Whatever your solar questions, we have the answers
When it comes to installing solar within your home, you want to be sure that you select the right system for your needs and circumstances — which is why it’s so important to do your research.
As a trusted solar power company, we’re here to provide you with the answers to your many questions. We also make it our mission to impart the vital solar information you NEED to know, but might not be aware of yet.
Our Frequently Asked Questions range from basic to complex, and we hope you will find them to be an extremely useful part of your solar education and awareness.
If you would like to know more, please give us a call today on 1300 75 00 55.
- What should I be looking for in a solar power company?
- What is a kilowatt hour (kWh)?
- Are solar electricity and solar hot water the same thing?
- Will my electricity bill go down once I get solar?
- What should I look for when choosing solar power panels?
- How important is the inverter?
- Can I expand my solar power system in the future?
- What is a Normalised Power Output (NPO)?
- How can I judge the performance of a solar panel?
- What does the warranty cover?
- How can I find out about the embedded energy of a solar system?
- How can I find out about the environmental performance of silicon solar panels?
- Do solar power systems require batteries?
What should I be looking for in a solar power company?
When you invest in solar, the company you choose to supply and install your system will be your main point of contact – which is why it’s essential that you fully understand the services they offer. It’s always worth choosing your solar power company very carefully, taking locality, company history and their amount of industry knowledge into account.
When feed-in tariffs change in different states, it can often lead to smaller, unscrupulous companies moving around to wherever the money is. Rather then working to build networks and businesses in their main area, they set up shop while the going is good and leave when the situation changes. To be fully confident that you can rely on your solar company, you need to understand more about how long it has been established, and how stable it is within the industry. You should look for a company that hasn’t just been operating in the boom periods, but has (and will continue to have) a commitment to the solar revolution overall.
Another good idea is to ask lots of questions. The more a company knows about their products, manufacturing process, installation requirements, performance and longevity, the likely they are to help you make an educated decision. If a solar power company is clueless from the start, it’s a telltale sign of short-term thinking, and shows an inability to help you do what you really want – eliminate your power bill.
What is a kilowatt hour (kWh)?
To really comprehend solar, the most important element you need to understand is the kilowatt hour. Once you have a grasp of this terminology, you can measure all systems against each other and accurately compare the return on investment.
Kilowatt hours (kWh) are how we measure electricity consumption and production. Kilowatt hours measure the power consumption/production of a device over time. For example an electric stove that’s rated at 1kW used for 2 hours will consume a total of 2-kilowatt hours (1kW x 2 hours = 2kWh).
If you look at your power bill, you’ll be able to see that all the readings and usage patterns are calculated and displayed in kWh. It’s important to understand that solar power production is also measured in kWh. Even though you may purchase a 3 kilowatt-sized system this is a theoretical figure, and the kilowatt hours produced by this system will be vastly different depending on the real-world performance of these modules over time. (See ‘How can I judge a panel’s performance?’)
Are solar electricity and solar hot water the same thing?
One of the most commonly asked questions when people start to look into solar products is to do with the difference between solar electricity and solar hot water. These are often mistaken for the same product, or it’s thought that both products perform the same task. But although both systems run off the sun’s energy, they use this in different ways and each have a different outcome.
Solar hot water uses the sun’s heat energy — either directly or via heat transfer — to increase the temperature of water. Depending on the strength of the sun and the starting temperature of the water, circulation of water may need to go through the solar collector multiple times to reach the desired result. Although solar hot water is a simple process, it has a solid return on investment because we all use hot water. If the need for hot water in the property is high, the return on investment of changing an old storage tank for a solar option may be greater than any other solar alternative on the market.
On the other hand, solar power is the process of using the sun’s light energy to create DC electricity. This process works more efficiently with less heat energy, and greater watt per square meter of sunlight. Traditionally spring and autumn are the best times for solar power production, as they often feature bright sunlight without too much heat.
Although solar power can provide electricity for your entire house, it may not be the best option to start with when trying to lower your bill. Due to feed-in tariff incentives, your consumption during daylight hours will affect the cost savings you get from your solar power system, and therefore all solar options for your home should be explored first.
Will my electricity bill go down once I get solar?
Yes – but please do bear in mind that solar isn’t magic and your mileage will vary. There are different feed-in tariffs across different states, but here in Queensland we have a Net feed-in tariff of 44 cents per kilowatt hour exported back to the main electricity grid. What this means is that you only get to access this Solar Bonus Scheme when you have excess power that has been produced from your solar and has not already been used in your home.
It’s important to understand that any power produced by your solar system will be used in your home first. Only excess power will be sold back to the grid at the premium feed-in tariff rate. If you are using more power then is being produced by the solar system then the balance of your consumption is bought from the power grid as normal. Consistently using less power than your solar system produces is the best way you can reduce your power bill.
A few basic steps you can take to lower your power bill are:
- Practicing general energy efficient behaviour around the home,
- Changing energy-hungry devices where-ever possible (Lighting, hot water systems, etc)
- Turning electrical devices off properly, rather than putting them on standby
- Installing a high performance solar power system to make the most of the sunshine everyday.
What should I look for when choosing solar power panels?
One of the greatest indicators of high quality solar modules is the history and the basic production standards implemented by the manufacturer.
As solar is a long-term investment, it’s important to seek out long-term testing and case studies on the panels to know how they will last under the harsh Australian sun. If data on performance and longevity isn’t available, it should trigger questions on whether the manufacturer and distributor can guarantee results in the future, or whether their performance is theoretical.
Advanced solar manufacturing started in the late 1970′s, and companies that have been in the industry for all those years understand what it takes to build modules that are not only durable and long lasting, but that also deliver high kWh production. With so many inexperienced companies and factories entering the market in the last few years, this proven experience, knowledge and testing is the ONLY way to completely trust long warranties.
There are many stages in the manufacture of solar photovoltaic panels. The most crucial component in a panel is the solar cell itself. The performance of solar cells depends on the grade of the raw material used (polysilicon), the quality control of the production process and the requirements of the manufacturer. Companies making cheap panels need cheap solar cells, but unfortunately poorly manufactured cells start degrading badly right from their first day in the sun.
There are multiple grades of polysilicon available worldwide, with premium silicon only available to the highest bidders. Manufacturers who use the highest quality base product ensure that the solar cells have the capacity to perform not just now, but also well into the future.
Other production standards to take into consideration include factors like where the cells were produced, who assembled the final product, and if it was made to a physical size or specific power output. If the manufacturer has outsourced the production of the panels, there will be far less attention to detail then if vertical integration had occurred (where the same manufacturer carries out the entire process, transforming raw product to completed solar module). The last thing you want is a module made solely for a low price, rather than for the purpose of electricity generation.
How important is the inverter?
The solar inverter is a unit that converts the direct current (DC) coming from the solar panels into alternating current (AC) – the type of current we run our homes and businesses on. It’s an essential part of any system and there are many types and brands available on the market today.
The inverter can be likened to the gearbox in a car. It’s not considered as important as the engine (the solar panels), but you can’t drive anywhere without one. Like solar panel manufacturers, many new inverter manufacturers have entered the market in the last few years. Always look for an inverter manufacturer that has been in the industry for an extended period of time and produces inverters that are built to last. Before buying any solar system, make sure you check the history of the inverter company.
Inverters are rated via a system called Euro-Efficiency. This rating allows you to see the weighted average conversion efficiency of the inverter and understand how much power loss (generally due to heat) will occur over time. If an inverter has a Euro-Efficiency of less than 95%, you can start to see the overall loss of power will really add up over the life of the system. A greater investment in a higher performance inverter will pay for itself in no time.
The warranties on inverters are traditionally shorter then on solar modules, but if you pair a well respected, high quality inverter with the right solar panels you will enjoy the superior power production a long lasting, high conversion system brings.
Can I expand my solar power system in the future?
It’s very common to purchase a solar power system that has solar modules rated at a lower input then the capacity of the inverter e.g. 2kW of panels on a 3kW inverter. This allows the owner to expand on their system in the future. While expandability is desirable, there are few things to keep in mind:
- Generally you will need to use the same solar panels when expanding as were originally installed. This is necessary to match the electrical characteristics and capabilities of the panels. Unfortunately, you can’t just buy another brand of panel and install them onto the same system without severely affecting performance. If you’re unable to source the same panels in the future, expansion may require a new inverter or an individual power maximiser system, which will result in costs you didn’t expect at the time of the initial install.
To get around this, start by purchasing a system from a recognised brand with offices in Australia so that you won’t have any problem getting expert advice directly from the manufacturer in the future.
- The solar inverter may come with extra space for expansion, but how easy is it really to have new modules installed? This is the question you should ask before installation to understand all your options. It may be that the inverter has two maximum power point trackers (MPPT) to allow two different arrays on the same roof, or alternatively has one MPPT and can only be expanded in equal size increments until it reaches capacity.
The option to expand the panels gradually over a period of time may be seen as the most desirable option for your situation and budget. But do bear in mind that understanding how your inverter works is key to any future solar system expansion.
What is a Normalised Power Output (NPO)?
The Normalised Power Output of a system is the estimated kWh production per kilowatt of panels per day averaged over a year (kWh/kW/day). Knowing the Normalised Power Output (NPO) of different systems allows us to accurately compare various brands of solar panels. Generally higher quality systems have higher NPOs, meaning that they will pay you back faster (usually within five years).
The NPO is one of the most important tools for selecting and sizing the right solar power system for your situation.
How can I judge the performance of a solar panel?
The only certain way to get performance data on solar modules is to see long-term testing results from sites in Australia. If the panel manufacturer isn’t able to provide Australian performance testing, then there is a real possibility that their products haven’t been tested for long-term durability. Due to the harsh and sometimes unpredictable nature of the Australian sun, long-term testing and research data will allow the greatest perspective of the lifespan you can expect from your solar system.
By comparing the NPO of different manufacturers you can actively compare the performance of modules in kilowatt hours, and then relate this back to your own electricity bill to calculate your average savings. By understanding the performance of comparable systems, you can see that all solar panels produce different amounts of electricity resulting in different return on investment figures.
What does the warranty cover?
Different warranties will apply to the different components within your solar power system. You often see the ’25 year Warranty’ used in advertising material, but these performance warranties are based on the minimum warranted output of each individual solar panel over their 25 year estimated life. For example, many solar panels are warranted to produce at least 90% of their original power output for the first 10 years and at least 80% of their original power output for the next 15 years (25 years total).
It is important to understand that these performance warranties don’t guarantee that the solar panel will still work after 25 years – just that if it does, it should produce a certain amount of power. If a solar panel fails due to water ingress or something similar outside of its manufacturers warranty (typically 5 years), then the performance warranty will then be null and void.
If an electrician is required to test the panels before the warranty is even enforced, this cost may not be recouped back from the warranty holder.
Other warranties include the durability of the panels, the inverter, and the labour warranty when the panels were installed.
The most important thing to look for when assessing the warranty characteristics of a system is to find out who holds the warranty. Reading the fine print to understand what your obligations and costs are – and who you should deal with – is critical should you ever need to exercise your warranty rights in the future.
There have been situations in the solar industry where warranties are held by companies overseas, and this makes it incredibly difficult to claim if there is a problem.
When purchasing a solar system, you can request evidence of warranty claims in the past and full details of whom you would contact in the event of a system malfunction.
Warranty support is far more important than warranty length. Remember: a long warranty isn’t worth ANYTHING if it turns out you can’t claim it.
How can I find out about the embedded energy of a solar system?
The embedded energy level of a solar system relates to how long a solar system has to operate to recover the energy—and the associated generation of pollution and CO2—that went into making the system in the first place. A document released by the U.S. National Renewable Energy Laboratory in 2004 says that a modern crystalline silicon solar panel system has an energy payback of just two years; meaning that over it’s expected 30-year life a solar system will produce far more energy than it cost to produce.
How can I find out about the environmental performance of silicon solar panels?
For information on the environmental impact of the solar panel manufacturing process, ask to see a copy of the manufacturer’s annual environmental report.
The Chinese photovoltaic manufacturing industry has been linked with environmental damage via the dumping of toxic waste including silicon tetrachloride. Other issues have come from lack of environmental controls leading to the unexpected dumping of pollution into waterways.
Do solar power systems require batteries?
Traditional solar power systems required batteries to store the power, as often there were no other sources available. These were called off-grid systems and the battery helped to not only provide power once the sun went down, but also to regulate the flow of electricity so spikes and variations didn’t damage any appliances used.
Now we promote and install ‘grid-connected’ solar systems, which allow a two-way flow of electricity through the main electricity grid. This system includes the installation of a grid-connected inverter so that the DC power from the solar can be converted into AC power (to be used in the property and by the mains grid). Grid connected systems have no need for back-up batteries and the maintenance associated with these – instead we use the grid like one big battery to allow extra power when needed, especially at night.
It’s important to realise that because there are no batteries installed in the system, if a grid blackout occurs your property will lose power until the connection is reinstated.