Solar Terms



Common Terms Used


Community Solar

CHP - Combined Heat and Power

Combined Heat and Power - CHP

Distributed Energy aka Distributed Power


Feed-in tariff


kWh aka Kilowatt Hour



Micro Inverter


Net Metering


Solar Gardens



Solar Cell Efficiency


STC Standard Test Conditions



Tax Credit (ITC)



Azimuth: Real simple 0 degrees is true north, 90 degrees is east, 180 degrees is south and 270 degrees is west.


CHP: This is often referred to as district heating where distributed power is power generated at or near the point of use and may include electricity and or thermal for heating


Distributed Energy: otherwise known as onsite generation of small scale production. Solar panels are refered to this at times.  Distributed power is power generated at or near the point of use.


Efficiency: Under Standard Test Conditions: are the basis for comparing optimum output


Feed-in tariff: (FIT, feed-in law, advanced renewable tariff or renewable energy payments) is a policy mechanism designed to encourage the adoption of renewable energy sources and to help accelerate the move toward grid parity.Under a feed-in tariff, an obligation is imposed on regional or national electric grid utilities to buy renewable electricity (electricity generated from renewable sources, such as solar power, wind power, wave and tidal power, biomass, hydropower and geothermal power), from all eligible participants.In addition, FITs typically offer a guaranteed purchase for electricity generated from renewable energy sources within long-term (15-25 year) contracts. These contracts are typically offered in a non-discriminatory way to all interested producers of renewable electricity.


Inverter: Converts DC energy to AC energy. Represents an installed inverter. Displays the energy sum produced by the strings or modules connected to it.


Meter: Represent a production meter connected to the site and measures the energy supplied to the grid. Displays the energy read by the meter.


Micro-inverter: is a device used in photovoltaics that converts direct current (DC) generated by a single solar module to alternating current (AC)


Micro-inverters for the RA System are attached to each individual solar panel or module.


There are numerous advantages to this type of system.


It allow us to monitor each module for performance and be proactive for maintenance and problem solving.


With the RA System unlike a string system if one panel is compromised it will not affect the remaining panels in the system 


Each micro inverter feeds into the main inverter where it is fed into the home or building.


Module: This term is interchanged with solar panel and depending on the type it can be for used to describe a Photo Voltaic PV or Thermal Collection device.


Net Metering: is a special metering and billing agreement between you and your utility or electric service provider (ESP). Normally your electric meter spins forward as it measures how many kilowatt-hours of electricity you buy, and is read by your utility once a month.

A Net Metering agreement allows you to use the electricity you generate first, reducing what you would normally buy from your utility or ESP. If you generate more electricity than you use, the excess goes through your electric meter and into the grid, spinning your meter backward. Your meter shows the net amount, measured as the difference between the electricity you generate and the electricity you purchase from your utility or ESP.


Shared solar, also called community solar or solar gardens: is an increasingly popular option for deploying solar technology. Shared solar projects allow customers that do not have sufficient solar resource, that rent their homes, or that are otherwise unable or unwilling to install solar on their residences or commercial buildings, to buy or lease a portion of a shared solar system. The subscriber's share of the electricity generated by the project is credited to their electricity bill, as if the solar system were located at the home or business.


Site: Represent the site level. Displays the energy produced by the site for the selected period.


SMI: Represents an installed Safety and Monitoring Interface unit. An SMI unit is installed in sites where the RA modules are connected to inverters. The SMI unit connects the module to the inverter and to the monitoring portal.


Solar Cell Efficiency: are generally stated in ideal standard test conditions.


SPPA: A solar power purchase agreement (SPPA) is a financial agreement where a developer arranges for the design, permitting, financing and installation of a solar energy system on a customer’s property at little to no cost.


STC Standard Test Conditions:  are as follows:

Temperature of 77 °F 

Irradiance is the measure of solar energy per 1000 Watts per 10.76391ft²  generally it is referred to as watts per meter squared.


String: Represents strings of module. Displays the energy sum produced by the modules comprising the string.


Sustainability: In ecology, sustainability is the capacity to endure; it is how biological systems remain diverse and productive indefinitely.


Tax Credit (ITC): for solar is specified by the Internal Revenue Code, Sections 48 (commercial) and 25D (individual). The ITC allows for owners of photovoltaic (PV) systems to take a one-time tax credit equivalent to 30% of qualified installed costs. 


Watt: This is a measurement of power named after a Scottish engineer James Watt. This refers to the amount of energy used over a 1 hour period and is generally a basis for your utility billing.  If you turn on a 100 watt light bulb for 1 hour you are using 100 watt hours.  If you turn on 10 100 watt light bulbs for 1 hour you are using a kilowatt commonly refered to as a kilowatt hour aka kWh or 1000 watts.   Bump that up times 1000 and you get 1,000,000 watts or a megawatt.

Small power plants are measured in mega watts and large ones are measured in gigawatts this is a mega watt times 1,000 or 1,000,000,000 watts.