Design Task: There is more than one solution to this design task. The aim of this task is to see that you are capable of thinking through a design problem and coming up with a solution that meets the customer’s needs.
Ms Architect has two properties: a two-storey house in Sydney, NSW, and a single storey holiday home in Melbourne, Victoria. She would like to install solar modules at both properties as she is environmentally conscious and would like to use a green energy source. She is considering a 5kW system for her house in Sydney and a 2.0 kW system for her house in Melbourne, but is thinking about expanding the system size for her Melbourne house (to 4.5kW) in the future and is interested in system design options that allow for this.
You need to design an appropriate system for each property. Please read the information below for relevant data on each property.
SYSTEM 1 : Two storey house, Sydney, NSW (5kW system)
The roof, which is a pitched tile roof, faces 20° east of north and is sloped at an angle of 20°. There are two large trees to the west of the proposed site which are approximately 10m tall. The neighbours also have a tree to the east of Ms Architect’s house, which is currently about 7m tall. Please see the sketch on the Page 5 of this document.
Please note: If the system design has a nominal output over 5kW, it will need to be split over multiple phases as per the state wiring rules.
SYSTEM 2 : Single storey holiday home, Melbourne, Victoria (2.0kW, expandable to 4.5kW)
The holiday home has two potential installation locations for a system. One is the pitched tin roof of the property, which faces north-west and is sloped at an angle of 20°. There is a tree on the northwest which is 5m tall. Please see the sketch on Page 6 of this document.
The other location is on the ground. An appropriate site without shading has been identified 20m from the house. It is possible to face a ground mounted system in any direction and at any tilt.
In designing the system for the holiday house, you should consider which PV system will be more cost effective (i.e. which system will have the cheapest $/W) and some of the advantages and disadvantages of a roof mounted system compared to a ground mounted system.
The following pages outline the information you require for designing the systems:
1. Requirements for each system
2. Temperature, irradiation and GHG emissions data for Melbourne and Sydney
3. Scope of materials: you must choose your modules, inverters and mounting frames from this list
4. Site plans for the Sydney and Melbourne properties
5. Information on how to submit your work
6. Declaration that must be signed and accompany any submitted work
7. Checklist and marking criteria for the design task
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REQUIREMENTS FOR EACH SYSTEM.
In each design you are to specify:
1. The modules, inverter and mounting system you will use.
a) Please choose from the products specified on page 4 of this document.
b) Using the information provided, include calculations and brief conclusions as to why you chose each of the major components. This should include matching the input characteristics of the inverter with the output characteristics of the array, including the power, voltage and current. Ensure that the minimum and maximum temperatures for each site are taken into consideration.
c) Explanation regarding how your selected major components for the Melbourne site will accommodate the future expansion from 2.0kW to 4.5kW.
2. Details of the system design, including all balance of system components. Include:
a) Explanation regarding your choice of design for the holiday home (i.e. roof-mounted vs. ground-mounted).
b) All required specifications for equipment (i.e. IP rating for all equipment, fuse rating, DC isolator size and rating and AC and DC cable size and ratings).
c) Earthing requirements for the modules and/or mounting systems .
d) A site plan, showing relevant dimensions including: edge zone, cable run length and locations, modules, inverter and switchboard.
e) Electrical schematic, showing all electrical components, ratings and connections.
3. Performance of the system. Include:
a) Any assumptions made about operating conditions, losses, shading etc.
b) Calculations of the losses and where these occur
c) Calculations of any voltage drops on the DC and AC side of the inverter
d) Expected average yearly output (please use irradiation and temperature data provided)
e) Greenhouse gas emissions avoided by installing the solar system (please see data on greenhouse gas emissions per kWh)
4. Installation preparation. Include:
a) List of tools, components and accessories
b) List of safety issues/concerns for each installation site and how to minimise the risk
5. Approximate costing of materials, including:
Inverter, Panels, BOS costing, Labour
6. FOR SYDNEY SITE ONLY
a) Calculation of how many Renewable Energy Certificates (RECs) Ms Architect can create, over a 15 year life of the system assuming she is eligible for the Solar Credit bonus, and how much this is worth in the current market (see https://www.rec-registry.gov.au/rec-registry/app/calculators/sgu-stc-calculator for more information)
b) Calculate the expected yearly benefit (savings from self-consumption of energy + income from export to grid) of the system, assuming Ms Architect consumes 70% of generated energy at time of generation and the remaining 30% gets exported to the grid. (Typical of a home where one or more residents are consistently present during the daylight hours) The import tariff is 22c/kWh (flat rate not Time of Use) and the export tariff is 6c/kwh
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Microsoft Excel spreadsheets may only be used if you display the equations you have used and explain how they work. Showing full working is preferred over the use of calculations within spreadsheets. If the full working for calculations are only contained within a spreadsheet, then we will ask for you to resubmit your full working to us.
SITE INFORMATION
Minimum, Maximum and Average Ambient Temperatures for Melbourne and Sydney sites
Location
Minimum Cell Temperature
Average Ambient Temperature
Maximum Cell Temperature
Sydney
0°C
23°C
70°C
Melbourne
-5°C
19°C
75°C
Note: these figures should not be used for actual installations; the designer should verify temperatures for their particular site
Daily Irradiation on a Horizontal Plane in PSH (kWh/m2/day)
Sydney, NSW
Melbourne, VIC
Latitude
34°S
38°S
January
6.5
6.7
February
5.7
5.9
March
4.7
4.5
April
3.6
3.2
May
2.7
2.1
June
2.4
1.7
July
2.6
1.9
August
3.4
2.6
September
4.6
3.6
October
5.6
4.8
November
6.2
5.9
December
6.6
6.5
Average PSH
4.6
4.1
Source: Australian Solar Radiation Data Handbook V4
Tables on the effect of orientation and tilt angle can be found on the CEC’s Solar Accreditation website (www.solaraccreditation.com.au) in a document called “Grid-connect Design Guidelines”.
Greenhouse gas emissions (kgCO2) per kWh
Sydney, NSW
Melbourne, VIC
1.06
1.31
Source: Energy Today (www.energytoday.com.au)
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PRODUCT INFORMATION
To access the data for these components:
1. Log into the NECA website (https://www.necagses.com/) using your username and password
2. Click on “Access my enrolled courses”
3. Click on “Grid Connect” in the left hand menu
4. Click on “Design Task” at the bottom of the left hand menu
Solar modules
Canadian Solar: CS6P-235 – 255P
Trinasolar: TSM-250/255/260/265 PC05A/05A.08
Suntech: STP 270S-275S 20/Wem
Yingli: Panda 250-280W
Inverters
Fronius: IG15/20/30/40/50/60 HV SMA: SB 3000TL/4000TL/5000TL
Growatt: Sungold 1500TL-5000 TL
Samil Power: 1100TL-5200 TL
Mounting systems
Conergy
Unirac
