Around half a million or one in three Queensland homes has a solar system installed and the Queensland Government expects this figure to reach up to 1 million by 2020. And while uptake has slowed since the Solar Bonus Scheme ended in 2012, many homeowners are still getting on-board.
But is it right for you? Here is a rundown of how solar power works, and what types of benefits you might be eligible for if you install solar panels in Queensland.
What is solar energy?
Solar energy is energy created by the heat and light of the sun that’s harnessed using a range of constantly evolving technologies.
An important source of renewable energy, solar energy and its technologies are broadly classified as either ‘active’ or ‘passive’ depending on how they capture and distribute solar energy or convert it into solar power. Active solar techniques include the use of solar water heating, concentrated solar power and photovoltaic systems. Passive solar techniques include selecting materials with favourable thermal mass and designing spaces that naturally circulate air.
What types of solar energy technologies are there?
In terms of solar power, there are two main types of solar energy technologies – solar thermal technology and solar photovoltaic (PV) technology.
Solar thermal electricity is the conversion of solar radiation into thermal energy or heat. Thermal energy carried by water, air or other fluids is commonly used directly, for space heating or to generate electricity using turbines and steam.
On a small scale, solar thermal electricity is commonly used for hot water systems, and concentrating solar thermal technology to harvest the sun’s heat can also produce efficient, large-scale power generation. This process uses a field of mirrors to reflect sunlight onto a thermal receiver, which then transfers the heat to a thermal energy storage system. Energy can then be released from storage as required, night and day.
Solar photovoltaic (PV) energy converts sunlight directly into electricity via solar panels, which are made up of a number of solar cells. Solar power is produced when energy is converted into electricity or used to heat air, water or other substances. Solar panels can be put on rooftops, integrated into vehicles and building designs, or installed across fields to create large-scale solar power plants. Both types of technology can also be combined into a single system that generates both heat and electricity.
The amount of solar energy available makes it a highly sought-after source of electricity. According to the International Energy Agency, solar energy technologies can reduce pollution, enhance sustainability, reduce the use of fossil fuels and lower the costs of global warming.
How do solar panels work?
When sunlight hits the PV cells in solar panels, electrons are knocked loose from their atoms and move around. These loose electrons can be captured so that they move in the same direction around a circuit. If conductors are attached to the negative and positive sides of a cell, it forms an electrical circuit. When electrons flow through such a circuit, they then generate direct current (DC) electricity.
Multiple cells make up a solar panel and multiple panels (called modules) are wired together to form a solar array. The more the panels the more energy that can be generated. In homes and businesses across Australia, we use 240-volt alternating current (AC) electricity. Therefore, an inverter is used to convert DC electricity to alternating current (AC) electricity so it can be used in your home.
What happens on a cloudy day?
Even on a cloudy day, your system will still generate at least some solar power. However, in solar panel arrays, shade can block the flow of electricity through the panels, and even if shade is on only one of the panels it can still affect the output of the entire array.
There are a number of things you can do to alleviate a loss of solar power. Panels can be originally positioned in areas free from shadows and things that create shade like buildings and trees. You can also ask your installer to split your solar panels across different parts of your roof and have them facing in different directions.
Many modern solar panels these days also come equipped with devices called bypass diodes. These reduce the effects of partial shading by enabling electricity to ‘flow around’ shaded areas.
How does solar power work in Queensland?
In terms of solar power in Queensland, in most cases, panels are mounted on top of the roof and connected to the mains power grid supply through an inverter. The inverter transforms solar power into electricity for use in your home.
Several factors can affect how much power is generated, including your system’s capacity, the average hours of sunlight in your location, and your inverter’s rating in kilowatts, which should be equal to or more than the panel’s output. Electricity generation is also affected by how your panels are positioned on the roof. Ideally, they should face north and be angled to collect the most sunlight.
What types of benefits are there?
In Queensland, most households use around 18 kWh of power each day, which means if you live between Brisbane and Cairns, for example, and you have solar panels, your power bill could be reduced by up to a third. Electricity customers in south-east Queensland are also able to choose their energy provider, so a bit of research can go a long way towards savings on your power bill.
You may also be eligible for government solar incentives when you buy solar panels and these differ by state. The number of credits will depend on the size of your system, when you bought it, where you live and whether you’re directly connected to mains power. In Queensland, two types are available – feed-in tariffs and small-scale technology certificates (STCs), and these schemes help to reduce the cost of solar power by helping you make a return on your investment.
If your solar panels produce electricity and nobody uses it, the power is transferred to the shared energy grid. For every kWh of electricity your panels export, your energy provider will offer you a rebate (or feed-in tariff) on your electricity bill and obviously, this is determined by a number of factors. In 2018, the Queensland government also announced it would be introducing a voluntary opt-in time varying feed-in tariff to regional Queenslanders.
In terms of STCs, these are part of a federal scheme that rewards customers with rebates. If you install a solar hot water system or solar panels, you can receive certificates that can be sold or given to your solar installer for discounts. The number of STCs you receive depends on your location and the size of your system and the country is basically split into STC zones 1 through to 4.