How Much Roof Space Or Ground Space Is Available
Once we have an idea of your energy needs from your past electricity consumption patterns and your estimated future usage, well look at the available space for your panels, whether on the roof or the ground.
The square footage of your roof is not enough information to accurately size a solar system.
Even if you know the exact size of the site where you want to place your panels, it is likely that not every inch of that will be suitable for solar.
You must also consider the number of hours of sunlight that roof or groundspace receives. If it doesn’t get enough hours of sunlight then it cannot be used for solar. .
To determine whether a site is suitable for solar panels, weve got to look out for objects that will shade the panels from the sun. Are there chimneys or other permanent rooftop structures that will cast shade on your roof panels? What about neighboring homes or other buildings? Are there any trees that will shade part of the roof seasonally?
Once you figure out how much of the site is really useful for solar panels you can then start thinking about where those panels should be placed to maximize energy production.
What Is Solar Panel Efficiency
This measures how much of the available sunlight can be used to create electricity. On average, the existing solar panels have an efficiency rating of 20%.
Suppose you have a panel with a 14% efficiency rating vs. a 21% efficiency rating. In that case, the higher rating will produce 50% more power with the available sunlight than the lower-rated panel.
As a rule, higher efficiency rated panels are more expensive but worth the extra investment.
Some Chinese manufacturers like Trina Solar, Canadian Power, and LongGi produce panels with higher efficiency at lower costs per W than some US manufacturers like LG, Panasonic, and SunPower.
How Many Solar Panels To Power A House
When estimating how many solar panels your home could need, its important to consider the size of your home. An average homeowner would need about 28 to 34 solar panels to fully offset their electricity usage. The chart below is an estimate of the number of panels you could potentially need based on the size of your home.
*Data from the Residential Energy Consumption Survey.
How many solar panels do I need for a specifically sized solar system?
To determine the number of panels you need to achieve a given solar system size, divide it by the wattage of each panel .
For example, if youre aiming for a 4 kW system, youll divide 4 kW by 320 watts to get 12.5. Round up the answer to 13, which is the number of panels you need.
How many solar panels do I need for common appliances?
You can also determine the number of panels you need on a per appliance basis. This approach is helpful if you want to add panels because of increased usage or when buying a new appliance.
To calculate this, divide the average annual wattage of the appliance by the panel wattage. For example, a 600 kWh refrigerator would need two solar panels
Recommended Reading: How To Charge Ev With Solar Panels
Is It Possible To Install Too Many Solar Panels
Believe it or not, its not always beneficial to install as many solar panels as you can possibly fit on your roof. Adding extra panels that arent needed just increases the cost of your initial investment, and if you dont have a way of capturing or getting credit for the extra energy that youre generating but not using, then you’re not getting a good return on that investment.
A good solar installation should offset as close to the exact amount of energy that you use as possible. Thats why we typically ask for samples of previous power bills when designing a system. These power bills help us estimate your power requirements, and design a system that matches your specific needs. Some months you might use more energy than your system produces, and some months you might use less energy than you produce, but at the end of the year, the goal is to generate about the same amount of energy as you use.
That said, there are some instances where it makes sense to install more solar panels to generate more energy than you plan on using. The first is if you plan on installing an energy storage system to capture that excess energy. Solar battery storage lets you use the energy you generated during the day to power your home at night, and also gives you a backup source of power in case you have a blackout or other issue.
In general its not possible to install too many solar panels but there just might not be a significant advantage to doing so.
Your Average Energy Consumption
You can easily determine how much electricity you use by looking at the back page of your last power bill. The amount of electricity you consume will be shown in kilowatt hours . This is the first step in determining how much you can save with solar energy as well as which system is right for you.
Typically, larger properties or households with higher energy demands will require a solar energy system around the 5kW range or higher.
A 5kW system in Australia generates between 18kW/h – 25kW/h of solar electricity on average per day. Refer to your bill to see how many kW/h or units you are currently using.
Some regions are limited by the size of the system they can install to find out more information, contact us.
Also Check: Is First Solar A Good Stock To Buy
You Dont Need To Offset Your Entire Power Bill To Save Money With Solar
There is a major misconception about solar, especially in the Pacific Northwest, that we would like clear up. We talk to homeowners every single day who think that solar is only a good investment if you can offset your entirepower bill with your solar panels. Were here to tell you the same thing we tell all of our customers : thats simply not true!
By the above logic, solar in the Pacific Northwest, where winter days can be short would be a total waste. And if that were true, nobody in Oregon would switch to solar energy! However, solar projects are on the rise in the Pacific Northwest. Companies like Intel, Ikea, and Albertsons have switched to solar at their Oregon locales, and in 2018, 70% of Oregons utility-scale net electricity generation came from renewable sources, including solar.
How To Calculate Your Daily Power Consumption Using Your Utility Bill
Knowing your average daily, monthly, and annual energy usage is essential as this will determine how many solar panels would be needed to offset your usage. Here, your utility bill will give you all the information you need.
Find the line item that shows your kWh usage from the current or previous month, which will give your energy usage for that period. Ideally, you want the total annual energy usage to get an accurate monthly and then daily average.
You can calculate this by taking your monthly kWh usage and dividing it by 24 to get an average hourly usage. To get an annual usage, take that exact kWh figure and multiply it by 12 to give you a yearly usage.
Read Also: What Can You Run Off A 100 Watt Solar Panel
Need Help With Solar System Sizing
Of course, sometimes its easier to talk to an expert who knows how to size a solar system and can walk you through the design process. Once youre ready, we do encourage you to schedule a free design consultation with us so that we can double-check your sizing, find compatible products, and ensure the system works within your constraints .
The fastest way to get a thorough evaluation of your solar needs is to call us at 1-800-472-1142 and connect with one of our designers. Wed love to help you design the perfect grid-tied system to meet your solar requirements.
Factors Impacting San Antonio Energy Production Needs
The energy production needs in Texas are high, but the possible offset for these needs isnt always 100 percent. The first step to determining the offset possible for a Texas home is to determine its energy needs which are different for each home.
Several factors help solar companies determine these energy needs. These include the amount of sun in the area, the electricity usage of the home and the type of solar panels installed.
Don’t Miss: How Much Does A 10kw Solar System Cost
How Many Kwh Can Solar Panels Produce And How Many Panels You Need On Your Roof
The amount of power your solar energy system can produce depends on the number of solar panels that can absorb solar energy and convert it into electricity.
Assuming you are going to choose standard-efficiency solar panels, here are the most common sizes for residential solar systems and their kWh production potential to give you an idea of how many panels you would need to run a house.
- A 3kW solar system which consists of 12 panels can produce an average of 4,200 kWh per year. You will need a roof space of about 194 sq ft for a 3kW system.
- A 5kW solar system which consists of 20 panels can produce an average of 7,000 kWh per year. You will need a roof space of about 340 sq ft for a 5kW system.
- A 10kW solar system which consists of 40 panels can produce an average of 14,000 kWh per year. You will need a roof space of about 680 sq ft for a 10kW system.
Keep in mind that the amount of power your solar system can produce depends on how much sunlight your roof receives and your location.
For example, California has more sunny days annually than Washington. In this case if you live in Washington you would need a bigger solar system to get the same power as you would get with a smaller system in California.
The Renewable Resource Data Center provides average daily total solar resource information on grid cells by state and its free to use so check it out.
Is 100% Solar Offset Possible For My Texas Home
Reaching an offset of 100 percent is harder than it looks and sounds. While many Texas homeowners own solar homes, most dont have 100 percent offset.
To most, the notion of less than 100 percent offset is ludicrous, but there are multiple reasons for it. Some of these reasons include available space for panels, solar not making financial sense to the customer or utility regulations.
While most Texas solar homes in larger cities, like San Antonio, dont have a 100 percent offset, they still save money and saving something is better than saving nothing.
Recommended Reading: How Much Does It Cost To Lease Solar Panels
How Many Solar Panels Do I Need For My Home
Its no use installing just one solar panelyoull need more than that to reap the financial benefits of a solar panel system. While the answer isnt always so simple, weve put together some example cases to help you understand, at a high level, how many solar panels you need to install an effective solar array.
How Much Energy Do You Want To Offset With Solar
Typically most people want to offset as close as possible to 100 percent of their consumption. However, not everyone can afford to offset all energy consumption with a stand-alone solar system as the overall cost of the full home solar power system and its installation can get quite expensive.
Installing a smaller system and participating in the net metering program is still a great way to reduce your electricity bill up to 50 percent or more.
Recommended Reading: Does Pine Sol Keep Ants Away
How Much Energy Is Used In A 2000 Square
The average 2,000 square foot home in the United States uses around 1,000 kWh of electricity per month. That works out to be about 32 kWh per day. Again, this is an average that factors in energy use in all regions of the United States and in all climate zones where heating and cooling needs may differ dramatically4.
How To Put Solar Panels On Your Roof
Your homes roof space is just one of the factors that determines the optimum solar power system for your familys needs. The arrangement of panels and the difficulty of the installation is determined by your roof, but you also need to consider your familys energy needs, any future changes that your family might expect, your local incentives and net-metering programs, and a variety of other factors. Fortunately, Palmetto can help figure out the precise number and type of panels that will work best for your roof, and make it easy to get a system thats perfectly matched to your familys needs.
To find out how many panels you can put on your roof, get started with a free solar estimate, and a Palmetto solar expert will help design a system thats just the right size to meet your energy goals.
Recommended Reading: How Long Until Solar Panels Pay Off
Solar Offset And Net Metering In Texas
Net metering and other solar policies in the state, county and utility company region often play a large role in solar offset. Texas doesnt require utilities to provide net metering, so those who dont live in a regulated utilitys district need to look for a utility that offers net metering. CPS Energy is one of the biggest utilities in San Antonio, and they provide net metering to solar-powered homeowners.
Electric utilities that pay the full retail rate for excess solar energy put onto the grid during the day have true net metering. Most utilities have a variation of net metering that pays solar customers less per watt for the power they put onto the grid than what they pay to pull electricity from the grid at night.
Metering that doesnt allow customers to trade their excess energy during the day straight across the grid means that these customers have to produce more than they need, or purchase battery backup to get the right offset and solar savings for their San Antonio homes.
Solar Panels And Electricity Usage Offset
To get the most out of your solar system, its important to know what the electricity usage offset your solar should provide. Electricity usage offset is the percentage of a homes electrical consumption provided by its solar panels. A simple calculation can show how much of a homes electrical usage is offset by its solar panels.
How Many Solar Panels Do You Need For A 2000 Sq Ft Home
Estimating the number of panels based on home area is an indirect approach, since you must assume the kWh consumption. Some homes have more efficient appliances, and habits also influence electricity usage. However, average values can be calculated from official data:
- The US Energy Information Administration estimated that the average home uses 867 kWh monthly
- The US Census Bureau determined that single-family homes have an average area of 2467 square feet
- When dividing these values, you obtain 0.35 kWh per square foot
Assuming 0.35 kWh for a 2,000 sq. ft. home, the estimated electricity consumption is 700 kWh. At this point, you can use the calculation procedure described in the previous section. Considering 6 peak sun hours per day and 300-watt panels, you need 16 to produce 700 kWh each month.
If you have limited roof space, the best recommendation is installing the most efficient solar panels available. This will maximize the watts installed per square foot, compensating the area limitation. Finding out how efficient solar panels are is simple: you must only divide their individual wattage and area. The panels with the most watts per square foot have the highest efficiency.
How Much Power Does Your Home Use Annually
To calculate how many panels you need. It would help if you determined how many solar panels are necessary to offset the amount of kWhs across a full year. Based on the average amount you consume daily or monthly, you can calculate how many kWhs of power your home consumes on an annual basis. A kWh is a unit of measurement for the amount of energy that the utility company uses to gauge how much electricity your home consumes. Your electricity cost is based on kWh and how much you consume.
The easiest way to determine your annual kWh consumption is by taking the average daily usage and multiplying it by 365 . This number is typically found on your electricity bills first page, near the bar chart graph.
Recommended Reading: Can You Recycle Solar Panels
How Many Solar Panels Do I Need For 1500 Kwh Per Month
1500 kWh per month is equivalent to about 50 kWh of energy consumption per day. So, how many solar panels do you need to produce 50 kWh of energy per day?
On average, a solar energy system that produces 1500 kWh per month , would be rated at 10 kW. This is roughly equivalent to 30 residential solar panels. However, the size of a PV system that produces this much energy, will mainly depend on the amount of available sunlight.
For example, on average, a person in Iowa City, IA would need a 10.6 kW system consisting of about 32 residential solar panels to produce 1500 kWh per month. A person in Los Angeles, CA would only need an 8.2 kW system consisting of about 24 solar panels to produce the same amount of energy.
This is because the amount of direct sunlight that a solar panel receives differs from location to location. However, thankfully, the amount of sunlight that an area receives is measurable and somewhat predictable.
The energy that an area receives from the sun is measured in kWh/m² and is referred to as Peak Sun Hours. 1 Peak Sun Hour is equivalent to 1 kWh/m².
Peak Sun Hours are used to predict the amount of energy that a solar installation would produce. If we know how much energy needs to be produced, Peak Sun Hours can be used to determine the size of the system that we need .
System Wattage = Daily Energy production ÷ Daily Peak Sun Hours
System Wattage = Daily Energy production ÷ Daily Peak Sun Hours
System Wattage = 50 kWh ÷ 5.33
System Wattage = 9.38 kW