Going solar is becoming an increasingly popular option for homeowners looking to take control of their energy costs and reduce their carbon footprint. With solar panel costs dropping and technology improving more homes than ever are choosing to install rooftop solar panels.
Recent data shows that over 25% of homes in the U.S. now run entirely on electricity with a growing portion using solar power. If you’re considering joining the solar movement and want 25% or more of your home’s energy to come from the sun, here’s what you need to know.
How Much Solar Do You Need for 25% of Power?
The first step is calculating how much solar you’ll need to reach the 25% threshold. This depends primarily on two factors:
- Your home’s annual electricity usage
- Your solar panel system’s production capacity
On average, a U.S. home uses around 10,000 kWh of electricity per year. To get 25% of your power from solar, you’ll need a system that can produce around 2,500 kWh annually.
With today’s solar panels that usually have 300-400 watts of capacity, that means a 6-8 kW solar system would get you to the 25% solar mark for an average home. Of course, your specific home’s energy use could be higher or lower.
Doing a full energy audit and examining your utility bills can give you a tailored estimate of your annual electricity consumption. From there, you can back-calculate exactly how large a solar system you need.
How Many Solar Panels For 25% Solar Power?
Once you know the required solar system size in kilowatts, determining the physical number of solar panels is straightforward.
For a 6 kW system using standard 400 watt panels, you’d need around 15 solar panels on your roof. For an 8 kW system, you’re looking at 20 panels.
Panels with higher wattages over 400W will require fewer total panels, while lower output panels will need more to reach your 25% solar goal. Carefully choosing high-efficiency solar panels can help maximize your roof space if it’s limited.
Roof Space Needed for 25% Solar
Speaking of roof space, you’ll want to ensure you even have the physical room for 15-20 solar panels. That will occupy 200-300 square feet of roof space, on average.
For context, a typical 2,000 sq ft home likely has around 4,000 sq ft of total roof space once both the front and back sections are included. So for most homes, carving out 200-300 sq ft for solar should be very feasible.
Before installing your system, have your roof evaluated to make sure it gets ample unobstructed sun exposure throughout the day. If roof space is at a premium, also consider getting quotes for more efficient solar panels that take up less physical area.
Cost for 25% Solar Power
The final key consideration is cost. What will it take to get 25% of your power from solar panels?
Right now, a typical 6 kW solar system costs around $16,000 before incentives and tax credits. For an 8 kW system, expect to pay $20,000-$22,000 depending on your location and installer.
That’s just the upfront price. Once you factor in the 26% federal solar tax credit and additional state/local incentives where available, out-of-pocket costs drop significantly.
Over the long run, your solar system will pay for itself through energy bill savings, providing free electricity for decades to come. With a properly sized system providing 25% or more of your home’s power, you’ll insulate yourself from utility rate hikes.
Additional Benefits of 25%+ Solar
Beyond the cost savings, what are some other advantages of getting a quarter or more of your energy from the sun?
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Reduce carbon footprint – Solar power emits zero greenhouse gases. Going 25% solar for a typical home prevents around 5,500 lbs of CO2 emissions per year.
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Increase home value – Homebuyers are willing to pay a premium for a solar-powered home. 25%+ solar can boost your resale value.
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Improve energy resiliency – With battery storage, solar gives you access to reliable backup power when the grid goes down.
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Earn money from net metering – Many utilities pay you for excess solar electricity sent back to the grid through net metering programs.
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Lower maintenance costs – Solar panels are durable, require little upkeep, and can last 40+ years with minimal degradation.
Is 25% Solar Right for You?
If the idea of slashing your energy bills while also doing your part for the environment appeals to you, aiming for 25% or more solar power is a worthwhile goal. With batteries, you can even take things a step further and create a mostly self-sufficient solar home.
Start by checking into local solar incentives and having an installer provide a free assessment of your home’s solar potential. They can advise on the ideal system size and panels for your roof and energy needs.
Going solar is more affordable than ever. And with solar technology continuing to advance, your panels will likely outperform expectations over their lifetime. Now is the perfect time to harness the sun’s free power and take control of your energy future.
How to calculate how many solar panels you will need
You can use this formula to calculate how many solar panels youll need. But first, youll need to know:
- Your homes monthly energy consumption
- The wattage of the panels you plan to install
- The amount of peak sunlight hours your home receives per day
Jake Edie, an adjunct professor at the University of Illinois Chicago suggests taking the following steps:
Step 1. Review your monthly electric bill: Its important to determine how many kilowatt-hours of electricity you consume monthly. As an example, we will use 1,500 kWh every month.
Step 2. Convert monthly energy use to daily use: Given 1,500 kWh is consumed per month, to ascertain the daily usage, we need to divide this figure by the average number of days in a month, which is roughly 30.42 days (365 days divided by 12 months).
Hence, the average daily use = 1,500 kWh / 30.42, approximating 49.3 kWh daily.
Step 3. Determine peak sunlight hours: This factor varies based on location and climate. For this example, lets assume that this home receives an average of about 5 peak sunlight hours per day.
To calculate the total daily energy production required, divide the daily energy consumption by the number of peak sunlight hours. This gives the amount of energy your solar panels need to produce per day.
Energy production required = 49.3 kWh per day / 5 hours, which equals 9.86 kW.
Step 4. Calculate the number of panels: Lastly, youll need to determine the wattage of the solar panels you plan to install. The average solar panel efficiency in the US is rated between 250 and 400 watts. For this example, well use a rating of 350 watts.
By dividing 350 by 1,000, we can convert this to kilowatts or kW. Therefore, 350 watts equals 0.35 kW.
Step 5. Determine the required number of solar panels: Divide the daily energy production needed by the solar panels power output.
Number of solar panels needed = 9.86 kW / 0.35 kW per panel, which equals 28.17 panels.
This hypothetical homeowner will need approximately 29 solar panels to generate enough electricity to match their current usage from the electric company. While this calculation may seem straightforward, there are many factors that can affect the effectiveness of solar panels, such as shading, roof orientation and seasonal variations in peak sunlight.
We highly recommend that you seek the guidance of a professional solar installer who can assess your circumstances and provide a tailored solution to meet your needs.They should be certified from the North American Board of Certified Energy Practitioners, which is the solar industry standard. CNET also has a well-researched list of best solar companies.
Factors that affect how many solar panels you will need
The number of solar panels youll need depends on a variety of factors and is going to vary drastically by household. A few factors affecting the amount of panels youll need are:
- Wattage per panel
- Panel efficiency
- How much energy your solar panels are producing
- Your households energy consumption
- Size of the panel
- How many hours of peak sunlight you receive
- The condition and shading of your roof
- Your own personal energy goals and needs
How Many Solar Panels Do You Need? Follow This Easy Breakdown!
FAQ
How much solar is needed to power a home?
Can a house run 100% on solar?
How many solar panels for 25 kWh per day?
Why are solar panels only 25% efficient?
How many solar panels do you need to power a house?
The goal for any solar project should be 100% electricity offset and maximum savings — not necessarily to cram as many panels on a roof as possible. So, the number of panels you need to power a house varies based on three main factors: In this article, we’ll show you how to manually calculate how many panels you’ll need to power your home.
Should you choose solar energy for your home?
Before starting the process of powering your home with solar energy, homeowners should investigate their energy use and consider potential efficiency upgrades. Homeowners should be well aware of their total electricity usage, and consider low-cost and easy-to-implement efficiency measures before choosing solar.
How many solar panels does a tiny home need?
A typical tiny home needs around 15 solar panels to power it completely. However, most tiny homes can only fit a few solar panels on the roof. To compensate for the lack of roof space, you can install a ground-mounted solar array with solar panels lined up adjacent to the house.
Do solar panels increase the value of your home?
Installing solar panels can increase the value of a home by an average of $15,000. Not only can they significantly reduce greenhouse gas emissions, but this addition is becoming more common, with enough solar panels installed across Texas to power over 350,000 homes.
How much does it cost to run a house with solar?
You can run your house using entirely solar energy, but it is a significant investment. Solar panels cost $2.86/W on average, and the total cost of an installation averages $20,000 for a 10 kW system (after accounting for the 30 percent federal solar tax credit).
Can you use 100% green energy in your home?
You can use 100% green energy in your home without the challenges of solar panel installation and at rates as affordable as regular electricity companies, according to Chariot Energy. However, it can take the average U.S. homeowner nearly 8 years to break even on solar panel installations.