Monitoring Solutions for Solar Rooftops

The Government of India has set an ambitious target for Solar Rooftops (SRT) of 40 GW by 2022. As of today, huge gap exists between the target and actual installed numbers due to multiple reasons. Despite challenges such as higher initial cost of ownership and unfavorable government policies, commercial and industrial users with large unutilized roofs are increasingly stepping forward to take advantage of SRT to serve their local consumption, reduce diesel consumption and minimize dependence on erratic grids. Once a policy focused on residential rooftops is in place (a matter of time), it would be a truly game-changing development.
 

We, at Megamic, are ready  now with a slew of Monitoring Solutions targeted for the Rooftop segment! We have differentiated and optimized solutions, whether it is a large commercial SRT spread across many roofs or a tiny residential SRT.
From a monitoring perspective, rooftop installations can be broken down into three broad categories: 
  1. Small systems installed at residences - typically less than 10 kW
  2. Mid-size systems installed on a single large roof or multiple roofs close to each other - typically less than 100 kW, maybe an apartment complex, large industrial warehouse shed etc.
  3. Large systems installed on multiple roofs distributed over a wide area - typically less than 1MW, such as buildings in an educational campus, industrial complex etc.
 
 
 
Small Residential Rooftop systems
These are systems installed at homes, using a single Inverter and import-export energy meter provided by the DISCOMs. It is a very cost-sensitive category. Many of the inverters serving this segment have builtin communication cards, which link to their own proprietary mobile app. This usually serves the limited purpose of keeping the end-user informed about the performance of his system. However, they do not provide visibility to the system installer who will also have a maintenance contract for a few years. Often, disputes arise at the end of every month when the customer feels the Energy Units generated is lesser than expected. Usually there is no account for generation loss due to issues like grid unavailability. Due to anti-islanding protection feature inverters don’t generate any thing without grid being available. 

Megamic’s Solution:
nano Gateway:
To cater to this segment, Megamic has launched its  nano Gateway. This is an ultra-low cost, compact communicator card. The card works in tandem with Megamic's own mobile App. A major advantage  is that the  nano can interface to  any inverter model with an RS-485 port (even the ones without their built-in communication card). Secondly, the data from any inverter model can now be routed to Megamic’s solarNXT App. Thirdly, the nano can also interface to the import-export energy meter in the customer premises. Data from energy meter can be seen on the App.
 
solarNXT App:
Unlike the apps provided by the inverter vendors, this app can be used by both   end-user and  System integrator! Among various useful charts and reports, the app records absence of grid and actual generation. This information can be used to substantiate differences in expected and actual units generated. Thereby reducing friction between end-user and System integrator ! A detailed PDF report downloadable from the App helps the system integrator in understanding how the systems are behaving over time and across installations. This information can be used to reduce costs in the maintenance cycle and provide satisfying service to their customers. 
 
 
Mid-size Systems on a Single large Roof
These systems are characterized by having multiple String Inverters (typically up to 5) to cater to several strings (or arrays) of solar panels spread over multiple levels in a single roof, for example. Such systems also include the energy meter and additionally a weather station consisting of a solar irradiance sensor. From a monitoring perspective, the number of devicces and amount of information available is much more than the residential case.
 
Megamic’s Solution:
micro Gateway+logger:
To enable monitoring multiple devices, Megamic has developed the  micro. It is capable of interfacing to multiple inverters, energy meter, weather station etc. micro is a Gateway plus Logger with many rich features such as:
  •  Gateway feature to communicate to Cloud-based platforms or Mobile app.
    • Besides interfacing to Megamic’s solarNXT Cloud and Mobile app platforms, the card can also be configured to connect to a customer or vendor specified third party platform
  • Logger feature with on-board local data storage. This allows storage of monitoring data for those times when the internet connectivity is down. Data for up to a month can be stored
  • Multiple Input ports – can be configured to interface with current or voltage output sensors, RS485 or RS232/DLMS interfaces
solarNXT Cloud:
The solarNXT mobile app is available here too. However, considering the amount of information to be monitored and the size of the plant, the solarNXT Cloud solution is recommended. This can be accessed from any laptop or desktop with an internet connection.
 
 
Large Rooftop Installations spread across buildings in a wide area
The major features of these installations are the higher inverter count (typically up to 20) and distributed nature of the installations. Conventional monitoring solutions are either messy (link all inverters using wires running across buildings and the entire campus) or expensive (using separate gateways in each building).
 
Megamic’s Solution:
wino wireless RF nodes:
Megamic has developed  wino, a proprietary  wireless product, for precisely such an application. The product consists of radio frequency (RF) nodes operating in a mesh network. Each node interfaces to an inverter (or group of inverters in the same roof) and sends the monitoring data to a central Gateway, by hopping through its neighbours, located on other roofs. The mesh network offers advantages such as alternate paths (auto-rerouting) and is a reliable and proven solution in multiple scenarios.

uno Gateway+Logger:
uno, another Megamic product, is a more powerful Gateway+Logger that manages large amount of data from inverters, and other devices. The data is streamed to the solarNXT Cloud, that allows users to monitor performance, download reports, get alerts and many more features, using a laptop or desktop with an internet connection. Using wino + uno, an elegant solution without inter-connecting wires and minimum number of gateways can be realized.
 
Do you have a Rooftop Solar plant that you want to monitor effectively? 

Reach us at: contactus@megamic.in Phone: +91-80-41162103