Sizing a Standby Generator for a Louisiana Outage

Sizing a generator sounds like a math problem, and part of it is, but the part that actually matters for a Louisiana homeowner isn't on the spec sheet. It's what a real outage here looks like: not four hours while a crew resets a line, but three, five, sometimes seven days after a hurricane knocks out transmission infrastructure across the parish. Sizing for that reality is different from sizing for a generic outage, and it's worth walking through deliberately rather than just picking the biggest unit you can afford.

Start with what you can't live without for a week, not a day

A four-hour outage and a five-day outage put different pressure on your list of essentials. Refrigeration matters in both, but over five days in August, air conditioning stops being comfort and becomes a real health consideration, especially for anyone elderly, very young, or managing a medical condition in the house. A well pump, if you have one, isn't optional at any duration. Medical equipment that needs continuous power isn't a maybe. Start your list from a week-long outage in July, not a four-hour outage in March, and you'll size closer to what you actually need when it counts.

Whole-house versus essential circuits, honestly compared

Whole-house coverage means you don't have to make decisions during an outage. Every circuit in your panel, both AC zones if you have them, every outlet, runs exactly as it would on a normal day. The cost is a larger generator and a transfer switch rated for your full service amperage, which is real money upfront. Essential-circuits coverage runs a defined subset, sized to a smaller generator, and the trade-off is that you have to decide in advance what's on that list and live with it during the outage. Neither is wrong. A retired couple in a smaller Geismar home with a straightforward electrical load has a very different calculation than a family running a home office, two AC zones, and a well pump in a larger Prairieville property. We walk through your actual panel and your actual life during an outage before recommending either.

Run time is a fuel question as much as a generator question

A generator that's correctly sized for your load still needs fuel to actually run for the duration you're planning for. Natural gas, where a line is already at the property, solves this cleanly: as long as gas service stays up, which it usually does even when the power grid doesn't, the generator runs indefinitely without you managing a fuel supply. Propane requires a tank, and tank size becomes its own sizing decision tied directly to how many days of unattended run time you want. A common mistake is sizing the generator correctly and then treating fuel capacity as an afterthought, only to find out mid-outage that the propane tank was sized for a weekend, not a week.

Surge load versus running load

Air conditioning compressors, well pumps, and refrigerator compressors all draw a short surge of power on startup that's significantly higher than what they draw once running. A generator has to be sized to handle that surge, not just the steady running total of everything on at once, especially if multiple things could start up close together, like an AC compressor and a well pump both kicking on within the same minute. This is where a load assessment done by someone who actually measures your equipment, rather than going off nameplate numbers alone, prevents a generator that looks correctly sized on paper from tripping under real conditions.

Sizing before the season, not during it

Hurricane season here runs June through November, and the honest pattern we see is that most sizing conversations happen in the days right after a storm, when demand and lead times are both at their worst. A load assessment done in the spring, before the season starts, gives you an accurate number based on your actual panel and equipment, with enough time for permitting and installation to be done properly rather than rushed. If you're only going to do one thing proactively this year about outage preparedness, get the assessment done before June, not after the first outage of the season.

What we walk through with you before recommending a size

In practice this starts with a look at your panel and a conversation, not a form. We want to know how many people are in the house, whether anyone has a medical need that depends on continuous power, whether you have a well pump or a sump pump, and how you actually used the house during the last multi-day outage you lived through, because most Ascension Parish homeowners have one to compare against. That real history is a better sizing input than a generic square-footage chart, and it's why we do the load assessment in person rather than quoting a size over the phone from a description alone.