Page 19 - Hybrid-Renewable Energy Systems in Microgrids

4 Hybrid-Renewable Energy Systems in Microgrids

Figure 1.2 Wind power output (W) at Victoria University, Melbourne.

output power from either solar or wind alone cannot guarantee to meet the changing
load demand. However, most often, solar is available during the day, whereas wind
is available during the night [7]. In practice, this implies the possibility of forming a
hybrid power system to mediate the power imbalances, with the PV cells providing
electricity during the day and wind providing electricity at night in winter and summer
seasons [8]. In consideration of the behavior of the renewable energy resources, solar
and wind actually have complementary behavior as seen in Figs. 1.1 and 1.2. Hybrid
system with the combination of PV and wind renewable sources therefore ensures the
enhancement of the overall system reliability, reduction of storage size requirement,
and contribution to lower generation cost [9].

3 Hybrid renewable energy system configuration

To ensure maximum prospect of RESs and to minimize their adverse impact on elec-
tric grid, it is preferable to utilize the RESs production locally, and considering this
fact, RESs are most popularly used as DER in a grid-connected and standalone mode
in a remote islanded operation. Among the other available combination of RESs, PV–
Wind hybrid combination is much more attractive worldwide because of its technical
advancement, economic operation, and availability in abundance. Typically, Hybrid
RES (HRES) includes several forms of renewable energy to generate electricity.
HRES (in this chapter) is a combination of PV and wind to generate electricity as
a unit and to maximize the power capacity of a MG. A very general structure of a
HRES may consist of any combination of renewable energy resources depending on
the availability of resources in an individual area, load demand, and all the associated
costs, including installation, operation, and maintenance costs. However, according
to our understanding, in a typical PV–wind hybrid MG, it may consist of PV–wind,