Renewable Energy Systems 1

This document discusses renewable energy systems, focusing on Australia's electricity generation and the growth of renewable energy resources. It also covers topics such as solar hot water, sun path diagrams, and the growth rates of biomass and wind energy. The document provides valuable insights and information for those interested in renewable energy.

RENEWABLE ENERGY SYSTEMS 1
RENEWABLE ENERGY SYSTEMS1
By (Firstname Lastname)
Renewable Energy Systems1
Assessment 1
Professor
Griffith University
September 1, 2019

RENEWABLE ENERGY SYSTEMS 2
Problem 1: Renewable Energy and Australia’s Electricity Generation (Zahedi, 2010)
Total amount of electricity generated 2015/2016 ¿ 257.4 TWh
Percentage from renewable energy 2015/2016 ¿ 14.8 %
2020/2021 target ¿ 20 % from renewable energy resources.
Annual growth rate ¿ 2.5 %
Part 1
Total amount in 2015/2016 ¿ 257.4 TWh
Total amount produced by renewable energy resources in 2015/2016
¿ 14.8 %∗257.4=38.0952TWh
Growth rate ¿ 2.5 %
Total energy from renewable resources in 2020/2021 = ¿ 38.0952 (1+ 0.025 )5=43.101 TWh
Equating the projection to the target, we have;
If 14.8 %=43.101 TWh
20 %=?
¿ 43.101∗20 %
14.8 %
¿ 58.245 TWh
Thus, the amount of electricity to be generated from renewable resources in 2020/2021 will be
58.245 TWh.

RENEWABLE ENERGY SYSTEMS 3
Part 2
Assume that the rate of growth of energy production is equal for all energy resources.
From table 4.2, total amount of energy from renewables = 38146 GWh.
Mix and their percentage contribution will be;
i) Hydro
Contribution ¿ 15318
38146∗100 %=40.156 %
ii) Wind
Contribution ¿ 12199
38146∗100 %=31.980 %
iii) Bioenergy
Contribution ¿ 3790
38146∗100 %=9.936 %
iv) Solar PV
Contribution ¿ 6838
38146∗100 %=14.926 %
Part 3
i) Hydro
Capacity ¿ 40.156 %∗58.245=23.389 TWh
ii) Wind
Capacity ¿ 31.980 %∗58.245=18.627 TWh
iii) Bioenergy
Capacity ¿ 9.936 %∗58.245=5.7872TWh
iv) Solar PV

RENEWABLE ENERGY SYSTEMS 4
Capacity ¿ 14.926 %∗58.245=8.694 TWh
Problem 2: Solar Hot Water
Part 1
We draw a graph as shown below.
0.22 0.275 0.312 0.4 0.415 0.455 0.512 0.58 0.615 0.679 0.71 0.72
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
(Ti-Ta)/G (Km^2/W)
Collector efficiency

RENEWABLE ENERGY SYSTEMS 5
The gradient of the graph is -6.667. The value of gradient is equal to −FR U L.
FR U L=6.667
Efficiency η=FR τα −F R U L (T i−T a
G )
Taking values in the first row in table and substituting back; we get;
0.72=F R ( 0.97 ) ( 0.92 ) −( 6.667)(0.014)
FR =0.911
Part 2
Overall heat transfer coefficient U L=6.667
FR
¿ 6.667
0.911 =7.318 W /m2 K
Part 3
Useful energy gain Qu=FR A [ Gτα−U L ( T i−T a ) ]
Substituting the values;
Qu= ( 0.911 ) ( 3.96 ) [ ( 750 ) ( 0.97 ) ( 0.92 )− ( 7.318 ) ( 28−15 ) ]
¿ 2071.338 W

RENEWABLE ENERGY SYSTEMS 6
Part 4
Stagnation temperature T p=T a + ( τα ) G
U L
¿ 15+ 0.97∗0.92∗750
7.318 =106.4590 C
Problem 3
Part 1
Sun path diagram for a house located at a latitude 30o 18’ South and longitude 153o 8’ East
(Bahadori & Nwaoha, 2013)
Part 2
Constructing a shading diagram on your sun path diagram

RENEWABLE ENERGY SYSTEMS 7
Part 3
Estimating the hours of sunlight and the times of the day when sunlight reaches the
collectors on equinoxes, winter and summer solstice
Equinoxes
Autumn Fall Equinox
Hours of sunlight = 12 hours 18 minutes
Times of the day: 05:36 to 17:44 solar times
Spring/vernal Equinox
Hours of sunlight = 12 hours 7 minutes
Times of the day: 05:52 to 17:59 solar times
Winter Solstice
Hours of sunlight = 10 hours 11 minutes
Times of the day: 06:40 to 16:51 solar times
Summer Solstice
Hours of sunlight = 14 hours 6 minutes

RENEWABLE ENERGY SYSTEMS 8
Times of the day: 04:46 to 18:52 solar times (Rosario, 2014)
Problem 4
Part 1
Hydro
Part 2
Energy Resource Period
2006/07 2012/13 Difference Percentage change (%)
Biomass 3953 3143.5 -809.5 -25.75155082
Wind 2611.1 7959.6 5348.5 67.19558772
Hydro 14517 18269.6 3752.6 20.54013224
Small-scale solar PV 104.7 3826.3 3721.6 97.26367509
Geothermal 0.5 0.5 0 0
Wind energy had the largest increase in production in terms of absolute values. In terms of
percentage, small-scale solar PV had the largest increase over the period. (Muschaweck &
Spirkl, 2013)
Part 3
Energy
Resource Period
2006/0
7
2012/1
3
Differenc
e
Percentage change
(%)
Growth rate
(%)
Biomass 3953 3143.5 -809.5 -25.75155082 -3.746962921

RENEWABLE ENERGY SYSTEMS 9
Wind 2611.1 7959.6 5348.5 67.19558772 20.4142698
Hydro 14517
18269.
6 3752.6 20.54013224 3.9063351
Small-scale solar
PV 104.7 3826.3 3721.6 97.26367509 82.16798562
Geothermal 0.5 0.5 0 0 0
The fastest growth rate was obtained by small-scale solar PV. (Byrnes, et al., 2013)
.Part 4
Biomass had the largest decline in absolute amount. This was due to advancement in technology
which make use of cheap natural resources to generate energy.

RENEWABLE ENERGY SYSTEMS 10
References
Bahadori, A. and Nwaoha, C., 2013. A review on solar energy utilisation in Australia.
Renewable and Sustainable Energy Reviews, 18, pp.1-5.
Byrnes, L., Brown, C., Foster, J. and Wagner, L.D., 2013. Australian renewable energy policy:
Barriers and challenges. Renewable Energy, 60, pp.711-721.
Muschaweck, J. and Spirkl, W., 2013. Dynamic solar collector performance testing. Solar
Energy Materials and solar cells, 30(2), pp.95-105.
Rosario, A., 2014. Calculating the Solar Energy of a Flat Plate Collector. Undergraduate
Journal of Mathematical Modeling: One+ Two, 6(1), p.1.
Zahedi, A., 2010. Australian renewable energy progress. Renewable and Sustainable Energy
Reviews, 14(8), pp.2208-2213.