Solar systems are installed for both off-grid (totally stand alone) and net-metering (interconnected to the utility) applications. Based on my home inspection experience, here’s a quick primer on what to look for in an installed system.
For net-metering applications, be sure to locate:
- Locate the certificate of agreement with the utility.
- Check to confirm that there is a label on the electrical utility meter that identifies that there is a second source of power at the house.
- Identify the main disconnect that separates the solar system from the utility. The meter and disconnect must be clearly labelled and have provision for lock-out.
For off-grid applications:
- Locate the emergency back-up generator. Review its condition and wiring to the main panel.
- Is the generator start-up procedure and in particular the powering-on sequence to the panel clearly identified?
For all applications:
- Locate the wiring diagram. Can the wiring be traced?
- Locate the structural engineer’s report on the roof mounting method. The issues here include: the point loading on the roof sheathing, the impact of the load on the trusses below, the attachment spacing and ballasting method (if repquired) to be employed.
- Inspect the roof penetration sealing method used for all the point supports and supply cables.
- Inspect how the roof wiring has been installed. It should never be touching the roof itself.
- Is there a pest barrier around the roof panels, to prevent them from accessing the underside for shelter?
- Is there any physical damage to the surface of the panels? This can be either from impact (hail, balls) or scorch marks due to arching within the panels.
- How old are the batteries and where are they with respect to the remaining service life? Is the battery enclosure ventilated?
- How old are the electronics and where are they with respect to the remaining service life?
- Is the service life of the roof appropriate for the age of the solar panels? the life expectancy of the roof should be similar to the photo-voltaic panels.
Solar power systems are special constructions and in some cases may have been installed as DIY projects. As a result, the as-built standards vary widely. Be sure to take the time to understand how it functions. If available, always request one-on-one instruction from the seller on its operating procedure.
As a home buyer with such a system, you are to be congratulated for acquiring a renewable energy system!