Knowing how many solar panels a house will need for complete power generation requires ascertaining the amount of power consumed over a duration. For instance, a large house with numerous appliances and light bulbs will consume more energy than a smaller one. This also means more solar panels. Of course, it’s always easier to determine your solar consumption by contacting a reputable solar company that specializes in such things. They can quickly calculate your average power consumption, meaning they can tell how many solar panels your house will need for power generation.
Determining Power Consumption
Before determining the number of solar panels needed to power a house, you’ll need to know how much power is consumed. This determination needs to account for certain factors. These include;
i)Electricity Usage: How much electricity your house uses will depend on the number of appliances you have. Ideally, it’s best to consider electricity usage over a full year. This is because electricity consumption is rarely constant. This ensures that any kind of consumption fluctuations are fully accounted for. It is estimated that the average American household uses nearly 11 000 KWh of electricity each year. However, you can simply add up all your monthly electrical consumption (in KWh) for the past year and divide it by 12 months. This will be your average electricity usage.
ii) Production Ratios: This is the technical term to refer to the expected energy output of a solar installation to its actual size. This is measured over time. Ideally, the ratio should be 1:1. However, due to inefficiencies in the system and things like geographical location. To calculate this, consider a 10 KWh system that produces generates 15 kWh per year.
The production ratio here is calculated as 15 KWh/10 KWh, giving a ratio of 1.5.
iii) Solar Panel Wattage: This refers to the energy output of a single solar panel under ideal conditions. Also known as a solar panel’s power rating, it is measured in watts (W). Most solar panels fall within the range of 250 to 400 W. For purposes of power consumption calculations, 340 W is the average.
The number of solar panels used is determined using the following formula:
Number of panels = system size/production ratio/wattage
Plugging in our earlier values,
Number of panels =11 000/1.5/340
This gives 21. 56, meaning such a house will require 21 solar panels for adequate power. Such a house’s power consumption will equal 21x 340W, giving a value of 7.14 KWh.
Factors that Will Determine Your Solar Energy Output
Solar power production and consumption are critical to determining the number of solar panels needed to power a house. These factors include:
1)Panel Efficiency
Depending on the wattage of your solar panels, you may need more or fewer solar panels. For instance, if your house size usually requires 25 solar panels of 250 W to power it, opting for 400 W panels will significantly reduce the number needed to power the house. Higher-efficiency panels are better at capturing more sunlight, meaning they can generate more power from limited amounts of sunlight compared to lower-grade ones. Using the latter type means you’ll need many of them to power your house.
2) Energy Use
This is key to determining the number of solar panels you’ll need. Consuming large amounts of electric power means that you have appliances that require significant wattage. For instance, if you have appliances like large refrigerators and water heaters, these tend to consume significant power. This means you’ll need to have more panels to provide enough electricity to power all such appliances.
3) Geographical Location
Places with plenty of sunshine year-round tend to be ideal for the use of solar panels for electricity generation. Even when the solar panels are not of the highest quality, they can still generate enough power for the whole house. For a similar house size, fewer panels will be needed to power it in a region with plenty of sunshine compared to one in a cold region.
4) Buyback Programs Offered By Your Utility Company
Many people that rely on solar panels for their electricity are still connected to the power grid. This ensures that they avoid outages at night when sunlight is unavailable. The same meter calculates electricity consumption regardless of whether it’s from the power grid or your solar panels. Some utility providers have a system that enables you to send excess power generated by your solar panels to the grid. This earns you credits, credits that you can redeem when purchasing regular power later on. Understanding how such a credit system works will determine how many panels you should install to get more credits and, therefore, power at night.
All in all, reputable solar professionals can help you with all aspects of solar power consumption