A school hall in Wanniassa
A forty-kilowatt array on a school hall, referred in by a residential builder and delivered inside the term break.
What the customer wrote
Thank you for delivering this project before the start of a new school term
System specifications
- Panels
- Trina Solar
- Inverter
- 30 kW Sungrow commercial
- Solar
- 40 kW
- On site
- Five days, six staff
About this job
The deadline is the design constraint
A school is unavailable during term and busy during the break. The window is fixed before anything is drawn. That decides more than the schedule. It sets how much of the set-out is pre-assembled off site, how many people are on the roof at once, and how much contingency the plan carries for weather. Five days with six staff is what forty kilowatts on one hall roof takes when the date cannot move.
Working through somebody else's site
This project came to us through a residential builder, who referred us to the team coordinating the works. Sunstak was one trade among several on a live construction site. Access, crane time, roof loading and the order of trades belong to somebody else's programme. The electrical scope has to fit inside it.
Why a school suits solar
A school uses most of its power in the middle of the day and almost none at night or on weekends. That is close to the shape a north-facing array makes. During the planning phase we estimated that close to 90% of the generation would be used on site during school terms. That estimate was made before the system existed. It is the reason the array is sized the way it is, and it is why a school gets more out of solar than a house with the same roof area.
Commercial-scale hardware
Forty kilowatts of Trina panels through a 30 kW Sungrow commercial inverter. Oversizing the array against the inverter is normal and deliberate: panels rarely make their rated output, and a slightly under-sized inverter spends more of the day near its efficient band. The trade is a few hours of clipping at midsummer noon against more energy across the year.
