Solar energy is increasing in popularity across Australia. One of the main reasons for this is that the country’s solar radiation levels are among the highest globally. Also, several financial incentives are available for switching to solar, making it very appealing to Australians. The country’s excellent natural resource combined with a supportive government is the basis for Australia’s rapid uptake of solar panel systems.
How Do Solar Panels Work?
To determine whether your solar panel system needs backup power, you must first understand how solar panels work.
Solar panel systems generate power by converting sunlight energy into electricity. The panels are made of photosensitive materials that release electrons when exposed to sunlight. The free electrons flow through electric circuits in your system. This flow of electrons creates an electric current that can power everyday electronic devices like air conditioners, washing machines, and kitchen appliances.
So, if they only generate electricity when exposed to sunlight, how do solar panels work at night?
Solar panels don’t generate direct power when the sun sets or is obstructed on cloudy days. Yet, depending on your settings, you can integrate backup power solutions into your system.
Solar Backup Power Systems in Australia
This article guides you on the main backup power solutions for solar panel systems in Australia. Below is a list of the four solutions we will review.
- Solar Batteries
- Solar Capacitors
- Regional Power Grid
- Diesel Generators
Read on if you want to know more about how solar backup power systems work.
Solar Batteries
The most widespread backup power solutions for solar panel systems are batteries. You can define solar batteries as energy storage systems. In simple terms, solar panels use abundant solar resources to charge batteries during the day. The batteries then provide the stored energy for use when the resource is no more available.
The charging action of batteries is an energy conversion process. The batteries convert the electric energy generated by the solar panels and store it as potential chemical energy. When needed, your solar inverter and control components activate the battery’s stored chemical energy to generate electrical energy.
Several battery systems provide reliable backup power in Australia. The Tesla Powerwall home battery system has some of the most reliable results in Australian settings. It can withstand the country’s harsh conditions and extreme weather. Below is a list of the four types of batteries recommended for solar power backup systems.
Lead-Acid Batteries
- Have been available for the longest period
- Lowest priced solar batteries available
- Require regular maintenance
Examples: - Flooded
- Valve Regulated Lead-Acid (VRLA)
Lithium-ion Batteries
- Long lifespan
- No maintenance
- Expensive
- Recommended for residential backup systems
Examples: - Lithium Nickel Cobalt Aluminium Oxide (NCA)
- Lithium Nickel Manganese Cobalt Oxide (NMC)
- Lithium Manganese Oxide (LMO)
- Lithium Iron Phosphate (LFP)
Nickel Batteries
- Ideal for operation at extreme temperatures
- Use simple battery management systems
- Recommended for commercial-scale solar projects
Example: - Nickel Cadmium (NiCd)
Flow Batteries
- Large in size
- Very expensive
- Ideal for large-scale battery storage
Examples: - Redox Flow Batteries (RFB)
- Hybrid Flow Batteries (HFB)
If you opt to use batteries for solar backup power, the Australian government has various incentives to reduce the capital cost of your system. Below is a list of incentives geared to encourage uptake of battery backup systems:
Queensland solar and battery rebate
South Australia Home Battery Scheme
Victoria Battery Rebates
Next Generation Energy Storage Grants
Solar Capacitors
While batteries store solar energy in chemical form, capacitors store it as an electric field. In its simplest form, a capacitor consists of two conductors separated by a non-conductive material such as glass or ceramics.
When an electric current passes through a capacitor, it retains the negative charges on one conductor while positive charges accumulate on the other conductor. The non-conductive or insulation material prevents the negative electrons from flowing to the positive conductor. The size of the conductors and insulation material determine the capacitor’s power storage capacity.
Capacitors store energy as electric fields. As such, capacitors have no limit on charging cycles. By storing energy in electric fields, the backup power in capacitors is readily available for immediate use.
Recent technology has led to the development of Supercapacitors that can increase the energy density of standard capacitors. Supercapacitor conductors have rugged surfaces rather than flat ones. The rugged conductor plates increase the surface area available for energy storage. In addition, instead of non-conductive media, the supercapacitor plates are separated by an electrolyte.
Regional Electricity Grid
If the electricity grid provides reliable power, you can use it as a backup. Your system will run on solar during the day and the regional grid at night. Grid-connected solar panels are also known as grid-tie solar systems.
If you own grid-tie solar panels in Sydney, then you can generate extra income for yourself. The Australian energy system allows you to sell your excess solar power to the grid during the day. The revenue you generate can offset your electricity bill at night. If the income from your panels exceeds your electric utility bills, your solar system will give you a positive cash flow.
Diesel Generators
If you don’t have enough batteries, capacitors, or direct access to the grid, you can use diesel generators for your backup power options. Diesel generators provide a low capital backup power solution for off-grid solar panel systems. Diesel generators use fossil fuel-powered motors to generate electric currents.
Diesel generators have higher operational costs than other backup systems due to the cost of fuel. Also, diesel generators are not ideal if your reason for going solar is to reduce pollution and go green.
To sum up, your solar panel system needs backup power if you intend to use it on cloudy days or at night. Commercial solar farms that only provide power during the day may not require significant backup power. Yet, most industrial and residential solar panel systems require backup power to work effectively. Your choice of backup power depends on the size of your solar power system, your budget, and the financial resources available to you.
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