Business Use Depreciation For A Solar System

My son is in the solar business.  He works with several different installation companies.  In early 2023 he had one of his installers put a solar system on his house.  During the year he used it multiple time as a selling tool showing what a solar system can offer.  This resulted is many sales.  Can he depreciate a portion of the cost as a business expense?  He operates the business from his home and has a dedicated office there. Total cost, after tax credit, was $18,000.  Suggestions are appreciated, thanks in advance.