For the solar panel owner

The house has a 24-panel, 9.6 kW array on the south roof, and a string inverter on the garage wall turns it into house power. The inverter's own monitoring reports output as a percent of expected. Pollen, dust, and the birds on the ridge pull that number down between washes. The wash waits for two conditions together: 90 days since the last one, and output under 85%.

You know the last wash. June 1, 2026: Brightside Solar Care washed the panels for $180, and the monitoring read 99% that day. Muse writes the row from one sentence in ChatGPT, receipt and reading included. Ninety days puts the clock due on August 30, 2026. On October 5 the monitoring reads 91%. On October 6 the wash is not due: the row is waiting on the output alone, 6 points above the 85% line.

You know the other dates too. The inverter air filter was swapped June 1, a $22 filter. The production meter reading right after the swap, on August 1, said 42,000 kWh, so the filter's kWh line sits at 52,000, and every 12 months puts the next swap on June 1, 2027. On October 5 the meter reads 47,000 kWh. The roof and racking inspection went to Ridgeline Solar Service on April 10, 2026, $150, and the April 1 line puts the next one on April 1, 2027, about 176 days left.

Before the next wash, ask Muse what's due on the array. Nothing on the board reads due on October 6, and the board says so, then it names what is coming. The wash comes back with the output line only: 6 points of room above the 85% line, output falling about 8 points in 126 days, which puts the 85% line around January 7, 2027. Ask what is due in the next two weeks and the wash stays off the list; ask about the next 120 days, four months, and it shows up, about 93 days out. The filter comes back with both branches on the row: 5,000 kWh left, the kWh line around December 9, 2026, the June 1, 2027 clock beside it. The roof comes back with April 1, 2027 and the 176 days. The board subtracts on the calendar and names what is left.

The panel wash is one job with two conditions, and the row waits until both read met. The 90-day clock came due August 30, 2026, so on October 6 the wash hangs on the output alone: 91% on October 5, 6 points above the 85% line. A condition that is already met contributes nothing to the row, so the row does not show August 30, and it does not show zero days left. The met clock still reads on its own line when you ask Muse to show both conditions: met since August 30. The output falling about 8 points in 126 days puts the 85% line around January 7, 2027. Wash the panels, log it with the date and the reading, and the clock restarts from the day you washed.

The order can flip, and the row still names only what it waits on. A wash logged September 6, 2026 puts the next 90-day date on December 5, 2026, 60 days left as of October 6. The output can drop under the line first: 82% on October 5, down from the 88% it read right after that wash. The row now waits on the clock alone, December 5, 2026, 60 days left. The output side leaves the row with its zero runway and its 85% mark, so the wash carries no output eta. Asking for rows within 5 points of their output line does not pull the wash in. And when both read met, the row fires: with the June 1 wash, a reading of 80% means both conditions are met and the wash is due, about 37 days past the August 30 clock, 5 points under the line.

The inverter air filter carries the other shape: every 12 months, or every 10,000 kWh through the production meter, whichever comes first. The last swap was June 1, 2026, and the reading right after it, on August 1, said 42,000 kWh, so the kWh line sits at 52,000. The meter read 47,000 on October 5, so 5,000 kWh are left. At 5,000 kWh in 65 days, the line lands around December 9, 2026, ahead of the June 1, 2027 clock, and the row shows both. If the meter hits 52,000 first, the filter is due that day, with June 1, 2027 still named on the row.

The array gets the observation habit too. Bird droppings on the lower row, a pigeon nest under the panels, a squirrel-chewed wire, an inverter error light: tell Muse what you saw in the same breath as the date. Muse keeps each one as a note on that line, so the array's history stays with the house. The notepad in the garage can retire. Mention the pigeon nest when you log the next wash and the note lands on that row.

The board can call ChatGPT too. Subscribe once and ChatGPT hears when the panel wash lands on the due board: a signed webhook names the job and how late. An agent that speaks MCP can hear the same board. The ping arrives without a question from you.

Every row you log stays in the service log: panel washes with their receipts from Brightside Solar Care at $180, air filters at $22, and the roof and racking inspections with their receipts from Ridgeline Solar Service at $150. So the day the house sells, say it once: archived. Muse archives the array and the due board drops it that day, and the history stays: years of wash dates, what the output read after each one, which April the inspection came back clean. If the deal falls through, one ask puts it back on the board.

One line, said plainly: Maintenance Due is a personal due board and service log for the array. It keeps the notes you give it. The inverter monitoring measures the output, and the board counts the days and the readings you tell it.

The house log on /home-maintenance-checklist shows how calendar rows look. Copy the prompt on /for-your-agent and paste it into Muse. Free.