Updated: Aug 23
Going solar is like going on a journey in which you will discover how it works, how many solar panels you will require, how much it will cost, and how to find the best solar company for your solar needs. In this blog, you will learn all this stuff from a person who has 12 years of industrial experience, who knows all of what you need to know, and who can explain all this to anyone in the easiest possible way.
To estimate the numbers as well as the cost of solar panels needed to generate 1500 kWh per month, or 50 kWh (=1500/30) per day in the United States. You must be aware of several things, like
Various factors influence a solar panel's ability to generate power.
How the size of solar panels can affect the utilization of your rooftop space.
Area required for the installation of solar panels
Factors that can influence the price of solar systems.
How to choose the right solar company.
Calculating solar panels for 1500kWh per month (50kWh per day)
The power generation of a solar panel is directly dependent on the peak sun hours of the state, here peak sun hours differ from daylight hours. Peak sun hours are defined as the time of day when the intensity of sunshine is greatest. In other words, most electricity is generated by solar panels during peak sun hours.
The below map shows the average peak sun hours in different regions of the USA.
And compare the above map with the below map (which shows the average power generation in the USA by 1 kW of solar system per day) you can see how peak sun hours affect the power generation of solar panels.
In the USA, a state with 4.5-5 peak sun hours, 1 kW of solar system can 4.5kWh of power per day, hence to generate 1,500 kWh per month (50 kWh per day) you need (50/4.5=) 11 kW of solar system having (11000/400 = ) 28 numbers of 400 Watt solar panels.
Similarly, in the USA a state with 3.5-4 peak sun hours, 1 kW of solar system can 2.8 kWh of power per day, hence we need more numbers of solar panels to generate 1500 kWh per month (or 50 kWh per day). For a state with 3.5-4 peak sun hours you need (50/2.8=) 18 kW of solar system having (18000/400 =) 45 numbers of 400 Watt solar panels.
Similarly, you can calculate how many solar panels are needed to generate 2,000 kWh/ 3000 kWh /900 kWh per month or you can do a reverse calculation to find out how much power any number of solar panels can generate in your state. Click here for a reverse calculation example.
How many solar panels are needed for 1500 kWh per month (50 kWh per day) in the USA?
28 numbers of 400-watt, solar panels are required to generate 1500 kWh per month (50 kWh per day) in the states of the USA where peak sun hours is between 4.5 to 5. Whereas, in states where the peak sun hours are 3.5-4, it will require 45 numbers of 400 watts of solar panels to generate 1500 kWh per month.
If you are living in states like Michigan and Wisconsin where the per day peak sun hours is 3.5-4 hours then you will require 63% more numbers of solar panels to generate 1500kWh per month (50 kWh per day) as compared to states like Texas and California where the average peak sun hours is national highest.
Size of solar panels: For our estimation, we are using 400-watt solar panels, because it is recommended to go with higher-rated solar panels. FYI, a 400-watt solar panel is only 28% bigger than a 250-watt solar panel but it generates 60% more power. Going with the higher-rated solar panels will also reduce the solar panel's load on your rooftop.
Furthermore, in every quarter the rated power of a single solar panel module increases with a slight increase in its dimensions. However, the per-watt cost of the highest-rated solar is also the highest. Hence, to find the right price you might need to go with little less wattage of solar panels, for example, the price of a solar system with 365-watt solar panels will be lesser than one with 415-watt solar panels.
Area required for solar panels: 400-watt solar panels are 22.75 square feet and installing 28 numbers of them will cover 637 square feet of rooftop space. Moreover, installing 45 numbers of them will cover 1,023.75 square feet. Furthermore, you cannot cover the whole rooftop with solar panels you need space on a rooftop for the cleaning of solar panels, as per the thump rule you can cover 40 % to 50% of your rooftop with solar.
Hence in states with 4.5-5 peak sun hours, you will require (637/0.4=) 1500 square foot area to install solar panels for 1500kWh per month considering 40% rooftop space and to generate the same amount of power per month you will need (1,024/0.4=) 2500 square foot rooftop for the state with 3.5-4 peak sun hours.
However, if you did not have that much space then going with a small-size of solar system will also help to cut down your electricity bills.
>> Take a solar survey to find out how many solar panels can be fitted on your rooftop.
Factors that affect the power generation of solar panels.
There are some factors that affect the power generation of a solar plane, and understanding these factors will help you to understand why solar surveys are necessary.
The Direction of Your Roof Slope: In the United States a south-facing solar panel, generates the highest amount of power. This is because the United States is located in the Northern Hemisphere of the Earth, and the SUN is always in the southern portion of the sky in the Northern Hemisphere. Hence installing solar panels on the south-facing slope of your rooftop will generate the highest amount of power.
Furthermore, if you do not have south facing rooftop that does not means that you cannot install solar panels, but that means you will need a slightly higher size of the solar system. However, you need to take a solar survey to find the right number of solar panels you need to produce 1500kWh per month.
Shading: Solar panels (or cells of a solar panel) that received lower sunlight than the rest, acted as loads and caused a drop in current, power, and efficiency. Hence, a shadow-free space on the rooftop must be determined before installation.
However, if your rooftop (or part of the rooftop) has some shadow for a short period then you do not need to worry, you can install solar panels there too. Take a solar survey now, to find out how much solar your need.
Roof Angle: the rooftop incline angle also affects the power generation of solar power plants. In comparison to solar systems put on rooftops with a 20–30 degree inclination, those with a greater incline angle produce less power.
Here again, a greater incline does not mean you can’t have solar, but this means you need a higher size solar system and to find out what size of solar you need you need to take the solar survey.
Dirt: Accumulation of dusty particles on solar panels blocks the sunlight and hence reduces its capacity of producing power. However, having a duty neighborhood does not mean you cannot go with solar but you need to clean it more frequently.
Considering all these factors, without a solar survey it is hard to tell eject amount of power that solar panels generated on a particular rooftop.
1500 kWh per month (50 kWh per day) Solar system cost.
The cost of a solar system in the USA varies from $2.1 to $2.95 per watt. Hence the cost of 1500 kWh per month (50 kWh per day) solar system will be varied between $23,520 to $33,040.
In addition to the above you may also need to pay some more extra for the solar installation due to different factors that influence the cost of a solar system like rooftop conditions and battery backup, some of the major factors are mentioned below.
Factors that can influence the cost of the solar system.
Rooftop type: Solar Installation cost for a flat rooftop is higher than inclined rooftop because a flat rooftop required more structure and takes more time for installation than an inclined rooftop.
Age of Rooftop: An old rooftop may require repairing before the installation of solar panels. Installing, solar panels on rooftops without inspection may lead to much higher repair costs. So, don't skip the survey part.
Solar panels type: Solar panels are classified into two types: monocrystalline and polycrystalline. Monocrystalline solar panels are more expensive than polycrystalline panels. Monocrystalline, on the other hand, is more efficient and smaller.
Monocrystalline panels are preferable for rooftops with smaller shadow-free areas.
Solar inverter type: For rooftop solar systems there are two types of solar inverters are used, that is micro-inverters and string inverters. Micro-inverters are directly mounted on each solar panel, whereas string inverters are mounted in your houses and DC cables from all solar panels are connected to string inverters.
Going with a string inverter is cheap; however, the performance of micro inverters is very much better in terms of efficiency as well as in the expendability of the solar system.
Furthermore, string inverters come with 5 years of warranty, whereas micro-inverters come with 25 years of warranty.
Tracking system: A tracking system tracks the weather with weather monitoring sensors as well as solar power generation. Weather tracking helps estimate the actual efficiency of the solar panels and it comes with a cost too.
However, for a household solar system, you will not require weather monitoring tracking. It is only required for utility-scale systems (>100kW)
Battery Backup: If you need battery backup with solar for backup power during a power outage, then you will need to pay more for the same. The cost to pay for battery backup is subject to the size of the battery bank and the size of the battery backup is subject to the duration of the power outage and the rating of the load to serve power.
How to choose the right company for solar installation?
Now you know how many solar panels are needed to generate 1500kWh per month or we can say 50 kWh (=1500/30) per day as well as you know how much it cost and now you are in the semifinal stage of your solar journey. In the semifinal stage of your solar journey, you have to make a decision on how to choose the right solar company in five easy steps.
Step #1 Credentials: A right solar company must have all the credentials required for installing solar systems.
Organizations such as the North American Board of Certified Energy Practitioners (NABCEP) issue industry-standard credentials, which are commonly regarded as the gold standard among renewable energy system installers. Make certain that the solar installer you select is licensed, bonded, and insured to install residential solar installations in your region. Also, do forget to ask whether they will use subcontractors on your job and double-check their credentials.
Step #2 Customer service: A great solar installation, required great customer service.
However, depending on online reviews is not the right parameter to check customer service, because people tend to submit negative experiences more than positive ones.
Hence, don’t hesitate to ask for one or two references in your or nearby area that can serve as a reference and if possible pay a visit to their reference too.
Step #3 Credibility and Expertise: It much have expertise and credibility for installing solar equipment and be knowledgeable about all aspects of the process. A good rule of thumb is to work with installers who have at least three years of experience.
Step#4 Addressing Roof Conditions: When you hire a solar contractor, one of the first things they should do is inspect your roof. Inquire with your installer whether they recommend roof repair prior to installation. Also, make sure you understand who is responsible for any roof damage or leaks that may occur.
Step #4 Warranties: Before, signing up the company understands how their warranties work, and what are the key points of their warranties. FYI, both the workmanship and installed equipment have different warranties period. Always, go with the solar company, which has transparencies with their warranty conditions.
Step #5 Never select a company only on price: A low-quality solar panel and installation material can make a huge difference. Always chose a solar company on the basis of feedback and reviews, if a solar company didn’t have much or any reference but quote very low, just strikeout them from your list.
If possible, visit their installed solar system (one old and one newly installed) and talk with the property owner. This will help you to understand their work finishing and how solar make a change in people's life.