A home battery in Holly Springs does one of two jobs, and being honest about which one you want changes the system you should buy.
The first is outage backup: keeping some part of the house running when the grid goes down. The second is shifting when you draw power, which matters if you are on a Duke Energy time-of-use rate or you have solar and want to use your own production in the evening rather than exporting it cheaply.
Most homeowners want the first. Quite a few end up benefiting from the second without having planned for it.
Deciding what you actually want to back up
This is the step that determines cost, and it comes before choosing hardware.
An essential loads sub-panel is the standard approach. Your electrician moves the circuits you care about onto a separate panel that the battery feeds during an outage. Typically that means the refrigerator, some lighting, internet equipment, and a few outlets for charging devices. A single battery handles that comfortably for a day or two.
Whole-home backup is a different proposition. Air conditioning is the reason. A heat pump running through a July afternoon in Wake County will drain a single battery in hours. If you want to keep cooling running through an outage, plan on two or more units and a correspondingly larger budget.
Well pumps matter for parts of southwest Wake outside town water. They draw hard on startup, and that surge has to be within the battery’s output rating, not just its capacity.
What it costs in Holly Springs
A single installed unit generally runs $10,000 to $15,000, including electrical work and the essential loads sub-panel. Two units for broader backup roughly doubles it.
The federal residential clean energy credit that covered 30% of battery cost expired on December 31, 2025. That was a meaningful subsidy and it is gone. Quotes that still show it are out of date, and the number you are quoted now is much closer to the number you pay.
Pairing with solar under current Duke Energy rules
Battery storage has become more attractive in NC specifically because export credits fell.
New Duke Energy Progress solar customers are credited below retail for power sent to the grid. A battery lets you store afternoon surplus and use it yourself in the evening, capturing full retail value instead of a low export rate. That improves the economics of both the solar and the battery, which is why the two are increasingly quoted together here.
On PowerPair: Holly Springs is Duke Energy Progress territory and Progress capacity is exhausted as of June 2026. It also requires solar and battery installed together for the first time at the property, through a Duke Energy Trade Ally. Do not let it into a budget unless Duke or a Trade Ally confirms you hold a reservation.
Sizing without overbuying
Work out your daily essential load in kilowatt-hours, then match the battery to it, rather than starting from a product and hoping it fits.
A fridge, lights, internet, and device charging typically add up to 5 to 10 kWh a day. A 13.5 kWh battery covers that with margin. Adding a well pump, a home office with real equipment, or any cooling changes the arithmetic quickly.
Ask for usable capacity rather than rated capacity when comparing quotes. The depth of discharge figure is what determines how much of a battery’s nameplate rating you can actually use, and the difference between the two numbers is not always obvious on a spec sheet.