You will still be a customer of the utility. When the sun is shining the landlord will distribute solar power generated onsite to your unit for consumption instead. Any power you require that the solar power system can’t supply will be provided by the utility the same as always

You will receive a monthly clean energy statement detailing the exact amount of solar kWh you used instead of utility power, and the discounted rate you’ll pay to the landlord for the clean power portion.