Local monitoring is the most complex monitoring allowing us to data log information about a large spectrum of parameters as:  

• Array voltage - VDC (V)

• Grid voltage - VAC (V)

• Array current - IDC (A)

• Grid (injected) current - IAC (A)

• Array power - PDC (W)

• Grid (injected) power - PAC (W)

• Module temperature - Tmodule (°C)

• Ambient temperature - Tamb (°C)

• Solar radiation - G (W/m2)

• Daily/monthly solar insulation - H (J/m2)

• Wind speed 

Local monitoring offers the possibility to collect information and locally to display that  information. All the listed parameters are usually monitored, data logged and stored in inverter's memory or external data loggers for a particular time and they are called to generate reports or are triggering allarms concerning system functionality.

Remote Monitoring can be realized with RS485 connection or via grid (power line or WiFi connections). Distances up to 4000ft represent no problem, several tenth inverters can be connected in chain and monitored at the same time. For remote monitoring we can use different ways of communication: Ethernet, Internet, Dial up Access, GSM etc. Systems can send alerts and status messages to the control centre or user. This type of monitoring becomes more speeded, they are associated with a lot of benefits as flexibility and multiple source monitoring at the same time and can be scaled on different levels.

A very basic rule when we choose monitoring equipment is to make sure we will meet all compatibility requirements. Most of the time it is useful to use same brand across a monitoring system. In situations when the installation are geographical spreader monitoring can be performed using satellite services designed for PV industry. SPYCE (Satellite Photovoltaic Yield Control & Evaluation) It is based on more than ten years of research by well-known European institutions. The SPYCE methodology was developed by the EU project PVSAT. Some of SPYCE's features are: Automatic failure detection and alarm dramatically minimizes any down time. Failures may be detected before expiry of warranty.

Here is a list of remote monitoring services using PVSAT project offered by companies specialized in a such operation:
 

GreenPowerMonitor - GreenPowerMonitor is the all-in-one monitoring solution for grid-connected installations and for off-grid installations.
 

Logic Energy Ltd. - Logic Energy Ltd. specialises in providing monitoring and reporting services via the Internet, principally for the renewable energy industry. This system allows remote monitoring of energy systems, reporting and control of failures all via a web browser. Is using  graphical interface is easy to use and understand and can be accessed from any web-enabled device, such as a mobile phone, from anywhere in the world.

Skytron Energy - This system allows remote monitoring of energy systems, reporting and control of failures all via a web browser. The graphical interface is easy to use and understand and can be accessed from any web-enabled device, such as a mobile phone, from anywhere in the world.

Heliotronics Inc. - SunViewer.net™ is a powerful, interactive tool that enables you to view the performance of your distributed generation systems over the Internet. In addition to graphing a variety of quantities of interest, SunViewer.net™ allows users to download data in a spreadsheet compatible format for further analyzis.