School of Electrical Engineering and Telecommunications
Term 3, 2021
Tutorial 04 (Week 07)
ELEC3111
Distributed Energy Generation
Page 1
PV Generations in Distribution Networks
Q1: Like many countries around the world, Australia is moving towards a low-carbon future in response to cli-
mate change. As a result, more renewable generations are being installed, especially PV panels. The annual report
released by Australian Energy Council shows that the installed residential PV capacity increased by 20% to reach
1.4 GW in the year 2018 and there’re more than 2 million installations across the nation, and the numbers keep
growing. The following table shows the average solar panel cost of various sizes in different locations across
Australia.
Table: Average solar panel costs by city& system size (October 2019)
State/Capacity 1.5kW 3kW 4kW 5kW 6kW 7kW 10kW
Adelaide, SA $2,550 $3,160 $3,620 $3,970 $4,170 $5,360 $8,010
Brisbane, QLD $3,260 $3,830 $4,660 $5,300 $5,730 $7,050 $10,140
Canberra, ACT $3,040 $4,010 $5,020 $4,780 $5,220 $6,700 $8,650
Darwin, NT $5,890 $7,360 $8,140 $9,410 $9,790 $11,240 $12,050
Hobart, TAS $3,170 $4,040 $5,050 $5,640 $6,840 $7,990 $11,660
Melbourne, VIC $3,130 $3,950 $4,390 $4,960 $5,830 $7,610 $10,540
Sydney, NSW $3,070 $3,420 $3,900 $4,280 $4,720 $6,430 $8,350
Perth, WA $2,390 $2,550 $3,110 $3,070 $3,510 $5,390 $9,100
Average $3,313 $4,040 $4,740 $5,180 $5,730 $7,220 $9,810
https://www.solarchoice.net.au/blog/solar-power-system-prices
Assuming the energy consumption of a three-bedroom home in QLD is around 15 kWh and the roof size is 92.
Now depending on the day light received on average per day, a 1 kW solar power system will usually produce
around 5 kWh of energy per day, and each 1 kW PV panel occupies about 22. If regulated electricity price in
QLD is 20 c/kWh, and retailer export payments is 10 c/kWh. The solar system lifetime is 10 years. The discount
rate is 8% annually. Please answer the following questions.
Q1-1: If the home wants to install PV panel by choosing one of the sizes in the table, how many options does the
homeowner has and which one/ones can averagely cover the daily energy consumption of the home?
Q1-2: Which size of PV can bring the most benefit to the home?
Q1-3: Can the calculated benefit be realised by merely installing PV panels? Why?
Page 2
Q2: The single-line diagram of a 5-bus system is given below, followed by the network parameters and demand
data.
1
23 5
4
PV
Demand
Demand
Demand
Demand


Table 1: Line parameters in the network
Line Index From bus To bus Line impedance-R (p.u.) Line impedance-X (p.u.)
1 1 2 0.0058 0.0029
2 2 3 0.0308 0.0157
3 2 4 0.0228 0.0116
4 2 5 0.0238 0.0121

Table 2: Bus demands in the network
Bus Index Active Load (MW) Reactive Load (MVar)
1 0.00 0.00
2 2.25 1.34
3 2.02 0.89
4 2.70 1.78
5 1.35 0.67

The voltage at bus 1 (root bus) is always kept at 1.05 p.u.. Now if a PV farm is going to be installed at bus 5 and
the network service provider does not want any over-voltage issue occurs after the installation. In other words,
the voltage magnitude of any bus should not exceed 1.1 p.u. under the given load condition. Choose the base val-
ue for power as 10 MVA and try to calculate the allowable installed capacity for this PV farm. (The power factor
of the PV farm is assumed to be kept at 1.0)