Why Does The Biggest System Not Have The Largest Savings
There may be days throughout the year where you consume more energy than your solar system produces, and days where you consume less. Many electric utilities add up all the excess energy that you generate during the year, and subtract it from your total energy consumption during that year. You only have to pay the difference. This is called net metering.
Some utilities will not give you full credit for generating electricity beyond what you consumed that year. Therefore, to maximize your savings, you want to base your system size on your expected electricity usage, without generating a lot of net excess over the year that you cant use.
Our recommended system size on your order is based on offsetting your current energy usage, determined by the average electric bill that you enter. If you plan to add an electric vehicle or other electric appliances in the future, you may want to consider getting a larger system size.
How Much Do Solar Panels Cost
These are a few main factors that will determine exactly how much it will cost to install solar panels on your home:
- Your homes average utility costs and energy usage
- Your rooftops solar potential, or the amount of sun it receives yearly
- The average local cost for a solar panel system in your area
- The average labor costs and demand in your area
- Local incentives and rebates you could receive
Keep in mind that the cost to install solar panels varies from state to state. However, according to the Department of Energy, the cost to install solar panels is dropping nationally year over year due to new solar energy initiatives.
Solar costs dropped dramatically in the last few years, when the Chinese government influenced the worldwide solar market by pouring low-cost financing into the sector, which boosted solar panel manufacturing more than ten-fold. The DOEs goal is to cut solar installation costs by half by 2030, which means now is the time to invest.
Finding The Right Installer For A 10kw Solar System
To find the best installer for your 10kW solar system, you should get multiple quotes from different solar companies. You can then do a solar quote comparison, which will help you get the best price for installing solar panels on your roof.
Start with local installers with licensed contractors in your area, as they can give you personalized service, and they typically have a good understanding of what incentives are available in your area.
We make it easy for you to find the best local solar companies and certified contractors in your area, thanks to hundreds of customer reviews and our state-of-the-art solar calculator.
How much can you save annually by going solar?
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The Output Of A 7kw Solar System
According to the Clean Energy Council guidelines, a 7kW solar system in Sydney facing north will produce an average of 28 kWh a day, outputting more power in summer and less in winter. We have found that this guideline is a conservative estimate and that by using the top brands you can get considerably more out of our system, for example, our Enphase systems give our customers on average 110% of expected output. On an average day in summer, a 7kW system will give our customers around 35-40 kWh of power. Because this can be too much power for many households, we often recommend considering battery storage so that any excess solar power can then be used during the evening.
How Will You Know How Much Electricity Your Solar Panels Generate

Your solar panels will come with a meter that will be placed in an accessible location within your home. This meter will record the amount of electricity being produced by your solar panels.
Some solar brands are also rolling out online monitoring tools, which means youll be able to see how much power your solar panels are generating with the click of a button on your computer or phone.
As solar panels require virtually no maintenance, it can be easy to forget about them once they’re installed on your roof. We’d recommend checking them regularly, however, to ensure they’re clean and in good condition.
It’s worth monitoring your meter frequently too, to make sure they’re generating the expected amount of power. If your solar panels’ power output is particularly low, it could be a sign of a problem.
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What’s The Payback Amount/time On A Solar Electric System
The simple math says that the system costs $5540 and pays back around $340 per year in energy savings. That equates to a 16 year payback. Overly optimistic salespeople will try to say that there is cost inflation of 4% to 6% annually, but it is more like 2% depending on where you live. Some places it is as high as 6% some things you need to research for yourself. That is not to say that the costs of power cant or wont jump unexpectedly. I just dont subscribe to the overly optimistic approach it makes customers unhappy when they dont see the return they were promised. If rates do jump, then your payback gets accelerated. If I run a spreadsheet for the modified internal rate of return with a borrowing rate of 3% and a reinvestment rate of 6% , it comes back with a 5% return on the investment without factoring in utility cost inflation.. These savings are post-tax not pre-tax.
Remember the economy of scale from economics class? This is a small system so the payoff is longer larger systems return their investment faster.
Number Of Solar Cells And Solar Panel Size
To make things easy, we can divide solar panels into two size groups: 60-cell solar panels and 72-cell solar panels. Usually, 60-cell solar panels are about 5.4 feet tall by 3.25 feet wide and have an output of about 270 to 300 watts. On the other hand, 72-cell solar panels are larger because they have an extra row of cells, and their average output is somewhere between 350 to 400 watts. 72-cell panels are usually used on larger buildings and in commercial solar projects, not on residential homes.
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How Many Watts Of Energy Does A Solar Panel Produce Individual Products Compared
The graphic below presents a view of power output from many of the manufacturers who supply solar panels to the U.S. market. Because panel manufacturers often produce more than one line of solar panel models, the power output of most companies has a significant range. The table below lists the minimum, maximum, and average power outputs of the solar panels within each manufacturers portfolio.
Electricity output of solar panel manufacturers
Solar Panel Manufacturer |
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Kw Micro Inverter System
Solaray is the largest and most experienced installer of Enphase Micro Inverter systems in NSW, and our system design team are experts at putting together a solar array that will maximise solar output in all conditions.
The main benefit of microinverters is that each panel is independent of the others, making it possible to design an array across different orientations and at different angles. A common panel layout is to have some panels facing north, and the others west to spread the output of solar power across the day, making it easier to use more of the solar power as it is generated. Having panels west is also advantageous if you are on time-of-use billing, where households typically pay around 50c per kWh between 2 pm and 8 pm for power on weekdays.
Find out all you need to know about Enphase: 10 key benefits of microinverter systems.
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Calculate The Number Of Solar Panels
Now were at our last step. We know our system size, so its very easy to figure out how many solar panels youll need to install on your roof. The typical residential solar panel is around 275 watts, so just divide your total system size by the solar panel wattage.
For my own home, I simply divide 1.8 kW by 275 watts and find I would need 7 panels to cover my entire energy use. The average US home would need 28 panels.
Calculate the number of panels
7600 watt system / 275 watt panels | 28 panels |
And there you go. Thats it. Figuring out exactly how many solar panels you need is actually quite simple!
How Many Solar Panels Does A House Needs
To calculate your solar requirement you have to perform the following steps
Lets see an example to get the idea crystal clear.
You look into your latest electricity bill and find out monthly consumption for the last 12 months is as follows 500,120,300,400.600.550,100,800,600,300,450,400.
Lets take an average of these 12 values to get average monthly requirement of power.
Average = Sum of values / No of values.
In our example sum of values = 5,120
No of values = 12
Hence average is 426.66 KWH
So your house needs on an average 427 KWH of electricity every month.
Now we know that average monthly generation of power from 1 kW of solar is 120 KWH
Therefore your solar requirement is 427/120 = 3.55 kW.
If we assume you are planning to use 330 Wp of solar panel then no of solar panels required to power your house with solar will be 3550/330 = 10.75.
We can round it of to 11 solar panels each of 330 watts.
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Factors That Determine How Many Solar Panels You Need
You may think that the size of your house determines how many solar panels you need, but it doesnt! To really understand how many solar panels your solar energy system needs, you need to determine the following:
- Your energy usage: The more electricity you use, the more solar panels you need to cover your electricity costs
- Sunlight in your area: Homes in areas that receive less sunlight will need more solar panels to eliminate their electricity bills than those in sunnier states. As a rule of thumb, the southwestern United States gets the most sun in the country, while the northeast gets the least
- Panel wattage: The wattage of the solar panels you choose, also called the power rating, determines how much energy the panels will produce and most solar panels installed today have a power rating of about 320 watts per panel fewer panels are needed when you install panels with high wattage ratings
Below, solar expert Will White breaks down everything you need to know to figure out how many solar panels you need to power your home.
Understanding Your Electricity Usage

You can’t correctly size your solar PV system unless you know how much electricity your home uses now . The easiest way to figure this out is to look at past electricity bills, which should tell you how much power you’ve used in the previous month or quarter. From this you can figure out the average daily usage. This is even easier if you have a smart meter installed you should be able to see your daily usage either on the bill or by checking your account online.
Your power consumption is measured and billed in kilowatt-hours .
A typical Australian home uses 1520kWh per day. But households can vary considerably in their electricity consumption, depending on the number of people living there, the area they live in, whether they use gas for cooking or hot water, and many other factors. For example, a single-person home will typically use about 812kWh per day on average, while a household of five people with a pool could use 3040kWh per day.
Time of day and seasonal usage
It’s important to consider when you use electricity. Is your home generally empty during weekdays, with everyone at work or school, so that your main power consumption comes in the evening? If so, your solar panels might not be used most effectively, as it’s better to use the generated power during the day than export it to the grid.
Also consider whether some days are more power-hungry that others the weekend for instance, when everyone is at home. And do you use more power in summer or in winter ?
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What Roadblocks Are There To Filling Your Roof With Solar Panels
Besides the obvious , the other obstacle preventing you from maxing out your roof with panels are limitations set by your Distributed Network Service Provider, or DNSP.
You can see all of the DNSP rules for each state here.
But, to use an example, here in South Australia, SA Power Networks is our only DNSP.
They have set system size limits of:
- Single-phase homes: 10 kW inverter limit, 5 kW export limit.
- Three-phase homes: 30 kW inverter limit, 15 kW export limit.
Meaning if you have a single-phase home in SA, you could have up to 13.3 kW of solar panels on your roof with a 10 kW inverter. Remember you can oversize an inverter by 33%. But youd be export limited to 5 kW
Export limitations mean your inverter will intelligently ramp down solar power production to ensure a maximum of 5 kW is sent to the grid at any one time.
Some homeowners ask me If my energy needs are low-to-moderate, isnt it pointless to install a large system if Im export limited?
The answer, surprisingly, is no. You lose less generation than youd expect with export limitation due to a variety of factors.
How Long Will A 3kw Battery Last
The battery stores abundant power created from solar system panels during the day so that it can be used during the night. Various other elements decide how much energy is being used at a given time and how your battery will act over the long period of usage. If your requirement is 12kW during an entire day, you will need a battery that can store at lead 10kWh of energy for use when the sun is notshining. The energy stored will cover you for 24 hours.
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Can You Install Your Own 10kw Solar System
Yes, you can buy DIY solar kits to install a 10kW solar panel array on your own.
10kW solar DIY kits often sell for between $12,000 and $24,000, which is slightly cheaper than the installed price you would get with a solar company. However, DIY solar can be dangerous if you dont know what youre doing.
Plus, creating the right system design, including the location of the panels and which solar inverter to choose can be quite challenging. Sometimes, installing panels yourself can even void the warranty on the panels.
Youll oftentimes need the help of a solar industry professional or a licensed electrician in order to properly install a DIY system and pass inspections, which can actually cause you to spend more money than if you had just gone with an installer in the first place.
Find out if installing your own solar panels is right for you by checking out this blog.
How Much Does A Solar Power System Produce
One of the biggest misconceptions people have when sizing up a solar system is to think that a solar power system produces its size, for example, a 5kW solar system will produce 5kW of power at any one time.
The reality is a 5kW system will output a bit less than that, with peak output on a good day being somewhere between 4kW and 4.7kW during the middle of the day, and a less in the morning and afternoon:
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How Much Electricity Does One Solar Panel Produce
Before we start with the calculation lets get used to some basics terminology
- Watt and kilowatt are units of power. It basically shows the rate at which power is consumed by a device. For example a 100 watt TV will consumes power at a rate of 100 watts per hour. 1 kilowatt = 1000 watt.
- Kilowatt hour is the actual energy consumed by the device in an hour. For example a 100 watt TV running for 24 hours consumes 100 watt x 24 hours = 2400 watt hour or 2.4 kilowatt hour of electricity a.k.a 2.4 units of electricity.
For more detailed explanation check this article What is watt, kilowatt and unit of electricity?
On an average in India we receive 5 sun hours in a day so the total power generated by 1kW of solar is 1 kW x 5 hours = 5 kilowatt hour .
This is an ideal figure which considers uniform solar irradiance throughout the day, proper installation with best orientation, angle of tilt and no shadow impact on solar panels for 5 hours without any dust accumulation on surface.
If we calculate for ideal condition then average monthly power generation from solar panels will be 5 KWH X 30 Days = 150 KWH of electricity.
But not all days are equal some day we will get sunlight some day we wont, some days the panel will be clean and some days they wont be, hence we will assume 20% loss of power which gives us average daily generation for 1 kW solar panels to be 4 KWH of electricity and monthly generation to be 120 KWH of electricity.