Understanding Solar Quotes

Solar quotes can be difficult to understand. To start with, there are so many different products of varying quality that you really need to be an expert to know if what you are being quoted is fit for purpose. It is extremely important to trust the salesperson and make sure they know their stuff. When you start considering the federal and state based incentives and rebates and the different payment options it can all become overwhelming.

For this post, we will focus on how to understand what you are actually going to be paying for your new solar system. This sounds like a trivial task but we are constantly meeting clients with competitor quotes that they don’t really understand what they are up for!

The first thing to look for in a quote is the Total System Price. This is the cost of the system before any incentives have been deducted. This includes GST which must make up 1/11th of this price. If the Total System Price was $11,000 then the GST must be $1,000. If it’s not shown or is a lesser amount, through the quote in the bin; that retailer will not be in business for long!

In Australia, there are federal incentives called Small Scale Technology Certificates (STCs) for all new systems under 100kW. That covers all residential systems and small to mid size commercial solar systems but we will only discuss residential here as there are some tax differences.

You usually sign over these STCs to your solar retailer in exchange for an upfront discount. Your retailer will usually fix the price they will pay per STC but read the fine print; some will pass on the market value at the time of installation. This might give you a better return but exposes you to risk. Prices can fluctuate. They will never exceed $40 each (just trust me!) but have dropped to around the $17 mark in the past.

The number of certificates created is based on the capacity of the solar panels, the geographic location and the installation date. The more panels installed, the more STCs are created. (Note that it is not based on your inverter capacity). Systems in sunnier locations generate more energy so are given more certificates (based on postcode). Certificates are based on the expected generation of the system until the scheme ends in 2030. If installed in 2020 it’s based on 11 years, 2021 – 10 years and so on. That means next year the STCs drop by 1/11.

You can calculate the number of STCs a system is eligible for here: https://www.rec-registry.gov.au/rec-registry/app/calculators/sgu-stc-calculator. Your quote should have listed exactly how many the system is eligible for and what value they will offer you per STC. There is no GST on these so they simply reduce the amount you pay.

If there are no state rebates (eg. WA), then once you subtract the STCs from the Total System Price you are left with the Net System Price. This is the actual amount you are expected to pay.

If there are state rebates, you must also subtract these too. For example, in Victoria, you may be eligible for the solar panel rebate under the Solar Homes Program. At the time of writing, this is worth up to $1,888. It is paid directly to the solar retailer so can be treated as a discount and the Net System Price will reflect this.

Just a side note: This kind of fixed rebate skews buyers towards cheaper or smaller systems as they can appear much cheaper. As an example, if a system was $1,000 “upfront” its true cost could be $8000. Another system might cost $2,600 upfront but its true cost could be $9,600. It appears to be 260% more expensive but is really only 20%. The upfront difference may seem huge, but paying a bit more could save heartache later.

Perhaps the trickiest part is when partial loans are involved. In Victoria, there is a loan option as part of the Solar Homes Program Solar Panel Rebate. It is also worth up to $1,888. However, it is an interest free loan so needs to be repaid. The upfront cost of the system is reduced but you are still paying the full amount. Depending on the retailers quoting system, the Net System Price might show this lower figure but it should be clear if they have applied the loan or not. If comparing quotes, its probably easier to just ask them not to apply the loan to the quote. You can compare quotes knowing that you are comparing the amount you will actually pay (in the end).

You might also be using finance to fund the difference. If you are offered interest free finance, understand that you are paying a premium for the service. You should consider the total cost of using standard finance (with interest) on a competitors quote and see what works out cheaper in the long run. Solar retailers generally aren’t registered financial agents. The solar retailer should forward you to a registered financial agent to discuss fees and charges and your ability to service the loan before you proceed.

When you look at the quote breakdown, it should look something like this:

  • Total System Price (including GST)
  • Less STC incentive
  • Less State rebate (if available)
  • = Net System Price


  • Total System Price (including GST)
  • Less STC incentive
  • Less State rebate
  • Less interest free loan (to be repaid over x years at y rate)
  • = Net System Price

Never compare the Net System Price of the first type with the second. The second will seem cheaper but it has the loan which still needs to be repaid. To compare them, add the loan amount to the second Net System Price and you will be comparing the actual costs of the systems. If the quote doesn’t show this breakdown, again throw it in the bin as they won’t be in business for long. One way to minimise dealing with these type of businesses is to ensure you only deal with Clean Energy Council Approved Solar Retailers.

You also need to check when payments are required. A deposit or inspection fee may be required. Payment may be required in full before installation, on installation or some time after installation.

There is still a lot more to understanding quotes but at least you should be able to understand what the cost of the system really is and what you are actually paying and when.

Once you have decided to go ahead, you should not pay a deposit or inspection fee or any other fee until you have been approved for a rebate as getting it back can be difficult. You should not pay for any preparation works you would not have otherwise done until the rebate and network pre-approvals have been granted. If you are rejected for any reason it can be costly.

Just a final note; the Total System Price is the amount you would have to pay for the system without any incentives. If you ever need to replace the system entirely (it happens too often), this could be what you are required to pay next time. Some incentives are on off so it makes sense to get the best you can afford and plan for the long term.

Enphase IQ8 microinverter to work during blackouts

Enphase just released a video detailing the company’s new grid-agnostic Ensemble system, built around the 8th generation IQ8 microinverter. This is very exciting stuff, particularly for those in areas prone to power outages.

More than 98% of solar PV systems around the world are grid tied. They are required to disconnect from the grid when there is a power failure. They simply can’t create their own grid when the power goes down.

Hybrid systems are starting to gain some traction, particularly as governments provide incentives to encourage the uptake of batteries. However these are still very expensive and are often limited.

Enphase has developed the Ensemble solution to combat this problem. There are five key elements of this solution.

  1. The IQ8 microinverters are the base on which the system is built. They have all the advantages of microinverters but this 8th generation is also grid agnostic; if the grid fails, they will continue to provide power to the home (with sufficient sunlight).
  2. The Encharge Battery is designed to optimize energy generation to save money when tied to the grid and maximize availability during emergency when off-grid capability is enabled.
  3. The Enpower switch seamlessly isolates a home for operation during a blackout.
  4. The IQ Combiner enables real-time connection of a solar system to the cloud with the most efficient, effective and reliable communication protocols. The IQ Combiner ensures the longevity of the warranty for the lifetime of a system and allows the installer and Enphase to troubleshoot if needed to provide the best ROI.
  5. The Enlighten Cloud Software delivers real-time monitoring and insights of solar generation, energy usage, connection to the grid and battery usage.

Manufacturer release dates are usually optimistic but we expect this Ensemble system to be available in Australia in 2020. In the meantime, the IQ range of microinverters will be compatible with the new system so you don’t have to wait to install a system.

Why the best solar still doesn’t work very well

When considering a solar PV system, it can be very hard to know what to look for. You can spend countless hours researching products and review sites to make sure you are getting a quality system. If you’ve done all this research, you might be trying to steer clear of the cheap equipment and decide that you will only go for the best on the market. That is an excellent choice. However, you’re still not guaranteed a great performing system.

A solar PV system is more than a bunch of components simply strung together. It appears simple – a few panels placed on the roof and connected to an inverter connected to your switchboard. Unfortunately, today’s systems and regulations are more complicated than they used to be. Having the cheapest guys install your system might end up costing you dearly, even when using the best equipment.

We won’t go into all the issues you might come up against with a cheap solar system. You can browse through the Crap Solar Facebook page to see what you might be getting into. We’ll focus on how the service of the company installing your system makes a difference to the performance with a real life case study.

Distance – Cable Size – Voltage Rise -> performance loss

When an inverter produces more power than what is being consumed at the time, it pushes the excess back into the grid (called exporting). In doing this, it lifts the voltage a bit. The further away from the grid and the smaller the cables the more the voltage rises. Recent regulations mean that when the voltage rises too high, the inverter has to either reduce power output or cut off entirely. This is a situation you want to avoid!

If you live on a larger property, your power supply may be running quite some distance from the street. Even if it’s not that big a property, if you’re installing the solar on a shed then you could be introducing extra distance and the cabling could be smaller than we need. Your solar provider must take this into account before quoting the system. If you in this situation and they don’t mention it, then they may not be considering your best interests (or just not know what they are doing). 3 Phase Solar will provide alternatives or walk away from a job that will cause too much voltage gain.

Even if you live in metro areas, there is a good chance voltage issues may still affect you. With more and more people installing solar, there are more and more systems pushing the voltage up a little bit. Even if it doesn’t impact you on day 1, it may be a problem in a year or so down the track. You will need to count on your installation company to help you out when this happens.

Even the best installed system can perform poorly: a case study

We recently installed the absolute best quality system you can buy. It had 18 x SunPower E20 327W panels (5.9kW) connected to a Fronius Symo 5.0 inverter (5kW). These are both the best on market in their categories. This is a system we’d love to install for every customer.

The Fronius Symo is a 3 phase inverter which is required when the customer has a 3 phase supply. Normally, this means the voltage issue should be less of an issue: we are only putting 1/3 of the power down each phase so the voltage rise is 1/3 that of a single phase inverter.

When we installed the system, completing the work in the afternoon when the sun was low in the sky, we commissioned everything and the system was working perfectly. We hooked up the monitoring and showed the customer how it worked and how to read the display and said we’d keep an eye on the system to ensure it was actually working correctly.

It was a good thing we did.

They had a near perfect sunny day a couple of days later. Since the Solar PV array was larger than the size of the inverter, we expected the inverter to putting out it’s full capacity in the middle of the day. However, this is what we saw on the monitoring system:

Notice that it hits about 4.2kW and flat lines for about 3 hours. When we look closer at the actual voltages, you can see what is happening:

At 11:15am the voltages are over 250V. This is the point at which the inverter is required to start limiting its power to prevent voltage rise. The voltage is still rising so the power reduces a little more in response. By 2:20pm the system is no longer able to produce as much power so drops away as it normally would.

It gets worse though. The next day, there was a voltage surge to over 257V! The inverter disconnected to protect itself. The voltages never recovered that day and all output from the surge onward was lost.

Because we actively monitor every system we sell (since we have a performance guarantee to meet) we received notification of these events. We looked at the data and saw the voltage issues. At this point, you might immediately blame the distributor but it’s better to check you haven’t done something wrong on your end. Since we install extra metering at the connection point, I could see there was no local cabling issue. It is 10m to inverter so if we had done something wrong, there would be a noticeable voltage differential between the two monitoring systems.

We contacted the local distributor to see if anything could be done. Since this was a once off event, they couldn’t agree to do anything their end but allowed us to adjust the parameters in the inverter. Luckily the inverter is top quality and has the flexibility to be reprogrammed so we went out the next day and adjusted it.

This is a new installation so we’re still waiting on the results. There have not been the ideal conditions since we rectified it, but there have been no further performance limitations due to voltage since. When we get another good day, we will post the output curve to show how this fixed the system.

Even if it doesn’t fix the system completely, we are proactively monitoring the situation. If the voltages remain too high we will request the local distributor adjust the voltages in the street so this does not happen again or at least so rarely it does not significantly affect production.

Service matters

Had we not gone to the effort to setup and configure monitoring systems for the customer, it is quite possible this issue could have done undetected. The typical customer who walks past the inverter to look at the display and see’s it working just wouldn’t notice.  Considering there is a move from just about all inverter companies to remove displays entirely, this will further hide the issue.

Most modern systems have built in monitoring but setting them up is not always included or guaranteed in the cheap prices advertised. Additional monitoring can also be installed to measure your consumption and provide performance assessments so you can make better use of self generated energy, ensure top performance and see exactly how much the system is saving you in real dollars. We include this as standard since it gives extra information right at the connection point (some distributors are harder to convince there is a problem).

From this case study, you can see that using a proactive company with excellent service levels and technical experience can ensure your system performs at it’s best. Simply going for the best equipment (at perhaps the cheapest price) does not guarantee you a well performing system.

So how do you know the company will look after you?

They will ask questions about your energy usage AND the site before the sale. They will listen to you and not necessarily agree with everything you tell them (eg. best placement of panels). They will be knowledgeable and be able to answer most of your questions on the spot. They will want to see the site. Most systems work ok when first installed so people tend to leave nice reviews as they are excited at this time. Look for reviews about their service when issues occur after installation (it happens).  You won’t feel you are simply getting a sales pitch. They are trying to provide a service to you and meet your needs. If it doesn’t feel right, then perhaps look elsewhere.

Or simply come to 3 Phase Solar for your system. We will provide expert advice and a good value quality system. We’ll actively support you to ensure top performance for the life of the system. We’ll have your back.

50% off Solar PV for Victorian Homes

The Victorian Government has announced a new program to help reduce the cost of solar PV systems for up to 24,000 households in the state from 19 August 2018 to 30 June 2019.

The rebate will cover up to 50% of the cost of the system, up to $2,225 for eligible households. They equate this to 50% of an average 4kW solar panel system which sounds about right for a bare bones standard system. Premium systems can cost more and there are a lot of low quality systems available for less!

If re-elected, the Andrews Labor Government will expand the program to 650,000 homes from July next year and will allow households to install a solar panel system for half price and pay the rest of the cost back over four years with an interest-free loan.

To be eligible for the rebate, you will need to meet the following criteria:

  • Have a combined household income of less than $180,000 per annum before tax (base on the most recent tax assessment notices for home owners)
  • Is an owner-occupier of a home valued at under $3,000,000 (a copy of a recent council rates notice will be required). Sorry renters, still nothing for you.
  • The household does not already have a solar panel system installed.
  • Chooses Clean Energy Council (CEC) approved products and uses a CEC accredited installer (all 3 Phase Solar products and installers are approved / accredited).
  • Has had an eligible solar panel system installed on or after 19 August 2018.
  • Engages an installer who can provide a statement that they have not received a WorkSafe infringement notice in the past three years.

Now is a great time to consider solar panels but you will need to be careful. When the cost of something becomes so cheap, the cowboys really come out to milk the system and risk the safety of those buying and installing. Remember the pink batts program?

The last eligibility criteria is an attempt to reduce the risks but is inadequate.  Many solar companies pop up from the ashes of dodgy old ones and we expect to see many new companies pop up in response to this program offering “fantastic” deals.

The details on the program are light at the moment; to keep a track of any updates, check out the new agency Solar Victoria set up by the Government. Unlike the existing Federal Government incentives which you’ll usually see written up as an STC discount, this will be a rebate so will go directly to the home owner. That means you will need to fork out the full cost still but the rebate will come back to you.

Since you are getting up to a 50% rebate, you can afford to choose a company with a good reputation offering excellent products and service. You’ll only get one shot at the rebate so take your time researching and make the right investment in a system that will last 25 years.  Or just make the quick decision to do it right and go with 3 Phase Solar.

If you’ve had a system installed since 19 August 2018, you can now apply for the rebate here: https://analytics-au.clickdimensions.com/cn/a7n4a/PostInstall_v4

If we installed the system for you, we will provide all the documentation required to claim your rebate with your system manual.

Should I Add a Battery to My Existing Solar System?

So you have a solar system and you’ve heard how great it will be if you add a battery to it. Perhaps the sales company told you your system was battery ready but the prices on batteries aren’t quite there yet.  Are we nearly there yet? Let us show you the financials of a battery and you can better decide if they will work for you.

There are different types of hybrid battery systems out there. Some will provide emergency backup when the grid fails and some provide other tangible economic functions but most are there simply to help you use the energy you generate rather than exporting it to the grid. We will focus purely on the latter.

But first, can you even add a battery to a system you bought years ago? It’s not battery ready is it?

Actually, batteries can be added to nearly any solar PV system.  They are simply added in parallel with a measuring device put in your switchboard.  In most cases, you can add a battery.

A Battery Add-on System

We could go on and on about sizing the battery appropriately and how to do that. We will just focus on the economics and leave that for another post.

It is probably easiest to start with the perfect scenario where the battery completes a full charge and discharge cycle in one day. We’ll use a perfect 10kWh battery for our example.

If your solar system has the capacity to completely charge this battery and you use all the energy stored then you avoid paying 10kWh of electricity per day. People pay different rates of electricity so lets assume that it’s 25c/kWh. It looks like the savings are simple:

10kWh / day x 25c/kWh = $2.50 / day

Fortunately however, you were likely to have been paid something for that energy had it just been sent to grid. This varies a bit so we will work on 10c/kWh. Simply sending the solar energy to the grid instead you save:

10kWh / day x 10c/kWh = $1.00 / day

This means, the saving due to the battery is only:

$2.50 – $1.00 = $1.50 / day

This ideal battery will save no more than $550 a year to someone who has a solar system with the capacity to use it effectively. You must remember that this is with an ideal battery being utilised to capacity every single day.

Unfortunately there are days like this, when even a 10kW system only exports 7kWh so wouldn’t get through a complete cycle. The only way to make sure you can charge it every day is to undersize it, in which case you probably wouldn’t notice the savings at all.

A 10kW System in Winter

Furthermore, even if you produce the extra 10kWh, your charging device might be limited to how much it can handle at one time. For example, if you are producing 6kW but can only charge at 2.5kW, you’ll export 3.5kW. You will lose storage potential if the charging is restrictive.

You will be lucky to get 90% utilisation from the battery if it is well sized to your solar PV system. A battery that is too big could easily be down to 30% utilisation. That brings the savings down to less than $500 a year.

Batteries also have inefficiencies. A lithium battery will typically only return 90-95% of the energy put in to it. That 10kWh battery is really only giving 9kWh (or needs 11kWh to charge 100%). Yearly savings are now only $450 a year.

Batteries also degrade. A Lithium battery with a 10 year warranty, might only be producing 60% – 80% of it’s rated capacity by that time. We’ll be generous and assume nearly 90% of total energy throughput of the 10kWh/day advertised. Yearly savings are now only averaging maybe $400 a year.

A good quality 10kWh battery can cost more than $10,000 when fully installed with the required electronics. Over it’s 10 year warranted life, it will save you perhaps $4,000. Probably doesn’t sound that attractive does it?

You could shop around for a cheap battery but if you’re not careful, you might get lower capacity, lower charging rates, lower quality (degrades faster or fails) or lesser warranty. They’ll see you coming and sell you on the good feelings you’ll have when you join the battery owners club.

In conclusion? It’s expensive, but you can add a battery to your existing solar system. There are plenty of other reasons to get a battery, just don’t expect it to make economic sense until battery prices drop significantly.