Page 21 - Design of Solar Thermal Power Plants

14 1. INTRODUCTION

3. Output characteristics of power generation: smooth. Due to different
power generation principles, the output characteristics of CSP
generation are superior to those of solar photovoltaic and wind
power generation. This is especially true for the thermal generator
unit through thermal storage units, as it is capable of generating
power on a significant, smooth basis while reducing output
fluctuations. Based on different thermal storage modes, the
utilization hours and power generation of the power plant can be
improved by varying degrees, which can improve the adjustment
performance of the plant. Furthermore, the output characteristics of
CSP generation are normally ameliorated through afterburning or in
combination with conventional thermal power generation so that it
can be used during the night for constant power generation,
including for stable output and undertaking basic load operation.
4. Characteristics for power grid connection: flexible and steady. An
CSP plant with thermal storage and afterburning facilities is
distinguished from other energy sources, such as wind power and
solar photovoltaics, that experience fluctuating power supply.
Thermal storage facilities can be used to generate power in a smooth
manner, improve the flexibility of the power grid, make up for the
fluctuation characteristics of wind power and photovoltaic power
generation, and improve the capability of the power grid by
eliminating fluctuating power supply. Meanwhile, an CSP
generation system that has been equipped with thermal storage
facilities converts partial solar energy during daytime into thermal
energy and stores it in a thermal storage system; at night or when
peak regulation of the power grid is required, it can be used to
generate power and satisfy power grid requests while ensuring
more stable and reliable power output. Photovoltaic power
generation directly converts optical energy into power, and the rest
of the energy can only be stored using batteries, for which the costs
are far greater than they are for solar-concentrating power
generation (which uses thermal storage). Thus it is easier to store the
excessive energy to realize constant and stable power generation
and peak regulation. It is the most important and obvious advantage
of CSP generation against wind power, solar photovoltaics, and
other renewable energy power generation modes; it is conducive to
stable operation of the power system and is easier to connect to the
power grid. Furthermore, because it drives a steam turbine for
power generation through the production of superheated steam,
CSP generation has the same power-generation mode as that of
conventional thermal power, so it will not have a negative impact on
the power grid. It provides reactive power using a generation mode
that is friendly to the existing power system.