GRID-CONNECTED SOLAR PV SYSTEMS Design guidelines …

1 GRID-CONNECTED SOLAR PV. SYSTEMS . Design guidelines for accredited installers NO BATTERY STORAGE. January 2013. 0. TABLE OF CONTENTS. 1 GENERAL 3. _____. 2 DEFINITIONS 3. _____. 3 Design AND INSTALLATION STANDARDS 3. _____. 4 LICENSING 4. Extra low voltage 4. Low voltage 4. _____. 5 DOCUMENTATION 5. _____. 6 RESPONSABILITIES OF SYSTEM DESIGNERS 5. _____. 7 SITE-SPECIFIC INFORMATION 5. _____. 8 ENERGY YIELD 6. Energy yield formula 7. Specific energy yield 11. Performance ratio 11. _____. 9 INVERTER SELECTION 13. Multiple inverters 13. Inverter sizing 13. Array peak power 13. Array peak power inverter sizing 13. Array de-rating formula 14. Matching inverter/array voltage 15. Minimum voltage window 17. Maximum voltage window 18. Inverter DC input current 19. Effects of shadows 19. _____. grid connected SOLAR PV SYSTEMS (No battery storage) 1.

2 Design guidelines for accredited installers Last update: January 2013. These guidelines have been developed by Clean Energy Council. They represent latest industry best practice for the Design and installation of GRID-CONNECTED PV. SYSTEMS . Copyright 2013. grid connected SOLAR PV SYSTEMS (No battery storage) 2. Design guidelines for accredited installers Last update: January 2013. 1 GENERAL. The objectives of these guidelines are to: improve the safety, performance and reliability of SOLAR photovoltaic power SYSTEMS installed in the field encourage industry best practice for all Design and installation work involving SOLAR photovoltaic power SYSTEMS provide a network of competent SOLAR photovoltaic power SYSTEMS designers and installers to increase the uptake of SOLAR photovoltaic power SYSTEMS , by giving customers increased confidence in the Design and installation work.

3 The performance of a reliable installation that fulfils customer expectations requires both careful Design and correct installation practice. Compliance with relevant state health and safety regulations is also necessary. NOTE: These guidelines alone do not constitute a fully definitive set of rules and are to be read in conjunction with all relevant Australian standards. Where these guidelines have additional requirements above that stated in the Australian standards then these guidelines should be followed. 2 DEFINITIONS. This document uses the same terminology as outlined in AS/NZS 5033. Two important definitions are: Where the word shall is used, this indicates that a statement is mandatory. Where the word should is used, this indicates that a statement is a recommendation. 3 STANDARDS FOR INSTALLATION.

4 Accredited installers shall comply with the following standards where applicable: AS/NZS 3000 Wiring Rules AS grid connect - Installation AS/NZS5033 Installation of AS/NZS 1768 Lightning Photovoltaic (PV) Protection Arrays AS/NZS Stand-alone Power AS/NZS 3008 Selection of cables SYSTEMS - Design AS Wind Loads The grid -interactive inverter shall be tested in accordance with the AS 4777. (parts 2 and 3) and listed on the Clean Energy Council's approved inverter list. grid connected SOLAR PV SYSTEMS (No battery storage) 3. Design guidelines for accredited installers Last update: January 2013. The system shall comply with the relevant electrical service and installation rules for the state where the system is installed. (NOTE: the local electricity distributor may have additional requirements.). These guidelines set additional requirements to the standards.

5 An accredited installers or supervisor is expected to follow these guidelines in addition to the requirements within the relevant standards. These guidelines will become mandatory on 1 February 2013. 4 STANDARDS FOR INSTALLATION. Extra Low Voltage (ELV). All extra low voltage wiring should be performed by a competent' person, which is defined by the Australian Standard AS/NZS stand-alone power SYSTEMS as: A person who has acquired through training, qualifications, experience or a combination of these, knowledge and skill enabling that person to correctly perform the task required.. Low Voltage (LV). All low voltage work: >120V DC or >50V AC shall be performed by a licensed electrician. A licensed electrician is required to be responsible for the safety of the system wiring prior to connection of the system to the grid .

6 If the system contains ELV wiring installed by a non-licensed person, then a minimum level of inspection by the electrician prior to closing the PV array isolators would include: an open circuit voltage test on each PV string and on the total array. A visual inspection of an open PV junction box (randomly selected) and the master array junction box is required to complete a job. These inspections/checks shall confirm: the array voltages are as designed and specified the appropriate cables (CSA and insulation), junction fittings and enclosures have been used. Both the non-electrician ELV installer, as well as the licensed electrician, are expected to carry out the checks on the ELV wiring. grid connected SOLAR PV SYSTEMS (No battery storage) 4. Design guidelines for accredited installers Last update: January 2013.

7 5 DOCUMENTATION. The designer is required to provide the following documentation to the installer: A list of equipment supplied. A list of actions to be taken in the event of an earth fault alarm. The shutdown and isolation procedure for emergency and maintenance. A basic connection diagram that includes the electrical ratings of the PV array, and the ratings of all overcurrent devices and switches as installed. Site-specific system performance estimate. Recommended maintenance for the system. Maintenance procedure and timetable. 6 RESPONSIBILITIES OF SYSTEM DESIGNERS. System designers must comply with the following responsibilities. Provide full specifications of the system including quantity, make and model number of the SOLAR modules and inverter. Provide a site specific full system Design including all shading issues, orientation and tilt, along with the system's site-specific energy yield, including average daily performance estimate in kWh for each month of SOLAR generation.

8 Ensure array Design will fit on available roof space. Ensure array mounting frame installation will comply with Ensure array configuration is compatible with the inverter specification. Ensure all equipment is fit for purpose and correctly rated. Obtain warranty information on all equipment. When designing a grid connect battery backup system the Design shall be performed by a person(s) with CEC grid connected Design accreditation and CEC stand-alone Design accreditation . 7 SITE-SPECIFIC INFORMATION. To Design a system the following site-specific information is required as a minimum: occupational safety risks of the site (scaffolding, fall protect, elevated work platform required). whether the roof is suitable for mounting the array SOLAR access for the site whether any shading will occur and its estimated effect on performance orientation and tilt angle of the roof where the inverter will be located location of AC switchboards whether any switchboard or metering alterations are required.

9 grid connected SOLAR PV SYSTEMS (No battery storage) 5. Design guidelines for accredited installers Last update: January 2013. 8 ENERGY YEILD. Australian SYSTEMS are typically sold based on price or the size that will fit onto the available roof space. Once the size, in kWp, is selected then the designer shall determine the system's energy output over one year (known as the energy yield). There are many commercial tools available to assist in calculating energy yield, for example PV- GC, SunEye, PVSyst, SOLAR Pathfinder, etc. Some of these make an allowance for shading. It is recommended to use one of these tools on the site visit to provide accurate estimates of energy yield. Energy Yield Formula The average yearly energy yield can be estimated as follows: Esys = Parray_STC x man x dirt x temp x Htilt x pv_inv x inv x inv_sb where: Esys = Average yearly energy output of the PV array, in watt-hours Parray_STC = Rated output power of the array under standard test conditions, in watts man = de-rating factor for manufacturing tolerance, dimensionless (refer to section ).

10 Dirt = de-rating factor for dirt, dimensionless (refer to section ). temp = temperature de-rating factor, dimensionless (refer to section ). Htilt = Yearly (monthly) irradiation value (kWh/m2) for the selected site (allowing for tilt, orientation). pv_inv = efficiency of the subsystem (cables) between the PV array and the inverter inv = efficiency of the inverter dimensionless inv_sb = efficiency of the subsystem (cables) between the inverter and the switchboard NOTE: The above formula for energy yield could be rearranged to determine the size of the array, if the system is to be designed to provide a predetermined amount of energy per year, for example when a customer wants a system that meets their total annual energy usage. Manufacturer's output tolerance The output of a PV module is specified in watts, with a manufacturing tolerance and is based on a cell temperature of 25 C (STC).