600V service to the building and no access to building drawings.
We were informed by the building owner that the electrical service was 480V, for which there are many commonly available commercial solar inverters. When we were permitted access to the site, it turned out the service was actually at 600V. Also, the building structural drawings were not available to assess the capacity for solar panels, and it was determined that the roof needed repairs in certain areas.
We adjusted our design to accommodate for the 600V service.
We responded by adjusting our design to suit the 600V service, sourcing a less common inverter that matched the building voltage. This step is important, as it eliminates energy lost in 480V to 600V transformers. Transformers used in solar arrays run unloaded all night and can introduce losses of 5-10% of the annual solar output.
We worked with our structural engineering partner to assess the building capacity with onsite measurements and calculations, and received a signed Letter of Assurance to proceed with the solar installation.
Finally, we worked with a roofing consultant to determine the parts of the roof in best condition to install solar, so that the solar panels would not need to be removed for repairs in the future.