3kW Solar System Load Capacity

Is your electricity bill sky-high? Thinking about switching to greener energy sources? Going solar is a top-notch option to think about. Choosing a 3 kW system might just be the perfect fit, whether you’re new to the solar game or have a smaller pad. Still, it’s crucial to get your head around what the system can do before you get it set up.

  1. A 3-kilowatt (kW)1 solar system has a capacity of generating 3 kW of power under ideal conditions. It does not have a load capacity of 12 kW. Load capacity refers to the maximum amount of power that can be drawn from the system, not generated by it.
  2. A 3 kW solar system typically produces around 12 to 12.5 kilowatt-hours (kWh) of electricity per day. The daily output can vary based on factors such as location, weather conditions, and system efficiency.
  3. The monthly production of a 3 kW solar system would then be approximately 360 to 375 kWh, assuming consistent daily production.
  4. The annual production of a 3 kW solar system would be around 4,300 to 4,500 kWh.
  5. While a 3 kW solar system can indeed power a two to three-bedroom home or a small business, the actual suitability depends on factors such as energy consumption patterns, efficiency of appliances, and geographic location.

Read on to learn more about the load capacity of a 3 kW solar system.

3kW Solar System Load Capacity

The load capacity of a solar system is how much electrical load it can handle. This electrical load is all the electrical appliances like TVs, Light bulbs, washers, dryers, etc. operated in that home.

Anything that uses electricity is an electrical load on the system. The more appliances connected to the solar system, the higher the electrical load will be.

A 3 kW solar system has an electric load of about 375 kWh or 12 kW. It is enough to power an average-sized house with a home pool or a small business. The 3 kW solar system can power2 Led Lights, fans, a fridge, a microwave, a washer, a dryer, a split air conditioner, an HP motor, LED TV, and a water dispenser.

What can I run on a 3kW solar system?

For an average two-three bedroom home, the above-listed appliances are common place. A 3 kW solar system can support an electrical load of 12 kW daily. The total above comes to 11.900 Watts (11.9 kW) and can be run by a 3 kW solar system.

Here is a detailed table of what you can run on a 3kW solar system.

ApplianceWatts per hourAvg. Hrs used dailyTotal Watts
10 LED lights for a 2-3 bedroom house706420
Split Air conditioner320026400
1 LCD televisions305150
Washing machine5000.5250
1 Laptop1006600
Total 11,964

Note; The average hours depicted below are an estimate of the average household and may be less or more than yours so make sure to evaluate when calculating for your household.

How much power does a 3 kW solar system produce?

The 3 kW solar system is one of the best choices2 for many average households. It can also accommodate small businesses.

The amount of power generated by a 3 kW solar system will differ from place to place with some having a higher output and others having lower outcomes. This is due to different factors such as the number of solar panels and batteries, the amount of sunlight daily, the weather stability of the area, and many more.

Places with high levels of daily sunlight are likely to have higher outputs than areas with less sunlight. Areas with more sunny months have a higher annual output than areas with less sunny months. Homes with more solar panels and solar batteries are likely to have higher outputs than those with fewer solar panels and batteries and so on.

How many solar panels do I need to charge a 3 kW battery?

For a 3 kW solar system, usually 12 solar panels of 250 W3 each are required with around 20 square meters of roof space. However, with the advent of more powerful panels, such as those around 415W, the number of panels required and the corresponding roof space may vary. Also, this configuration is commonly used in residential and small commercial installations. The actual amount of solar panels is determined by a lot of factors such as roof space, cost, etc.

If you have a 3 kW solar system, the number of solar panels required will depend on the following factors.

How many solar panels do I need to charge a 3kW battery

1. Efficiency rating of the solar panels

The higher the efficiency of the solar panels, the less you will need4. For example, if you purchase 250 watts of solar panels, you will need 12 solar panels for a 3 kW solar system (250 W x 12 = 3 kW).

However, if you purchase 375 kW solar panels, you will only require 8 solar panels for a 3kW solar system (375w x 8 = 3kW).

2. Available roof space

If you have a small house or your roof is occupied, you may need to go for high-rating solar panels to reduce the number of solar panels5 needed and reduce the amount of roof space required to install them.

Given that residential solar panels typically range between 330 watts and 400 watts nowadays, a 3-kilowatt (3,000 watt) solar system will necessitate approximately 7 to 10 solar panels. With each panel typically measuring around 1 meter by 1.7 meters, a 3 kW system will occupy roughly 12 to 17 square meters6 of roof space, contingent on the wattage of the panels.Solar panels should be south-facing when installed.

3. Price point

While solar panels with high ratings and efficiency are better options, they are not the most affordable. The higher the rating and the efficiency, the higher the price.7

So if you are on a budget, you can decide to go for a few high rating and low efficiency solar panels or more low rating and low efficiency panels. Ask your solar installer for advice on the best options for your home.

4. Location

If you live in an area with abundant sunlight, whether your solar panels are low or high rating, they will receive enough sunlight for a 3 kW solar system.8

However, if you live in a less-sunny area, you may require more solar panels. This may be to increase the surface area exposed to the sun to capture more sunlight, enough for a 3kW solar system.

How many batteries do you need for a 3 kW solar system?

There are different types of solar batteries available on the market, however, the lead-acid battery is one of the best choices. For a 3 kW solar system, you will need a battery of voltage 24 Volts, and a current of 125 Ampere (3000W/24V=125A).9

For a 3 kW solar system, to run a full load for a long time, we suggest you use 125A*10H=1250AH, 13 batteries in parallel. If it is 48V, it needs 14 batteries, 7 in parallel and 2 in series.

The size of the solar battery required can be calculated based on the load Amp hour & required backup time. However, a 30 – 50 Ah Battery is sufficient for a 3kW solar system. If the battery banks you want to purchase are also 50Ah, you will need six of them for a 3000-watt inverter.

To know how long a 3kW battery will last, simply calculate the running time using the below formula;

Running time (h) = 3kWh / power consumption (W)

If you consider the average daily consumption of an Australian home, which is 12 kWh per day, and consider that you only really use energy about 16h a day (except the fridge, which runs 24h a day), then a 3 kWh would last about 2.5 – 3 hours after a full charge.

Is 3 kW enough to power a house?

Well, a 3 kW solar system is enough to power an average 2-3 bedroom house in Australia with 3-4 occupants10. For the above household described, the average power consumption can be covered by a 3 kW solar system.

Small businesses and offices can also employ the 3 kW solar system. However, whether or not a 3 kW solar system can power a house depends mainly on the power consumption of that home.

High wattage appliances such as air conditioners, pool pumps, etc will make the battery run down faster. So it is important to take note of how much power is used by your home before purchasing a solar system. Larger homes and businesses may need to purchase a 5 kW or an 8 kW solar system depending on their power needs.

How much does a 3 kW solar system cost

Well, if you are considering purchasing a 3 kW solar system in Australia, the exact cost will depend mainly on where you live. For instance, a 3 kW solar system costs on average $4,500 in Hobart but costs only $3,900 in New South Wales.

The cost of a solar system in Australia depends on location. The location is very important as the solar rebate adjusts according to how much sunshine your postcode receives. The cost can also differ due to the difference in the quality of components available and the labor costs of different installation companies.

New South Wales$3,900
Western Australia$3,900
South Australia$3,755
Aust. Capital Territory$3,755

Is a 3 kW solar system worth it in 2022?

Whether or not a 3 kW solar system is worth it depends on whether or not it can meet your power needs. If you live in a 2-bedroom house, a 3 kW solar system should be able to meet your electricity needs.

However, people in larger houses use more power and will require a large solar system. If however, you are looking to just add a power source rather than fully substitute, a 3 kW solar system is affordable enough.

  1. Ben McInerney , (2024), 3kW Solar System with Battery Price: New 2023 Guide, Accessed on 28th April 2024: https://gosolarquotes.com.au/cost/3kw-solar-system/with-battery/
  2. Ana Almerini, (2024), How much does a 3kW solar power system cost? Accessed on 28th April 2024: https://www.solarreviews.com/blog/how-much-does-a-3kw-solar-power-system-cost-and-how-much-electricity-does-it-produce#:~:text=A%203kW%20system%20will%20produce,you%20live%20in%20rainy%20Washington.
  3. Solar quotes, (2024), 3 kW solar system, Accessed on 28th April 2024: https://www.solarquotes.com.au/systems/3kw/#:~:text=How%20many%20solar%20panels%20will,square%20metres%20of%20roof%20space.
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  5. Tamara Jude, (2024), How Many Solar Panels Do I Need? Accessed on: 28th April 2024: https://www.architecturaldigest.com/reviews/solar/how-many-solar-panels-do-i-need#:~:text=Most%20solar%20panels%20emit%20between,panels%20needed%20for%20your%20project.
  6. Jeff Sykes , (2023),3kW Solar Panel Systems: Costs, Output, and Returns, Accessed on: 28th April 2024: https://www.solarchoice.net.au/system-size/3kw-solar-system/#:~:text=As%20residential%20solar%20panels%20are,the%20wattage%20of%20the%20panels.
  7. ENERGY.GOV, (N.a), Solar Performance and Efficiency , Accessed on : 28th April 2024, https://www.energy.gov/eere/solar/solar-performance-and-efficiency
  8. Liam McCabe , (2023), What’s the best direction and angle for solar panels? , Accessed on : 28th April 2024, https://www.energysage.com/solar/solar-panel-performance-orientation-angle/#:~:text=South%2Dfacing%20panels%20give%20you%20the%20most%20bang,south%2C%20so%20the%20panels%20get%20more%20sunlight.
  9. Marketing-CNBOU , (N.a), How many batteries do I need for a 3kW off grid solar system? , Accessed on : 28th April 2024, https://www.cnbou.com/products/how-many-batteries-do-i-need-for-a-3kw-solar-system.html
  10. Nishi ChandraJan , (2024), Is 3KW of Solar System Enough for a Home? Accessed on : 28th April 2024, https://www.loomsolar.com/blogs/collections/is-3kw-of-solar-power-system-is-enough-for-a-home
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