What Actually Goes Into a New Solar System

By the time most homeowners are shown a solar proposal, every decision that matters has already been made — usually by software, in about four minutes, from a satellite image and one month of a utility bill.

That is not a design. It is a quote with a rendering attached. The distinction becomes obvious in year eight, when the array is producing less than the estimate, the panel could not carry the storage you now want, and the company that sold it is no longer answering the phone.

Here is the work that should sit behind a new system, in the order it should actually run.

1. The load profile comes first

Not the roof. Not the panel count. What the house actually draws, measured across a full year — winter peak and summer peak, because a large home's demand is lumpy and the two peaks rarely look anything alike.

That means interval data where the utility provides it, and a real accounting of the loads that never show up on a spec sheet: well pump, HVAC compressors and their start current, pool equipment, a shop or outbuilding on the same service, EV charging, and the standing draw of a house that is never entirely off.

A system sized from an annual kilowatt-hour total can be perfectly correct on paper and wrong every January. Annual totals hide the shape of the year, and the shape of the year is the design problem.

2. The site, not just the roof

Roof geometry is the obvious part: planes, pitch, azimuth, and how much of each plane survives once dormers, chimneys, vents, and code-required fire pathways are subtracted. Less obvious, and more consequential:

• Structure. Rafter dimension and spacing, sheathing condition, and whether the framing carries the added dead load plus snow without reinforcement.
• Roof covering. Asphalt, standing-seam metal, slate, and tile each demand a different attachment and a different flashing detail. Slate and tile in particular are unforgiving of a crew that treats them as asphalt.
• Shading, measured rather than assumed. Including what the mature canopy on the property looks like in ten years, not what it looks like in the aerial photo taken in March.
• Roof age. Covered below, and the single most commonly skipped question in the trade.

Where the property carries land, the ground is evaluated alongside the roof rather than as a fallback. Often it wins on production and leaves the architecture untouched — we set out when and why in When the Land Is the Better Answer.

3. Array design

Module selection, orientation, row spacing, wind and snow loading, setbacks, and access pathways. Then the question most proposals never raise: which plane the array sits on, and what that does to the house. On a home where the elevation is the point, the most productive plane and the right plane are not always the same one, and that trade-off belongs to the owner, not the designer.

4. Inverter architecture

String inverters, microinverters, and hybrid inverters solve different problems. The relevant differences are where the electronics live, how the system behaves when one module underperforms, how granular the monitoring is, and — critically — what the choice permits you to add later.

An inverter architecture chosen for the lowest install cost can quietly foreclose the storage configuration you want in year five. This decision is made before the design is finalised, not after, because reversing it later means replacing hardware that is working fine.

5. Storage is decided at design time

Battery storage can be retrofitted to an existing array, and we do that work. It is still cheaper, cleaner, and better engineered when the array, the inverters, and the electrical service were designed with it in mind from the start.

If outage performance matters to you, decide the target now: a handful of circuits, or the whole house. Those are different systems, not different sizes of the same system, and we explain why in Whole-Home Backup, Not Partial Backup.

6. The electrical service

Main panel rating, busbar capacity, available breaker space, meter location, and the conductor runs between all of it. The electrical code limits how much generation can be interconnected to a given panel, and on older services that limit arrives before the roof does.

This is where project budgets move, and it is why a panel or service upgrade should appear in the design conversation rather than as a change order after a contract is signed.

7. Permits, inspection, and interconnection

A township or borough permit, often with structural and electrical review. An inspection after the install. Then a separate utility interconnection application, which ends — if everything was done correctly — in Permission to Operate.

Until PTO is granted, the system is not permitted to run, regardless of what is on the roof. That step is where a surprising number of installations are abandoned, and it is the reason we have a whole service line for systems that were installed and never switched on. Ask, in writing, who is responsible for carrying the interconnection through to approval.

8. Commissioning and monitoring

A finished install is not a commissioned system. Commissioning means every module and every inverter is confirmed reporting, output is measured against what the design predicted, and a baseline is established that a future service call can be compared against.

Insist that the monitoring account is created in your name, with your credentials. Homeowners whose monitoring is registered to a defunct installer's email address spend months recovering access to their own system's data, and that data is exactly what a technician needs first.

The twenty-five year question

A solar array outlives the sales relationship that produced it, frequently by decades. The roof it sits on will need replacing at least once underneath it. Inverters and optimizers are electronics mounted outdoors and will fail on their own schedule.

So the question worth asking before anything is ordered is not who installs it. It is who fixes it in year twelve. Many companies decline to work on systems they did not install. Many others are simply no longer in business, and their workmanship warranties left with them.

Six questions worth asking anyone

Bring these to every company you talk to, including us. The answers are more revealing than the proposal.

• What data did you size this from? Twelve months of interval data is a different answer from one bill and a satellite image.
• What is the inverter architecture, and what can I add to it later? Specifically storage, and specifically how much.
• Who pulls the permit, and whose licence is it issued under? If the answer involves a subcontractor you have never heard of, keep asking.
• What entity is the workmanship warranty written against? A warranty is only as durable as the company behind it.
• What happens if production falls short of the estimate? Listen for whether there is a remedy or only an explanation.
• How old is the roof, and what is the plan when it needs replacing? If nobody raised this, they were not designing for the life of the system.

That last one has a number attached to it that most homeowners never see until the roofer is already on the phone. We priced it out in What a Detach and Reset Costs When the Roof Comes Off.

How we work

Every system is engineered individually, against the measured demand of the specific household and the real constraints of the specific property. There is no standard package, because there is no standard house in the range we work in.

See if your home qualifies, or request a private consultation below and we will start where the work should start — with what the property actually uses.