The Mountain Vista United Methodist Church in West Jordan found it extremely challenging trying to cool the church’s open layout with high ceilings during the hot summer months. Unlike a typical Park City installation, where offsetting wintertime electric bills is the main focus, summertime cooling bills were the target here. After examining the church’s past bills and other factors, we decided a 19.2kW system would fit their goal of achieving a net zero electric bill. These calculations are all based on the number 5.3. That’s the average number of hours of sun/day in Utah year-round. When we decide on an installation’s potential total usage needs, we divide that total by 5.3 to find how many watts we need to provide per hour.
Our installation area of the church’s roof is relatively flat, which is good for tracking the path of high summertime sun, but not as effective in the winter when the sun stays lower in the sky. This roof was a 4/12 pitch (1/12 is flat), so we built extra capacity into the system to allow for the flatter panel orientation.