Optimization of rooftop photovoltaic installations to maximize revenue in Finland based on customer class load profiles and simulated generation

Abstract

The profitability of a rooftop solar photovoltaic (PV) system depends on several factors, such as the retail price of electricity, the load profile of the building, and orientation of the solar PV modules. If there are consumption peaks in the morning, evening, or both, the solar PV modules can be oriented eastward, westward, or east–west, respectively, in order to increase self-consumption. However, the market price of electricity varies, which makes it challenging to evaluate the revenue of a solar PV system in advance.In this study, solar PV module orientation is considered based on profitability. The study uses hourly data of 13 different statistical customer class load profiles, historical electricity market price data for the years 2016–2020, and simulated solar PV yield from southern Finland. A comparison is made between single-azimuth and dual-azimuth systems, the latter of which having the orientation of half of the modules mirrored respective to the north–south axis.A single-azimuth system is usually more profitable when compensation is paid for surplus electricity. The optimal orientations are at azimuth angles of −15°–5° and at tilt angles of 35°–45° with both fixed and dynamic electricity purchase prices. However, if no compensation is paid for surplus electricity, it is usually more profitable to minimize the electricity purchase by orienting the solar PV modules in two azimuths between east and west with tilt angles of 10°–55° depending on the capacity of the solar PV system and the load profile. The revenue is not very sensitive to moderate changes in orientation.