Dynamics and Control of Electric Transmission and Microgrids

11Solar Power Generation and Energy Storage

11.1 Introduction

Solar energy can be converted to electricity in the following ways:

1. Solar thermal power conversion: Solar radiation (photons) interacts with a material to increase the kinetic energy of atoms (heat). This heat is used to produce steam, which is then used to drive a turbine. The turbine is coupled with an electrical generator, which produces electricity.
2. Solar photovoltaic (PV) conversion: Photons falling on a semiconductor P‐N junction cause a voltage to be generated across the junction (photovoltaic effect). This can drive current into an external circuit and deliver power to it.

Electricity generation systems based on both solar thermal and solar PV technologies have been deployed in the world. The global installed capacity of solar PV in 2015 was about 220 GW [1], while for solar thermal conversion systems it was less than 5 GW. Solar PV systems have seen the highest annual growth rates among the renewable energy systems due to numerous advantages such as quiet conversion, easy design and installation, and falling costs.

The size of solar PV plants may vary from a few kilowatts (e.g., roof‐top solar plants) to large farms of hundreds of megawatts. Depending on their capacity, the plants may be connected to the low or medium voltage distribution grid or the high‐voltage grid. They may also be operated in the stand‐alone mode (no grid connection). The largest solar PV plant in 2015 had a total power rating of 579 ...