Going solar is an energetic experience. It takes energy to manufacture the system, energy to install, and creates energy while simultaneously using less energy (from the grid). Every aspect of this “energy salad” has its importance in the process of home solar power conversion. It is a metamorphosis of sorts, from the dirty to the clean, the old to the new, the wasteful to the renewable.
Photo Credit: Solar Power Ninja
Today, we will examine the many different forms and functions of energy in the home solar power conversion. Much time is spent analyzing energy savings (usually in monetary terms), and rightly so, as energy and money savings are the all-stars of the home solar power movement. But energy is a key ingredient in every step of the solar conversion process. Beginning with the solar panel…
The production of a solar panel consumes energy in many ways, from the mining of the silicon or other semiconductor material to the production of the solar cell and assembly of the module. A 2008 report from the American Chemical Society studied the production of three types of solar panels: monocrystalline silicon (widely used today), ribbon silicon (think Evergreen Solar) and thin-film cadmium telluride (think First Solar).
The ACS study produced relatively positive results for the life cycles of solar panels, especially when compared to fossil fuels. Researchers found that PV production emits 90 percent less pollutants and greenhouse gases than fossil fuel energy production. The best of the three solar technologies studied was thin-film cadmium telluride because the panels are quicker to produce and don’t require the aluminum frame of silicon-based panels.The report’s findings haven’t gone unchallenged. And there’s no denying that the life-cycle of home solar panels could be cleaner, especially since most panels today are produced in China, where environmental regulations are disturbingly low.
First Solar and a handful of other companies are working hard to make sure that their products are recycled at the end of their life. But considering that the majority of solar panels in use are relatively new and expected to last for 25 years or longer, the “end” of the solar panel must be considered as well. There’s going to be a stockpile of panels, many filled with toxic materials, ready for dismissal in about 20 years. A white paper by the Silicon Valley Toxics Coalition outlines these concerns in detail. Regardless of what report you read or how it’s disputed, there is no denying that home solar power conversions are a major upgrade from the fossil-fired electricity that still dominates our electric grid.
Of course, once a panel is created, it must be installed to generate clean energy and offset the dirty energy used to make it. This requires some expert work from a fast-growing field of home solar power installers. According to the Mayo Clinic, a 200-pound person on a stair treadmill (which, for lack of a more exact comparison, I’ll equate with installing home solar power since the workers spend most of their time walking up and down a pitched roof) burns about 800 calories per hour.
Now, let’s say it takes three eight-hour workdays to perform a home solar power conversion. At 800 calories per hour, an installer burns 6,400 calories per day and 19,200 total. That’s a good deal of human energy, and a good reason why your solar installer is probably in fairly good shape. Please feel free to put a calorie-meter on you installer, and if he’s not burning calories at a rate of 800 per hour, tell him he’s not working hard enough! …Just kidding, don’t do that.
Now to the popular portion of the program. We’ve covered the ugly side and the silly but sweaty side of home solar power conversions, and we’re on to the prettier side. It’s all in solar technology’s uncanny ability to absorb and convert sunlight into electricity. Now, the actual energy created by your home solar power system depends on the size of the system and the amount of sunshine you get each day and year.
A 3,000-watt system is a good size for our needs, one that will provide well over half the energy needs of the average home. Let’s say you get 5 hours of optimal sunlight each day. In simple terms, a system with 3 kilowatts-worth of panels will produce 3 kW of solar energy per hour, and with 5 hours of sunlight to work with, produce 15 kW (15,000 watts) of energy per day. Assuming your town gets 300 days of sunlight per year, that translates into 4,500 kW of energy per year, or 4.5 million watts.
These are simplistic numbers, but they do show that a truly awesome amount of energy can be produced by a handful of solar panels attached to your roof. No motors, no gas, no carbon – just the power of the sun and a flow of energy. All that energy produced also translates into less energy taken from the local energy grid, which has a number of benefits for our struggling electricity infrastructure.
Photo Credit: Eco-Friendly Mag