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2 KW Solar System: Is It Worth It? What Appliances, No. of Batteries and Solar…

2 KW Solar System: Is It Worth It? What Appliances, No. of Batteries and Solar…

    This Is How Many Solar Panels You Need to Power Your House

    This formula will tell you how many solar panels are needed to meet 100% of your home’s energy demand.

    Jackie Lam is a contributor for CNET Money. A personal finance writer for over 8 years, she covers money management, insurance, investing, banking and personal stories. An AFC® accredited financial coach, she is passionate about helping freelance creatives design money systems on irregular income, gain greater awareness of their money narratives and overcome mental and emotional blocks. She is the 2022 recipient of Money Management International’s Financial Literacy and Education in Communities (FLEC) Award and a two-time Plutus Awards nominee for Best Freelancer in Personal Finance Media. She lives in Los Angeles where she spends her free time swimming, drumming and daydreaming about stickers.

    • She is the 2022 recipient of Money Management International’s Financial Literacy and Education in Communities (FLEC) Award and a two-time Plutus Awards nominee for Best Freelancer in Personal Finance Media.

    Taylor Freitas is a freelance writer and has contributed to publications including LA Weekly,, and Hospitality Technology. She holds a B.A. in Print and Digital Journalism from the University of Southern California.

    Chi Odogwu is a digital consultant, professor, and writer with over a decade of experience in finance and management consulting. He has a strong background in the private equity sector, having worked as a consultant at PwC and a research analyst at Renaissance Capital. Additionally, he has bylines in well-known publications, including Entrepreneur, Forbes, NextAdvisor, and CNET. He has also leveraged his writing talent to create educational email courses for his clients and ghostwritten op-eds published in top-tier publications such as Forbes, CoinDesk, CoinTelegraph, Insider, Decrypt, and Blockworks. In addition to his writing, education, and business pursuits, Chi hosts the top-rated Bulletproof Entrepreneur Podcast. Through this podcast, he engages in insightful conversations with talented individuals from various fields, allowing him to share a wealth of knowledge and inspiration with his listeners.

    High inflation and the soaring costs of power bills can make powering your home with solar energy quite appealing. And if the allure of going green and saving money has you wanting to go solar, you’ll need to figure a few things before the installer swings by. For one, the number of solar panels to adequately meet your home energy needs.

    A common misconception is to gauge how much bang for your buck you’re getting purely based on wattage, says Courtney Corda, co-founder of the California-based solar company Corda Solar. Knowing how many panels you need isn’t just about wattage, but the costs involved in installing, panel performance, location and your usage needs, Corda explains.

    Here’s how to figure out how many panels can support your energy needs and what other factors can interfere in your production goals.

    solar, system, appliances, batteries

    Can solar panels save you money?

    Interested in understanding the impact solar can have on your home? Enter some basic information below, and we’ll instantly provide a free estimate of your energy savings.

    How to calculate how many solar panels you will need

    To get a realistic estimate of how many solar panels a home might need, we turned to Jake Edie, an adjunct professor at the University of Illinois Chicago. Edie provided us with a straightforward calculation method.

    solar, system, appliances, batteries

    If you’re curious about how many solar panels your home might require, here’s how you can figure it out, Edie says. Let’s say your household uses 1,500 kWh of electricity each month. Here are the steps to calculate the solar panels you’ll need.

    Can solar panels save you money?

    Interested in understanding the impact solar can have on your home? Enter some basic information below, and we’ll instantly provide a free estimate of your energy savings.

    Step 1. Review your monthly electric bill: It’s important to determine how many kilowatt-hours of electricity you consume monthly. In this example, this particular home uses 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, let’s assume that this home receives an average of about five 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, you’ll need to determine the wattage of the solar panels you plan to install. The average solar panel in the US is rated between 250 and 400 watts. For this example, we’ll assume the selected solar panel has 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.

    To determine the required number of solar panels, we must divide the daily energy production needed by the solar panel’s power output.

    Number of solar panels required = 9.86 kW / 0.35 kW per panel, which equals 28.17 panels.

    This homeowner will need approximately 29 solar panels to generate enough electricity to match their current usage from the municipal 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.

    It is highly recommended 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.

    solar, system, appliances, batteries

    Other factors that affect how many solar panels you need

    There are a variety of factors to take into consideration that will help you and an installer determine how many solar panels you need to power your home. Here is a breakdown:

    Solar panel wattage

    One big part of a solar panel’s performance is its wattage and will affect how many panels you need. The higher the wattage, the more power a panel can generate.

    Most residential solar panels have ratings of 250 to 400 watts. The most efficient solar panels on the market are 370 to 445-watt models. The higher the wattage rating, the higher the output. In turn, the fewer panels you might need.

    For example, you might buy a solar panel with a listed output of 440 watts. You’ll need to multiply the panel’s wattage by how many hours of sun you get every day to understand how much energy it will produce.

    If you don’t have much space, you might want to invest in solar panels with higher efficiency and wattage ratings since they’re equipped to generate more energy per panel. But they’re also more expensive, so bear that in mind if the solar budget for your home is tight.

    Output efficiency

    If your roof has limited space for panels, you’re going to want to get the most performance per square inch of panel that you can, explains Corda.

    Scientists and technical developers of solar panels have been working hard for decades to try to make each solar cell on the panel able to convert more of the sun’s light to electricity than before, or to make them more efficient, says Corda.

    As she explains, currently, the most efficient panels on the market have anywhere from 18% to 22.8% efficiency, with most panels hovering around 20% efficiency. So the higher the efficiency, the fewer solar panels you might need.

    In reality, a more efficient solar panel will require fewer panels overall for your home, assuming all other factors are equal.

    Production ratios

    A production ratio for solar panels helps you determine how much energy you can get from a panel. The production ratio, or performance ratio, is an important measure of the effectiveness and efficiency of a solar system. It compares the actual output of the system to the output it would produce under ideal conditions. This ratio takes into account factors that reduce output, such as temperature, dust, snow, shade, aging of the panels and inefficiencies in the inverter.

    The performance ratio is expressed as a percentage, with a higher ratio indicating that the PV system is producing a greater percentage of its theoretical output. For example, a performance ratio of 80% means that the system is producing 80% of its rated output in real-world conditions. The higher the production ratios, the fewer panels you might need.

    Panel size

    There are three main sizes for solar panels: 60-cell, 72-cell and 96-cell. The 60- and 72-cell panels are more common for residential installations are generally about 3 by 5 feet, or 15 square feet.

    Where you live and hours of sunlight

    The more hours of sunlight your roof is exposed to, the fewer panels you’ll probably need to install. This is based on the direction, pitch and orientation of your roof, the weather and how much shade covers the roof. It also depends on the time of year and where you live.

    In the winter [the solar panel] produces less than in the summer. So your energy production from solar will change throughout the year and then the usage within your home will change depending on what appliances are using electricity, says Justin Draplin, CEO of Eclipse Cottages, a sustainable home technology and development company.

    So if you live in a really hot climate, then during the summer months, your electrical bill is going to be a lot higher to cool your home versus if you’re in a cold environment, your electrical bills are going to be a lot higher in the winter.

    How much shade your roof gets always plays a factor in how many solar panels you’ll need for your home, Corda says. If your roof is covered by large oak trees or a chimney and gets a lot of shade, this will bump down solar panel output. In turn, you might need more panels to power your home. But if your roof doesn’t get much shade, your solar output will be higher for the same space.

    Roof type and condition

    The orientation, angle, shape and type of roof will affect the number of panels you can reasonably fit into a given area, explains Corda.

    A home without a complicated roof structure, pitched at a 10 degree angle and south-facing is best for solar panels.

    That would be an ideal roof for solar because you’ve got it tilted, it’s facing south, and the pitch of the roof is neither flat nor very steep, which is ideal for putting panels on there to capture as much energy from the sun as possible, says Corda. A house with a more complicated roof structure won’t be able to fit as many panels, she adds. For instance, Spanish tile-roofs are considered solar unfriendly and require special attachments.

    Cost and budget

    While powering your home on solar energy can save you money, it does require a serious investment upfront. The costs to power your home on solar and your budget will determine how many solar panels you can afford.

    Currently, the average cost for a home solar panel system is around 3 per watt, according to data from the research firm Wood Mackenzie. Based on this figure, an 8-kilowatt sized system would be 24,000 before any tax breaks or incentives kick in.

    Whether you are paying cash or financing, knowing what you can afford will play a factor in how many panels you add to your home.

    Annual electricity usage

    To know how many panels will meet your energy demand, you’ll need to know your annual energy usage. You can log onto your account online, review statements, you’ll see how many kilowatt hours of electricity you use. You’re going to want to look at your patterns over the course of a year.- if not the last couple of years, says Corda.

    Once you have that number, you’ll know how much solar power you need to generate to cover your needs.

    Besides recent use, factor in the future energy needs, Corda points out. For instance, do you anticipate purchasing an electric vehicle? Or do you plan on growing your family? Or are you and your spouse going to be working from home more? If so, then your energy needs will go up in the future years. On the flip side, if your teens will soon leave the nest to go to college, then you can expect your energy usage to taper off.

    Your personal solar goals

    Determining your personal solar goal is figuring out what you want to achieve with your solar panel addition. Living completely energy independent and off the grid would mean more solar panels. If you want to power your whole house, you have to really oversize it to make sure you have enough power in the winter, even though you’re going to be over producing in the summer, says Draplin.

    Adding battery storage will also play a factor in how many panels you need. With solar battery storage, you can essentially bank energy and store it for later use when you’re producing excess energy.

    If your goal is to lower your energy bill or reduce your carbon footprint, then maybe you won’t need as many panels, says Draplin.

    Figuring out the number of solar panels you need is only part of the equation. Learn more about the benefits and costs of home solar from CNET:

    Solar panel FAQs

    Can I run my house on solar power only?

    The simple answer is: Yes, you can power a house entirely on solar power. To meet your energy ends, you’ll want to factor in a handful of variables: the size, pitch and orientation of your roof, the size of panels you’d like to install, the amount of shade, output efficiency and wattage. Plus, you want to figure out current and future usage needs, and whether you want your entire home to be powered on solar energy or just part of it.

    kW Solar System: Is It Worth It? What Appliances, No. of Batteries and Solar Panels to Use

    Are you considering an alternative power source for your RV or cabin? Is it worth it?

    A 2 kW solar system complete with an appropriately sized inverter can run many household appliances reliably.

    You need to make sure that the solar system components – batteries, charge controller, inverter, and connected appliances are properly sized for the system to work well.

    So in this guide, I discuss whether a 2 kW solar system is worth it, share some information to help you get started with selecting the right capacity of components – number and size of batteries, inverter rating.

    I also give examples of appliances that you can connect to make the most of your 2 kW solar system investment without damaging it.

    Is it Worthwhile Investing in a 2 kW Solar system?

    If your objective is to save money, then investing in a 2kW solar system is not worth it from a financial savings standpoint unless there are subsidies available.

    At the time of writing, a complete 2 kW solar system – solar panels, batteries, charge controller, inverter system costs about USD 3,000 plus installation.

    You are looking at a payback period of 7-10 years if there are no subsidies and at that point, you will likely have to invest in a replacement set of batteries.

    Note: this assumes a tariff of 13 cents per kWh.

    That said, solar systems are generally low maintenance compared to a generator, do not produce fumes, and are silent too with minimal running costs.

    If these benefits are important to you and budget is not an issue then it is probably worth it.

    How Many Batteries Can You Use for a 2 kW Solar System?

    There are several possible battery setups you can use. Some examples are provided below:

    AGM or GEL Batteries

    2,400 Wh Battery Bank consisting of:

    4pcs of 100 Ah batteries. You can connect them such that you have 2 strings connected in parallel of 2pcs of 12 AGM or gel batteries connected in series for a 24V bank.

    Note: This harvests only about 30% of the generated energy of the solar panels estimated at 8 kWh.

    You can use 200Ah batteries to store more of the 8kWh from the solar panels.

    Lithium Batteries

    3,600Wh battery bank consisting of:

    6pcs of 50 Ah batteries. You can connect them such that you have 3 strings connected in parallel of 2pcs of 12V lithium batteries connected in series for a 24V bank.

    Note: This harvests only about 50% of the generated energy of the solar panels estimated at 8 kWh.

    You can use 100Ah batteries to store as much of the 8kWh from the solar panels.

    Connecting the battery bank in a 24V configuration or higher enables you to use less thick cables that are easier to handle, are generally more affordable while lowering the system currents.

    This can reduce the severity of damage in the event of a fault like a short-circuit as an example.

    What Can a 2 kW Solar System Run?

    A 2 kW solar system complete with battery bank and inverter can run several appliances from the lower power consumption appliances such as lights, TVs, laptops, low power tools, microwave, washing machine, coffee pot, air conditioner reliably provided:

    • The inverter’s continuous and surge power consumption is not exceeded.
    • The total daily energy consumption of the connected appliances does not exceed the energy generated and stored by the batteries.

    Drawing more power from the inverter than it can handle results in an overload condition which usually shuts down the inverter and in extreme cases can damage it.

    Here is an indicative list of appliances (with estimated runtimes that you expect from a 2 kW solar system). This assumes daily storage of about 2.4 kWh.

    • Lights: 10 watts, 9 pcs running for 5 hours = 10 x 9 x 5 = 450 watt hours
    • TV: 50 watts, 1 pc running for 4 hours = 50 x 1 x 4 =200 watt hours
    • Laptop: 40 watts, 1 pc for 5 hours = 40 x 1 x 5 = 200 watt hours
    • Washing machine: 250 watts for 3 hours = 250 x 1 x 3 = 750 watt hours
    • Microwave: 800 watts for 1 hour (total) = 800 watt hours

    Total = 2,400-watt hours total power consumption is 1,990 watts which can be handled by a 3,500 watt rated inverter.

    Important to note that the combined surge rating should not exceed approximately 7,000 watts, the estimated surge rating of a 3,500 watt inverter.

    Check your inverter’s owner manual for its surge rating.

    How many panels to use in a 2 kW solar system?

    You can have 10 pcs of 200 W ( 5 strings in parallel of 2 solar panels connected in series) or 195 W solar system or 20 pcs of 100 W solar panels ( ( 10 strings in parallel of 2 solar panels connected in series) for a 24V system.

    Note: This is just an example, there are probably other configurations you can use.

    Related questions

    Can a 2 kW Solar System Run an AC?

    Yes, it can run an AC provided its continuous and surge power rating does not exceed what the inverter can handle.

    Make sure that the AC is rated for a 115V for it to work with the 110/115V inverter output.

    Can a 2 kW Solar System Power a Whole house?

    The estimated 8 kWh supplied by this 2 kW solar system is not enough to power the entire house going by the estimated daily energy consumption of an average house in the US, 2020 of about 30 kWh according to the United States Energy Information Administration (USEIA).

    It can power some appliances but will likely not be enough for an average house.

    It can ably power an RV, off-grid cabin or an outside shed, or any other setup whose daily energy demand is about 8 kWh.

    Make sure you have enough batteries to store this much energy.

    kW Solar system |How Much Electricity it Generates

    Daily electricity output

    A 2 kW solar system can generate an estimated 6 – 8 kWh ff energy per day assuming your location receives about 3-4 hours of sunshine.

    Monthly electricity output

    A 2 kW solar system can generate an estimated 180 – 240 kWh Of energy per day assuming your location receives about 3 – 4 hours of sunshine.

    To get as much power as possible, the solar panels should be angled to face the sun as much for as many hours as possible with no shadows cast on the panels.

    Clean the panels to remove any dust or other debris that can obstruct the sun from reaching the panels for maximum power output.

    solar, system, appliances, batteries

    Final word

    If you are looking to save money, you have access to the grid and there are no subsidies then from a financial savings standpoint, it is likely not worth it unless benefits use of clean, no noise pollution is important to you.

    Should you decide to invest in one, while there are several possible battery bank configurations, you can consider, 2,400Wh battery bank made up of 4pcs of 100 Ah AGM batteries – 2 strings connected in parallel of 2pcs of 12V batteries or 6pcs of 50 Ah batteries – 3 strings connected in parallel of 2pcs of 12V lithium.

    Related topics

    kW Solar System

    Subscribe to updates – we’ll let you know when 2kW Solar System are back in stock. Normally, we update products every 2 weeks.

    kw solar system

    If you are looking for a Smart energy solution for your RV or a boat, you can purchase a complete 2kW solar system for steady power supply. A grid-tie solar installation can also substantially lower your electric bills and eventually will pay for itself this way. At A1SolarStore we offer complete systems where all the components are already sized together.

    How can you use a 2kW solar kit

    There are three types of systems which are good for different circumstances. The most popular design is a grid-tie system. You use solar panels for the needs of your house but the commercial electricity remains available to you. You can sell excess solar energy to the utility: it’s called net metering. The utility gives you credits in return which you can use to pay your bills

    Hybrid 2000 watt solar system is similar to a grid-tie one in a way that your house is still connected to the power grid. However, all grid-tie systems shut down during blackouts — it’s a safety requirement. A hybrid inverter, on the other hand, supports a battery which powers your home during power outages and helps avoiding peak electricity rates.

    An off-grid installation is a great option when your house can not be connected to a commercial grid. Mobile solar installations, such as systems for RVs and boats, fall into the off-grid category as well. Off-grid systems always have batteries that help at night and on cloudy days. Keep in mind, however, that 2kw solar panel kit may not be able to power a medium-sized home on its own. You can expect it to produce around 6 to 12 kWh of power per day, depending on your location, weather and the efficiency of your panels.

    kw solar system cost

    Panels, their brand and specifications play a big role in your system’s production and its cost. 2000 watts solar systems require 5-6 panels. Chinese companies offer the cheapest PV modules: look for brands like Jinko, Trina, JA, LONGi Solar who are the absolute leaders on the solar market. North American panels from brands like Silfab, Canadian Solar and Mission solar are slightly more expensive, but their quality is higher. You can also find premium-class panels for home installation from Panasonic, LG, REC. Their panels may cost a lot but they show great production levels.

    The configuration and the way you want to install your panels is also going to impact the final 2kw solar system price. Ground-based systems are cheaper to build, but they occupy space in your yard or a field and they get dirty quicker. Grid-tie system is the cheapest option, besides net metering is the main way in which solar panel system brings you money. Hybrid system is slightly more expensive, but it sometimes pays for itself quicker because you can avoid peak utility rates. Off-grid systems are the most expensive because you always need energy storage with them.

    Use incentives to your advantage

    Since solar energy is clean, the American government and utilities encourage people to go solar and even offer financial help. You can offset the upfront 2kw solar system costs by applying for solar loans with a low interest rate. Every state has a different set of policies and incentives for solar energy. Don’t forget to apply for Federal Solar Tax Credit: in 2022 you can get back 26% of your system cost through taxes — that includes shipping and labor services. Consult with your installer about the incentives that are available to you.

    Why buy from us

    We offer a variety of different systems and each 2000 watt solar panel kit that we have for sale was checked by our engineers. Don’t hesitate to ask our managers about the components of our systems, warranties and delivery options.

    • Our fulfillment centers are located on the east and west coasts of the USA: California, Washington, Colorado, Texas, Florida, New Jersey, and Missouri.
    • We process all orders within 24 hours, and ship them within 48 hours. Delivery takes 4-7 business days.
    • We work only with trusted manufacturers and we offer affordable for solar panel equipment.

    Frequently Asked Questions

    Your utility bills contain the energy consumption data for your home. All you need to do is divide the daily figure by the number of peak sun hours in your area. The result will be a gross estimate of a system size needed to offset 100% of your energy needs. Please refer to our article on sizing solar panel systems for more detailed instructions.

    You can browse through our catalog and pick a system with desired power output and functionality. Our engineer with 20 years of experience will adapt it based on the information you provide. He will take into account your location, roof pitch, house orientation and other factors. You don’t need to know a single thing about solar – we will support you at every stage.

    It is impossible to give a good recommendation without knowing any details, but we can share the general principles. A grid-tie system is the standard choice: it is the most affordable and lets you take advantage of net metering. You need an off-grid system if the grid is unavailable or full independence is desired. A hybrid system is a mix of the two, performing equally well with and without a grid connection. You can find a more nuanced take on the difference among the three types in our article.

    Yes, our systems include absolutely all components. You won’t need to buy any extra parts to install it and start generating power.

    Currently we do not provide installation services. You will need to contact an independent solar installer.

    All components of our systems come with a manufacturer’s warranty. We also stand behind the work of our engineers who configure the systems and guarantee full compatibility.

    We work with the top freight carriers like XPO, FedEx, ODFL, RL, etc. We also offer a free pickup option so that our clients could get the equipment cheaper and faster. Note that pickup is dependent on the availability of equipment in our fulfillment centers, and may not be feasible in your location.

    What is the benefit of buying a solar panel system compared to buying all the equipment element by element?

    Our systems are configured by an engineer with more than 20 years of experience. We will adapt the kit to your conditions and ensure compatibility.

    The equipment manufacturers normally provide user manuals for their products. These can be accessed via our website or the official websites of the respective manufacturers. Aside from that, we do not provide any other materials, but we’re ready to consult you along the way.

    Free and usefull digest on solar energy. No spam

    How much power does a 2kw solar system produce?

    In the summer, with the right weather conditions, a 2kW (2000 Watts) solar system could produce up to 2 kiloWatts (or 2000 Watts) of power, or even more in some cases.

    However, what really matters at the end of the day, literally, is not the amount of power (in Watts or kiloWatts) that the system produces, but the amount of energy (in Watt-hours or kiloWatt-hours) that it generates.

    So, really, rather than asking “how much power does a 2kW system produce?”, the question that should be asked is “how much energy does a 2kW solar system produce?”.

    In this article, I’ll discuss the amount of energy that a 2kW is capable of producing and the variables that influence this amount of energy. Then, I’m going to put that amount of energy into perspective by discussing what you can do with it.

    How much energy does a 2kw solar system produce?

    The daily energy production of a solar system of any size mainly depends on how much sunlight the system receives. And the amount of sunlight that a solar system receives itself depends on many variables, such as weather conditions, location, season, and the tilt angle of the solar system and the direction it is facing.

    However, as a rule of thumb, a 2kW (2000 Watt) solar system will on average generate around 8 kWh of energy per day, which amounts to about 240 kWh of energy per month, or about 3000 kWh per year.

    Depending on its location, tilt angle, and the direction it’s facing, a 2kW solar system can generate as much as 15 kWh of energy in a single day in the summer or as little as 4 kWh in the winter.

    You can get some pretty accurate predictions and estimates using the PVWatts Calculator by NREL (the National Renewable Energy Laboratory).

    The tool uses the location and the size (kW rating) of the solar system, along with other variables that describe the installation, to predict the energy production of the system throughout the year.

    To get these estimates, the first step is to go to the PVWatts Calculator and submit the area in which the 2kW solar system is going to be located.

    Then go to the “System Info” section of the tool and submit the correct details:

    As shown in the image above, in the “System Info” section of the tool, you’ll see 6 fields. I recommend you leave the Module Type, Array Type, and System Losses fields to their default values, and change the values in the following fields:

    DC system size (kW):

    This represents the Power rating of the solar system in kiloWatts (kW). In our case, the solar system is rated at 2 kW.

    This represents the angle at which the solar panels are going to be titled.

    The tilt angle of the solar system is going to influence the amount of sunlight it receives, and therefore, it’ll influence the amount of power and energy the solar system produces. Make sure to submit the correct tilt angle of your 2kW system to get the most accurate estimates.

    For example, if the solar panels are going to be installed on a flat surface, such as the roof of your RV, the tilt angle is 0 degrees.

    If the solar panels are going to be installed on a tilted roof, you can click on the information “I” icon to the right of the field to see the equivalent of your roof pitch in degrees. For example, a 4/12 roof pitch is equivalent to a tilt angle of 18.4 degrees.

    If you don’t know what your roof pitch is, you can use a smartphone app such as Measure for iOS or Bubble Level for Android to determine the tilt angle.

    Azimuth (deg):

    Azimuth represents the direction that the solar panels are facing. An Azimuth of 0 degrees means that the solar panels are facing North. An Azimuth of 180 degrees means that the solar panels are facing South.

    The direction that the solar panels will be facing also influences the amount of sunlight they receive and the amount of power and energy that they produce. So make sure to submit the correct Azimuth to get accurate estimates.

    In the U.S., or in any location north of the equator in general, the most optimal direction for the solar panels to face is South (180-degree Azimuth). In locations south of the equator, such as Australia, the most optimal heading is North (0-degree Azimuth)

    If your solar panels are going to be roof-mounted, and since not all roofs face South or North directly, you can use a compass app such as Commander Compass Go for iOS or Azimuth Compass for Android to determine the exact direction your roof is facing.

    Once you submit the size of the system (2kW), its Tilt Angle, and Azimuth, the last step is to go to the “Results” section of the PVWatts Calculator to get your estimates.

    To give you an example, I’ll submit the following details to the calculator and show you the results:

    • Address: an address in Phoenix, Arizona.
    • DC System Size: 2kW.
    • Tilt: I’ll assume the system is roof-mounted with a 5/12 roof pitch, which is equivalent to a tilt angle of 22.6 degrees.
    • Azimuth: I’ll assume that the only unshaded roof section available is facing South-West, this equates to an Azimuth of 225 degrees.

    In the Results tab, the calculator provided the following table:

    The PVWatts Calculator has estimated that a 2kW solar system in that particular location in Phoenix, AZ, that is titled at an angle of 22.6 degrees, and that is facing South-West, would on average produce 3382 kWh of energy per year.

    In the table, you can also see energy production estimates for each month, which you can divide by 30 to determine the average daily energy production for a specific month.

    For example, while the 2kW solar system would only produce about 198 kWh of energy in December, which translates to 6.6 kWh of energy per day, the 2kW system would produce around 359 kWh of energy in May, which is equivalent to about 12 kWh/day.

    Once you’ve estimated the amount of energy that a 2kW system is going to produce, the next section will help you put this amount of energy into perspective.

    Is 2kW enough to power a house?

    The short answer is no, a 2kW solar system would not be able to offset the energy consumption of the average American household.

    According to the EIA (U.S. Energy Information Administration), the average annual energy consumption of a U.S. residential utility customer is around 10600 kWh. A 2kWh solar system, on the other hand, would not exceed an annual energy production of 3500 kWh.

    In other words, a 2kW solar system would only be able to offset 25 to 30% of the energy consumption of the average American household. However, if your daily energy consumption does not exceed 8 kWh/day, a 2kW solar system should be enough.

    For example, let’s say you’re trying to run a 20 Cu. ft. refrigerator, a 5000 BTU air conditioner, a 32″ LED TV, 2 laptops, and 3 LED light bulbs.

    The amount of energy the refrigerator and the air conditioner use will depend on the outdoor temperature. But on average, a 20 cubic feet fridge would consume about 1.8 kWh per day; and assuming it’s left on for about 8 hours a day, a 5000 BTU air conditioner would consume about 2.5 kWh of energy per day.

    A 32″ LED TV uses about 40Wh of energy per hour (0.04 kWh/hour). So assuming the TV is left on for 5 hours a day, it would consume about 200Wh of energy per day or 0.2 kWh/day.

    A laptop uses around 60 Wh of energy per hour of use (0.06 kWh/hour). So assuming the 2 laptops are also used for about 5 hours a day, both laptops would consume around 600 Wh of energy per day or 0.6 kWh/day.

    An LED light only uses about 10 Wh of energy per hour (0.01 kWh/hour). Assuming the 3 LED light bulbs are left on for 6 hours a day, they would use about 30 Wh of energy per hour, which translates to about 180 Wh of energy per day, or 0.18 kWh/day.

    • Refrigerator: 1.8 kWh/day
    • Air conditioner: 2.5 kWh/day
    • TV: 0.2 kWh/day
    • 2 Laptops: 0.6 kWh/day
    • 3 LED light bulbs: 0.18 kWh/day

    If we add all of these together we can determine our daily energy consumption:

    Daily Energy Consumption (kWh/day) = 1.8 2.5 0.2 0.6 0.18

    Daily Energy Consumption (kWh/day) = 5.28 kWh/day

    With a daily energy consumption of 5.28 kWh/day, a 2kW solar system would definitely be enough.

    If you’re trying to offset 100% of the energy consumption in your house, you might find one of the following pages useful:

    How many panels will you need for a 2kW (2000 Watt) solar system?

    Typically, you would need between 5 and 10 solar panels for a 2kW solar system. The number of solar panels required for a 2000 Watt system would depend on the power rating of the solar panels you’re planning on using.

    For example, if you’re planning on using solar panels that are rated at 400 Watts each, you would need 5 of these panels to form a 2kW system (5 x 0.4 kW). If the solar panels are rated at 200 Watts each, you would need 10 panels (10 x 0.2 kW).

    How many batteries for 2kw solar system?

    As mentioned above, on average, a 2kW (2000 Watt) solar system produces around 8 kWh (kiloWatt-hours) or 8000 Wh (Watt-hours) of energy each day. To store and access this amount of energy, you would need – at least – 8 batteries rated at 12V-100Ah, 4 batteries rated at 24V-100Ah, or 2 batteries rated at 48V-100Ah.

    However, the battery bank that you need for your solar system should not be sized based on the potential daily energy production of your solar panels but based on your daily energy consumption.

    Other factors such as Depth Of Discharge (DOD) and Days of Autonomy should also be taken into consideration when calculating battery capacity.

    Solar Panel Output: How Much Power Does a Solar Panel Produce?

    Emma Stenhouse is a marine scientist, educator, and writer with more than 16 years of experience. She holds an M.S. in Marine Science from the University of Plymouth.

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    On average, solar panels designed for domestic use produce 250-400 watts, enough to power a household appliance like a refrigerator for an hour. To work out how much electricity a solar panel can produce in one day, you’ll need to multiply the wattage by the hours of sunlight.

    The higher the wattage of each panel, the more electricity produced. By combining individual panels into a solar system, you can easily generate enough power to run your entire home.

    In 2020, the average American home used 10,715 kilowatt-hours (kWh), or 893 kWh per month. If you want a solar system to power your entire home year-round, you’ll need to install a system that can supply all of these energy needs.

    The actual output of each individual solar panel will also depend on a range of factors including your location, local weather conditions, plus the angle and direction that the panels have been installed.

    What Are Watts and Kilowatts?

    To understand how much electricity a solar panel can produce, we first need to get comfortable with some units of power and energy.

    If you’ve been reading about solar panels, you’ll have noticed some specific units being mentioned: watt (W) and kilowatt (kW), plus watt-hours (Wh) and kilowatt-hours (kWh). Watt and kilowatt are units of power, and indicate how much power a solar panel can provide; 1,000 watts (W) = 1 kilowatt (kW).

    Watt-hour and kilowatt-hour are units of energy, and are used to show how much work (by work we mean running a light or an air conditioning unit) can be completed in one hour; 1,000 watt-hours (Wh) = 1 kilowatt-hour (kWh).

    How Is Solar Panel Output Calculated?

    The maximum or peak amount of electricity that can be produced by a solar panel is defined by its wattage. Remember this is measured under standard test conditions (STC) of 77 degrees F, 1 kW of solar radiation per square meter, and no wind. You’ll rarely find these conditions in nature, so expect your solar panel’s output to be a little less than this peak rating provided by the manufacturer.

    Once you know the wattage of your solar panel, you can use the following calculation to work out how much electricity your solar panel can produce in one day:

    Solar panels watts x average hours of sunlight = daily watt-hours

    This calculation relies on you knowing (or being able to estimate) the number of sunlight hours your panel receives. You can either estimate this or use a solar calculator like the National Renewable Energy Lab’s solar resource maps. Let’s look at some examples:

    Your solar panel has a rating of 250 watts, and your home receives six hours of sunshine per day. Multiply 250 x 6, and we can calculate that this panel can produce 1,500 Wh, or 1.5 kWh of electricity per day.

    On a cloudy day, solar panels will only generate between 10% and 25% of their normal output. For the same 250-watt panel with six hours of cloudy weather, you may only get 0.15-0.37 kWh of electricity per day.

    Upgrade to a 400-watt panel, and with the same amount of sunshine, you would now get 2,400 Wh, or 2.4 kWh of electricity per day. On a cloudy day, the electricity generated may only be 0.24-0.6 kWh per day.

    For reference, the average American home uses about 29 kWh per day. Install a solar power system with 20 panels of 250 watts each, and in the same six hours of sunshine, your system will generate 30 kWh, which is just enough to power the average home for one day.

    Variables Affecting Solar Panel Output

    In addition to the amount of sunlight received per day, there are other factors that affect the output of your solar panel or system.


    Anything that builds up on the surface of your solar panel can affect the output. This can include dust, leaves, snow, or bird droppings. A clean solar panel can be 6.5% more efficient than a dirty and dusty panel.

    Roof Direction and Angle

    Solar panels are most efficient when directed in a south-east to south-west direction, at an angle of 30-45 degrees. Systems at other directions and angles can still work, but your outputs will be decreased.


    Solar panels are very sensitive to shade, including trees, or a building next door. Minimal shading in the morning or evening is fine, but significant shading throughout the middle part of the day will significantly impact the amount of electricity a panel can produce.


    The amount of sunshine and Cloud cover will affect the amount of energy a solar panel can produce.

    Time of year

    Solar panels can produce electricity year-round, even on overcast days. Through summer, the days are longer which generates more output, but shorter days in winter mean your output will be lower over these months.


    As solar panels age, their efficiency decreases at around 0.5% each year. The life cycle of the system is approximately 25 years before performance has decreased to the point a new system is needed.


    The efficiency of solar panels is usually measured at 77 F, and temperatures above this can end up decreasing their efficiency. Solar panels can work well in cold weather, and can still generate power in snowy conditions, too.

    How Much Electricity Does My Home Need?

    One solar panel on its own isn’t going to create enough electricity to power your entire home, but a solar panel system can. To work out what size system you need, you’ll need to complete some basic calculations that we’ve covered in our article How Many Solar Panels Do You Need?

    To fully power an average home using 11,000 kWh per year, a typical solar power system will need between 21-24 panels of 320 watts each. The exact number and wattage of panels, as well as the output they can produce, will depend on where you live and the setup of your specific system.

    Types of Solar Panels and Output

    There are three main types of solar panels used for domestic systems:

    • Monocrystalline. These are the most popular type of panel, made with pure silicon. They have an efficiency of 24.4%, with a moderate cost and a long lifespan.
    • Polycrystalline. These are made of silicon crystals that have been melted together. They have an efficiency of 19.9%, a low cost and a moderate lifespan.
    • Thin-film. Made with a variety of materials including small amounts of silicon, thin-film panels have an efficiency of 18.9%, with a high cost and a shorter lifespan.

    The output of each type of panel will vary depending on the individual manufacturer, but will always be stated as a power rating in watts. The higher the watts, the higher the output. You may also see a kilowatt peak rating, which is the maximum power the panel can produce under the standard test conditions mentioned earlier.

    Cost vs. Value

    The solar market is very cost competitive, but some brands will offer you a more efficient system for a slightly higher investment. These systems will generate more electricity over the life of the system, so in the long run, they will create more value with consistent increased output.

    Remember to look into federal tax credits and other incentives designed to reduce the cost of solar panel installation.

    Given your house gets about six hours of daily sunshine, a standard 250-watt solar panel would produce 1.5 kWh of energy in a day.

    You would need about 20 250-watt solar panels to generate the amount of energy the average American home uses in a day.

    You can increase solar panel efficiency by cleaning the dirt off your panels regularly, pruning any trees that could be shading the panels, optimizing the panels’ angle (ideally to a 30- to 45-degree angle facing south), or installing an automatic solar tracker that rotates the panel to keep it aligned with the sun.

    • How Many Solar Panels Do I Need for My Home? EnergySage.
    • How Much Electricity Does an American Home Use? U.S. Energy Information Administration, 2020.
    • Do Solar Panels Work at Night or on Cloudy Days? EnergySage.
    • Hussain, Athar, et al. An Experimental Study on Effect of Dust on Power Loss in Solar Photovoltaic Module. Renewables: Wind, Water, and Solar, vol. 4, no. 9, 2017., doi:10.1186/s40807-017-0043-y
    • Solar Panel Performance: How Much Does Roof Orientation and Angle Matter? EnergySage.
    • Jordan, Dirk and Sarah Kurtz. Overview of Field Experience—Degradation Rates and Lifetime. National Renewable Energy Laboratory, 2015.
    • Mow, Benjamin. STAT FAQs Part 2: Lifetime of PV Panels. National Renewable Energy Laboratory, 2018.
    • How Hot Do Solar Panels Get? Effect of Temperature on Solar Panel Performance. EnergySage.
    • Belyakov, Nikolay. Chapter Seventeen—Solar Energy. Sustainable Power Generation: Current Status, Future Challenges, and Perspectives. 2019, pp. 417-438., doi:10.1016/B978-0-12-817012-0.00031-1

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