**1. Introduction**

Grid-tied photovoltaic systems are power-generating systems that are connected with grids. Solar PV energy that is generated must be processed with the help of a grid-connected inverter before putting it to use. This inverter is present between the solar PV arrangemen<sup>t</sup> and the utility grid; it could be a single unit or a collection of small inverters attached to the individual PV units. Due to the lowered cost of power electronic devices and advancements in renewable energy technology, there is significant encouragemen<sup>t</sup> for the power industry to utilize PV solar energy and to attach it to a medium or low voltage distribution grid. The renewable electrical energy market has experienced an extraordinary increase in scope in recent years. Its main catalyst in 2016 was solar photovoltaics, whichare boosting the capacity of renewables all over the world. Due to reductions in costs, solar and wind energy are playing an increasingly important role and are proving to be competitive with fossil fuels in many

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countries. Two-thirds of overall electricity additions in 2016 were from renewable sources of energy [1]. According to the International Energy Agency, solar is leading in additions compared to wind and hydropower. The statistics of net additions and retirements in electricity capacity are shown in Figure 1.

From [2], it is noted that Solar PV has dominated all other forms of electricity production. Its capacity comprises almost 600 Giga Watt (GW) more than all other forms of energy combined. Thus, with this increasing trend in use of Solar PVs, it becomes even more important to study the obstacles faced in extracting energy from solar PV systems and then exporting it or integrating it with the grid. The primary factors to be borne in mind while integrating PV solar energy with the grid are:


Henceforth, a detailed review is done, keeping in mind the current trend and effectiveness of energy produced, and the simplicity of its integration with the grid. This paper is organized as follows:

Section 2: Ancillary services in electric market


Section 6: References

**Figure 1.** Net additions and retirements of Electricity capacity in 2016. Reproduced from [1], International Energy Agency: 2017.

### **2. Ancillary Services in Electric Market**
