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Large inverters are much cheaper per watt. Another reason to expand the solar power system.
When people ask me how much solar energy I should install on the roof, I usually answer...
"try your best."
I am not saying that you should borrow money from the mafia or cunning financial companies to do this. Nonetheless, considering the budget, roof space, and restrictions on the number they allow you to install in your area, I recommend installing as many solar panels as possible.
Three reasons for the lower cost per watt of solar energy in Australia:
I will quickly explain why it is a good idea to be bigger and why many labor costs remain the same, but the main focus of this article is how solar inverters can reduce their cost per watt as their size increases.
Microinverters are an exception, because their cost per watt remains the same regardless of the size of the system.
I will also show what happens to the cost per watt of SolarEdge inverters, which is a special case because they require a SolarEdge optimizer for every solar panel. The cost per watt of the SolarEdge system decreases as the size increases, but not so fast.
This is a good reason to install as many solar panels as possible on the roof-money. If your roof has no shadows, paying a little more for a larger system may be the best investment you can make. Outside of Western Australia1, this may be the case even if no one is at home most of the time. This is due to the solar feed-in tariff you receive when you send your excess solar energy to the grid.
Benefit #1-Use batteries for better results
Although most household battery systems do not do a good job of reducing prices, they will become cheaper. When this happens-if you want to charge them regularly during winter and cloudy weather-you will need a large solar power system. A larger solar system will increase the return on the battery.
Benefit #2-Electric cars are better
The driving of the future is electric. If you have money-trust me-if not now, you will soon want an electric car. If you don't believe me, please try some sporty ones. If you don’t have a lot of money, considering that cheap cars built in China will improve quickly, electric cars may soon become the cheapest option for new cars. If you want to charge an electric car without spending power-off fees, then a large solar system is your best choice.
Benefit #3 – The more solar power, the faster we can decarbonize
But the most important reason for vigorously developing solar energy is the environment. I have only recently realized that it may not take many years for me to become a grandfather, which makes me deeply aware of the importance of keeping the earth in good condition. Nevertheless, it is undeniable that it did not impress people as much as I almost mastered the Dragon Immortal Stone.
I got this gain at the beginning of December, but it seems that I gained weight again during Christmas.
Recent analysis shows that the fastest and cheapest way to achieve 100% solar, wind and batteries is to "overbuild" renewable energy generation. The magic number is approximately three times.
When installers install solar energy on your roof, installing a 6.6 kW system is not much more difficult than installing a 3.3 kW system. This is because the following areas require the same effort:
The only major difference is the number of panels on the roof. Installing solar panels is not easy. Installing 20 panels is much more difficult than just installing 10 panels, but it is still much easier than installing two independent 3.3 kW systems.
Just like larger rooftop solar systems, larger solar inverters require less effort per watt. Both a 2 kW and a 5 kW inverter require approximately the same labor to manufacture. Although most of the work is now done by machines, it is still an expense, and the "work" required to build an inverter with doubled capacity is far less than twice that.
In addition, the "brain" of the inverter-the control electronics-is the same in terms of function and cost of solar inverters of different sizes. This means that the higher the inverter capacity, the lower the cost per watt of these smart components.
I have put the price per watt of several inverters in the chart so you can see how it decreases as the size increases. To get the price per watt, I used my malicious connection to find the approximate wholesale price of the inverter, increased it by 20% to reflect the retail markup, and then added a 10% goods and services tax. Then I divided it by the watt capacity of the inverter.
Just because I provided a specific price per watt for the solar inverter, it doesn't mean you can buy it for that much money. My method is just a consistent estimation method. The actual price offered may be higher or lower because the retail markup may be very different from the 20% figure I used. In addition, even if my estimate is correct, wholesale prices will change rapidly. Although the overall trend is declining, if supply exceeds demand, their prices may rise. In addition, sudden fluctuations in the value of the Australian dollar can immediately change the price in any direction.
Some people are confused about the quotations they received for various components of the solar system. However, the exact cost of equipment such as inverters, panels, racks, or STCs that reduce the cost of rooftop solar energy is usually not important. For homeowners who have access to solar energy, there are only two things that matter:
If you are satisfied with these two things, you should be fine.
Many solar installers will tell you that SMA is a manufacturer of high-quality solar inverters. Some people will not. First, I will look at SMA's Sunny Boy single-phase inverter.
The price per watt of the 6-kilowatt Sunny Boy is half that of a 1.5-kilowatt inverter. The 1.5 kilowatt inverter is almost exclusively used to replace old inverters that have failed.
If you decide between a 3 kW or a 5 kW inverter, the larger inverter is nearly a third cheaper per watt:
Sunny Boy has only 6 sizes, but SMA's three-phase Tripower inverter has 10 different capacities. This is a good range, but only the smallest 6 may be used for residential installations. Even so, the 15 kW Tripower inverter requires a huge roof to make sense.
The figure below shows that a 10-kilowatt Tripower is 26% cheaper per watt than a 5-kilowatt one. But if we compare the largest and smallest, the cost per watt of the huge 110 kW Tripower is 83% cheaper than the 3 kW Tripower:
Although no one might use a 110-kilowatt inverter at home, the low cost per watt of large solar inverters shows why so many companies are installing large commercial solar systems. This is usually the most cost-effective way for them to reduce energy bills.
Line chart of SMA Tripower
In order to make the Nazi Party happy and use a line to show how the cost per watt has fallen, I made the following chart, which shows the first 5 Tripower inverters with a capacity multiple of 5 kW. The solid blue line shows the actual price per watt, while the dashed line is a straight line drawn between these points:
Using the straight-line average of these 5 inverters, the price per watt will be reduced by 18% for every 5 kW increase in capacity. This is an impressive drop.
Many people think that SMA is a high-quality inverter brand, which is reflected in its price. This chart from our Solar 101 guide shows that all solar inverters we are happy to be reliable and well supported in Australia, the right one is more expensive. As you can see, SMA lives in the high-end area of the inverter graphic town:
Instead of considering the cost per watt of similarly priced inverters such as Fronius, I decided to look at the cost per watt of entry-level solar inverters that might attract budget consciousness. I decided to check Solis instead of Goodwe simply because I saw its information first.
Although I don't want Solis inverters to last as long as Fronius or SMA, I still think they are worth the money, and I hope their service life will usually exceed the 5-year warranty.
Solis 4G single phase inverter
The following is the estimated price per watt of Solis 4G single-phase inverter:
Although it is about half the cost per watt of SMA Sunny Boy inverters, between 1.5 and 5 kilowatts, the price per watt has fallen very similarly, with Solis 47% lower and Sunny Boy 49% lower. It seems that both high-cost and low-cost solar inverters follow the same downward trend in cost per watt.
Compared with SMA 3-phase inverters, Solis 3-phase inverters have a slightly larger price drop per watt as the capacity increases. Or at least they will do this until we reach 25 kilowatts and the price will rise instead of fall. What a pity... They did a great job before that! But despite the unexpected price increase, I still want to point out that the 25-kilowatt Solis three-phase inverter is still one-third cheaper than the SMA three-phase inverter of the same size:
Solis 3-phase line chart
The power of the Solis 3-phase inverter is only a multiple of 5 kW. Although this makes people have fewer choices, it does mean that each bar in the figure above represents the same increase in capacity, which may be enough to get me out of Graphstapo's control. But if not, I have made a line chart of information for those who appreciate this kind of thing:
If we look at the first four solar inverters, on average, for every 5 kW increase in capacity, the cost per watt decreases by 18%-the same as the average value of the SMA 3-phase inverter. But if we include a 25-kilowatt inverter, the price per watt will drop by only 13%.
The SolarEdge inverter is a special case, because each panel must have a SolarEdge optimizer 2 for the system to work. These are small boxes of electronic devices that can regulate current, so even when they are shaded, each solar panel can provide maximum power.
They can eliminate some-and only part of-the damage caused by shadows and dirt. But because they use a little bit of electricity themselves, some people—especially a Danish—say that they can better shade solar panels without them. The optimizer does not consume much, SolarEdge says they only consume 0.5% of the panel output. Since I don't want to participate in more than 0.5% of the battle, you have to decide for yourself whether it is worthwhile for a roof with almost no shadows.
Unfortunately, like most things you buy, the SolarEdge optimizer costs money. They retail for approximately US$73 each and can be used for panels with power up to 370 watts. I assume that the average solar panel capacity it uses is 350 watts. This will increase the cost of the SolarEdge system by 21 cents per watt of inverter capacity. This is higher than the total cost per watt of a 4 kW Solis single-phase inverter. As you can see, installing a system with an optimizer on each panel will significantly increase the cost.
For a 6.6 kW solar power system, the cost of the SolarEdge optimizer will increase the price by approximately $1,400. A cheaper optimizer is available for non-SolarEdge systems for only 13 cents per watt (6.6 kW is $850). The good news is that most optimizers, including SolarEdge's, have a 25-year warranty, so hopefully they will have no problems during the life of the system.
You can also use Maxim integrated panels with built-in optimization functions, which add about 7c per watt, such as panels made by Suntech.
Solar edge inverter + optimizer price per watt
SolarEdge inverters come with an impressive 12-year warranty, and there are 5 single-phase inverters to choose from, with power ranges from 3 kW to 8 kW. I can take the price of the inverter per watt and add their optimizer cost 21 cents per watt, but this only works if the solar panel capacity is equal to the inverter capacity. For most installations, the panel capacity can be increased by up to a third. Since it is usually a good idea to get as close to this limit as possible, I assume that there will be 1.3 watts of solar panel capacity per watt of inverter capacity. This means that the cost per watt of the SolarEdge optimizer will be 27 cents per watt of inverter capacity.
This is the information, put in the chart:
As you can see, the optimizer constitutes a large part of the cost of the SolarEdge system. With 5 kW inverters, they are almost half the cost, while for 8 kW inverters, they cost slightly more than half.
Although the total cost per watt of the SolarEdge inverter plus optimizer will indeed decrease as the size of the solar inverter increases, the decline is not as significant as the SMA and Solis inverters. On the other hand, the SolarEdge system will have the advantage of an optimizer, so we are not comparing the same things.
If we look at the cost of a SolarEdge inverter without an optimizer, then from 3 kW to 6 kW, the price per watt will drop by one-third, which is the same as the SMA inverter, and from 2 kW to 4 kW The price is about the same. KW Solis inverter.
I am too lazy to make a chart for every standard inverter on the market, but when I tell you that their cost per watt decreases with increasing size, you can trust me. (Lazy people are very trustworthy.) But there is a solar inverter that is not suitable.
Micro-inverters are micro-inverters, each solar panel has one 3. This is very simple, because it allows each panel to operate independently, and the overall impact on power generation is similar to having an optimizer on each solar panel.
But as the solar system becomes larger, the micro inverter does not help reduce the cost of the solar system. This is because whether you use 1 unit or 100 units, the cost per unit is the same. If your system now has microinverters installed, you can be pretty sure they will be Enphase IQ 7 or the newer Enphase IQ 7+. I estimate the cost per watt of Enphase IQ 7+ is 59 cents, IQ 7 is slightly higher.
It doesn't make sense to make a graph to show how the cost of microinverters per watt varies with capacity, because it doesn't. With Enphase, whether you want 1 kW or 100 kW, it will always be 59 cents per watt.
Micro inverters are suitable for high-quality small systems
If you are willing to pay for high-end solar inverters, and your roof does not have obvious shadow problems, then Enphase micro-inverters may be a good choice for solar power systems with a total inverter capacity of less than 3 kilowatts. This is less than 4 kilowatts of solar panel capacity.
If your roof has shading issues, or you like the idea of optimizing panels, then if the total solar panel capacity is less than 5 kW and the panel capacity is about 6 kW or less, you may want to consider a micro inverter.
If you have a tight budget and want a low-cost system, you may never want to use a micro inverter unless there are special circumstances. With or without an optimizer, low-cost inverters such as Solis or Goodwe are cheaper.
I have shown how solar inverters can reduce the price per watt as the capacity increases, and are suitable for high-end and entry-level inverters. All in all, I can repeat myself and explain again how this helps to make solar filling the roof a good idea — or I can write a song about it.
As an amazing person, of course I decided to end with a musical ending. I have exceeded my budget and commissioned a talented person to record for you a special performance of my ode to the large solar system.
Ladies and gentlemen, I present "Go Big" (apologies to the villagers).
(Get bigger) This is the only way,
(Bigger) It may pay a price.
(Get bigger) to fill up your roof,
(Bigger) Ronald gave the proof,
(Bigger) The electricity bill will not be so high,
(Bigger) More power from the sky,
(Bigger) reduce carbon dioxide emissions,
(Bigger) This is your mission.
Ronald Brakels was born in Toowoomba many years ago. When his township collected a collection and sent him to Japan, he became famous internationally for the first time. This was the furthest place they could manage with the funds raised. When the local mayor greeted him at the airport and explained that it was too dangerous for him to return to Toowoomba due to climate change and mutations attacking goats. After returning to Australia, he developed a keen interest in environmental issues. Ronald then moved to a property in Adelaide Hills, where he now lives with his horse Tonto 23.
Great article-but you didn't mention the benefits of reducing the size of the array (larger inverters) to handle the Volt-Var response pattern during peak production and absorb less energy loss. The improper regulation of the line voltage in Australia and the overcapacity of the inverter is a very useful thing. Maybe a follow-up work?
The panel is now cheaper per watt than the inverter plus installation, it is time to pay attention to the inverter, next time you install it?
I suspect that some manufacturers are now doing what the medical electronics industry is doing, because they manufacture a single product and then configure the software specifications (so maybe a 3Kw inverter is the same as a 5 or 7.5Kw inverter, but the software is limited to 3Kw. Manufacturers do less at the low end and it is cheaper, but there is no larger inventory. I heard some people complain that their 5Kw inverters can only produce 4Kw max, but after the manufacturer reloads the firmware, the output reaches the correct 5Kw. This This leads to a problem, if we need more output, we can "upgrade" our inverter to install more panels. (Of course, provided it is one of these models...)
The song at the end is very nice
The title of the above article and its content, as well as the published answer to my question related to another article in the blog (I think it is about inverter overload or export restrictions), regarding the possible claimed STC limits. Unfortunately, STC There is no need to pay for the full solar panel power generated by the allowed inverters.
An example of this is the one I cited in this query; Goodwe GW5000-MS, which generates A/C power limit of 5kW, and allows an overload factor of 2; allows the total power generation of solar panels to be 10 kW, This is a good thing for days when there is less solar energy available for conversion to electricity.
Moreover, I know that the cost of the inverter is only $300 higher than Goodwe GW5000D-NS (which we own).
However, I think it is still worth it to get the GW5000-MS, because it has the function of 3 MPPT, connected to the current STC 6.5 (or 6.6?) kW panel power generation capacity qualified limit, hope that one day, we will get a federal assembly , The council will provide STC for the entire maximum panel power generation capacity of the allowed inverter.
I think one of the main things you forgot to mention is the Victorian government tax rebate (for the people of Victoria). Since it is a fixed amount of $1,850, regardless of the size of the system, does it make more sense to install smaller systems in some cases because they will be much cheaper after this rebate?
The bigger the better, but some suppliers limit the inverter to 5kw.. They also start to limit the inverter's output to the grid. Friends will have solar energy, but there is no cash back on their bills.
I think it depends a lot on your usage. Most people I know say that the smaller the better, because the rebate amount is fixed regardless of the size of the solar system, so for smaller systems, it is not uncommon for the Victorian government to rebate almost half of the system cost. For example, I recently received a quotation for a 6.6KW system, which was $2,350 after the rebate-I wish you a larger system at $356 per kilowatt-I'm sure if I get a smaller system, the price It will be cheaper per kilowatt. Another reason for getting a smaller system is that the feed rate for electricity has been decreasing for many years and may continue to do so-the smaller the system, the higher the percentage of electricity generated is used instead of feedback into the grid almost No.
Wendy-If you consider a system like https://www.deepcyclesystems.com.au/hybrid-solar-package-7-44kwh/, except for BMS and inverter, replace Goodwe with something similar GW5048D-ES inverter can complete the work of both at the same time, and the panel capacity is reduced to 6.6kW, if you consider https://energysaver.nsw.gov.au/households/solar-and-battery-powered/given solar energy to the house Battery loan discount;
"Through this discount, you can get up to:
US$14,000 for solar photovoltaic and battery systems (repayable over a period of up to 8 years)"
The interest-free loan needs to be increased to 20,000 US dollars, and the repayment period needs to be increased to ten years. Then, the combination of the system and interest-free financing (provided that it has no deposits and no financing fees), it should solve the problem of export bans, And it should be the ideal solution for most single houses in Australia.
This is "only" for the state/territory government to conduct election campaigns and provide appropriate funds to the households.
If you use a solar system to get the battery, then I can see the rationale for "bigger is better", because it means you may be able to completely disconnect from the grid and avoid electricity costs. In my case, my electricity bill is only about 50-60 US dollars per month (without solar panels), and my average daily usage is about 2.8 kWh, so even if I have a 14,000 US dollar system and disconnected from the Internet, I It also takes 23 years to achieve a balance of payments-far beyond the life of the battery. I know that almost all households use much more electricity than mine, so as long as they plan to live in the same house long enough, as long as they have proper financing (as you mentioned), this system is great It may be worth it for most people.
Going off the grid to avoid daily service charges is almost always a false economy. From a financial point of view, it almost always makes more sense to stay connected to the grid and charge feed-in tariffs, and the environmental benefits of sending clean energy to the grid are huge. But I can understand the considerations of Western Australians because the feed-in tariff for new solar power there is now so low. (It may be less than 4 cents per kilowatt hour on average.)
My problem with BIIIG is to do this, I need a triple MPPT inverter East/North/West. Do you have?
I can install about 5.4k/w on NORTH/WEST, but East can easily increase it by a third.
There are residential inverters that provide three MPPTs. Goodwe is an example of an inverter manufacturer that produces them. Using a flexible inverter (such as Fronius), where appropriate, the solar panels can also be faced in three directions, and there are only two MPPTs.
If you want to know, for three directions with two MPPTs, what you especially need is an inverter that can withstand enough current to support two parallel solar panel strings (for example, Fronius).
This allows you to connect two parallel strings to the same MPPT input, as long as the two strings have exactly the same number and type of panels and are not shaded, then the optimal operating voltage of each string will be close enough to cause loss of operation It is trivial on the same MPPT (maybe less than 1%). It works because the optimal voltage actually does not change much under different lighting, but the optimal current does, and arranging the panels in this way allows different directions to work at the same voltage, but different currents may be very Close to the best of them both at the same time.
It may still be much easier to use only inverters with three inputs or stick to a slightly smaller system and inverters with only two directions, but it is possible under the right circumstances.
For more information, please visit https://www.solarquotes.com.au/blog/an-eastwest-spit-of-solar-panels-on-a-single-string-can-work-well/.
When considering the inverter output of the marginal power generation time of the day and the total life output of the solar system, the relationship between the internal resistance of the inverter and the size of the inverter may also be a consideration.
When it comes to solar photovoltaics, "go big or go home" seems to be the usual recommendation, but I can't help but think that the size of the system should still be suitable for the actual and expected energy consumption and consumption patterns of the family.
Given that a large number of households will only use a small part (about 20%) of their solar photovoltaic power generation, and the FIT is still falling, there must be a period of time when it becomes bigger and less attractive.
In addition, higher FITs are usually limited to smaller photovoltaic systems.
Take a look at the high FIT solar plan of the electricity retailer. All high-FIT plans have restrictions on the system size, usually under 10kW (peak panel capacity). Or they have a stepped FIT model, where FIT is reduced after a certain amount of kWh is output every month.
If you have a large photovoltaic system, then high FIT will be a thing of the past.
A 10kW system that costs US$10,000 will generate approximately 140,000kWh of electricity in 10 years at approximately 7c/kWh (prepaid). Yes, it may last longer, but not everyone will stay at home for that long.
Given that FIT now tends to be about 8c/kWh, and may be reduced (although not zero), if your home's photovoltaic self-consumption rate is low, then unless you have a way to also significantly increase your self-consumption rate.
However, the incremental cost of additional panels is often lower. Therefore, if the cost of 10kw is US$10k and the cost of 6kw is US$8k, then you will get an additional 4kw of US$2k, which is only 3.5c. A FIT of 7c per kWh is sufficient to prove that even if there is no self-consumption (although the additional self-consumption will be very low, there will always be some additional self-consumption).
Costs obviously vary based on many factors, but if you want to use your logic, then you should look at the cost per kWh based on the additional cost of the larger system, no matter what your scenario is, not the overall per kWh cost.
Uh, I just want to know why the two local brands that are sold across the country, Victron and Selectronic, have disappeared?
My brother has two 5 kW Victrons in his new 4 inverter 19 kW array + 10 kWh battery installation, and I am looking for a larger Selectronic battery inverter and a PV inverter.
Going down from two in each inverter to a battery inverter and a PV inverter will lose redundancy, that is, fault tolerance. Therefore, I think the 4 inverter installation is more robust when off-grid. But there are always generators.
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1. Preferred real name-you should be happy to add your name to your comment. 2. Put down the weapon. 3. Assume positive intentions. 4. If you are in the solar industry-try to understand the truth instead of selling. 5. Please keep the theme.
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