How Much Power Does a 10kW Solar System Produce Per Month?

If you’re considering investing in a solar power system for your home, you probably have many questions…

For example, how much money can I save on electricity bills by offsetting or eliminating energy consumption from my utility company?

Determining the viability of an investment in home solar power requires determining how much electricity you currently consume in kilowatt-hours (kWh) on average and how many kWh you can expect a 10 kilowatt (kW) solar panel array to generate on a daily, monthly, or annual basis.

You may also wonder if a 10kW solar system produces enough power to run all the high-wattage and HVAC systems in your home.

Getting an accurate answer to these questions is complex…

Nationwide averages are of limited use because so much of how much power a 10kW solar system can produce depends on the unique characteristics of your home.

However, doing the homework is essential before making a significant investment in a solar panel system that may — or may not — meet your needs.  

Let’s start with some basics, and then we’ll go through the process step-by-step.

What’s the Difference Between Power (kW) and Energy (kWh)?

Power and energy are often used interchangeably, but knowing the difference is essential to understanding how electricity is measured and how it works.

Power Output and Requirements in Watts

The power output of generators and battery-based power supply systems is typically measured in watts (W) and kilowatts (kW).

Power rating measures the rate at which electricity is being used or generated at a specific moment in time.

Think of it as the instantaneous demand or supply of electrical energy.

For example, a 10kW generator can output a maximum of 10 kilowatts of electricity at any given instant.

The AC output rating in watts measures the maximum capacity of a generator or other power source to deliver energy.  

For example, a 10kW generator can output a maximum of 10 kilowatts of electrical power at any given instant — its maximum capacity to provide continuous energy. 

Depending on the type of generator and the electrical load connected, it may output less energy much of the time.

The power requirements of most home appliances are also measured in starting and running watts. 

Many high-wattage appliances, especially those with motors — such as refrigerators and air conditioners — require a brief surge of additional power to start.

Thanks to proprietary X-Boost technology, EcoFlow solar generators deliver up to double their continuous AC output as surge power.

For example, EcoFlow DELTA Pro 3 offers 4000W (expandable to 12kW) of continuous power and 8000W (expandable to 24kW) of starting wattage.

By comparison, most gas and inverter generators offer surge power of 10% or less above their maximum power output.

Electricity and Energy Consumption in Watt-Hours

Energy measures how much power is consumed over time.

Watt-hours (Wh) are typically the base unit, but kilowatt-hours (kWh) are far more familiar to consumers.

Cents per kWh is how you’re charged for electricity by your utility or power company on your energy bills.

If you know how much power an appliance requires to operate, it’s easy to calculate how much energy it consumes during use.

For example, a 50” LCD television that requires 150W of power consumes 150Wh of electricity for each hour it’s turned on.

If you watch TV for 3 hours a day on average, it will consume:

• 450Wh per day
• 12.6kWh per month
• 151.2kWh per year

The basic formula for calculating energy consumption in kilowatt hours is:

Power (watts/kilowatts) × Time (hours) = Energy (Wh/kWh)

Learn how to calculate kWh consumption for your home.

How Much Power Can a 10kW Solar System Produce Per Month?

The total amount of electricity a 10kW solar panel system can generate depends on numerous factors, including:

• Location 
• Solar irradiance
• Average peak sun hours per day
• Photovoltaic system type
  • Grid-tied: PV modules (like solar panels or shingles) and a solar inverter connect bidirectionally to the utility grid. During daylight hours, your home consumes the electricity your PV array generates. If it produces more electricity than you consume, excess power is transmitted to the utility grid. In some locations, you may receive credits for electricity you “sell” through net metering programs. At night or on days when you consume more electricity than your solar panels generate, your system will switch to grid power. Grid-tied systems don’t work during blackouts.  
  • Off-grid: Relies solely on electricity generated by your PV array and stored in a solar battery. No connection to the utility grid. 
  • Hybrid solar system: Solar + storage system that charges with solar panels and grid power. Depending on the model, it may also offer other charging options, such as an inverter generator or 800W alternator (vehicle) adapter. Ideal for whole-home backup and standby generator applications. It may or may not transmit electricity to the grid, depending on the system type.  
• Solar panel efficiency
  Measures the percentage of direct sunlight hitting the PV modules that will be converted to DC electricity per square meter of photovoltaic cells.   
• Type of Solar Panels

Usually monocrystalline or polycrystalline silicon. Primary determiner of PV module efficiency.

• Direction, tilt, and angle of PV modules
• Type and pitch of your roof (or other installation location)
• Temperature
• Obstructions and shade
• Cleaning
• Local weather patterns (for example, consistent cloud cover can reduce output) 
• Degradation and Age: Like everything else, PV modules degrade over time. However, decreases in efficiency are slow — typically less than 1% per year. Most solar panels last 25-30 years or more before having to be replaced.

With so many variables to consider, it’s impossible to determine how much energy a 10kW system will generate per month in kilowatt-hours at any given location.

Fortunately, NREL’s free PVWatts calculator can help you accurately estimate electricity production based on your exact address, system type, and other advanced parameters.

The electricity generation potential of a 10kW solar system will vary from house to house, let alone from state to state.

However, here are some ballpark estimates that you may find helpful.

Average Monthly Electricity Generation from a 10kW PV System in the US

• Nationwide: 700kWh to 1800 kWh.
• Southern States (e.g., AZ, CA, TX): 1200 kWh to 1800 kWh
• Mid-Atlantic and Midwest States (e.g., PA, IL, OH): 900 kWh t0 1400 kWh 
• Northeastern and Northwestern States (e.g., WA, MN, NY): 700 kWh to 1100 kWh

Please take these estimates with a massive grain of salt — there’s no substitute for doing your homework.

Is 10kW Enough To Run a House?

On average, most American households use considerably less than 10kW of continuous AC output during most hours of the day.

Often, 3kW – 5kW is sufficient.

However, it’s far from unusual for a house to consume MORE than 10kW during peak times of day — particularly if you use electricity for air conditioning or space heating.

Almost 90% of American households use AC at least part of the year, and 66% have central HVAC systems…

If you’re hoping to power HVAC systems with a generator or home backup battery system, it’s essential to determine your peak consumption — even if it’s at that level for just for a few hours or less during the day.

For example, consider a family preparing dinner on a hot summer day.

• Central AC: 4 kW
• Preheating an electric oven: 3 kW
• Electric stove burner on: 1.5 kW
• Water heater cycles on: 3 kW
• Fridge compressor starting: 0.5 kW
• Lights and home office/entertainment systems: 1 kW

The above use case is hardly an unlikely scenario, but all these events occurring simultaneously would require 13kW of AC output — about 30% more than a 10kW gas or inverter generator can supply.

Most modern standby gas generators have overload protection and will auto-shutdown almost immediately when maximum output is exceeded.

Older generators may keep running briefly, but this can permanently damage components and cause frequency and voltage drops, endangering appliances and sensitive electronics.

The additional surge power provided by a solar generator like EcoFlow DELTA Pro 3 (double its continuous output) helps meet initial peak demand from high-wattage appliances cycling on, such as refrigerators and water heaters.

However, it’s essential to size your system accurately to meet your peak demand needs.

If budget is a primary concern, backing up only essential appliances can help you strike a balance between convenience and cost. 

You definitely want to keep your refrigerator running, but maybe you can do without a washing machine and dryer during an outage.

If central AC consumes a significant portion of your peak demand load, consider using a portable air conditioner like EcoFlow WAVE 2 or a window AC unit to cool a single room during a blackout.

Remember, all the above figures are estimates. 

You must calculate your peak energy demand accurately to determine your home backup or standby generator needs.

A qualified electrician or solar installer can use professional tools to conduct a precise load calculation and ensure that you purchase the appropriate size standby generator or backup battery system for your needs.

How Is Solar System Size Calculated?

All of the factors that determine how much electricity a 10kW solar system can generate — including location, peak sunlight hours, and panel orientation — must also be considered when calculating the size and type of solar power system you need.

For most homeowners, the first step is calculating their energy consumption in kilowatt-hours and setting a realistic target for how much power a photovoltaic system can generate to reduce grid reliance and realize a favorable return on investment.

If your primary goal is emergency home backup or going off-grid completely, solar battery storage is a prerequisite…

You must determine the type of battery and how much storage capacity you need to meet your requirements.

Here’s a step-by-step guide to calculating solar system size.

1. Determine Annual and Average Daily Electricity Consumption (kWh)
   The simplest way to do this is to add up 12 months of consumption in kWh from your electricity bill. Divide the annual total by 365 to determine your daily average (kWh per day).
   
2. Estimate Photovoltaic Potential at Your Location

NREL’s free PVWatts Calculator can accurately estimate the electricity solar panels can generate at your address based on historical solar irradiance, peak sun hours, and climate pattern data, among other factors.

Take note of the peak sun hours. We’ll be using them in the subsequent calculations.

3. Determine Your Daily Energy Offset Target

Many people aren’t interested in going 100% off-grid but instead use a residential solar power system to supplement utility power and reduce electricity bills.

In that case, decide what percentage of your daily electricity consumption you want to offset with solar — this is your daily energy Offset Target. 

Want to reduce your electricity consumption by 75%?

The Offset Target is 75% (0.75)

Want to cut your electricity bills in half? 

Your Offset Target is 50% (0.5) — and so on.

Using this formula, you can calculate the amount of energy in kWh a PV system must generate to meet your goals. 

For example, if your Offset Target is 50% for 29kWh of daily electricity, your Electricity Generation Target is 14.5kWh.

4. Calculate the Unadjusted Solar System Size (kW) 

If you aim to offset 100% of your energy consumption and live off-grid, use the following formula to calculate the required solar panel system size in rated watts.

Daily Energy Consumption (kWh) / Peak Sun Hours = System Size

For example, if your daily electricity consumption is 29kWh and you receive 4 hours of peak sunlight, your PV module array’s total rated power wattage should be at least 7.25kW.

To generate only a portion of your household electricity from solar, replace total daily energy consumption with your target energy generation goals as determined in Step 3.

(Electricity Generation Target (kWh) / Peak Sun Hours = System Size

For example, if your daily electricity generation target is 14.5kWh and you receive 4 hours of peak sunlight, the minimum system size is 3.625kW.

Here’s the calculation.

14.5 / 4 = 3.625kW

The next step is accounting for system inefficiency, known as the derate factor. 

5. Factor in System Losses (Derate Factor)
   No electrical system is 100% efficient. 

It’s standard industry practice to assume that 20% of the rated power output of PV modules and balance of system components will be lost to inefficiency,

However, actual system losses will vary depending on various factors, including manufacturing quality.

To account for the derate factor, take the unadjusted solar system size in kW and divide it by 80%.

For example:

3.625 / 0.8 = 4.53kW

4.53kW is the Adjusted System Estimate of how much total output you need from your solar panel array to meet your energy generation goals.  

6. Calculate the Number of Solar Panels Required

Now that you’ve estimated how much energy your solar system needs to generate to meet your goals, it’s time to assess how many — and what type — of PV modules you need.

90% of PV modules in current use are solar panels that generate DC electricity using monocrystalline or polycrystalline photovoltaic cells.

Rigid solar panels with a rated power output of 300W to 450W are the most common choice for residential rooftop installations. 

It’s essential to understand that rated power indicates the maximum output of a solar panel under ideal laboratory conditions, roughly equivalent to peak sunlight hours on a cloudless day.

Solar panels don’t generate their full rated power during every hour of daylight.

Output will be lower in the early morning, early evening, and cloudy days when the Earth’s surface (and your rooftop) receives less visible light.

That’s why average peak sunlight hours at your location are such a crucial factor and what we use to calculate average energy generation each day.

Generating the US average household electricity consumption of 29kWh daily in a location with four hours of peak sunlight would require a minimum of 23 400W rigid solar panels.

To estimate how many solar panels you need to meet your specific electricity generation target, take the Adjusted Estimate in watts from Step 5 and divide it by the rated power of your PV modules. 

Adjusted System Estimate / Rated Power Output = Number of Solar Panels

For example:

4.53kW / 400W = 11.325 400W Panels

Round the number of panels up to 12, and you should be able to meet your energy offset goals.

If you have the budget and the installation space, adding an additional 20% of photovoltaic potential above your estimated requirements is never a bad idea.

However, you can always install more panels in future — as long as you don’t exceed the maximum solar input of your inverter or battery charge controller.

7. Assess Your Available Installation Space

Measure the viable installation surface area of your home.

For example, if you’re installing solar panels on a rooftop, calculate how many square feet are available — preferably facing south with no regular obstructions or shade during peak sunlight hours. 

East and west-facing roofs may still capture enough sunlight to make a solar installation worthwhile.

North-facing rooftop installations are generally not a viable investment due to the lack of direct sunlight they receive.

A general rule of thumb is that you need 100 square feet of installation space per kilowatt of solar panels. 

For example:

12 x 400W Solar Panels = 4.8kW of rated power output.

4.8kW × 100 sq. ft. = 480 sq. ft.

Of course, this is just an estimate.

480 sq. ft. of viable rooftop may be sufficient for 12 x 400W solar panels, depending on:

• PV module dimensions
• Type of mounting system
• Solar panel efficiency 

If you’re short on viable installation space, consider purchasing high-efficiency monocrystalline silicon solar panels.

Monocrystalline panels are typically more expensive upfront than polycrystalline, but they produce more electricity per square meter, making them better suited for installations where space is at a premium.

For example, EcoFlow’s 400W rigid solar panel provides 23% efficiency.

Cheaper polycrystalline PV modules typically offer an efficiency rating of 15% – 18%.

Because solar panel efficiency measures how much electricity is generated per square meter of photovoltaic material, modules that are 5%-7% less efficient will take up significantly more space.

Not only that, higher efficiency mono panels can shorten your solar payback period and maximize your ROI in the long run.

8. Size Your Balance of System Components

Now that you’ve determined your electricity generation goals and the number of solar panels required to achieve them, it’s time to size your balance of system (BOS).

Solar panels don’t generate household electricity alone.

BOS in solar power refers to all the components — except the PV modules — required to make a residential solar system work. 

Depending on whether you opt for grid-tied, off-grid, or hybrid, BOS components include:

• Solar inverter
• Charge controller*
• Solar battery*
• Battery Management System* (BMS)
• Cables and Wiring
• Mounting Hardware
• Transfer switch (for integration with home circuit board/wiring if needed)

*Not required for grid-tied systems

It’s possible to purchase each component separately from different manufacturers, but cross-compatibility issues are common, time-consuming, and expensive.

Alternatively, you can purchase a modular whole-home generator like EcoFlow DELTA Pro Ultra, which has all the components required to operate a hybrid solar + storage system built-in.

Regardless of which BOS option you choose, it’s essential that the combined output of your solar power array doesn’t exceed the input capacity of your solar inverter or charge controller.

For off-grid and hybrid systems, ensure that your solar battery has sufficient storage capacity (kWh) or alternate charging methods for when your PV array doesn’t generate sufficient (or any) energy to operate your chosen appliances and systems.

If in doubt, talk to a solar professional or direct-to-consumer manufacturer that offers consultations and reliable customer support.

9. Testing, Installation, and Permits

In most cases, it makes sense to test your system thoroughly before installing it on your roof.

While it’s possible to install rooftop solar panels yourself, how you connect the PV modules array to each other — in series, parallel, or hybrid — determines the amperage and voltage output of the combined array.

Solar panel wiring diagrams are complex, essential for large arrays, and best left to a professional.

Additionally, determining the optimal direction, angle, and tilt of your panels will significantly impact how much energy the array generates.

For large solar panel installations, working with a reputable professional is almost always worth the additional cost.

Last but not least, all grid-tied and most 10kW off-grid or hybrid solar power systems will require permitting and certification by a licensed electrician.

Before making a purchase, make sure to check if there are any zoning, homeowner’s association, building code, or other restrictions that may prevent you from installing and operating your system.

Frequently Asked Questions

Final Thoughts

If you’ve gone through this guide step-by-step, you’ll now have a solid estimate of how much electricity a 10kW solar system can generate monthly in your home at your location.

There’s no one-size-fits-all answer, but hopefully, you’ve now got the tools to make an informed purchase decision based on how much money you can save on energy bills. 

EcoFlow DELTA Pro Ultra is a modular whole-home solar generator that can provide up to 21.6kW of continuous AC output and 90kWh of battery storage — enough energy to run almost any home indefinitely off-grid.

With multiple charging options — including grid power — and intelligent energy management, it’s also an ideal solution for people looking to offset electricity costs and ensure home energy security during blackouts.

EcoFlow has an expansive range of portable power stations, solar generators, and solar panels for everything from camping to whole-home off-grid power.

Check out our selection today.