Solar Nerd articles about: Panel Efficiency

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Illustration of two thermometers
Solar panel temperature coefficient explained
If you’ve ever looked at the product sheet for a solar panel, you may have been confronted by tables of cryptic numbers and electrical terminology. Unless you’re an electrician or electrical engineer, you’ll probably find these a little bewildering. Fortunately, the average consumer can ignore most of them. Unless you’re an installer or hobbyist, many of the numbers are electrical specs that won’t matter to you. One exception, however, is power temperature coefficient.
Closeup photo of a solar panel
When will solar panels be more efficient?
When it comes to buying solar panels for your home, the first thing that manufacturers usually tout is the panel’s efficiency. Solar panel efficiency refers to the amount of sunlight hitting the panel that gets converted into electricity. The intensity of sunlight can be expressed in watts - the same unit used to measure electrical power. For example, if 1,000 watts of sunlight is shining on your solar panel and it generate 200 watts of electricity, the panel is 20% efficient.
Photo of a large house.
How many solar panels are needed to run a 4,000 square foot or larger house?
If you have a very large house, you probably have high electricity usage too, possibly making your home a good candidate for solar. If you’re curious about solar and want to find out how many solar panels you’d need for your home that is 4,000 square feet or larger, the most accurate way to find that out is to get a professional solar installer to perform an analysis. A quick but somewhat less accurate way is to read your monthly electric bill and use our solar calculator to determine what your power generation and estimated system price would be.
Solar array on the ISS
How efficient are home solar panels?
Is your house actually a space station? Is NASA your landlord? If so, then your home solar panels might be made by Boeing and deliver a sky-high 32% efficiency. It costs about $10,000 to send a pound of anything into orbit, and packing the maximum power onto a small satellite is critical, so it makes sense to use the absolute best available technology. By comparison, the solar panels I had installed on my house back in 2013 only manage about 16% efficiency - just half of what you’ll get from high-tech photovoltaic panels in space.
Photo of a home solar array.
What are the best solar panels for your home?
Are you a meticulous number cruncher who breaks out the spreadsheet whenever you’re planning a big product purchase? I certainly am. The last time I bought a car, and made a spreadsheet with the specifications of all the car models I was considering. I rank-ordered them in each of the categories that were important to me, and made my decision based on which one performed the best. Figuring out which solar panel is best for you is a little like that, although with this article I hope to make is less complicated for you.
Photo of ground mounted solar panels
Why are my solar panels producing less than the rated power?
If you own a home solar panel system, you might find that your system isn’t generating as much electricity as you think it should. Or perhaps you’ve got panel-level monitoring and can see that one or more panels are generating less power than the others. Before you call your installer for service, here are some reasons why your system might be having trouble. In this article: There are different reasons why your solar array will produce less energy than their theoretical maximum.