The solar array you need to power your washing machine and air conditioners is significantly smaller. In all likelihood, it will fit snugly on the roof of your house. Fabulous! As more Australians begin to explore the benefits of running their homes on solar energy,"What size of solar system do I actually need?"is by far the most common question from solar dealers and installers.
Ultimately, it's a question of numbers. But luckily for us, the numbers are pretty easy to digest, unlike the ridiculously large numbers required to measure space.
This article is all about helping you understandsize in solar terms. After reading this article and the accompanying links, and becoming familiar with a few simple terms, we are confident that you are sufficiently enlightened and much more familiar with solar sizing.
In fact, we think you'll have a pretty good idea of the size of solar system you need to buy to power your home now and in the future.
How to use this article
For many readers, some terms and languages will sound completely foreign - that's to be expected. This is relatively new technology in domestic terms, and much of the language hasn't made it into everyday conversation. Few of us use words likeKilowattor"photovoltaic"in one sentence.
Throughout the article we provideLinks to definitionsand other key terms that will enable you to become a solar lingo legend. Used in context, this language will begin to make sense to you.
Follow the links and do your best to familiarize yourself with the definitions. They are presented in a way that you and I can understand. You don't need a scientific degree - we want to create understanding. Solar is for the people.
Before you begin you need a few things. A recent utility bill, a pen, your thinking cap, and a jar of something tasty. Oh, and make sure your husband is out in the garden, he only makes things more difficult.
So where do I start?
When you first venture into the solar industry, you will find that questions lead to questions. From here we can hear you thinking. Do I need a 5kW system? What is 5kW anyway? How much power will a 1 kW system give me? Our roof area is not that big, how many solar panels will we need? Only two people live in our house, can we get a really small system and save money? All good questions.
The first option you have is to call a retailer or supplier and rely on them completely for all answers, information, calculations and advice.
A good retailer and installer is worth their weight in gold and can offer fabulous clarity and understanding.
However, a good option is to have your own workable understanding of solar size.This way you have a better chance of sorting the players from the pros. We cannot recommend that you blindly start your negotiations with suppliers if it can be avoided.All right, let's get started
There are a number of variables that need to be considered to determine what size solar system you need.
The two critical factors are the amount of electricity you use during the day and whether you install a battery to power the house at night.
1. How much electricity do I use?
This is where you need your electricity bill. Yes, we know it hurts to look at — that's why you're making the switch to solar in the first place.
Your bill is howeverthe most important tool to determine how much electricity you use.
OK, so from here we'll assume you've just earned a B+ in understanding utility bills and gone through yours. Brilliant.
The key number on your bill is the number that states your annual electricity consumption in kWh (kilowatt hours). Divide this number by 365 and you get the figure for your daily electricity consumption. Write that down.
A quick note on comparisons and relativities
It is important to consider the need for electricity in relation to the number of people in the house. It's a consideration, yes, but it can be misleading.
Here's an exaggerated example to illustrate a point.
Robert, your neighbor, lives alone. But Robert has an Olympic-size pool in the backyard that he heats, and it's lit by halogen lights big enough to glowthe gabba. It also has air conditioning that runs 24 hours a day.
He just installed a ferris wheel the size of the London Eye for the grandchildren. He now wants to set up a bumper car ride for said grandchildren and a particle accelerator for his own scientific entertainment.
You, on the other hand, have 5 people in your house. The family grills for dinner every day, religiously, and it's wood-fired. There are no air conditioners - they use fans. The hot water is gas, there is no pool and no garden lights or clothes dryer.
In fact, the whole family now uses candles to light the house to reduce your carbon footprint and you still use your great-grandfather's ice box for cooling. Plus, you're happy with it and don't plan to change your habits any time soon.
Apparently, Robert's sole power requirements far outweigh the needs of your 5-person household.
Obviously we used some fun exaggerations to get the message across here. Looking at other people's solar systems can be useful for guidance, but you need to understand your household usage to determine what size solar system you need.
2. When do I use the most electricity?
Think about how you work at home. Do you use the washing machine and dryer during the day or in the evening? Do you run the air conditioner at night or during the day?
In general, most people use most of their electricity in the morning and early evening. It's also important to note that you're out most of the day? Kids at school, mom and dad at work? Or are you retired and spending a lot of time on it?
Take notes on your daily habits, the habits that need power. Your installer will find this very handy when determining what size solar system you need.
3. Future Plans
Your electricity bill provides a very accurate measure of the electricity you are using now and your historical needs. But what about the future?
Make notes about your plans. This information is also very important for your dealer. Do you intend to install a pool? How large? will you heat it
Do you get ducted air conditioning? Are you planning a large family? Are you renovating your kitchen and adding larger, more power-hungry appliances?
Right off the bat, you can install a system that can handle your future needs. Alternatively, you can upgrade the solar system to meet current requirements to ensure there are options for upgrading and expansion in the future.
4. Solar calculator
With the proliferation of home solar energy, a wonderful array of useful resources have emerged to help consumers.
Solar calculators have been developed to give you a solid insight into your solar needs. And all you need are a few readily available numbers.
Follow these links to an independent solar calculator.
This link will take you toa solar calculator that measures the amount of electricity you need.
Note: For this calculation you need to know the pitch or slope of your roof. Mathematical or spatially aware people can make a pretty good guess.
For the rest of us, grab a protractor from your kid's pencil case and hold it for an approximation of the roofline.
You also need to know the orientation of your home. Do you face north, south, east or west? If you are not sure, take a look at a street map.
The map shows the orientation and you can determine in which direction your house is facing.
This link will take you toa solar calculator that suggests a solar system size to you.
It is important to note that the numbers provided with these calculators are nominal. It is almost impossible to give exact numbers, as each situation depends on several factors. Some of the variables affecting the numbers
· Your location affects the productivity of solar panels. Some areas are sunnier than others. Most calculators take this into account.
· Shadows above your roof also affect the efficiency of the modules. Calculators do NOT take this into account.
· ThePitch or slope of your roofalso determines the panel efficiency. Many calculators take this into account, but the numbers are determined by the accuracy of your measurement.
· TheQuality, type and capacity of solar panelsare big variables. The panels you install will largely be determined by your budget.
· The available roof area also plays an important role in the size of your solar system.
· TheUse of house battery poweraffects the required system size. Most solar calculators will ask you if you intend to use battery power.
Solar only? Or do you use a battery to power your home in the evenings?
Yoursolar systemgenerates electricity only during the day. It needs the sun. To maximize the value and savings of solar energy, battery power is ideal.
With an appropriately dimensioned solar system, excess electricity – i.e. electricity for devices that is not used during the day – is fed into the house battery.
When the sun goes down, a fully charged battery will take over your home's power needs. Yes, even though the sun has gone down, you will still be powered by solar energy. Brilliant.
It goes without saying that if you want to use battery power, you'll need to generate excess electricity during the day. It is likely that a larger solar array will be required to generate this surplus.
how big is big Put size in perspective
Common domestic solar systems generally range from 1.5 kW to 10 kW. There are variations on this, but 1.5 to 10 and everything in between is fairly common in Australia.
The 1.5 kW system
A typical 1.5kW system requires 6 panels assuming 270 watt panels. The panels are approximately 1600mm x 1000mm. An arrangement of 6 panels requires approximately 10 square meters of roof space. This system will generate an average of 6.3 kWh per day (averaged over seasons and locations).
This is indeed a small system and will only meet minimal power requirements. It is unlikely that a battery would be recommended for a system of this size. It is suitable for a small house with two bedrooms and air conditioning.
The 3kW system
A typical 3kW system is often chosen by many humble working class families in Australia.
It accounts for normal power consumption, including things like a standard-sized in-ground pool and some air conditioning. A 3 kW system generates approximately 12.6 kWh per day.
You need 12 panels with 270 watts per panel. The panel size is 1600mm x 1000mm and requires approximately 20 square meters of roof space.
The 10kW system
The 10 kW system is suitable for a very large family with high power requirements. You may have a large inground pool that requires multiple pumps and you may have 4 to 5 bedrooms with ducted air conditioning and under floor heating.
Typically you have mother, father, extended family e.g. Grandparents, 3 to 5 kids and a bunch of regulars.
A 10 kW system requires 37 solar modules and a roof area of around 64 square meters. They will likely feed electricity back into the grid or cover evening household needs on the battery. There is no doubt that this is an expensive array. A 10 kW system generates up to 42 kWh of electricity per day. That's big.
To give you an idea, this array can power up to two ducted air conditioners, multiple pool pumps and 30+ freezers. Yes, wow!
Look again at the numbers on your bill and the answers from the solar calculators. Now compare them to the Putting Size in Perspective section above.
By now you should have a pretty strong indication of what size solar system you need to power your household now and in the future - and how big is big.
Of course, this process seems like a lot to go through. For many of us, such calculations tend to rack our brains, or at least make us nervous.
However, it's much easier to digest when we consider that switching to solar will save us a lot of money.
In the long term, this will result in significant savings. Better still, we can significantly reduce our carbon footprint.
For the majority of Australians there is a solar system that perfectly suits our needs. Now that you know the size you need, it's time to take the next step.contact us today!
Interested in solar energy? By clicking below you can use our smart solar calculator to find out how much you can save with solar energy, what discount you are eligible for and your impact on the environment.
Don't wait for next quarter's bloated bill and get started today!
Click here to calculate your solar savings!
Join over 20,000 homeowners who have switched to Instyle Solar or the 1000+ positive reviewers who have been more than happy with their solar system.
Otherwise you can always contact us at1300 133 556, or email if you prefer firstname.lastname@example.org.
You can calculate how many solar panels you need by multiplying your household's hourly energy requirement by the peak sunlight hours for your area and dividing that by a panel's wattage. Use a low-wattage (150 W) and high-wattage (370 W) example to establish a range (ex: 17-42 panels to generate 11,000 kWh/year).How big of a solar system do I need for off-grid living? ›
If your energy needs are around 1,000 to 5,000 watts, go for a 24 volt system. If your energy needs are over 3,000 watts, go for a 48 volt system. Large off-grid houses often use 48 volt systems.How many solar panels do I need for emergency power? ›
To meet the average requirement of 29.33 kWh of electricity per day for your household, then, you'll need 17 solar panels. Of course, this is just one example. To find out how many solar panels it would take to power your off-grid system, schedule a consultation with SouthFace Solar & Electric.How many solar panels do I need for a 2000 square foot house? ›
Thankfully, we've got the answer for you! A 2000 square foot house will need 28- 34 solar panels, which comes out to an average cost of \$3.50 per watt. Not only will installing solar panels save homeowners money on their electric bill, but they can also increase the value of their home.How much will a 5kW solar system save me? ›
Using this number and multiplying the estimated system output by how much you pay for your power, you can see that with an investment of around $6,000-$8,000 for a 5kW solar system you can save up to & over $500 a quarter, and an impressive profit of $54,300 over 25 years on your power bills!How much power does a 5kW solar system produce per day? ›
How much electricity will a 5kW solar system generate? A 5kW solar system will generate approximately 20kWh per day, depending on your location and a variety of other factors.How many batteries and solar do I need to go off-grid? ›
If you want to save the most money possible, you'll need enough battery storage to cover your energy usage when your solar panels aren't producing – somewhere around 2-3 batteries. If you want to keep the power on when the grid is down, you'll usually just need one solar battery.How many solar panels and batteries are needed to run a house off-grid? ›
|Average Monthly Electric Bill||Solar System Size||Number of Panels (Based on 200W Panels)|
|$60||5 kW||26 panels|
|$120||10 kW||52 panels|
|$240||20 kW||105 panels|
|$600||50 kW||255 panels|
Using Tesla Powerwall batteries with 95% depth-of-discharge, that means you'll need a storage system with a total capacity of about 111 kWh, which comes out to a little less than 8 individual Tesla Powerwall batteries.What is the 120% rule for solar panels? ›
The NEC, 120% rule states that solar PV systems should be installed in electrical boxes up to 120% of the busbar's label rating. For example, if the home's electrical meter rating is 175 amps, the rule allows an additional 20%, an equivalent of 35 amps from the solar system.
How long can a solar battery power a house? Without running AC or electric heat, a 10 kWh battery alone can power the basic operations of a house for at least 24 hours, and longer with careful budgeting.Can you get too many solar panels? ›
No, there is no limit to the number of solar panels you can have. However, there may be a limit on how much power your system is allowed to generate. Some utility companies limit the amount of electricity that a grid-tied solar system can generate.Can AC run on solar panels? ›
Yes, you can power an A/C system or supplement your power supply with solar panels. The size of the unit and other factors will determine the number of panels required to power the system.Can I run my entire house on solar power? ›
Can a House Run Completely on Solar Power? The short answer: Yes, you can use solar energy to power your entire house. In fact, some people have used expansive solar panel systems to go off the grid completely, turning their homes into self-sustaining ecosystems (at least as far as energy is concerned).How much does Tesla solar panels cost? ›
For an average-size home, you can probably expect to pay $15,000 – $20,000 for a solar unit. Tesla solar panels are actually a little cheaper, averaging about $2,000 per kwh of solar capacity. Tesla solar has four different system sizes, and Tesla's costs range from $8,200 – $32,800.Will solar panels get cheaper in 2023? ›
Solar costs are very likely to decrease in 2023, making rooftop renewables affordable for more homeowners. In November 2022, the National Renewable Energy Laboratory (NREL) published its analysis of the cost of solar and energy storage (battery) system installations for the first quarter of 2022.Is 5kW enough to run a house? ›
In conclusion, a 5kW solar system can be sufficient for a home with an average energy usage of 3,000 to 4,000 kWh per year. However, it's important to consider the energy usage of your home and the weather conditions in your area before making a decision.How long until solar pays for itself? ›
The most common estimate of the average payback period for solar panels is six to ten years. This is a pretty wide range because there are many factors that will influence the number of years it can take to pay off your panels and the monthly savings you can expect.How many AC can 5kW run? ›
A 5kW solar power system is sufficient in supporting the electricity needs of a 2BHK, 3BHK and any other medium-sized houses with 2-3 ACs. It is a medium-capacity solar system for homes that has the capacity to generate up to 20kWh (units) of electricity.How many batteries required for 5kW solar system? ›
A hybrid inverter 5kw would require a minimum 450 to 500 ah 12 V battery. Alternatively, you can have two separate batteries of 250ah 12V that would power the system for 30 to 45 minutes.
You can run a washing machine, air conditioner, fridge, water heater, oven, and TV with a 5kw solar system. If you have these appliances in your home, a 5kW solar system is sufficient. It produces 20kWh per day.How big of a battery bank do I need to be off-grid? ›
In a typical off grid cottage application, you would have a 24 or 48-volt battery bank which is somewhere in the range of 600 to 800 amp hour. They can go as high as 6,000 amp hour or more in larger systems.What happens when off-grid solar batteries are full? ›
What Happens When Solar Power Batteries Are Full? Solar power systems use batteries to store solar energy. However, if the power generated exceeds the solar battery's capacity, it can overcharge the system. An overcharged solar system can severely damage a battery's life.Will solar panels charge batteries when grid is down? ›
Since a grid-tied solar system must turn off (by National Electric Code) when the grid goes down, installing rooftop solar panels doesn't guarantee that you will have power during a grid outage. However, if you combine your solar system with battery storage you can tap into stored solar power during a power failure.Can you have solar with a battery and still be connected to the grid? ›
A grid-tied solar power system with battery backup is also known as a "hybrid solar system" because it provides a hybrid of the benefits of grid tie solar - using clean, renewable solar power as your primary source of electricity and selling excess power to the utility through net metering - with the benefits of off- ...Could solar and batteries power your home when the electricity grid goes out? ›
A solar energy storage system collects energy from the panels and stores the unused portion in a battery. At the very least, you can use the solar battery during blackouts to: Light up your home.Can you live off-grid with just solar panels? ›
Yes. Even large-sized homes can run completely off the power grid thanks to today's advanced solar technology. Large solar energy systems require many solar panels, which can be housed on a roof or even on a ground-level platform (assuming there's enough space).What is the 120% rule for Tesla Powerwall? ›
The NEC 120% rule limits the size of additional power sources (PV or battery) to within an acceptable safety limit based on the equipment label rating. In this case, the PV breaker would be limited to a maximum of 40 amps.How long will 4 Powerwalls last? ›
The Tesla Powerwall is a home battery that stores solar energy and can last up to 10 years with proper maintenance. The Powerwall can provide backup power during an outage, and it can help you save money on your electric bill.How long can Tesla Powerwall run AC? ›
It can run an air conditioner or heater while also providing power for other appliances. The built-in rechargeable battery offers up to 10 hours of backup power before requiring its next charge.
Fact vs Myth: Can Solar Energy Really Power an Entire House? [2023 Update] One of the most frequently asked questions by homeowners in regard to solar power is, “can it really power my entire house?” The answer to that is actually quite simple – yes, solar can indeed power your entire home.Do I need to upgrade my electrical panel for solar? ›
Although most newer homes do not need to upgrade their electric panels when installing solar, it is relatively common in older homes. Electrical service upgrades can also provide numerous benefits in addition to accommodating your solar panel system.What can a 170w solar panel run? ›
For a quieter, more peaceful outdoor experience, replace your generator with our 170-watt solar kit. This kit offers enough power to charge most single or dual 12-volt battery banks. Power your RV, boat or trailer with 170-watts, or expand it up to 510-watts for larger rigs and equipment.How many solar panels does it take to run a clothes dryer? ›
|Washing Machine||2,500 - 3,000 W||2|
|Dryer||2,500 - 3,000 W||1|
|Ceiling Fan||31 W||1|
|Vacuum||650 - 800 W||<1|
Most solar inverters tie you to the grid, so if the grid shuts down during a blackout, your solar panels also stop generating and providing electricity to your home. This is in part for the safety of repair workers, who need to know that busted electric lines are not carrying electricity from solar panels.What is the lifespan of a solar power system? ›
Solar panels, also known as photovoltaic or PV panels, are made to last more than 25 years. In fact, many solar panels installed as early as the 1980s are still working at expected capacity. Not only are solar panels remarkably reliable, solar panel longevity has increased dramatically over the last 20 years.What happens if my solar panels produce more electricity than I use? ›
In most cases, if your solar system generates more energy than your home needs at any given time, the excess energy will flow back to your utility. Your utility company may provide you with a credit for energy you send back to it. This credit is called net metering.Is it better to oversize solar system? ›
By oversizing the array, you will make better use of your inverter's capacity, producing more power overall. You want to find the “sweet spot” where you get the most overall production possible per dollar spent on your system – even if that means clipping a bit more power.Should I overbuild my solar system? ›
If you have a storage system, it makes even more sense to overbuild. Especially if you have a Powerwall or other storage system, overbuilding your rooftop solar could effectively make your electricity production and use self sufficient.How many solar panels are needed for a 2000 square foot home? ›
Thankfully, we've got the answer for you! A 2000 square foot house will need 28- 34 solar panels, which comes out to an average cost of \$3.50 per watt. Not only will installing solar panels save homeowners money on their electric bill, but they can also increase the value of their home.
A 2500-square-foot home will usually need between 24 and 30 solar panels to provide 1,023 kilowatt hours of power. This is based on the average consumption of power for a home this size.How many solar panels do I need to run a 3 ton air conditioner? ›
How Many Solar Panels To Run 3 Ton Air Conditioner? It would require around 15, 325 Watt solar panels to run a 3-ton air conditioner for 8 hours a day and around 22, 325 Watt, solar panels to run the AC for 12 hours a day.Do solar panels work on cloudy days? ›
Photovoltaic panels can use direct or indirect sunlight to generate power, though they are most effective in direct sunlight. Solar panels will still work even when the light is reflected or partially blocked by clouds. Rain actually helps to keep your panels operating efficiently by washing away any dust or dirt.How many solar panels and batteries does it take to power a house? ›
An average home needs between 17 and 21 solar panels to fully offset utility bills with solar. The number of solar panels you need depends on a few key factors, including your geographic location and individual panel specifications.How many solar panels does it take to fully power a house? ›
How Many Solar Panels Are Needed to Power My Home? The average home in the U.S. uses 10,400 kWh of electricity per year. If you install the average 250-watt solar panel, you'd need around 28-34 solar panels to generate enough energy to power your entire home.Why is my Tesla solar bill so high? ›
During spring and summer months, your panels will be exposed to the sun more often than during the fall and winter months. You may notice a higher bill in the summer when your solar system is producing the most energy. This energy is typically applied as a credit by your utility for usage later in the year.How much does a Tesla solar roof cost 2000 sq ft? ›
Though expensive—a two-story, 2,000 square foot, 11.28 kW Solar Roof costs just over $55,300 before incentives, assuming you're replacing the original roof—the roof is intended to save money in the long run by reducing or eliminating a homeowner's electricity bill entirely.Is a Tesla Powerwall worth it? ›
The total cost of Tesla Powerwalls may be expensive upfront, but they are worth the cost due to higher battery capacity and a longer lifespan. If you have solar panels installed and want energy independence, the Powerwall will help you get there as the system stores any excess energy the panels produce.How many solar panels do I need for a 1500 square foot house? ›
How many solar panels are needed for a 1500 sq ft home? A 1500-square-foot home, on average, will need between 14 and 17 solar panels to power the home. This is based on an average energy consumption of 967 Kilowatt hours per month.How many solar panels do I need for a 3000 sq ft home? ›
|Home size||Estimated annual electricity needed||Number of solar panels needed|
|1,000 sq. feet||4,710 kWh||8|
|2,000 sq. feet||9,420 kWh||15|
|2,500 sq. feet||11,775 kWh||19|
|3,000 sq. feet||14,130 kWh||23|
To generate 2000 kWh per month you will require 37 numbers of 400-watt solar panels if your city has 4.5-5 hours of average sunshine per day over a year. Moreover, if your city has 3.5-4 hours of average sunshine per day over a year then you will require 60 numbers of 400-watt solar panels.What can a 300 watt solar panel run? ›
What Can a 300 Watt Solar Panel Run? A solar panel delivering around 300 watts of power would be able to run things like ceiling fans, lights, rice cookers, phone and laptop chargers, a television or computer, and even electric fences.How many kW solar do I need for 2000 sq ft house? ›
|Square Footage||Electrical Usage (kWh)||PV Watts Needed to Cover 100% of kWh Usage|
As of January 2022, the average cost of solar in the U.S. is $2.77 per watt ($11,080 for a 4 kilowatt solar system). That means that the total cost for a 4,000-watt solar system would be $8,200 after the 26% federal solar tax credit discount (not factoring in any additional state rebates or incentives).How many kW does a 3000 sq ft house use? ›
Average kWh usage for a 3,000 square foot home: 1,840 kWh. Average kWh usage for a 4,000 square foot home: 2.200 kWh.How big of a solar system do I need for a 2500 square foot house? ›
A 2500-square-foot home will usually need between 24 and 30 solar panels to provide 1,023 kilowatt hours of power. This is based on the average consumption of power for a home this size.How many batteries do I need for a 10kW solar system? ›
In conclusion, a 10kW solar system typically requires a battery bank with a capacity of 20-30kWh, which can require between 100-150 batteries with a capacity of 200Ah each.Can 10kW power a house? ›
Is a 10kW solar system enough to power a house? Yes, depending on where you live, a 10kW solar system would be enough to power the average home of a family of four and enough to power the average 2,000-square-foot home in the United States.How much will a 10kW solar system produce? ›
How Much Energy Does a 10kW Solar System Produce? On average, a 10 kW system will produce about 1,255 kilowatt-hours (kWhs) of electricity per month, or between 13,400 and 16,700 kWhs per year. Just like with price, the amount of energy your solar system produces will vary depending on where you live.What will a 3000 watt solar panel run? ›
Given that the majority of your homes appliances will likely not be rated more than 1800 watts (unless you start looking at power tools). This means that a 3000 watt solar generator will be capable of powering pretty much all your homes appliances individually.
Assuming that it runs for 8 hours a day, you would need around 1600 watts of power every day or approximately 9600 watt-hours per week. To generate this amount of energy from solar panels, you may need anywhere from four to eight solar panels with a total capacity of around 2000-2500 watts.How much power can a 300W solar panel produce in a day? ›
About 2.5 kWh per day can be generated by a solar panel with a 300-watt output. Multiplying the speed by 365 days gives us a yearly total of about 900-kilowatt hours. A single 300-watt solar panel may produce 900 kilowatt-hours of energy.