Solar and Storage, Sized to the House

Generation is the last decision in a net zero build, not the first. Here is why, and what it means for the array on your roof.

Solar is the visible part of a net zero home and the part people ask about first. It is also the part that should be specified last, because its size depends entirely on how much energy the finished house will actually use.

Design the envelope well and the array gets smaller. Design it poorly and you spend the saving on panels.

Flat reinforced concrete roof deck on the Gulf-front Pass-a-Grille build, formed and tied before the pour

Why It Works

Sized against a model, not a guess

The array is specified from the home's modelled annual consumption rather than from its square footage.

Roof planned for it from the start

Orientation, pitch, penetrations and conduit routes are decided while they are still drawings.

Storage treated as a separate question

Batteries solve outage resilience, not the annual energy balance. They are worth having for their own reasons.

Why generation comes last

Every watt of demand removed by the envelope is a watt that never needs generating, and envelope improvements are generally cheaper per unit than generation. Sizing the array before the efficiency work is settled means buying capacity to cover waste.

What a battery actually does

A grid-tied solar system without storage shuts down during a power cut, for the safety of line workers. That surprises people. If the house needs to keep running through an outage, that requires battery storage and an inverter capable of islanding.

Storage barely changes the annual net zero arithmetic — the grid already acts as the balancing account. It changes what happens on the day the grid is down, which in Florida is a reasonable thing to pay for.

Net metering and what it is worth

What you are credited for energy exported to the grid depends on your utility and on rules that change. Because that figure drives the payback arithmetic, we do not quote one — check the current terms with your own utility before relying on any number you read online, including ours.

Solar & Battery Storage FAQs

How big an array does a net zero home need?

It depends on the modelled consumption of that specific house, which is why the envelope is designed first. A more efficient house needs a smaller array for the same result.

Will solar keep my house running in a hurricane outage?

Not on its own. A standard grid-tied system disconnects when the grid goes down. Running through an outage requires battery storage and the right inverter, designed in from the start.

Can solar be added later?

Yes, and designing for it is cheap while it is still a drawing — roof orientation, structural allowance and conduit. Adding it to a roof that was never planned for it costs more.

What is the payback period?

That depends on your utility's rates and net metering terms, your consumption, and the installed cost on your roof. We will not quote a general figure, because a general figure is not about your house.