Performance Analysis of Rooftop Grid-Connected Solar PV System Under Net Metering System

Abstract

Renewable energy technologies enable us to generate clean energy that has a lower environmental impact than conventional technologies. They differ from fossil fuels principally in their diversity, abundance, and potential for use anywhere on the planet. Increased generation of green energy will, in turn, reduce greenhouse emissions, thereby helping to mitigate global warming. The process of acquiring photovoltaic (PV) power generation involves designing, selecting, and determining specifications depending on various factors like geographical location, weather condition, solar irradiance, and load consumption. This chapter mainly focuses on presenting a case study of “rooftop grid-connected PV with net metering” at G. Pulla Reddy Engineering College (GPREC), Kurnool, Andhra Pradesh, India. The institute is located geographically at 15°49’59.88” N 78°02’60.00” E and is enriched with an excellent average solar radiation of 5.5–6.0 kWh/m². The institute was started in the year 1985 with a small intake of 180 students, and at present, the intake is 840; this resulted in the increase of power consumption year by year. At present, to meet the load of the institute, a 500 kVA distributed transformer with a contract maximum demand (CMD) of 320 kVA is established in its premises. As per the Paris agreement, India is committed to reduce its greenhouse emissions by intensity of its GDP by 33–35%. To meet this requirement, the government of India has given various incentives/subsidies for establishing stand-alone and grid-connected PV systems. Also, the government of India is encouraging the prosumers (producer and consumer) to establish rooftop PV grid-connected system under net metering system by providing financial subsidy, which is limited to the capacity of transformer (in case of this institute, it is 500 kVA). Hence, the management of the institute had established rooftop grid-connected PV system under a net metering system. At the initial stage, 100 kWp was established in the year 2014, and successively, the capacity was extended to 400 kWp. Under a net metering system, the PV system will act as the primary source of energy generation, and any deficiency in the energy requirement will be drawn from the grid. As per the norms of the government, if the connection to the grid is lost, the prosumers shall not export the power to the grid to avoid any fatality. The main objectives of this chapter are carried out following case studies: During normal running conditions of the grid and institute, majority of the power requirements are met by the PV system and less power will be drawn from the grid. During normal running condition of the grid and light load conditions of the institute (usually on a holiday), majority power will be exported to the grid. Abnormal conditions: Connection to the grid is lost and institute is running at normal condition with a diesel generator (DG) set. Connection to the grid is lost and institute is running at light load condition with a DG set. Connection to the grid is lost and institute is running at normal load condition under unfavorable weather conditions with a DG set. Connection to the grid is lost and institute is running at light load condition under unfavorable weather conditions with a DG set. The economical aspects (payback period analysis). Analysis of actual power exported to the grid per month. Also, this chapter suggests a future plan to overcome the problems faced during abnormal conditions (case study 3).