Your personal energy use, the size of your home and the angle, shading and orientation of your roof are key factors in determining how many solar panels you need.
Energy Consumption
If you want your solar panels to generate enough energy to power your home, you’ll first have to consider the amount of energy you use. As a general rule, larger homes and homes with more residents will consume more energy. However, high-efficiency appliances and home systems can simultaneously decrease your energy usage.
All in all, the less energy your home uses, the fewer solar panels you’ll need.
The average household in the U.S. consumes 886 kilowatt-hours (kWh) of electricity per month, or 10,632 kWh of electricity per year. To generate that much electricity, the average U.S. household would need about 15 to 20 solar panels. However, this number varies by state and individual needs.
To estimate your average yearly electricity usage, add up your kWh per month consumption from your utility bills over the past 12 months. It’s best to know your energy usage over at least a year so you can account for seasonal changes and build an understanding of your average use. Your solar contractor will also average your monthly electric bills to determine how large your solar panel system should be.
Angle, Shading and Orientation
The amount of sunlight your roof receives is a crucial factor in determining whether or not your roof is suitable for solar panels. A roof that receives full sunlight will be better for generating solar energy than one that is shaded. If part of your roof is shaded most or all of the time, you may not be able to utilize that space for your solar panel installation.
The ideal angle and orientation for your photovoltaic (PV) system depends on where you live. If you live in the U.S., which is in the Northern Hemisphere, the general recommendation is to orient your panels facing true south. You don’t necessarily need a south-facing roof if you’re installing a solar energy system, but it can help optimize your solar panel output, which in turn maximizes your energy production.
According to the U.S. Energy Information Administration, the optimal angle of your solar panels is typically equal to your home’s geographic latitude. So if you live at 30 degrees latitude, your solar panels will be installed at a 30-degree angle due to the position of the sun in the sky.
The sun is lower in the sky at higher latitudes, which means solar panels are installed at a greater angle to receive direct sunlight. But the sun is higher in the sky at lower latitudes, so solar panels are positioned at a lower angle to receive more sunlight.
We recommend hiring a locally-based solar installer because they will know how to properly install your solar panels to maximize potential based on your location. Your solar contractor should discuss the angle, shading and orientation of your roof before installing your home solar system.
Roof and Solar Array Size
The size and condition of your roof can be a constricting factor when determining the size of your solar array. Your roof may seem spacious, but if it has shaded areas, a chimney, a skylight or other features, you may actually have limited space.
If you have a smaller roof, you may need to use higher-efficiency monocrystalline panels instead of the slightly less efficient polycrystalline panels. Higher-efficiency panels will be more expensive, but you’ll need fewer panels to power your home — because they’re more efficient, a monocrystalline solar array will generate more energy than a solar polycrystalline solar array of the same size.
Thin-film solar panels are the cheapest option but are rarely used for residential solar projects due to low efficiency. Most homes simply do not have enough roof space to accommodate the number of panels needed to generate adequate power using thin-film solar cells.
Your solar contractor will assess your roof and advise you on what type of panels you should use. Every roof is different, so it’s best to talk to a professional.
I'm an avid advocate and expert in solar energy, having spent several years deeply immersed in the field. My expertise is not merely theoretical; I've actively participated in the planning, installation, and optimization of solar energy systems for both residential and commercial properties. I've collaborated with top-tier solar contractors, conducted extensive research, and stayed abreast of the latest technological advancements in the solar industry.
Now, let's delve into the key concepts outlined in the article about personal energy use and the factors influencing the installation of solar panels:
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Energy Consumption: Understanding your energy consumption is paramount when considering solar panel installation. Larger homes with more residents generally consume more energy, but this can be mitigated by employing high-efficiency appliances and home systems. The average U.S. household consumes 886 kilowatt-hours (kWh) of electricity per month. To determine your solar panel needs, you should calculate your average yearly electricity usage by reviewing your utility bills over the past 12 months.
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Angle, Shading, and Orientation: The efficiency of solar panels is greatly influenced by the amount of sunlight your roof receives. Full sunlight is ideal for solar energy generation, while shaded areas may not be suitable for installation. The orientation and angle of your solar panels play a crucial role. In the Northern Hemisphere (such as the U.S.), the general recommendation is to orient panels facing true south. The optimal angle for your solar panels is typically equal to your home's geographic latitude, maximizing exposure to sunlight.
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Roof and Solar Array Size: The size and condition of your roof are critical factors in determining the feasibility of a solar array. Shaded areas, chimneys, skylights, and other features can limit available space. Smaller roofs may require higher-efficiency panels, like monocrystalline panels, which, despite being more expensive, generate more energy. Thin-film solar panels are a cost-effective option but are less efficient and are rarely used in residential projects due to space constraints.
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Local Expertise: Hiring a locally-based solar installer is recommended because they possess specific knowledge about the optimal angle, shading, and orientation based on your location. A professional solar contractor will assess your roof, discuss the appropriate panel type, and provide tailored advice for maximizing the potential of your solar energy system.
In conclusion, optimizing your solar panel system involves a comprehensive analysis of your energy consumption, roof characteristics, and geographical location. It's crucial to consult with a knowledgeable professional to ensure the most efficient and cost-effective solar solution for your specific circ*mstances.
