How much solar panel do i need
Solar panels have become increasingly common in recent decades. This is partly due to increased environmental awareness and a desire to save money by switching to cleaner, more natural sources of heating, cooling, and power. If you’re thinking of making this switch, you’re probably wondering how manyit takes to power a house.
When determining how much solar energy you need; your home’s average energy usage is the first thing to look at. According to the Energy Information Administration, the average home utility user consumed 10,649 kWh in 2019. That’s around 877 kWh per month. To figure out your own usage, look at your last twelve months’ utility bills. Most utility invoices provide this data. Divide that by 12 to get an idea of what yours will need to output each month.
Factors That Affect Solar Panel Output Efficiency
- All else being equal, the solar panel’s design influences its efficiency. So each square foot can convert sunshine into energy.
- Gridlines, for example, reduce active surface area. So they are less efficient than those without. Grid panels can sometimes peel, limiting efficiency.
- Quality matters, too. For example, poor construction can cause corrosion and cracking, reducing the panel’s ability to absorb sunlight.
- Residential solar panels typically produce between 150 and 370 watts. This amounts to a 15-watt solar panel per square foot.
How do we determine the number of solar panels we need?
To determine the number of solar panels required to power a house, you’ll utilize a formula that takes into account three critical variables: annual energy use, panel wattage, and production ratios. However, what does this actually mean?
Annual Electricity Consumption
The first step is to calculate your yearly electricity consumption; this is the total quantity of electricity consumed by your complete home over a 12-month period. This figure, expressed in kilowatt-hours (kWh), includes all electrical sources in your home, such as small and large appliances, air conditioning units, lights, air purifiers, and water heaters. According to the United States Energy Information Administration (EIA), the average household utilizes approximately 11,000 kWh of electricity per year.
The wattage of Solar Panels
While most solar panels seem the same, they are not all made equal, which is why you’ll need to know the wattage of the panels you intend to install. The wattage of the panel indicates the quantity of electricity emitted by the panel. Because the majority of solar panels range in power from 250 to 400 watts, it’s reasonable to conclude that 300 is the typical panel wattage you’ll find.
Ratios of Production
The production ratio of a solar panel system is the ratio of the system’s estimated energy output over time (in kWh) to the system’s actual size (in W). You might believe that this is a 1:1 ratio – that you get back exactly what you put in. However, differences in the amount of sunlight that shines down on your residence make this impossible.
A ten-kilowatt system that generates sixteen kilowatt-hours of electricity per year has a production ratio of 1.6 (16/10 = 1.6). It is entirely conceivable to have this type of ratio in a country like Hawaii, which benefits from long days and steady sunshine.
Solar panels are best suited for sunny areas like California and Arizona. With more sunshine, each of your individual solar panels will generate more power. For our calculations, we’ll assume that you get four hours of sunshine per day.