Converting your home to solar power is a great way to lower your electricity bills and help the environment. However, just how much energy from the sun do you need to power a house?
The amount of solar power you need to power a home depends on a variety of factors:
- Energy Usage
- Amount of Shade
- Energy Production of the Panels
To learn how these various factors affect the number of panels you will need to power your home with solar energy, continue reading below.
Probably the factor that affects the number of solar panels you will need to power your home the most is your energy usage. Obviously, the more energy your home uses, the more panels you will need.
A typical home of 1,500 square feet with average electricity bills of $100 per month will require 16 solar panels to fully power the house.
To calculate your energy usage, you need only look at your electricity bill. Look for “kWh” or “Kilowatt Hours Used” and also notice the time period. Usually, the bill is for 30 days.
Take the number of kilowatts used and divide it by the time period to get your average daily energy use. It is recommended that you do this for a few different electricity bills from different times of the year and then averages the results.
Once you have your estimated daily energy usage, add an additional 25 percent to the number. By adding this extra amount, you take into account the fact that solar panels do not operate at their full efficiency every hour of every single day.
Finally, take the number you have and divide it by the number of kilowatts a single solar panel provides. The resulting number will be the number of solar panels you need. If you get a decimal, be sure to round up.
What You Are Powering
Your energy usage is directly related to what you are powering within your home.
Here are the standard appliances or devices found in most homes, as well as the average number of kilowatts per year to power those devices and the number of standard solar panels required to meet that need:
- Air Conditioning Unit: 215 kWh/year – 1 panel
- Central Air Conditioner: 1000 kWh/year – 3 panels
- Refrigerator: 600 kWh/year – 2 panels
- Electric Vehicle: 3000 kWh/year – 10 panels
- Hot Tub: 3,300 kWh/year – 11 panels
- Heated Pool: 2,500 kWh/year – 8 panels
The age and efficiency of your appliances also affect your power usage. The older your equipment, the more power your equipment will need most likely.
In order to reduce the number of solar panels you will need, you may need to upgrade some of your appliances. When looking for replacements, be sure to look for the EnergyStar logo, which implies that the device is designed to draw as little energy as possible.
Another factor that affects how much energy you need from the sun to power your home is the location of your home.
A home located in the north where it snows will require enough solar energy to power its heating system while a home located in the south will require enough solar to power its air conditioner. Both of these homes will have different solar energy needs.
You can use a solar calculator to calculate how many solar panels you will need for your home based on its location as well as your average energy usage.
Below is a list of average energy usage and the number of panels needed for four different locations within the United States:
- New Jersey: 8,280 kWh/year – 25 panels
- California: 6,522 kWh/year – 14 panels
- Illinois: 8,929 kWh/year – 25 panels
- Texas: 14,112 kWh/year – 36 panels
Each region within the United States tends to have different power needs, which is just as each region has different heating and cooling needs.
To find out the average power consumption in your particular location you can always call some local solar providers. These companies will have up-to-date statistics on your actual location.
Many solar panel companies will even provide free consultations, which will include sending out a technician to do a survey of your home and estimate your power needs.
Another reason that location affects the number of solar panels you will need is the amount of sunshine available in that region. You will need fewer panels in California as a rule because the sun shines year-round.
Regions that are often cloudy or rainy will require more panels in order to catch as much sunlight available as possible when the sun is shining.
Also, areas that are prone to weather incidents such as large rainstorms, snowstorms, and hurricanes can have unpredictable moments that can affect solar panels. If there is no sunshine available, a panel can not collect it.
Additionally, these extreme weather conditions can actually cause damage to panels that will keep them from being able to collect solar energy until they are fixed.
If you live in an area prone to harsh weather incidents, be sure to check the warranty of your solar panels as closely as possible. Some solar providers will come out to fix certain damages to your panels at low or no cost to you.
Most solar providers also have maintenance plans available, For a small monthly or yearly fee, your solar company will provide a technician to come out and resolve any problems with your panels.
Location of Your Roof
Besides the geographical location of your home, the physical location of your roof also determines the number of solar panels you will need.
If you have a roof that faces east and west, you will require fewer panels because you will be able to get direct sunlight on your roof throughout the day.
If your roof faces north and south, however, you will require more panels in order to capture as much sunlight as possible.
Another factor to consider is the amount of space available on the roof itself. You will need a good amount of square footage on your roof to install the panels you will need.
The shape of your roof and whether it slants or is simply horizontal affects the amount of square footage available to install solar panels. Moreover, depending on how your roof slants or does not, you may get more or less sunlight throughout the day.
Some two-story houses that do not have the second story across the full first story actually have less available space for panels than some one-story homes. The reason this occurs is the second story actually casts the first story in shadow.
Amount of Shade
The amount of shade your roof receives on a daily basis also affects the amount of solar power you will need to power your home. If your home’s roof is in the shade a good portion of the day, then you will require more panels in order to try to capture as much sunlight as possible.
The amount of shade your home’s roof is in will vary depending on the time of year. If you contact a solar panel expert, he or she will be able to use a special instrument to measure shade production and provide an estimated number of panels you will need.
The amount of shade your home’s roof receives not only depends on the weather but also on your home’s surroundings. A home that has tall trees around it will be cast in shadow much of the day, while a home that has no trees around it will not be affected by shadow.
If your home’s surroundings are an issue, you may need to cut down the trees and plants around your house. Unfortunately, sometimes your surroundings are not within your control.
If your neighbor’s trees are casting shadows, for instance, you are probably not going to be able to get your neighbor to cut down his or her trees. Or if there is a tall home next to you, it will most likely cast your home in shadow for part of the day.
Your solar technician will be able to analyze the shadow situation on your property and make a suggestion as to the best course of action for your specific needs.
Energy Production of the Panels
Not all solar panels provide the same amount of energy. Panels come in low, medium, and high-efficiency levels. In general, solar panels range from 16 to 20 percent efficiency.
The more efficient a solar panel is, the better it is at capturing sunlight and converting it to power, which in turn means you will require fewer panels to meet your energy needs.
However, the more efficient solar panels are, the more expensive they are. Many homeowners need to find a balance between efficiency and affordability.
It is also vital to find a type of panel that provides enough power based on the amount of square footage available on your roof itself.
You will also need to take into account the aesthetics of the panels on your roof. Some homeowners do not want their roofs covered with unsightly panels. If this is the case for you, you may need to go with higher efficiency options because you will need less of them.
Research Your Panels
When deciding on a type of panel to use for your home, be sure to fully research the panels. There are numerous review sites online that provide you with honest and real feedback on each type and brand of panel on the market.
These reviews are written by real customers, which means they are true reviews and not marketing materials the panel manufacturers provided.
Consult an Expert
Because the process of finding the right solar panels that are within your budget but also fit your needs can be quite difficult, it is recommended that you consult with an expert solar installer in order to find the best solar panels for you and your situation.
Be sure to meet with various solar providers in your location. By meeting with multiple companies you will be able to find the best price for you. A lot of solar companies also offer price matches or guarantees.
So, if you meet with multiple providers, you can usually get the other providers to match or beat the best offer you received.
In addition, be sure to check the warranty offers each company has. There are times where you will need to repair a panel or something else in the system.
Warranties allow for various conditions where the manufacturer will come to your location to resolve your problems.
Not all warranties are created equal, so be sure to read through the fine print as carefully as possible.
Another factor to consider is how long it will take to pay back the cost of the installation with the energy savings you will be receiving. The more efficient the panels, the shorter the time period is for paying back.
For most homes with 16 panels at medium efficiency, it takes about six to eight years for the panels to save as much money as it cost to install them.
Solar panels not only vary in efficiency but also in size. The larger the dimensions of the panel, the more solar energy it can capture. However, not all roof areas can accommodate all panel sizes.
Be sure to ask your solar installer whether you are receiving the largest area panel possible for your roof. However, like the other factors, the size of the panel directly affects the cost of the panel. In general, the larger the panel, the more expensive it is.
One drawback of larger panels to keep in mind is if a panel is damaged by falling debris or a storm, you will lose more solar production than you would with a smaller panel.
For instance, if a single large panel that provides 50 kW is damaged, you will lose 50 kW of power until it is fixed. However, if you had smaller panels, you would lose less power.
Basically, if you have larger panels and one gets damaged, the loss of available solar energy will be much higher than a home whose panels are smaller.
Due to this fact, numerous companies recommend going with smaller panels for areas prone to weather incidents. It is cheaper and easier to replace equipment that is smaller and lighter.
Moreover, your overall energy production is affected less in systems that utilize smaller solar panels.
Good maintenance of your panels is vital to ensuring that they are working properly. This process includes checking your panels regularly to be sure that no leaves and other debris have built up on your panels, blocking them from absorbing sunlight.
It is also important to keep the panel surfaces clean to make sure they are running as efficiently as possible. However, be sure to consult with your solar provider before cleaning your panels.
Solar panels are a unique technology and need to be cleaned in certain ways. If you use the wrong type of cleaner on the panels you may leave a residue that will keep the panels from working as efficiently as possible.
As stated before, many solar panel companies offer maintenance plans that include coming to your home a few times a year to clean your panels and check on their efficiency.
It is highly recommended that you sign up for a maintenance plan, if possible. By doing so, you will help to maintain your panels and ensure that they are working to the best of their ability.
Remember You Can Always Change
A final point to keep in mind is you can always upgrade your panels. You are not stuck with the kind of panel you first chose. New technology is coming out on the market nearly every single day.
If at a later point you find a type of solar panel you like better than the one you currently have installed, you can have a technician switch out the panels for you.
Though this will be an added expense, the amount of energy the new panels provide will be a much-needed plus.
Another benefit of replacing your solar panels with a newer model is that you are able to sell your older solar panels. The income you make off of these devices will help to offset the cost of buying and installing the new panels.
The amount of solar power your home will need depends on a variety of factors, including your energy usage, home location, amount of shade, and type of panels chosen.
There are various tools available to help you estimate the number of panels you will need to power your home. However, it is recommended that you speak to an expert solar installer to get the best suggestions for your particular needs.
Though going solar can be a difficult process, once you have, the overall cost savings will be worth the trouble of the installation.