Welcome to SolarGo
Welcome to SolarGo
A basic solar power system can include:
Solar panels capture sunlight and convert it into DC electricity. The electricity can be directed through a solar regulator to safely charge a battery. DC appliances can operate from the battery or suitable DC circuits, while standard household appliances require an inverter to convert stored DC electricity into 240V AC power.
Modern grid-connected systems may use a hybrid inverter that combines several of these functions into one unit.
Solar panels are generally specified according to their power output in watts (W). A panel's wattage indicates its rated electrical output under standard test conditions.
The amount of electricity a panel produces each day depends on several factors, including:
Australia receives excellent solar resources, although available sunlight varies considerably between regions and throughout the year.
Connecting panels in series increases the system voltage while maintaining approximately the same current.
Connecting panels in parallel increases the available current while maintaining approximately the same voltage.
The correct configuration depends on the inverter, charge controller, system voltage and installation requirements.
A solar regulator, also known as a charge controller, controls the electricity flowing from solar panels into a battery.
Its primary purpose is to ensure the battery is charged correctly and protected from overcharging.
Many charge controllers also provide additional protection features, including:
MPPT controllers can make better use of available solar energy by adjusting the operating point of the panels to extract more usable power, particularly when panel voltage is significantly higher than battery voltage.
The controller must be capable of handling the maximum expected solar input. For basic systems, it is good practice to allow additional capacity rather than selecting a controller that operates continuously at its maximum rating.
Always check the manufacturer's specifications for maximum PV voltage, current and power before selecting a controller.
Solar panels and batteries produce DC electricity, while most household appliances use 240V AC electricity.
An inverter converts DC electricity into AC electricity suitable for household and other electrical equipment.
There are several types of inverters available, including:
Pure sine wave inverters produce an AC waveform similar to the electricity supplied by the utility grid. They are generally the preferred option for modern household equipment, electronics, motors, pumps and appliances.
When choosing an inverter, consider:
The inverter should have enough capacity to handle the expected load and any temporary startup surge from equipment such as pumps, refrigerators and motors.
Solar batteries store electricity so it can be used later.
During the day, solar panels can supply your appliances while excess electricity can be stored in the battery. The stored energy can then be used when solar production is low or when additional energy is required.
Modern solar storage systems commonly use lithium-ion battery technology, although other battery technologies are also available.
Important battery specifications include:
Battery capacity is commonly measured in kilowatt-hours (kWh). For example, a battery with a nominal capacity of 10kWh does not necessarily provide 10kWh of usable energy. The usable capacity depends on the manufacturer's specified depth of discharge and operating conditions.
The correct battery size depends on factors such as:
For larger residential or commercial systems, professional system design is recommended.
Choosing the correct solar system requires more than simply adding together appliance wattages.
A basic assessment should consider:
The following example demonstrates a simplified approach to estimating the requirements of a small off-grid system.
Imagine a small setup with the following appliances:
| Appliance | Power | Daily Use |
|---|---|---|
| 2 × 12V lights | 30W total | 2 hours |
| Water pump | 60W | 15 minutes |
| Refrigerator | 48W | 8 hours |
| Television | 50W | 2 hours |
| Microwave | 900W | 15 minutes |
DC Loads
Total DC consumption: 60 + 15 + 384 = 459Wh/day
AC Loads
Total AC consumption: 100 + 225 = 325Wh/day
If the inverter operates at approximately 85% efficiency: 325 ÷ 0.85 = approximately 382Wh/day
Total system requirement: 459 + 382 = approximately 841Wh/day
📌 The example system would require approximately 841Wh of energy per day, before allowing for additional system-specific losses.
Assume approximately five equivalent peak sun hours per day.
Basic calculation: 841Wh ÷ 5h = approximately 168W
Allowing for system losses and other practical factors, a larger panel capacity should be selected. For example, a system using approximately 300W of solar panels would provide a more practical starting point.
Actual solar production will vary depending on location, season, weather, shading, panel orientation and equipment efficiency.
The charge controller needs to be compatible with: total panel wattage, panel voltage, panel current, battery voltage, maximum PV input, and system configuration.
It is generally preferable to have some additional controller capacity rather than operating continuously at its maximum rating.
The inverter must handle the highest expected simultaneous load. In this example, the television and microwave could operate at the same time: 900W + 50W = 950W.
A 1,000W inverter may theoretically cover the calculated load, but a larger inverter may be more appropriate. A 1,200W to 1,500W pure sine wave inverter could be considered for this example, subject to manufacturer's specifications.
Battery capacity should be based on the amount of energy that needs to be stored and the required backup period.
For example, if the system needs approximately 841Wh per day and the owner wants several days of autonomy, the required battery capacity will increase accordingly.
A simplified battery calculation must consider: daily energy requirement, backup days, battery voltage, usable depth of discharge, efficiency, temperature, and manufacturer specs.
Not sure how many panels you need, whether you should add a battery, or what size inverter is right for your property?
Solar4AU can review your requirements and help you find a suitable solar solution.
