Perihelion Solar · Design journal & install shop · Quarrytown, Ferrow County & the Lark Basin · Est. 2015
Closest to the sun in the coldest week.
Perihelion is a two-person design studio that installs what it draws: arrays read against a decade of county weather notes, module-by-module budgets, and a quarterly letter that tells every client what their roofs actually made — January included, because the perihelion, the year’s closest pass to the sun, falls in the first week of it.
Issue 41 of the letter mailed this quarter · 168 roofs drawn, 151 built · every model signed by the person who drew it
The Garrow roof made 104% of its model in a year the almanac called grim. The note in the margin says the model was wrong twice — once pessimistic, once honest.
What we do
What the studio draws
Rooftops, drawn to the rafter
Every drawing starts at the structure: rafter spacing, load path, the plane the county wind map actually cares about. The array lands where the drawing says, down to the rail cut list — most Ferrow County roofs take 6 to 11 kW, and the drawing, never a catalogue, decides the count.
Ground mounts at the fence line
Where the roof faces the wrong way, the drawing moves to the field: piers below frost, a winter tilt the letter photographs every January, and a trench the studio stakes out personally. Roof and ground are drawn side by side with both production models — the honest one wins, not the bigger invoice.
Batteries & the quiet panel
Storage drawn as part of the house, not stapled to it: a garage-wall cabinet, the four circuits you name carried through an outage, and a monitoring page so calm it prints on one sheet. The letter reports battery behaviour every winter, including the February the Okoro house ran nineteen hours.
Quarterly figures
The studio, by its own count
How it goes
How a drawn roof goes up
The same sequence on every job — the only variable is your project.
Weeks 1–2
The drawing
Site walk, rafter notes, twelve months of bills, a decade of county weather. Out comes a scaled drawing with the array, the shade hours and a month-by-month model — signed across the corner the way a print is.
Weeks 3–5
The permit set
The drawing becomes the permit set: structural calcs, electrical one-liner, the utility filing. You sign the contract and one utility form; the studio chases every stamp between them and dates each in the letter.
Week 6
The build, two days
Two people drew it; a small crew the studio has used for nine years builds it — flashed, torqued, and photographed against the drawing before the ladder comes down.
Quarterly, after
The letter
Every client gets the letter for the life of the system: production against model, weather notes, and the one maintenance item the season actually asked for. It is why our clients stay alphabetical — and alphabetical is how the letter is addressed.
2025 — 2026
Drawn roofs, built and photographed
Six from the drawing file, each with the quarter its photo ran in the letter. The drawing for any of them will be on the studio table if you come by — with the model’s signature still on the corner.
Reader mail
From the letters, answered
The five questions the mailbox brings every quarter. Anything else, the studio line answers between eight and six, Quarrytown time.
What does the drawing cost?
Nothing, and it is yours either way. A roof study with a month-by-month model, drawn and signed, that you can carry to any installer in the county. About one in eight of our drawings gets built by somebody else — the letter has run the numbers on those roofs since 2019, and they do fine, which is the point of a good drawing.
Why sign the model?
Because a signature is accountability a spreadsheet is not. The person who drew your array reads your first winter in the monitoring platform and writes it up in the letter. If the model was wrong, the signature is where the apology starts — and the year-one floor of 95% is where it ends, at your net-metering rate.
Can you draw for a roof another installer condemned?
Often. The trade has a habit of condemning shade instead of modelling it. Bring the quote; we will draw the same roof with the trees in the model and tell you honestly which document is closer to January. Two of the six roofs on this page were condemned somewhere else first.
Do you do batteries and outages?
We draw storage onto the four circuits a Ferrow County outage actually threatens — furnace board, well pump, fridge, the internet that lets you read this. The letter has run a winter battery column since issue 29, and the median performance line is exactly as boring as it should be.
What happens if the studio gets busy?
We stay two people on purpose and the waiting list is published in the letter — currently five weeks to a drawing, eight to a build crew. Nothing about the schedule is a sales tactic: the letter prints it every quarter, and moving up it has never once been available for a price.
The drawing arrived in a cardboard tube, which should have told me everything. Signed, dated, with my two oaks shaded hour by hour on a transparent overlay. The build matched it to the rail cut, and the letter has reported my roof’s numbers with more candour than my bank reports my money.
Another company condemned our roof from the driveway. Perihelion drew it with the shade in the model, the array came in two kilowatts smaller than the condemned quote, and it has beaten its model both winters. Issue 38 ran our December numbers next to the almanac’s — that column is why we re-read the letter.
They drew a ground mount at our fence line and photographed it at winter tilt for the letter, in January, standing in snow to do it. Nine years of quarterly issues and our roof has appeared in four — including the one where the model admitted it had been pessimistic. That is a strange kind of subscription to love, but here we are.
Drawings booked five weeks out, builds eight · (555) 014-2837 · notes@perihelionsolar.example
Ask for the drawing first
Tell us the town and the roof. The study is free, signed and yours to keep whatever you build; if it says solar is wrong for your roof, the letter would still like your address. notes@perihelionsolar.example