Solar Photovoltaic Power System Handbook
Solar Photovoltaic Power System Handbook
Solar Photovoltaic Power System Handbook
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Output of a Typical Solar PV Power System ...................................................................................... 9 What Savings can I expect from my PV System .............................................................................. 10 8.1 8.2 8.3 System Rated Power .................................................................................................................. 10 Feed-in-Tariff ............................................................................................................................ 10 Load Management..................................................................................................................... 10
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Electricity Audit ............................................................................................................................... 11 Operating Instructions ..................................................................................................................... 13 Inverter Status ........................................................................................................................... 13 Maintenance ............................................................................................................................. 13
10.1 10.2
Solar Photovoltaic Array ...................................................................................................... 13 General System Inspection .................................................................................................. 14 System Circuit Breakers...................................................................................................... 14 System Performance .......................................................................................................... 14
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The objective of this handbook is to provide you, the owner and operator of the PV system, with the information needed to ensure a long system life with satisfaction and safety.
Should any problems occur with your PV system please contact one of the following telephone numbers. You will be asked to describe the problem in as detailed as possible, so please familiarise yourself with the Error Report Form found in the Appendix. You may ask the installer to help you fill out the details if required. Please record the important contact details below for future reference. Phone Numbers: Perth (08) 9456 3491, Sydney (02) 9078 8000, Brisbane (07) 3713 3444 Installer Name: ______________________________________________ Installer Phone: ______________________________________________ Invoice Number: _____________________________________________ Please retain your original invoice for warranty purpose.
This handbook serves to give you some background information on the operation and installation of the PV system. Although your system has already been installed, please follow all instructions carefully and familiarise yourself with the system operation and maintenance requirements.
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Throughout this handbook the following warnings symbols are used to draw your attention to an electrical safety issue and that a potential dangerous voltage or condition could exist, requiring that the service personnel must use extreme caution at all times.
Photovoltaic Systems make use of the photovoltaic effect (photo=light and voltaic=electricity), the basic process discovered by Edmund Becquerel, a French physicist in 1839. He discovered the PV effect while experimenting with an electrolytic cell made up of two metal electrodes; finding that certain materials would produce small amounts of electric current when exposed to light. Sunlight is composed of photons, or packets of energy. These photons have various amounts of energy corresponding to different wavelengths of light. When photons strike a PV cell, they may be reflected or
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(5) Inverter: Converts the DC power from the PV panels into AC in order to match the parameters of the utility grid (according to AS 4777). The inverter deactivates at night and automatically starts operating in the morning when sunlight is sufficient. The inverter is the operations centre of your system and as such, useful information can be obtained from the inverters display. (6) Main Switch Box: An additional AC Isolator Switch connects the PV system to the existing infrastructure. It also protects equipment from being harmed by eventual over currents from the inverter if it is in a fault condition. (7) Energy Meter: In most cases older electricity meters will be changed to a Bi-directional Digital Meter when the Solar Photovoltaic Power System is installed at a house. This is done through your electricity retailer.
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6.1
Tilt Angle
As shown in Figure 2, the tilt of the panel is the angle it makes to the horizontal. In summer the sun is higher in the sky than in winter, and therefore the tilt angle for the panels could be made less in summer. On the other hand, in winter the sun is low and the panels may be tilted more vertical. However, for most domestic installations the tilt angle is determined by the roof inclination and cannot be changed. The optimal tilt angle for a solar system is close to the latitude angle at the site. In same cases support brackets can be used to adjust the tilt angle of the panels.
6.2
Orientation Angle
Ideally PV panels should face true north, however the angle is ultimately determined by the orientation of the roof where they are installed. The range of proper orientation angles are shown in Figure 2. It is important to note how much of the energy yield (kWh) is lost by a non optimum orientation. Figure 3 gives the performance of the PV array with respect to orientation and tilt. For example, the panels in Figure 2 have a tilt angle of 25 and face -30 off north. This is in the red area of the plot, which means the system performs between 95% and 100% energy yield.
Figure 2: Tilt angle for panels installed on inclined roof (left); orientation angle for panel (right).
6.3
Shading
How much does shade from the tree on neighbours property take away from my energy yield? Shading is a critical issue for a PV system because the effect is counter intuitive. If one out of six panels is completely shaded the energy production does not decrease by 1/6 or 17%, but usually by about 100%. In addition, partial shading
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Figure 3: PV array performance with respect to tilt angle and panel orientation.
6.4
Another form of shading occurs when a dirt film is deposited on the panels. Such a dirt film has an evenly distributed impact on all panels and none of the panels stop working completely, meaning that the system can still work, however with a slightly reduced output. Normally natural rainfall washes the panels often enough to prevent a large accumulation of dirt, however in very dusty and dry regions it may be necessary to clean the panels using a water hose when a build-up occurs.
6.5
Temperature
The performance of PV cells are affected by temperature such that the higher the cell temperature, the lower the energy production. Cells can reach high temperatures, for example, when the solar radiation is at its strongest in summer around noon, the cells can heat up to around 70C. The heat is dissipated via the back of the panels by natural convection, as shown in Figure 4. For this reason, it is important to avoid heating the cells by restricting airflow underneath the panels. Do not use any sort of visual cover and make sure that obstacles, such as leaves from nearby trees, cannot accumulate and hamper the airflow. As a simple rule, a rise in temperature by 10C lowers the effective power output of the PV system by about 4% 5 %.
Copyright 2011 Regen Power Pty. Ltd. Page 8
6.6
System Degradation
The power output of the PV panels will reduce slowly over time, typically by 0.5% per annum. This means that the system will lose 12% efficiency after 25 years of operation. The warranty on the power output of the panels guarantees a degradation of less than 0.9% per annum, resulting in a minimum efficiency of 80% after 25 years. Table 1 summarises the drop in efficiencies over time.
Table 1: PV array degradation over time.
0 100% 100%
5 98% 96%
20 90% 83%
25 88% 80%
Figure 5 shows the performance of a typical 1 kW(p) PV system in Perth. As seen, there is greater energy in summer than in winter. Between November and February the output reaches 6 units (kWh) per day, whereas in winter months the output averages 3.5 kWh a day.
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Once installed, savings essentially depend on the size of the PV system (kW rating), the way you make use of its output energy, and the tariff structure in your State.
8.1
As a rule a 1 kW (peak) PV system will generate between 4 kWh to 5 kWh of electrical energy per day depending on location and the factors discussed in Section 6. This is based on annual average (365 days) as seen in Section 7. Using a conservative number of 4 kWh per kW installed, a 1.5 kW system will generate 6 kWh per day or 2,190 kWh per year. Experience showed for example that a 1 kW PV generates at least 1,500 kWh or 1.5 MWh per year. This energy is generated at the exact point of use rather than at a central coal-fired power station, avoiding transmission and distribution losses. Generating your own solar electricity thus means a reduction in CO2 and other gaseous emissions by approximately 2 metric tons per kW installed.
8.2
Feed-in-Tariff
The feed-in tariff is an incentive to support the generation of clean electricity by way of legislation that enforces utilities to buy excess energy generated from small-scale photovoltaic (and other renewable energy sources) such as the PV system you just installed. This system is well known around the world and can generally be one of two schemes: a gross feed-in tariff or a net feed-in tariff. The net feed-in tariff scheme pays for excess energy generated that is exported to the grid and measured at the point of utility. In this case, the PV generated energy feeds the house first and any excess energy beyond that is metered and purchased by the utility. For example, the tariff in Qld and is currently legislated at 44 cents/kWh although several electricity suppliers pay few cents more. Since we purchase electricity far cheaper than 44 cents/kWh it makes sense to conserve the use of this energy (kWh) during the day and sell it at a premium rate. The gross feed-in tariff scheme will pay up for all energy produced by the PV system irrespective of the load in the house and thus energy is measured at the output terminals of the inverter. This scheme which was introduced in NSW in 2009 offered initially 60 cents/kWh but has dropped to 20 cents/kWh. A feed-in tariff helps you to recover the investment on your PV system much faster.
8.3
Load Management
As explained above in the case of net feed-in tariff it is important to shift the use of electricity during the time the PV system is generating electricity in order to take advantage of the high tariff the utility is prepared to pay. Except for a refrigerator that must run continuously the use of heavy appliances such as ironing, cooking or washing can be done in the evening or the early hours of the morning. An energy audit can be done to examine ways by which energy can be saved. Lets now examine a situation where a 1.5 kW system is installed in a house in one of the major cities such as
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PV size (kW) Daily saving Annual saving 1.5 2.0 3.0 $2.75 $3.78 $5.83 $1,000 $1,380 $2,130
Electricity Audit
Energy audit can be done to examine ways to manage your electricity usage and help reduce your electricity bills. A sketch showing a typical household electricity profile (blue plot of power versus time) is shown in Figure 6, starting at midnight and ending midnight. As seen, there is a small rise in power use around 7 am and a peak around 7 pm. The area under the curve represents the daily energy consumption or kWh which we pay. Figure 6 also shows the simulated systems outputs for PV rated 1 kW and 1.5 kW during an average day between 6 am and 6 pm.
Figure 6: A daily load curve and the output of a 1 kW and 1.5 kW PV systems versus time.
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Appliance Refrigerator Freezer Electric heater Air conditioner Fan Iron Fluorescent light Incandescent light/globe Television Video Radio/Cassette Hair dryer Electric blanket Electric stove Electric oven Kettle Food processor Toaster Other kitchen appliance Washing machine Clothes dryer Computer Screen/monitor Printer Facsimile machine Swimming pool pump Electric hot water heater Other appliances Total Energy Consumption
Quantity
Power (W)
1000 - 2400 600 - 2400 60 - 120 1000 - 1200 10 - 40 25 - 100 100 - 400 80 -120 40 - 80 600 - 1000 20 - 50 1000 - 2400 1500 - 3000 900 - 2000 250 - 450 800 - 1200 600 - 900 200 - 500 180 - 250 180 - 250 100 - 200 100 - 200 700 - 1000 1800 2400 12,000 24,000
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10.2 Maintenance
The PV power system is characterized as low maintenance mainly due to the absence of moving parts. Regular maintenance involves inspection for damage and simple cleaning if necessary. If after following the suggestions below, your system still does not appear to be working or if you have any questions please call Regen Power on their number(s) listed in Section 2. 10.2.1 Solar Photovoltaic Array Periodically inspect for broken module glass, shading, and excessive soiling.
WARNING: Do not attempt to clean or otherwise come in contact with the surface of a PV module with a broken glass face; this could result in a dangerous shock.
The system can lose 4 - 8% of its production capacity from dirty modules if cleaning is not accomplished, depending on local conditions. Flushing down with a water hose should remove accumulated dust and dirt. Cleaning with a sponge and soapy water may be necessary if bird guano build up occurs. Incidental shading of the PV array by vegetation or other objects is to be avoided.
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WARNING: Regen Power expressly recommends that homeowners NOT explore the wiring systems or components beyond the level they are accustomed to as they encounter in the usual residential power systems and appliances.
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WARNING: The PV source circuits will be live (during daylight hours) from the PV array even when the DC isolator is open. A shock hazard exists in this area.
Verify integrity of the isolator. If found open, reset or replace with same type as installed. o Perform the Start Up procedure Inverter Installation and Operation Manual. Check open circuit voltage at each of the PV source circuits. o Open all PV source circuit isolators. o Each source circuit should be showing the same voltage characteristics (+/- 5 V DC). Under variable solar radiation conditions, perform the measurements repeatedly and rather quickly to determine consistency.
WARNING: The PV source circuits will be live (during daylight hours) from the PV array even when the DC isolator is open. A shock hazard exists in this area.
If the voltage test indicates a problem in the PV array:
WARNING: Working at elevations above grade requires safe working procedures. Consult your local Safety Regulations authority, and use recommended safety equipment.
On the roof, determine the location of the Array Junction Box. Check the connectors for all the PV source circuits. o If found to have loose connections, tighten them and re-check the voltage tests at the Array DC isolator junction box. Locate and replace the low voltage module(s). Test open circuit voltage on the leads into the Inverter DC isolator (Inverter end).
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Warranty Certificate
1. DEFINITIONS
The following have these meaning in these terms unless the contrary intention appears. (a) Regen Power or Regen: Regen Power Pty Ltd, a company duly incorporated pursuant to the Corporations Act (ACN 103 145 731) and having its principal office at 4/90 Catalano Circuit, Canning Vale, WA 6155. (b) Installation Site: the site at which the solar photovoltaic power system is installed. (c) Purchaser: the person named as Purchaser in the original contract signed with Regen Power (d) System: There are essentially two main parts in the solar PV system namely the PV panels and the inverter. (e) PV: abbreviation for phovoltoltaic. The solar PV panels (or modules) are installed on the roof at the Installation Site. This part of the System produces DC electricity when exposed to the sun. Your PV panels may be mono-crystalline or poly-crystalline. (f) Inverter: This part of the System converts the DC electricity to AC electricity in order to match the requirement of the electricity network according to AS 4777. Regen Power uses inverters from reputable companies. The customer is required to keep the Instructions Manual of the installed inverter in a safe place. The Instructions Manual is the first point of reference to use in case of suspected reduction in performance. (g) Auxiliary parts: In addition to the PV panels and the inverter, the system must be electrically wired using standard DC and AC cables and DC and AC circuit breakers. (h) Force majeure: circumstances beyond Regens control which Regen Power is unable to overcome by exercising reasonable diligence and reasonable cost (i) Nominated Output: the expected output for solar PV panels as advised. This is also termed Output Power at Standard Testing Conditions (STC) at 1000 W/m2, AM1.5 and 25oC.
Warranty Certificate
property, for economic loss, or for any other loss resulting from any cause whatsoever arising out of or related to the System, including but not limited to, any defects in the System, or from the use or installation of the System. 2.3 The warranties provided in clause 2.1 will not apply to any parts that have been subjected to: (a) misuse, abuse, neglect or accident; (b) alteration, improper alteration or reinstallation by Customer or any other person; (c) non-observance with use and maintenance instructions; (d) repair, modification or repositioning by anyone other than a service technician approved by Regen Power in writing; (e) power failure, power surge, lightening, flood, fire, accidental breakage or other events outside of Regens control; (f) the type or any part of the System being altered, removed or made illegible. 2.3 If the System components are installed in conditions which are different to the conditions under which the manufacturer assessed the Nominated Output, then the Nominated Output for the purposes of clauses 2.1(a) and 2.1(b) will be adjusted downwards by a factor which reflects those differences.
3. CUSTOMER OBLIGATIONS
The customer agrees to the following: (a) Periodically clean the PV panels and especially after dust storms. (b) Periodically remove any branches or droppings affecting the output of the panels. (c) Periodically observe of any shading by trees on the Installation Site or nearby trees or buildings which could affect the performance of the System. (d) Provide adequate protection for the inverter if placed outside. A canopy may be required to prevent direct heat and rain. The canopy must not obstruct airflow. Customer must refer to Inverter Instructions Manual for details on how to protect the inverter. The customer may wish to consult with the installer on the proper way to erect the canopy. (e) Provide adequate ventilation if the inverter is installed in a garage or a confined space. Customer must refer to Inverter Manual for details on how to protect your inverter. (f) Periodically check the inverter display for output performance particularly the total energy (kWh) generated to date. (g) Refrain from switching on and off the DC or AC circuit breakers and follow proper start-up and shut-down procedures as indicated.
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Warranty Certificate
Western Australia 4/90 Catalano Circuit Canning Vale, WA 6155 Tel: (08) 9456 3491 Fax : (08) 9456 3492 admin@regenpower.com New South Wales 20-21/17A Amax Avenue Girraween, NSW, 2145 Tel: (02) 9078 8000 Fax : (02) 9636 5252 admin.nsw@regenpower.com Queensland 7/32 Spine Street Sumner Park, QLD, 4074 Tel: (07) 3713 3444 Fax : (07) 3712 0618 admin.qld@regenpower.com
Warranty Certificate
Congratulations on your purchase of a Regen Power Solar Photovoltaic Power System. Your PV system should provide you years of trouble free electricity wherever there is sun.
5 years inverter
(Refer to inverter warranty declaration) Please complete the following details and retain with the original purchase document: Owners name: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Address: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . City: . . . . . . . . . . . . . . . . . . . . . . . State . . . . . . . . . . . . . . . . . . . . . Postcode: . . . . . . . . . . . . . . . . . . . Invoice No: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Date of installation of PV panels and Inverter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Date of installation of electricity meter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Installers name and telephone number: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Brand of PV panels: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Brand of inverter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . In the event that service is required, please call the National Service and Warranty Number. 1300 876 354 Prior to calling for Service or Warranty, please ensure you refer to your Inverter Operating Instruction Manual, and in particular the Troubleshooting section. www.regenpower.com
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The display / register list then repeats again. Note: The Exported values will appear with a minus or negative (-) symbol next to them, to indicate that you have exported power back to the grid.
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Date
Time
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As the system owner, you are required to ensure that PV panels are not shaded either partially or fully due to growing tree branches or by neighbouring buildings. You are also required to clean the panels periodically and after dust storms. If you are not able to do that task safely please contact the office in your State for advice. Charges will be on an hourly basis and will depend on type and size of installation.
Date Time Observation Preventative or Maintenance
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Contact Us
Western Australia (Head Office)
4/90 Catalano Circuit Canning Vale 6155 Western Australia Phone: (08) 9456 3491 Fax: (08) 9456 3492 Email: admin@regenpower.com
Queensland
7/32 Spine Street Sumner Park 4074 Queensland Phone: (07) 3713 3444 Fax: (07) 3712 0618 Email: admin.qld@regenpower.com
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