Techno-Economic Assessment of Integrating Renewable Power to Large Inductive Loads Under Power Compensation Schemes: A Case Study of Metropolitan Water Pumping Systems
Abstract
Large inductive loads such as motors and pumps require balanced active and reactive power for their operation. There are two major approaches that are adopted to reduce energy consumption. The capacitor bank scheme (CBS) is mainly used for reactive power compensation, whereas solar power integration (SPI) is used mainly to reduce the burden on the grid while providing active power. However, significant aspects that may need precise quantitative assessment are active power, reactive power, and the power factor variations under the CBS and SPI schemes. This research study proposes an evaluate, quantify, and compare (EQC) framework for CBS and SPI schemes that will help industries to systematically opt for the efficient and cost-effective operation of large inductive loads. Under the EQC framework, detailed quantified trade-offs between active power, reactive power, and power factor corrections were found. It was found that without integrating renewable power, the active power and reactive power on the LV bus were 115 kW and 58.9 kVAR, respectively, compared to CBS, where reactive power was reduced to 34.9 kVAR. SPI approach with unity power factor reduced active power and reactive power to 34 kW and 59 kVAR, respectively. However, the power factor was reduced to 50.4% from 80% in CBS. While integrating solar power with a 90% power factor, the active power was reduced to 34 kW, and the reactive power was reduced to 20 kVAR with the power factor increasing to approx. 90%, proving the suitability of the SPI approach. To further assess the SPI approach in terms of economics, the feasibility analysis for SPI was conducted on HOMER PRO. The NPC reaches up to 1.13 million, which is 30% lower compared to grid supplies. The operation capital cost for solar PV power is USD 63,453. The operational cost is 34% compared to the grid. One of the important parameters is the levelized cost of energy (LCOE). The cost of energy for the grid-based system is set at 0.210 cents, whereas for solar power, the LCOE is set at 0.126 cents, which is 40% less compared to the grid.