Reading a Production Report on a Claremont Home You Are Buying

Every solar home comes with a sales pitch attached. Panels on the roof, a brochure in the disclosure package, a seller who is certain the system covers everything.

None of that is evidence.

The production report is. It is the record of what the array has actually generated, month after month, and it is the most useful solar document a buyer can get hold of that is not a contract.

Where the data lives

Most systems installed in the last decade report to a monitoring platform. The inverter, or equipment attached to it, sends output data somewhere, and somebody holds a login that can display and export it.

That somebody may be the seller. It may be the installer. On a leased or service-agreement system it may be the provider, and the homeowner may have only a limited view of their own roof.

Older systems may report nothing at all. An array from the early era of residential solar can be entirely mute, in which case the only production record is the pattern on the utility bills, which is a much blunter instrument.

Ask early who holds the data, because the answer shapes everything that follows.

What to ask for

Ask for a FULL EXPORT, not a screenshot.

A screenshot of a good month is marketing. A multi-year monthly export is evidence. The whole point is the shape over time, and a single frame destroys the shape.

Ask for whole calendar months, consecutive, with no gaps. Gaps are not automatically sinister, but every gap is a question, and the seller is the person who can answer it while you still have contingencies.

Ask whether the platform reports at the system level only or at the panel level. Panel-level data is far more useful, because it shows which parts of the array are contributing and which have quietly stopped.

Ask for the utility bills alongside it. Production is one half of the picture and consumption is the other, and the two documents are not interchangeable.

Reading the shape

You are not trying to compute a savings figure. You are looking for PATTERNS, and only a few matter.

A seasonal curve is normal. Output rises through the long days and falls through the short ones, every year, in the same rhythm. A record with that rhythm intact is a record of a system behaving like a system.

A step down that never recovers is the finding you are looking for. Output runs at one level, drops on a particular date, and then continues at the lower level indefinitely. Something failed and nobody fixed it. That could be one string, one panel group, or one inverter channel.

A flatline at zero is either a genuine outage or a monitoring failure, and those are very different problems. A system can be producing perfectly while its reporting hardware is dead, and it can also be dead while somebody assumes the reporting is just glitchy.

Gradual decline over many years is expected to some degree. Steep decline over a short period is not.

You are looking for the discontinuity. Discontinuities have causes, and the cause is what you want named.

What the report cannot tell you

This is where buyers overweight the document.

A production report says NOTHING about who owns the equipment. A leased array and an owned array produce electricity identically, and the entire commercial difference between them sits in paperwork the monitoring platform has never seen. That split is the subject of the ownership guide.

It says nothing about what the household will pay going forward. What a system generates and what it is worth on a bill depend on the tariff, the rate schedule, the interconnection terms and the way consumption falls across the day. Those arrangements are set by the utility and by state regulators, they change, and they are not the seller's to promise. Verify current terms with the utility and with the California Public Utilities Commission before relying on any of it.

It says nothing about roof condition, mounting quality, or whether the installation was permitted.

It says nothing about warranty status, service history, or who to call when something breaks.

It is one instrument. Treat it as one instrument.

Access at closing

Get the monitoring account sorted as part of the transaction, not afterward.

A buyer who closes without platform access has bought a system they cannot observe. The first sign that something has failed is a change in the data, and if nobody is looking at the data, the first sign becomes an unexpected utility bill several months later.

Whether the account transfers, gets recreated, or requires the provider to act depends on the arrangement. On a leased or service system the provider controls the platform, and access belongs in the assumption conversation described in the lease transfer guide. On an owned system it may be as simple as the seller changing the email on the account, or it may require the original installer, who may no longer exist.

What to do with a bad finding

You have a contingency period. Use it.

A discontinuity in the record justifies bringing in somebody qualified to look at the hardware. A general home inspector will confirm that panels are present and that nothing is obviously falling off the roof. That is a different job from diagnosing why one string stopped reporting.

From there it is an ordinary negotiation. Repair before closing, a credit, a price adjustment, or a decision that the deal is not worth it. Which of those is available depends on how the array is owned, because on a leased system the person who has to authorize a repair may not be the seller at all.

The buyer tactics for that conversation are set out in the negotiation guide.

For sellers

Pull the export before you list.

If the record is clean, you have handed a buyer the strongest possible answer to the question they were going to ask anyway. If it is not clean, you have found out on your own schedule rather than on day eleven of an escrow, and you can decide what to do about it while it is still a maintenance decision rather than a negotiation.

A seller who cannot produce any production history is asking a buyer to take the array on faith. Some will. They will price the faith.

For the wider transaction picture, start at the solar homes hub, and read the first questions guide before you write an offer on a house with panels.

Anthony Grynchal has been licensed in California since November 2009.