14,000 for standby generator. For NH homeowners who prioritize maximum resilience and have the budget, this is the most capable solution.
Studies suggest solar plus battery systems add $10,000 to $30,000 in home value depending on system size and local market conditions. As grid reliability becomes a growing concern and electricity prices continue to rise in NH, buyers increasingly view solar plus battery as a desirable feature. Generac standby generators add modest value (estimates suggest $5,000 to $10,000) but are sometimes viewed as maintenance obligations by prospective buyers. The NAR (National Association of Realtors) reports that energy efficiency features increasingly influence NH homebuyer decisions.
NuWatt installs Tesla Powerwall 3, Enphase IQ Battery 5P, and Franklin apower2 in New Hampshire. We'll help you decide between battery, generator, or hybrid based on your home, utility, and outage history.