Articles tagged "panel efficiency"

Solar homeowners always want to see their solar panels generating as much electricity as possible. But even if you live in one of the sunniest cities in the country, there will always be cloudy days. Or maybe you live in a place where the weather is more temperate, and you experience a mix of sun and cloud. If you want to go solar, you might wonder if certain solar panels perform better than others in cloudy conditions.

The photovoltaic effect was first discovered in 1839 by Alexandre-Edmond Becquerel when he was 19 years old. Becquerel’s early experiments involved silver and platinum and generated only tiny amounts of electricity. It wasn’t until decades later that the first true solar cell was built using selenium by Charles Fritt in 1883. Those first cells still weren’t very efficient, only converting about 1% of the incoming light into electricity, but were a significant advancement.

If you pay a solar contractor to install solar panels on your home, most of the nitty gritty technical terms are hidden away from you. They will give you an easy to understand proposal, and then one day you have shiny panels on your roof, generating electrons. It’s nice! But if you’re undertaking a DIY project, all the calculations are up to you. One concept that you may come across is the solar panel derate or derating factor.

Solar panel manufacturers are always competing against each other to squeeze the most power out of the same size solar panels. If you installed solar panels on your home 10 years ago, you probably had panels with efficiency in the mid-to-high teens (by percentage of light converted to electricity). Today, you can commonly find solar panels that convert more than 20% of the incoming light into electricity, with the current best residential panels hitting nearly 23% efficiency.

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.

Solar panels don’t have any moving parts. They just quietly sit on your roof or in your backyard for a couple decades and generate electricity, day in and day out. How cool is that? A study by the National Renewable Energy Laboratory shows that new solar panels have a failure rate of only 5 in 10,000 per year. This means that every year, a solar panel has a 0.05% chance of failing, or a total 1.

When it comes to buying solar panels for your home, there isn’t a lot that obviously differentiates one solar panel from other. If you buy a car, there’s dozens, if not hundreds of different features, styles, and add-on options that you can take into account. But with a solar panel, there’s really only a handful of characteristics that make one product different from another. One of these is the type of material the individual solar cells are made of.

When you’re shopping for solar panels, one of the things that manufacturers usually tout is efficiency. A high efficiency panel turns more sunlight into electricity than a lower efficiency panel, which means a solar homeowner can get more out of their limited rooftop space. So if efficiency is a good thing, that must mean that you should shop for the highest efficiency panels you can get, right? No, not always. If you’re in a situation where it’s important to maximize your power generation - like if you have a small roof - then efficiency could be very important to you.

I live in Buffalo, New York. It snows a lot here. Some years, it seems like winter lasts for nine months. And yet, I have a solar panel system that still provides some electricity in the dark winter months. While there is definitely less production in the winter months, I still come out on top financially with home solar. To illustrate what this looks like from summer to winter, I’ll share some graphs from my system below.

Low light conditions are a normal situation that solar panels are well designed to handle. Whether it’s cloudy, rainy, or simply early in the morning or late in the afternoon, you should expect your solar panels to continue to generate power. The power output of your solar panels will drop, but with most panels the decrease is fairly linear. That is, if the sunlight drops by half, with most panels the output will also drop by about half.