When it comes to living green, home solar panels are the premier solution. With continuously falling prices and a payback time as little as three to five years, installing a set of panels is a manageable undertaking for any homeowner.
Home solar panels are also referred to as a photovoltaic system. Photovoltaic refers to the process of generating electricity from light via a semiconductor layer. What makes PV cells able to compensate for the energy demand of an average home is scale. Each panel contains approximately 10 modules, and each module contains 40 cells.
Each cell consists of four layers: a protective layer on the surface, two silicon layers, and backing. When sunlight strikes the cell, it travels through the protective layer and hits the positively-charged back layer of silicon. The photons dislodge electrons from this layer, sending them to the negatively-charged silicon above. Circuitry mounted on the top silicon intercepts the flow of electrons, thus generating electricity.
Grid vs. Off-Grid Systems
When installing home solar panels, one consideration is the grid connection. A grid-connected system has the advantage of backup power in the event of poor light conditions, but one is not completely independent from the energy company. However, grid-tied systems have the capability to “net meter” if the system is producing too much power for the demand. In this case, owners sell electricity back to the utility company in the form of credits which can later be used in months when the system underperforms.
The biggest drawback to the off-grid plan is the cost. The current average cost per kilowatt hour varies from $15,000 to $20,000, so the owner either needs to purchase enough capacity to completely run their home or invest in a hybrid system that uses a backup generator. Furthermore, an off-grid system requires an extensive battery bank to store power for nighttime and low-light use.
For home solar panels, the units are mounted depending on the hemisphere. In the northern hemisphere, the panels are mounted on south-facing roofs, and vice versa in the southern hemisphere. In certain cases, the city may allow the owner to mount the panels on a pole or mounting array for even greater reception. Lastly, the position of the panels will also depend on the homeowner’s place of residence. For example, sun-drenched Arizona will be much less discerning than upstate New York.