If your plan to go solar and take advantage of the tax credits and potential savings from generating electricity for your home using solar then perhaps a 6kW solar system might be the right one for you.
Even then, you’d want to know whether it is suitably sized for your requirements or an overkill, you may mind spending more than you need to.
Beyond this, knowing what savings you can expect, even if ballpark can help you make an informed buying decision.
This post, therefore, is intended to provide a rough guide on whether such a system is suitably sized for your home and the estimated savings you can expect when you install it.
Note: This is only a guide. You should consult a qualified salary system professional.
Is a 6 kW solar system big enough?
The estimated energy generated depends on the average number of sunshine hours your location receives.
If your location receives on average 4 hours per day then the 6 kW solar system will generate about 24 kWh per day.
Keep in mind that the energy output will noticeably be lower during the winter when you have fewer hours of sunshine.
Whether the 6 kW solar system is large enough ultimately depends on your home’s daily energy consumption and how much of your electricity bill you’d like to offset.
First, find out your home’s daily energy consumption. In my option, if it is 18-21kWh range then it is suitable sized, give or take and you might be able to offset at least a significant fraction of the entire bill if not all subject to when you have peak demands( hopefully during the day) and if you have battery storage.
Plan to have most of your appliances during the day that you are using as much of the generated energy instead of exporting it unless there is a surplus for maximum savings.
If your average daily energy consumption is considerably less, say 10kWh, and you do not anticipate an increase in consumption then it is probably an overkill.
How much Can you expect to Save? Is it worth it?
Savings from your daily consumption
Assuming an average daily output of 24 kWh of which you consume on average 20 kWh, with 4 kWh sold back to the grid, assuming an electricity tariff of 12 cents per kWh, then:
your daily energy savings based on consumption are USD 2.4, from 20kWh x 0.12
This works out to be USD 876 per year from your daily consumption.
Savings from Energy sold back to the grid
Assuming a feed-in tariff of USD 0.15, then annual savings are USD 219 per year.
Estimated annual savings from the system amount to 219 +876 =USD 1,095.
Target to run most of your appliances with the highest consumption during the day to realize the highest savings from generating your own.
This is because the Feed-in Tariff and associated savings from exporting to the utility may not be as high and attractive as when you use that energy.
This explains why investing in a larger solar system than you need may not be worth it as the savings from the energy exported can be small in comparison to the additional investment for a larger solar system.
How much space for a 6kW Solar system
The number of solar panels for a 6 kW solar system
This depends on the wattage of solar panels used as the building block for the system.
For example, you’ll need 24, 250 watt panels, from 24 x 250 = 6,000 watts. With 440 watt panels, only about 14 solar panels are needed.
How much space it takes up
As a rough guide, you’ll need about 429 sq. ft of roof space to mount the 24, 250w solar panels. Do you have enough roof space to accommodate that many panels on the side that receives most sunshine?
Note: This assumes the 250-watt solar panel dimensions of 5.5 ft by 3.25ft.
Is a 6kW solar system large enough to power a home?
This depends. Using the average annual electricity consumption of a home in the US of 893 kWh per month (US Energy Information Administration,2020), which works out to be 29.76kWh per day, then you can say it is large enough to meet at least 80% of the daily energy requirements of a house olds in America.
This assumes an average of 4 hours of sunshine for the solar system.
If your daily energy consumption is considerably less than 24 kWh then the system can in principle meet your energy requirement for a zero bill!
Is it worth getting a 6 kW solar system with a battery backup?
This depends too on if you have unreliable electricity and have critical appliances that you need to keep running in the event of an outage.
The size of battery depends on the combined power consumption of appliances you plan to keep running and for how long. Some 6 kW solar systems come with a 50Ah, 48V, or 100 Ah, 48Ah Lithium battery.
You could as well go for a grid-tie system with no battery bank as well. Keep in mind that should the grid be down then your grid-tie system will also not supply you with power.
A 6 kW solar system is large enough to meet at least 80% of the energy needs of most households in the U.S.
Energy savings from such a system depend on the tariff for your location, how much of the generated energy is used, how much is exported and the associated tariff.
With that being said, it is not unheard of to realise annual savings of USD 1,000+ depending on the prevailing tariffs.