General Solar Information
When designing an off-grid (not connected to utility power) solar or wind power system, it's very important to have an accurate estimate for how much energy you need.
Lightning is the number one cause of catastrophic failures in solar electric systems and components. The first major reason is that many PV systems are poorly grounded and poorly protected. That is also the 2nd and 3rd major reason.
This information is mainly aimed at reducing or eliminating radio, TV, cell phone, and other electronic noise and interference in photovoltaic and other DC powered systems and from equipment used in PV systems.
An "array" may be one panel or many in series and may range from a single panel 12-volt up to multi-panel high voltage arrays for grid-tie systems.
For designing a system, you nearly always use the worst case, or December-January map. "Flat-plate collector" is simply a solar panel.
The following is a listing of terms used primarily in the PV industry, but some general and solar heating terms are also included.
You often see inverters rated in volt-amps (VA or va) instead of watts. For a perfect resistance, such as a heating element, watts and VA are essentially the same. However, many appliances, especially motors, are not a "perfect" load. Thus, the watts actually used may be less than the VA - but the inverter sees the VA. The motor or appliance may be using only 100 watts, but the inverter sees an "apparent" power of 150 VA.
An off-grid solar electric system involves working with both alternating current (AC) and direct current (DC) voltages. These voltages can be lethal if all safety precautions are not followed.