Latest articles by The Solar Nerd

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.

There are thousands of rooftop solar installers across the United States, and most of them are honest companies that do good work. Unfortunately, like any industry, there’s always a few bad apples. There are great plumbers out there, but you could also end up with a company that tries to fix a leak with silly putty. This is why when you hire any type of contractor, whether it’s to install solar panels on your roof or fix a leaky toilet, it’s always a good idea to do a little research so that you can become a better informed consumer.

Many electric vehicle owners also happen to be interested in solar electricity. That makes sense, because if you’re an early adopter for either of these technologies, helping the environment was probably one of the factors in your buying decision. If you have a Tesla now or you’re planning to get one, you might want to know how many solar panels will you need to install on your house to charge it.

Those little solar powered landscape lights that you can buy almost anywhere are convenient, and look great too. The best part is being able to add landscape lighting to your yard without having to run wiring. Just stake them into the ground wherever you want, and you’re done! Where are often aren’t so great is product quality. I’ve thrown away a lot of cheap solar lights before concluding that I needed to spend a little more money to get something that I wasn’t going to break after only few months.

Installing solar panels on your house is a pretty big investment - one that you’d like to last as long as possible. So how long should you expect your home solar array to last? Solar panels last a really long time. You can expect at least a 25 year lifespan. Premature failures do happen, but they are often covered by the manufacturer’s warranty. Solar panels have been known to last much longer - as long as four decades - but there is little data because mass commercialization of photovoltaic panels really only started happening in the 1970s.

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.

The residential solar industry in the US is dominated by a few very large companies, and one of the biggest is Momentum Solar. According to Solar Power World, Momentum installed almost 90 megawatts of solar panels last year. For perspective, the average home solar system is 6.4 kW in size. If Momentum installed only average sized systems, their installations in 2019 would be equivalent to 14,000 home systems. That’s a lot!

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.

The average size of a home solar installation in the United States is around 6 kilowatts, which is about 17 high efficiency premium solar panels, or more if you go with a cheaper panel. That many solar panels takes up a lot of space, and you would need a large available roof area to accommodate them. But sometimes, your roof might not be ideal for solar. It might be oriented east-west (which generates less power than a north-south orientation) or, more commonly, you might have shading from nearby trees or buildings.

If you like to get off the grid, whether it’s roughing it in a tent, or you’re more of a “glamper” who likes to stay comfortable in a boat or RV, you probably still like to have electricity to keep your devices powered. We’ve written articles about some of the solar technology you can use to make this happen, such as flexible solar panels, charge controllers, and solar phone chargers. However, if you have big power requirements that involve keeping a larger battery charged, things get a little more complicated.