IEEE Electrification Magazine - June 2017 - 76

Table 1. The forecast for Singapore's forecast

renewable energy capacities and contributions
by 2025.

Source

Capacity (MW)

Energy
by 2025
(MWh/year)

Share
of 2025
Demand

2,000

2,400

4.8%

Biogas

350

0.7%

Biomass

785

1.6%

Wind

0.2%

Tidal

0.0%

Total

2,190

3,635

7.3%

PV: photovoltaic.

The benefits of renewable energy are obvious. However, it also poses challenges. Singapore's current grid is able
to accommodate only up to a 350-MW peak of renewable
electrical power. High penetration of renewable generation may threaten the grid's reliability and robustness.
Large-scale utility reinforcement may be unrealistic
because of the cost. Thus, policy makers and network
operators need to find novel solutions to permit the use of
new technologies to optimize the power system as a
whole. Microgrid systems are believed to be the optimum
solution for balancing renewable energy generation and
distribution with technical and economic constraints in
domestic and industrial energy transition and remotearea electrification.

Overview of the Microgrid

supplied from renewable energy sources (compared to
< 1% today), as shown in Table 1.
Singapore's electricity generation was 46 TWh in 2014.
Natural gas accounted for 95% of the electricity generated.
Due to limited indigenous energy resources, most of the
fuel was imported. Wide deployment of renewable generation can reduce dependence on imported fossil fuels and
improve the nation's energy diversity and security. This may
have the additional benefit of reducing the energy budget.
Due to Singapore's limited land area and high population density, artificial islands are being built or planned.
For power generation for these islands, renewable sources
may be able to supply the local demand with more
affordable capital expenditures when compared to connecting to the mainland utility grid by building overhead
lines or laying underground cables.

Power
Storage
Facility

A microgrid is a spatially limited energy system that can
comprise distributed generation, loads (flexible and passive),
and storage devices. It can optimize energy use, taking into
account varied operational constraints. When disconnected
from the main grid, the microgrid can balance and stabilize
generation, demand, and storage. It can also exchange
power (import or export it) with the main grid when connected to it. Figure 1 presents a generalized representation
of a microgrid. Advances in automation and protocols can
allow for seamless, plug-and-play interconnectivity between
the distributed energy resources (DERs), which can include
generators, storage systems, and end-user loads.
Microgrids offer a decentralized solution for energy
delivery, allowing for flexible and automated electricity
generation close to the loads, thereby increasing grid efficiency and reliability. They are traditionally deployed on
islands or in remote or rural areas with limited access to

Power
Storage
Facility

Wind

Biomass

Fuel Cell

Communications Line

Divisional Power-Receiving
Switch
Equipment

Microgrid
Controller

Figure 1. A schematic of a typical microgrid.

I E E E E l e c t r i f i c ati o n M agaz ine / j un e 2017

Power Line

Collective
Housing

Residences

Hot Water Pipe

Public/
Commercial
Facility

Table of Contents for the Digital Edition of IEEE Electrification Magazine - June 2017