Photovoltaic panels generate clean power by converting sunlight into electricity. This article will talk about the actual—verses the rated—power output of photovoltaic panels. Do not assume that a PV panel rated at 170 watts of power will actually give you that amount. It will probably be closer to 150 watts per panel. Because of the difference, care must be used when sizing the system for your electrical needs. Otherwise, you may find that you are generating less power than you need.

Designing a photovoltaic system for your green home starts with using energy efficient appliances and lighting inside the house. My rule of thumb is that it is cheaper to buy a new EnergyStar-rated refrigerator for under $1,000 than to spend an extra $2,000 on photovoltaic (PV) panels to power an old, inefficient refrigerator. The same goes for other appliances—particularly those that get a lot of daily use such as televisions.

The photovoltaic system for my small straw bale home (featured on the BuildingWithAwareness.com website and DVD video) cost around $12,000 in equipment. Without carefully choosing the most efficient appliances and  lighting, the cost would have been dramatically higher.  (more…)

This article will show how to attach commercially available solar panel mounting brackets to a corrugated metal roof that lacked flat surfaces. In the photo above, a ladder was used to slide the PV panels to the roof.

Photovoltaic (PV) panels produce all of the electricity for this straw bale hybrid home from sunlight. All of the PV panels are permanently attached to the south facing pitched roof.  Standing-seam metal roofs are partially flat, so mounting a rack is not a problem.  The roof on my house is corrugated metal and therefore has no flat surfaces for the aluminum mounting brackets to seat.  A stout connection is essential for the photovoltaic panels to survive high wind loads and to create a waterproof seal where the bolts penetrate the roof surface. What we needed was a mounting platform that both comformed to the convolutions of the metal roof and also had a flat surface for the foot bracket to contact.

Here is how we solved the problem. (more…)