Solar power and solar panels explained

Solar panels on red-tiled roof

RACV

Posted October 19, 2021


Thinking of installing a rooftop solar system but have no idea where to start or what questions to ask? You’re not alone. Here are the answers to your most frequently asked solar questions.

Did you know that Australia has the highest population of residential rooftop solar energy in the world?

Currently, there are around 2.15 million Australian solar homes and counting– as well as a growing uptake of battery storage. As well as being a more sustainable option for your residence and the planet, over time, solar can also help you save on your energy bills.

But what is solar power, and how can you use it? With emissions and bills rising, and financial incentives from the government, there’s never been a better time to have solar power explained.

In this article:


Solar power explained: Understanding solar panel systems 

What is solar power?

In simple terms, solar power, or solar energy,  is electricity that is generated by sunlight. Solar devices, such as panels that are installed on your roof, convert sunlight into electricity during the day that generates electricity for your residence, or can be stored in solar batteries or thermal storage for later use.

Versions of solar can be used by solar technologies for areas that emit energy in your residence, including electric (from your tv to your kettle), solar water heating (from your shower to your pool), solar heating and cooling, solar lighting, and even solar-powered vehicles.

Why should I get solar power?

The two main reasons are: it saves you money and saves the planet.

Solar is the cleanest and most renewable form of energy, because rather than needing to release greenhouse gas emissions from burning fossil fuels, the electricity is sustainable, as it is created from direct sunlight and can be used for electrical items in your home.

Plus, because you will be generating the power naturally, using solar energy in your home or business can help reduce the cost of energy bills, as well as create an energy back-up system.

Can solar energy power everything in my home?

A large system can produce an equal amount of power for household consumption and can be used by all electrical appliances in the home during the day, and store energy in a solar battery for the evening. 

If you don’t have a battery, by running a heat pump or hot water service during daylight hours, you are effectively storing energy as hot water. This can be a great way to maximise solar savings and reduce a household’s energy costs.

At night, your house simply draws power from the grid as if the solar was never installed. This happens automatically, as the solar system is wired in parallel with your main supply.

What happens to the energy I don’t use?

Excess solar power generally flows automatically back into the electrical ‘grid’, or into a battery if one is installed. By reducing how much power you need to draw from the grid during the day, you can make big reductions in your power bill. (more on the grid below). 

Any extra power or amount of solar you produce will automatically be sold back to the grid, which further increases your savings. The value of the power sold back to the grid is credited to your electricity bill by your retailer, reducing your bill.

Does it work at night or in bad weather?

In a word, yes. If you don’t have a battery, at night your house simply draws power from the grid automatically.

Additionally, solar power panels still work when it rains and on cloudy days. There is less solar power production on these days, as there are fewer particles of light available to create a high flow of electricity. While the power output is reduced, you are still saving money whenever power is still being generated by your solar system.

Who can get it?

All Victorian property owners are eligible for solar, provided their residence has the ability for solar installation. You can also get a tailored quote to talk about the best sustainable energy options for your household or workplace.

 

Men installing solar panels on house roof

The amount of energy absorbed by a solar panel depends on the quality of the product you select. 

Solar panels, batteries and grids – what’s the difference?

Solar panels

How do solar panels work?

Solar photovoltaic (PV) panels absorb energy from sunlight and convert it into direct current (DC) electricity that you can use in your home, or sell back to the grid.

Each solar panel is made up of many individual solar cells, which in turn are made from thin wafers of silicon sandwiched together. Sunlight hitting these silicon cells provides the energy for electrons to move between the silicon layers and this flow of electrons is the electricity the panels produce.

How many solar panels do I need?

This depends on available roof space and household usage. A typical solar system would be about 15 to 20 panels.

How long do solar panels last?

Provided households invest in quality components, a solar system can last several decades. Solar panel manufacturers typically offer warranties of 15-25 years.

So, you can safely assume that the average life of a quality panel is around 25-30 years; however, this can vary depending on a range of factors.

Typically, grid connected inverters have a lifespan of 10-25 years. You should expect most high quality units to last 10 years minimum.

Solar inverters have warranties ranging from 5-25 years, with an increasing number of manufacturers offering pay for service warranty extensions.

What is the role of the solar inverter?

Solar panels generate electricity in the DC form. The solar inverter converts the DC electricity to the Alternative Current (AC) form, which can be used to power your home.

Can you install solar panels on all roof materials?

RACV installs panels on tin, cement and terracotta roofs, but not slate. If your roof is made of a different material, speak to one of our solar experts.

My house isn’t north-facing. Does this matter?

In Australia, the best position for solar panels to face is north – but don’t stress if they can’t. It’s all about positioning them where they’ll get the maximum daily sun exposure. (This is one of the solar myths, debunked.)

Which are the best solar panels?

There are many good brands, but many more average and poor ones. Good solar panels should have a product warranty of 12 years or longer, with an efficiency higher than 310W. RACV uses only premium products and currently installs Winaico and LG panels.

The grid

What is the grid?

The ‘grid’ refers to the network that transports power from generators (coal plants, solar and wind farms, hydro projects, etc), through the high-voltage transmission network (HV powerlines), then the low-voltage distribution network (street power poles) and to consumers (homes and businesses).

Can I disconnect from the grid?

While it is possible to go completely off-grid, it is not the best solution for most homes. In periods of cloudy or rainy days, it is possible to deplete your energy supplies and you may find that you need to reconnect to the grid to sustain power to your home. Alternatively, you would need to invest in a very large solar-and-battery system that would be under-utilised most of the time, producing significantly lower savings than what it would cost to install.

Solar batteries

How does battery storage work?

Batteries allow you to store excess electricity generated when the sun is shining and use it at other times when you need it. It stores excess energy to be consumed after dark, increasing a household’s independence from the grid, ultimately saving more money. A battery may also offer a household limited back-up power in the event of an outage.

Because the value of excess electricity that you sell back to the power grid (feed-in tariff) is generally lower than what you are charged when you consume electricity, it is more efficient to store your own energy for later use.

Do I need a battery?

Batteries provide several benefits, mainly around maximising the amount of solar power that can be used in the home, and most can provide protection from blackouts. Whether or not these benefits are worth the cost of battery installation is a case-by-case question for households. The price of batteries is likely to come down as they become more common, but for now, most households install solar panels without a battery.

Will my battery cover me in a blackout?

Many home batteries have blackout protection, but not all. In the case of a blackout, power to the home will be cut for around 30 seconds while the system recognises the blackout and switches to blackout mode. Back-up systems fall broadly into two categories:
 

  1. Whole-of-home backup: where everything in the house can be powered in a backup. The risk is that this will drain the battery quickly if the household continues to use large loads, such as air-conditioners.
  2. Essential-load backup: when installing the battery, the electrician can isolate only certain circuits in the home to be protected in the blackout, to ensure things such as lighting and fridges can keep operating. This means the battery powers only these loads in a blackout to maintain charge for much longer.

How long could a battery power my home?

Battery power varies depending on the type of unit and the amount of power you expect to draw from it.

As a guide, a typical $10,000 battery being sold today will hold about 50 to 75 per cent of an average home’s daily electricity usage.

 

Row of solar panels on pitched metal roof

In Australia, the best position for Solar panels is to have them facing north.


 

Solar power costs

How much does the average-sized solar system cost to install?

This depends on the size of your house, your energy consumption, and the quality of the system. Basic solar systems can range from as little as $2000 after all the rebates (details below), to tens of thousands of dollars for high-specification systems.

High-spec systems will produce more power from the same number of panels and, importantly, last much longer than cheaper ones, meaning you can save for years and years into the future. The average price for a good system, after rebates, will be around $5000 to $7000.

How much will my electricity bills be with solar?

This depends on the system installed and how much energy you consume. Many household bills can be more than halved, with ‘negative bills’ in summer that can leave your account in credit and help offset winter bills as well.

For an estimation, you can plug your average daily energy use and the number of panels you want into the RACV solar calculator to estimate the cost of a solar system and your potential annual savings – both financial and carbon.

Am I eligible for solar rebates?

Yes. All solar systems installed by accredited installers and using approved products are eligible for Victoria’s Solar Homes Program. The value of this incentive will depend on the size of the system, but can be up to $1400 for a typical-sized residential system, with the ability to also take out an interest-free loan for the system. More information can be found with Solar Victoria.  

Additionally, the Solar for Business Program rebate can be up to $3500 or 50 per cent% of the total cost, whichever is the lesser

How long does it take to install solar in a standard home?

On most standard single-story homes, installation can be completed within one working day, weather permitting. For double-story homes, large systems (10kW+), or systems with storage, installation may take 2two-3three days, and disruption to the household’s power supply will be minimal (less than one-two hours in most cases).

Where can I get solar? Can I install it myself?

Solar panels can only be legally installed by an electrician, and they must be certified for solar for you to be able to claim government incentives and rebates. When shopping around for solar, look to buy from a Clean Energy Council (CEC)-approved solar retailer.

Additionally, if your system is installed by a non-accredited installer, you will not be eligible for government rebates. RACV Solar is a CEC-approved retailer and is eligible for the rebate program.

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