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Solar System Sizing Tool

Solar System Sizing Tool

The following tool is intended to assist users to determine a size of an entry-level solar system for home use, which includes the solar panels, inverter, batteries and user load. Products listed and its information is that of The Sun Pays solar products. The tool utilizes product information such as efficiencies in order to give a more realistic solar system design.

Disclaimer: The tool is intended to be used as a guide. The Sun Pays can not be held responsible for the outcome of the results of the tool. It is still the end-user's responsibility to confirm if the selected equipment will be suitable for the user's needs or to obtain professional help from accredited installers.

Feedback: The tool is still a work in progress. At the current stage, the tool is only for 48V solar systems. For requests and feedback, please contact us.

How to use the tool:
Step 1: Fill in the user load. A list of common items is provided. Choose the number of hours the items in used in the day and night
Step 2:Choose the battery type and configuration.
Step 3 A: Choose the solar panel configuration. The panel configuration will be the panels in series and how many series arrays will there be in parallel.
Step 3 B: Choose the type of solar panels.
Step 4: Choose the inverter type.
Step 5: Review the feedback and make changes to the system setup if required.

Solar System Block Diagram

Step 1: Power and Energy usage:

The power and energy usage is very important to determine the correct battery size. For this solar sizing tool, two methods is available:
Fast Method : Input your monthly electricity bill. This method is faster, but less accurate.
Accurate Method : Input applicance information (hours used per day). This method is recommended




Accurate Method:
The power and energy usage is divided into the day time use for 6 hours (10AM to 4PM) of sunlight and the night time use for the remainder of 18 hours. The list below can be use to estimate the energy consumption for day time and night time. Actual values will differ depending on appliance type and model. Click on a section below to fill in details.

Item Quantity Day (10am to 4pm) Nigh (4pm to 9am)
Tv (32") hrs hrs
Tv (40") hrs hrs
Tv (50") hrs hrs
Tv (65") hrs hrs
Decoder hrs hrs
Sound System hrs hrs
Play Station / X-box hrs hrs
Item Quantity Day (10am to 4pm) Nigh (4pm to 9am)
Dishwasher Washing cycles Washing cycles
Microwave min min
Electric Kettle Boil Cycles Boil Cycles
Stove plates no of electric plates hrs hrs
Oven hrs hrs
Fridge/Freezer (200L)
Bar Fridge
Ice Machine hrs hrs
Washing Machine Washing cycles Washing cycles
Tumble Dryer Drying cycles Drying cycles
Item Quantity Day (10am to 4pm) Nigh (4pm to 9am)
Laptop hrs hrs
PC hrs hrs
Printer hrs hrs
Wi-Fi Router hrs hrs
Cell Phone Charger Charges Charges
Item Quantity Day (10am to 4pm) Nigh (4pm to 9am)
Aircon 9000BTU (non-inverter) hrs hrs
Aircon 9000BTU (inverter type) hrs hrs
Aircon 12000BTU (non-inverter) hrs hrs
Aircon 12000BTU (inverter) hrs hrs
Aircon 16000BTU (non-inverter) hrs hrs
Aircon 16000BTU (inverter) hrs hrs
Item Quantity Day (10am to 4pm) Nigh (4pm to 9am)
Hair Dryer min min
Hair Straightener min min
Item Quantity Day (10am to 4pm) Nigh (4pm to 9am)
LED Bulb hrs hrs
CFL Bulb hrs hrs
Fluorescent Tube 4ft hrs hrs
Fluorescent Tube 5ft hrs hrs
Item Quantity Day (10am to 4pm) Nigh (4pm to 9am)
Lawn Mower hrs
Trimmer hrs
Pool Pump hrs hrs
Item Quantity Day (10am to 4pm) Nigh (4pm to 9am)
Inverter/s As per selection hrs hrs

Day Time Energy Useage (i.e. will be taken directly from solar panels): kW.h

Night Time Energy Useage (i.e. what needs to be stored in a battery) : kW.h




Load Instant Power requirement
Green = Inverter Power
Red = Bypass mode

Day Time Energy Consumption
Green = Battery charge + Load on solar
Red = Battery charge + Load on bypass

Night Time Energy Consumption
Green = Battery storage
Red = Bypass mode

For steps 2 to 4, the hardware (batteries, solar panels and inverter) needs to be chosen. You can either manually choose items or click the "Help me Choose!" button below


Step 2: Batteries and configuration:










Step3A: Solar Panel configuration:


Total number of panels =
Solar panels mounted @ 28° angle, facing North.

Step 3B: Type of panels used:


Summer
Winter

Step 4: Inverter:



Solar Array Working Voltage
Stay in Green Zone

Solar Array Open Circuit Voltage
Stay in Green Zone
May go to Yellow Zone

Solar Array Power
Stay in Green Zone

Solar Energy Generated
Available for Day Time Load
and Battery Recharge

Step 5: Results

Result Message
Solar Array Info
Open Circuit Voltage:V
Maximum Power Voltage:V Upper Limit:
Lower Limit:
Maximum Power:W
Potential generated energy during day: kW.h
Generated energy used to charge battery for night time load: kW.h
Generated energy used to supply day load: kW.h
Remaining energy used to charge battery additionally (rainy/cloudy days): kW.h
Battery Information
Battery state of charge @ 4pm: %
Useable Capacity @ DoD: kW.h
Used Capacity : kW.h
Power required to recharge in 6 hours: W
Maximum Charge Current (set on inverter): A
Battery nominal voltage: V
Hours to drain battery at night: h
Inverter Information
Min PV voltage: V
Max PV voltage: V
Max PV oc voltage: V
Max PV array power: W
PV Charger efficiency: %
Inverter rated power output: watt
Utility supply information
Instantaneous Max. Load: watt
Utility energy required for day time load: kW.h
Utility energy required for night time load: kW.h
Monthly cost for day time load make-up: R
Monthly cost for night time load make-up: R
Monthly cost for day time load if no solar is installed: R
Monthly cost for night time load if no solar is installed: R
Monthly savings: R
Annual savings: R
Annual CO2 emission reduction: kg

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