If you've ever looked at solar power as an option, you've heard of a photovoltaic system. But what exactly is a photovolatiac system, and how does one work?
A photovoltaic cell (PV cell) is a specialized semiconductor diode that converts visible light into direct current (DC). Some PV cells can also convert infrared (IR) or ultraviolet (UV) radiation into DC electricity.
An individual PV cell is generally quite small, ordinarily creating only around 1 or 2 watts of force. To support the force of the PV cells, they are associated together to frame bigger units called modules.
Modules, thus, can also be associated with structure into considerably bigger units called an array. Modules or an array by themselves don’t represent your entire PV framework, however.
Photovoltaic systems consist of primary and secondary parts, and depending on your unique requirements you may need both to successfully utilize solar power.
PV panels are the single biggest expense of a PV system, but today it is possible to get them on your roof for free. Their mounting and placement can affect your system’s performance more than any other facet of the job, so careful planning is of utmost importance. This is why it is recommended to consult a professional for installation of your system.
Mounting your PV panels should be done by a professional with experience! They need to be mounted so that they’ll get maximum sun exposure over the course of a year. But, even more important to keep in mind is the fact that they could be sitting there for 30 years or more!
Inverters take the low-voltage, high-current signals from the PV panels and convert them into 120VAC (or 240 VAC). This makes them directly compatible with grid power. From a reliability standpoint, it’s important to investigate inverters before you finally settle on one. They are generally considered to be the weak link in any PV system, so there should be absolutely no substitute for quality when investing in one.
Conventional power meters are capable of spinning backward, but utility companies usually change to a special digital meter in order to connect to the grid. This is due to the fact that most solar customers go to the TOU (time-of-use) rate structure, which requires more intelligent processing than a mechanical device is capable of.
Although not always necessary, these mechanical parts move the PV panels over the course of a day so that they directly face the sun at all times. Dual axis trackers are ale to change both azimuth and elevation while single axis trackers only match the azimuth.
Disconnect switches need to be mounted within easy reach for safety reasons, and everyone should know exactly how to turn the PV system off in an emergency. If any abnormal behavior occurs in your home’s electrical system, shut off the solar system immediately.
Although the wiring to your home’s main fuse box are minor hardware expenses, the labor cost for this job will amount to a big chunk of your total cost for installing a PV system. This is due to local laws which require licenced electricians with permits to connect your panels to the main grid, as well as pass rigorous inspections.
If you do opt for going totally off the grid, it takes some big batteries if you want to be prepared for several consecutive days without the sun shining.
In the current market, a backup generator that runs on diesel may be a better choice than an oversized battery bank that seldom has the opportunity to operate at full potential anyway.
Backup generators typically output AC. This can either be converted into DC for battery storage or sent through the inverter for direct use.
Tesla’s Powerwall may yet revolutionize the way we store energy, but for now, a backup generator may be essential.
Charles Clarkson
