How your roof’s azimuth angle effects solar panel efficiency.
There is a lot more that goes into what makes a roof ideal for a solar panel system than most homeowners realize. Even if you believe you have enough sunlight hitting your roof to go solar, we may still determine it does not. Although your home may have sunlight that hits a section of your roof at particular hours of the day, it’s possible it may not produce enough electricity due to its azimuth. The wrong azimuth angle reduces the energy output of a solar panel array down to 35%.
Your roof’s azimuth, or it’s orientation relative to magnetic North, and it’s slope, or tilt, determines how much sun you can collect over the course of a year. A South-facing roof will receive more sun than a roof facing any other direction, and a flatter tilted roof will generally produce more than a steep one. The same goes for your property if you are interested in a ground mounted system. The physical size of the system is governed by your roof’s dimensions. Once we know that, we can determine how many panels your roof will actually fit. Solar panels are rated in Watts, just like your light bulbs, except in the case of solar panels, they produce, rather than consume, electricity.
Solar energy production is based on the panel size multiplied by the number of sun hours your roof receives. Solar panel dimensions are, on average, about 3’ by 5’. However, the power rating of panels can range from 250W to over 320W each, based on size and brand. The amount of electrical energy that a system produces over the course of a year is called kilowatt-hours, or kWh (the same unit that’s on your electric bill), and it is determined by the power of the array in kiloWatts (1000W=1kW), and the number of hours your roof or property receives full sun, as discussed above.
In general, a one kilowatt of solar panels produces about 1,000 kilowatt hours (kWh) of electricity a year. So the total size of the system will be based on the number of solar panels required to produce enough electricity to equal or exceed your power usage. For example, if you use 20,000 kWh a year (from your electric bill), you’ll need a system that is roughly 20kW to meet your needs.
Sadly, some companies will still sell solar panel systems to homeowners that will not produce enough sunlight to offset the cost of a system – thus making the system extremely expensive and inefficient. However, Solar Energy World will never do that. We prefer to install fewer solar systems that will actually save money for our customers, to installing solar systems to anyone who asks us. We want what we install to work at the optimum level for our customers. Our integrity is one of the main reasons why we are the fastest growing, locally owned solar panel system design and installation company in Maryland.