Are grid connect solar panels better than battery storage?
The prospect of harnessing clean energy and saving, or even making money can be exciting for many solar energy consumers.
However, with so many different types of solar power systems out there, it can be difficult to know where to start.
As with any major purchase, it pays to do your homework before making a financial commitment. With such a huge array of installers and solar products available on the market, it is essential that you find out exactly what you are getting into, before you make a final decision.
To make the most suitable, informed choice you will first need to determine what type of solar system will best meet your needs, as well as which solar providers you can deal with. Below are some of the main types of standard solar systems you are likely to encounter.
4 Types of Solar
Grid connect solar
In Australia, most modern solar systems are grid connect. A grid connected system is linked to the mains electricity grid and doesn’t require the use of batteries. Any excess power your solar panels generate is fed back into the grid and you will be paid a feed-in tariff by your electricity retailer.
Most cost-effective and popular option
Easy to operate
Low-maintenance
Can be built to meet almost any scale of power requirement
Runs in tandem with mains grid electricity; any additional power required is drawn from the grid, any excess power produced is fed back into the grid
Electricity companies pay consumers for the surplus energy fed back into the grid (this is called a ‘solar feed-in tariff’)
Solar feed-in tariffs can vary depending on which state you live in and which electricity supplier you use and are subject to change
Grid connect systems will not work during a power blackout; for safety reasons, grid connect solar inverters are installed with cut-off sensors to prevent electricity from being fed back into the grid during maintenance
Hybrid solar systems
‘Hybrid’ can refer to a power system that is driven by two or more renewable energy sources, often wind and solar power. For the Australian market however, the term ‘hybrid solar system’ is generally used to describe a solar powered system that is connected to the mains grid, but also has a battery backup facility to store excess power.
Electricity is still available during a power blackout
Excess power can be sold back to electricity retailers
Hybrid solar users can enjoy ‘the best of both worlds’
Expensive
High-maintenance
Complex, with several components that can go wrong
Require specialist expert design and installation
Stand-alone or off grid solar systems
As the name suggests, stand-alone or off grid power systems are not connected to the electricity grid. Commonly used in remote areas where mains power isn’t available, a stand-alone solar power system operates independently of the grid and requires backup batteries to store power. An off grid system is also more affordable than connecting to the mains electricity grid.
May be the only option where mains electricity is not available
Can be cheaper than connecting to the grid in more remote areas
Negates the need to purchase electricity from a retail supplier
Off grid solar systems can be designed to power single items only (e.g. – water pumps, large appliances and solar hot water systems)
Most systems (except hot water) require the use of backup batteries which may only last about 3 years
Batteries require significant storage space (i.e. – an extra room or shed)
High-maintenance
Relatively expensive
More electrical components, so more that can go wrong
Require specialist expert design and installation
Portable solar systems
There are portable solar systems available for a wide range of applications including farming, fishing and camping. Designed for constant mobility, portable solar panels are typically lightweight and robust and can be set up quickly to provide power in situations where mains electricity is unavailable or difficult to access.
Easily transportable
Lightweight and robust
Generally very reliable
Designed for a specific purpose; from solar powered chargers for USB devices to portable solar panels for larger appliances and solar power electricity generators, there are many options available
Most portable solar products are limited in their range of applications and typically aren’t suitable for large-scale household or commercial energy generating applications
More solar power system features
Solar batteries – for off grid and hybrid solar systems
Stand alone solar power systems (off grid solar systems) and hybrid solar systems use battery banks to store energy for later use when there is no power being generated or there is an increased energy demand.
Benefits
- Power can be available during blackouts and / or periods of no power generation
- Independence from the electricity grid
- Batteries can provide additional power when needed
- Avoid time of use electricity charges
- Batteries are cool!
Modern solar batteries can be fitted to off grid solar power systems as well as grid connect solar power systems. Photo by: Rogeriko on Flickr
Drawbacks
- Potentially costly
- Can be very high-maintenance
- Limited shelf life
- Large storage requirements
- Some batteries are flammable and toxic
- Battery reliant systems need to be very carefully designed; a system that is too large or too small for your energy demands will be a waste of money
Expandable Solar Power Systems
Buying an expandable solar power system is an economically responsible decision if you have the space to add additional solar panels to your array!
If you have started to research solar power systems, you may have come across expandable solar power systems. An expandable solar power system is designed to allow you to increase the number of solar panels at a later stage. You may have enough room on your roof to install a 5kW system (20 x 250 Watt solar panels or equivalent) however your budget may only allow you to purchase 3kW worth of solar panels. If this is the case, you have the option to install a larger solar inverter now so you can add a further 2kW worth of panels at a later stage.
Advantages of an Expandable Solar Power System
The cost of a solar inverter
The difference in price to install a 3kW inverter compared to a 5kW inverter is minimal. When you take into account the time it takes to install the inverter, commission the inverter so that it connects to the grid, and register the inverter with the energy retailers. This process can be very time consuming. So to install a larger inverter now to cater for future expansion of your system will prevent the double up of installation costs.
Energy Retailers
When a new grid connect solar power system is installed and commissioned, the installer is required to register the system with the energy retailer by lodging a document outlining specific details about the new installation. These specific details include serial numbers, inverter capacity, number of solar panels and other information. When an energy retailer calculates the size of the system, they use the size of the inverter as a benchmark. So if you install 3kW worth of solar panels with a 5kW solar inverter, then the energy retailer will class your system as a 5 kW system. Once the solar inverter is installed, commissioned and registered with the energy retailer you will be eligible for the solar fee-in tariff. The solar fee-in tariff varies from state to state and can also vary depending on what energy retailer you purchase electricity from.
Examples:
- Queensland – If you installed a 3kW solar power system with a 3kW solar inverter before the 44c feed-in tariff cut-off date and you currently receive 44c per kW of solar energy exported to the grid, and you wish to install a larger inverter now to maximise your output, you then will forfeit the existing 44c feed-in tariff and have to re-register your system under the new policy and reduce your rate from 44c down to 8c per kWh.
- Queensland – If you installed a 3kW solar power system with a 5kW solar inverter before the 44c feed-in tariff cut-off date and you currently receive 44c per kW of solar energy exported to the grid, and you wish to install an additional 2kW worth of solar panels, you would not need to lodge any additional documents with the energy retailer and would not forfeit the 44c feed-in tariff.
Conclusion
Considering the above factors, expandable solar power systems are generally more versatile and cost-effective than non-expandable systems. If you have the available roof space, upgrading your solar inverter at the start will allow you to install more solar panels at a later date.
The right solar choice
Choosing the right solar power system for your home or business
Right now, grid connect solar and stand alone solar power systems are the most popular in Australia, however hybrid solar power systems are also gaining in popularity.
As we have shown, each system has its advantages and disadvantages. Before you spend any money, do your research and work out exactly what you need and can afford.
Knowing precisely what you are getting before you buy can mean the difference between a sound investment that will pay dividends well into the future, or being lumbered with a system that is too costly and / or inadequate for your energy requirements.
Finding the right solar installer
This is where Australian Solar Quotes comes in. Designed as a one-stop portal, we have teamed up with a large network of registered solar panel installers throughout Australia so you can access free, independent quotes from different providers.
When installing a solar power system, there are many things to consider. Through Australian Solar Quotes, you can find impartial information on modern solar technologies that will help you identify the most competitive, comprehensive quote for your needs.
Q: Will solar panels supply energy for my home during a power blackout?
A: “No”
This is because your grid connect solar inverter comes standard with an automatic cut-off sensor designed to protect electricians from being electrocuted whilst they are working on the issue that’s causing the blackout. So in the unlikely event of a blackout, you will not be making money from your solar power system and you will not be able to power your household appliances. Unless you purchase a hybrid system, which we will touch on later on.
4 Types of Solar Systems Explained:
1. Portable solar power systems
Configurations for off grid solar systems range from small portable solar panel kits that only require a small to medium solar battery, through to much larger kits designed for permanent installation in your home. Homes that install off grid solar systems tend to require additional storage or space the the solar batteries so this needs to be kept in mind when deciding which type of solar power system is right for you.
Smaller kits are typically rated from 3W up to 120W and designed for powering only a few small devices. These systems are useful for people who need to get out in remote locations (the ocean, the outback, forests) or for people who travel long distances by car or train and need to keep their appliances charged up. Of course you do need to make sure the kit you choose is appropriate for the environment that you’ll be using it in. Portable solar kits often have built-in solar batteries too.
2. Grid connect solar panels
Out of the above installation types, the most common residential solar power system setup is a grid connect solar panels.
With a grid connect solar panels, any excess power that you generate can be sold to your electricity retailer. This is a major incentive for many homes and businesses to install solar panels.
Be aware though, each of Australia’s state governments have their own set of rules relating to selling excess power back to the electricity retailers. We’ve broken this down for you on the solar panel rebates page. It’s also a good idea to ask your electricity retailer what the going rate is in your location, prior to committing to purchase.
Read our solar panel installation guide here!
3. Off grid solar systems
What is a stand alone solar power system?
Stand-alone solar power systems are used to provide electricity to appliances independently of the mains power grid.
This means that you can use them in any location, and you are not subjected to many of the inconveniences of a mains system such as blackouts. Solar energy puts you in control of your electricity.
What equipment is needed for stand alone solar power systems?
A typical stand alone solar power system that is installed for permanent use in the home will require the following items:
Solar panels
Solar panels are the key components for capturing energy from the Sun
Charge controller
These are small computers that regulate energy flowing from the panels to the solar batteries
Solar batteries
Solar batteries are used to store energy collected by the solar panels
Solar inverter
Transforms the current from low voltage DC power to high voltage AC power
How do I choose a stand alone solar power system?
The most important thing to understand about solar power systems is that there are many different types and configurations. In most cases the types of solar panel systems are compatible with the variety of solar storage batteries on the market and new technology including AC coupling enables batteries to be retrofitted to existing solar panel installations. Choosing the right type of solar panel system for your home involves understanding how much electricity you are likely to consume. You can often identify accurate energy consumption data with smart energy monitoring devices or you can get an estimate from your previous electricity bills. When using your energy bill to estimate usage, you should simply look for the highest amount of energy that you have consumed during the most recent period and use this as a benchmark for determining the type of solar panels and storage setup for your home or business. To make it simple, buy a solar panel system that can supply the minimal amount of kilowatts that you think you will need.
Are there different types of solar panels?
Yes. You can choose between CIGS and monocrystalline panels. CIGS panels are made using thin-film technology to produce cheaper and lighter panels. Monocrystalline panels are heavier and a bit more expensive, but will give a long lifespan and maximum reliability.
What about solar batteries?
Most types of solar panel systems in Australia that include solar storage technology utilise deep cycle solar batteries that are designed for long term use and multiple recharges.
Sealed gel batteries are a safe option because they can be used indoors. This provides you with safety, convenience, and low maintenance.
AGM batteries are more expensive but have a longer lifespan than sealed gel batteries, while still providing the same advantages.
The lowest cost option is a ‘flooded cell battery’. These batteries are similar to those used in cars and are not sealed and therefore not spill-proof. They are not suitable for indoor use because they produce toxic gas when charging. This also means that they require more maintenance than AGM and sealed gel batteries.
4. Hybrid solar power systems
Keep your solar batteries fully charged
Solar batteries are the most costly component of a renewable energy system. Therefore anything you can do to extend the life of a solar battery is a good idea that will save you money.
Battery lifespan is greatly affected by what is called ‘depth of discharge’. This means the amount a battery is allowed to discharge before recharging. When a battery drops to below 20% of its capacity, it is considered to be deeply discharged.
Allowing batteries to reach a deep discharge state before recharging is known as deep cycle recharging. Contrary to what many people believe, this practice will shorten the lifespan of the battery.
To maximise the lifespan of rechargeable solar batteries, shallow cycle recharging is recommended. This means trying to keep your batteries at 80% or more of their capacity at all times.
Using a hybrid solar system will help you achieve this goal more easily. Obviously solar cells don’t work at night, so if you have a wind turbine connected, your batteries will still be charging as long as there is some wind.
Wind turbines don’t work in the absence of wind, but as long as there is some sunlight, the solar panels will take over the job of charging the batteries.
And of course when it is both sunny and windy, your solar batteries will be charging up to twice as fast!
The future of solar storage in Australia
While hybrid solar storage systems are most commonly found in regional towns or properties on the fringe of towns and cities, the new technology and affordability has shifted the energy alternative into metro districts. The domestic solar market has thrived on grid connect solar panels for close to ten years now however families are now beginning to adopt hybrid solar storage technology to counter the time of use energy charges that are spiralling out of control. As I described earlier, hybrid solar systems give families the advantage of drawing energy from multiple sources whilst utilising smart technology that selects the preferred energy source automatically. Having this level of control gives the everyday consumer the ability to farm their solar energy, store the energy onsite and use the two channels to power their homes before switching to grid reliance at a much higher cost.
Put simply, hybrid solar storage powers your appliances before you need to draw energy back from the grid. Another popular benefit is that you have more control over the solar energy that you produce and sell energy back to the energy retailer.
