How Much Electricity Does a 6kw Solar System Produce?

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Are you thinking of setting up an energy independent home? Powerful but affordable solar systems are now available for this purpose, but will a 6kw PV system be enough? This guide will answer your questions.

A 6kw solar system can produce 25 kilowatts a day and up to 750kwh a month. This is sufficient to power a small energy household.

How to Calculate 6kw Solar System Energy Production

A 6kw solar system may consist of 16 to 25 solar panels, depending on the size of each PV module. Keep in mind that the given output is for peak production, which will change depending on various factors.

For example, an array consisting of 20 x 250W solar panels can produce up to 25000 watts or 25kw a day with 5 hours of sunlight.

250 x 5 = 1250
1250 x 20 =25000

Other 6kw PV systems may consist of 16 x 350W or 20 x 300W solar panels. These will produce more power than a 20 x 250W array given the same number of sun hours.

350W x 5 = 1750
1750 x 16 = 28000

300 x 5 = 1500
1500 x 20 = 30000

But these numbers are based on two assumptions: there are 5 sun hours and that each solar panel performs at peak output.

The number of sunlight hours will change depending on the season. This has a direct effect on the panel output so make sure your PV system has a high efficiency rating, at least 20%.

The easiest way to set up this system is contact a professional solar installer. They will conduct an estimate and determine how many solar panels you will need. If you prefer the DIY approach, start with a 300 watt solar panel kit – we like the Renogy RV Solar Kit – and add as many panels as required.

Factors That Affect 6kw Solar System Production

These calculations assume for instance, that a 250W solar panel produces 250 watts an hour for 5 hours. But during cloudy days the sun hours will be reduced along with the PV output.

A 20 x 250W solar array that produces 25kw a day will drop to 17.6kw if the panel output slips to 220W an hour with only 4 hours of sunlight. The same thing will happen with other large solar arrays under the same conditions.

The good thing is you can get a pretty good estimate for daily sun hours for your location. During summer you should get at least 5 hours a day if not more.

The more sun hours the more power the system will generate. If your home is grid tied, you can store the excess energy into the grid. If not, this extra power can be placed in a battery bank so you can tap into it later.

During summer there will not be an issue. At the very least you should get 5 hours of sunlight and maybe more in Arizona, Texas and other places. But you need to have backup or storage power as fall and winter come in.

Why is My 6kw Solar Panel Not at Maximum Power?

Even if there is plenty of sunlight, your solar panels may not always perform at peak level. That is, a 300 watt solar panel is not going to supply 300 watts an hour every day.

Solar panel ratings are based on their peak output. If your 6kw array has 16 x 350W solar panels, do not expect each one to generate 350 watts an hour the entire day.

The watt rating is the highest possible output, but the average output will likely be lower. Is it possible for a 300W solar panel to yield 300 watts for 5 to 6 hours? It is, but unlikely.

The sun’s intensity changes during the day. It is low at morning and reaches its peak at noon before setting in the late afternoon. Solar panels follow this route because they convert solar energy into current.

So while a 100W solar panel might reach 100 watts at noon, this could drop to 90 watts in the afternoon. When the sun sets the PV panels stop generating power.

There are many other reasons why solar panels may not reach maximum capacity. Shading, poor design, clouds covering the sky and improper orientation are just some of them.

Solar panels in the northern hemisphere should be oriented south for maximum sunlight for instance. If they are not facing this way, the sunlight conversion rate will drop.

Will 6kw Power a House?

The average American home consumes 20 to 30kw a day. A 6kw system that produces 25kw should be enough.

In fact the 30kw a day average is probably on the high side. If you live in a small house the daily energy usage is likely in the low 20s.

No matter what the national average is, what is important is your daily usage. Only you can determine how much energy you consume and if a 6kw solar system is enough.

The easiest way to find out is to check your power bill. The total kilowatt usage will be there so use that as a guide. Average the figure if it varies month to month. If your average energy usage is 25 kilowatts or less, a 6kw solar system will be sufficient, at least during the summer months.

Solar power production drops during winter so you have to factor that in. If your energy usage during winter is similar to the summer months, you have to compensate for the solar panel power loss.

if you are on the grid, it is not a problem. Just switch to grid power when the solar array production becomes insufficient. If you are off the grid, install a battery bank or generator. By checking the sun hour difference between summer and winter you can estimate how many kilowatts the array production will drop.

Deep cycle batteries and generators come in different sizes. Only you can determine what backup power size is ideal.

Because you don’t have the benefit of a power grid, you have to be as energy efficient as possible. Putting together a large battery bank can be expensive, so plan carefully and thoroughly before you go the off grid route.

Is a 6kw Solar System Enough?

It depends on your needs and situation. If you have a medium to large home with a power consumption of 25kw a day or less, a 6kw system is a good option.

Given the fact that solar power output varies by season, it is best to stick with the grid for now. This way you can determine how much you can depend on solar power and if it is insufficient, you can always go back to the grid.

There are many ways to install a large solar system like this. The easiest is to contract a professional solar power provider and let them handle the installation.

By contacting a professional solar service provider, you don’t have to worry about how many solar panels to install. They will first conduct an inspection to determine if your rooftop can support this type of array. They might offer professional solar panel cleaning services too.

Next they will give you a rundown of the cost, the expected output and how long before you recover your investment. This is one of the reasons why people prefer solar, so they can say goodbye to never ending monthly power bills.

Aside from the solar panels, the system will also require charge controllers, inverters and various MC4 connectors, wires, cables, safety fuses etc. It is a lot of work, so if you want to do this yourself, research each component first.

Considerations before Installing a 6kw Solar System

  • Consider your situation. If you are on the grid you only need to buy the solar panels. If you are off the grid, you must have a battery bank or a generator as backup during lower power days.
  • Calculate how much power you use. Just take a look at your monthly power bill to get an accurate figure.
  • Account for all the seasons. Sunlight hours and intensity will vary from summer, winter, fall and spring. Take that into consideration when setting up your PV system.
  • Go for quality. Get the highest quality solar system you can get. This is a long term investment so make sure to get your money’s worth.


investing in a 6kw solar system requires thorough planning. You need to go over each step and more importantly, think in the long term. Hopefully the information in this guide was able to provide some assistance.