Do You Need a Home Battery in 2026?

It depends on the battery size and your loads. A single 13.5 kWh battery (like a Tesla Powerwall) can power essentials — refrigerator, lights, Wi-Fi, phone charging, and a few outlets — for 10-12 hours. Whole-home backup with HVAC and cooking requires 2-3 batteries (27-40 kWh) and may last 6-10 hours depending on demand. Paired with solar, batteries recharge during the day and can sustain critical loads indefinitely during extended outages.

Yes. Batteries can be retrofitted to most existing solar systems. If you have a string inverter, you may need a battery-compatible hybrid inverter or an AC-coupled battery like the Tesla Powerwall or Enphase IQ Battery. If you already have Enphase microinverters, the Enphase IQ Battery integrates seamlessly. NuWatt evaluates your existing system and recommends the most cost-effective retrofit path.

No — not for homeowner-purchased systems. The residential clean energy tax credit (Section 25D) expired on December 31, 2025. Homeowners who buy a battery with cash or a loan receive $0 federal tax credit. However, batteries installed through a third-party-owned arrangement (solar lease or PPA) may still qualify for the 30% Investment Tax Credit under Section 48/48E, since the tax credit goes to the system owner (the leasing company), not the homeowner. State incentives and utility programs like ConnectedSolutions remain available and are often more impactful.

Installed costs range from $8,500 for a smaller 5 kWh Enphase IQ Battery 5P to $11,500-$12,500 for a full-size 13.5 kWh Tesla Powerwall or Franklin 13. These prices include the battery, gateway/transfer switch, electrical work, permitting, and installation. Multi-battery installations get modest per-unit discounts. State incentives and ConnectedSolutions revenue can significantly offset the cost.

Yes, but with reduced performance in extreme cold. Modern lithium-iron-phosphate (LFP) batteries like the Tesla Powerwall 3 and Enphase IQ Battery operate in temperatures from -4°F to 122°F. Below freezing, capacity may decrease 10-15%, and charging may be limited. Batteries installed in garages, basements, or conditioned spaces avoid extreme temperature exposure. In New England, most batteries are installed indoors and perform well year-round.

ConnectedSolutions is a utility demand response program available in Massachusetts, Rhode Island, and Connecticut. When the electric grid is under stress during summer peak demand, your enrolled battery automatically discharges stored energy to reduce grid strain. In return, you earn $225-$275 per kW of battery capacity per summer season — typically $1,000-$1,500 per year for a single Powerwall. You set a minimum reserve so backup power is always available. NuWatt handles enrollment for all customers.