Abstract

Due to high cost, solar Photovoltaic (PV) systems are not an attractive option for places where energy buyback 

programs are not available. Mostly because small scale PV systems are incapable of operating legacy high-powered 

electrical devices such as room air conditioners, induction motors and other compressor-based devices on 

renewable energy. This is because these devices show either capacitive or inductive behavior which results in 

a high transient power during their startup cycle, not accommodable by small-scale PV systems. Solutions to solve 

this problem such as Variable Frequency Drives (VFDs) are expensive and restrictive in their applicability.



In this paper, we propose an approach to operate high-powered legacy electrical appliances on small-scale solar PV. 

Our proposed method involves a real-time algorithm which detects the onset of a transient and shifts the appliances 

from PV to the utility during the transient duration. Upon reaching back to a stable state after the transient, 

the device is shifted back to PV. We have evaluated our transient detection algorithm on a two publically available 

datasets as well as on a specifically designed testbed system. Our evaluations show that for most common high-powered 

devices, the transients are detected fast enough to shift the load from PV to the grid and vice versa.