Home > Blogs > Orson Klender > Orson Klender's (oklender) Blog

Let’s Clear Up Some Confusion About Solar Panels - Via Houzz.com

Real Estate Agent with Equitas Realty

February 27, 2014 11:19 PM

Different panel types do different things. If you want solar energy for your home, get the basics here first.

I've recently noticed some confusion over the term “solar panel.” Before we get into a more advanced look at specific technologies for heating water and providing electricity to a home with solar energy, it’s necessary to understand the basics of what kinds of panels are out there. Some of them aren’t really panels at all, in fact, but rather tapes or films. Let’s clear things up.

Jim Burton Architects

Solar energy can do two things for your home:

It can provide power, in the form of solar energy converted to electricity, or
It can heat water, through direct or indirect solar radiation.

Panels that provide electrical power are photovoltaic (PV for short). Panels that heat water are often described as solar thermal collectors.

It gets confusing because we sometimes shorten “solar thermal collectors or panels” to “solar panels” in conversation, and that is easily mixed up and used interchangeably (even by professionals) with “PV panels.” But it’s important to understand that the work the solar energy does in both kinds of panels is different. In the first it provides electricity. In the second it heats up water.

Many people wonder, “When I see a house with a bunch of panels on the roof, what am I looking at?” Well, let’s take a look.

In this photo we’ve got a side-by-side comparison of the two. In the center are two darker panels. These are examples of one type of solar thermal panel, which is used to heat water.

Surrounding them you can see many photovoltaic (PV) panels. These are used to convert solar power to electricity. That electricity may be used for many things, including heating water in a more conventional electric system.

Arkin Tilt Architects

Solar thermal panels for heating water are usually fewer in number, thicker and boxier, and are attached to water pipes. They basically come in two forms. One is a flat-plate collector, which looks like a dark, weatherproofed, glazed box, as pictured here.

GO LOGIC

The other form is an evacuated-tube collector, pictured on this roof in the top center amid an array of PV panels. This kind of collector looks like a set of parallel glass tubes.

There is another kind of solar water heater, known as a batch system. However, this is not used frequently here in Europe due to its susceptibility to freezing temperatures and lower efficiency. Even in the U.S. (as we saw this year with the phenomenal polar vortex), there are few places with no risk of freezing temperatures.

Effect Home Builders Ltd.

Photovoltaic (PV) panels often appear on roofs in greater numbers. In some places any extra electricity created from the panels can be sold back to the grid for a profit.

Semmes & Co. Builders, Inc

Save Photo

As the technology of photovoltaic panels develops, so do the applications. You may sometimes see panels of solar cells used as an almost decorative way to shade an outdoor area, while still producing electricity.