Why India urgently needs ultra low cost monitoring for Solar Rooftops?

Solar market in India is growing rapidly. Solar has the potential to be the most reliable and affordable source of energy and it is the most cost-effective source of energy in developing countries, which can be deployed quickly. But because of high population density, large tracts of land required for large-scale solar projects will be hard to come by in India in the near future, small-scale rooftop solar projects can fill in the gap and address the ever-increasing domestic energy requirements.

Thousands of solar energy systems sit in disrepair just 12 or 18 months after installation. Thus they seem to be no longer cost-effective. High failure rates erode local demand for solar, and investors and donors often have no idea whether systems are working, deterring investment in critical energy access projects.

One of the key components for solar monitoring systems is the data concentrator, which collects and makes available the raw monitoring data from attached inverters, weather sensors, and power meters. Residential solar systems are characterized by a smaller size and a wider geographical distribution. For residential energy monitoring systems, raw computing power is less important than the ability to connect remotely over a wide area network. Flexibility with different communication interfaces is also significant because of the wide variety of inverters and micro inverters that may be installed at a site.

It’s critical for a data concentrator to strike the right balance between functionality and price since residential installations are much more cost sensitive than utilities and commercial installations. One of the biggest technical challenges faced by solar system solution providers is the management of communication between the different inverters, data concentrators, and cloud servers. Many installers are recognizing the benefits of utilizing one vendor although Zigbee and PLC are well-known technologies. Another technical obstacle to overcome is the network connection factor. Connections to cloud servers are often wireless or cellular, and it’s almost inevitable interruptions in network service. The ability to recover easily and automatically from any breaks in connection is especially important for residential systems, since the data concentrator is located remotely and isn’t readily accessible. But built-in tools or application programming interfaces (APIs) can help software programmers set the appropriate reconnection parameters and configure a hardware “watchdog” of sorts. This saves time, ensuring the system automatically reboots and restores after a network interruption.

Finally, the actual monitoring data presents its own challenges, since it must be put into a format that’s easily stored, presented, and analyzed. In practice, this usually means formatting the sensor and power meter data into well-defined XML or CSV files, which are stored on a cloud server and dropped into a database. This can involve a high degree of technical programming, so for efficiency sake, it’s preferable this process be as simple as possible for solar installers.

The Ministry of New and Renewable Energy (MNRE) launched a pilot scheme in 2013 for grid-connected rooftop PV power projects, which is being implemented by the Solar Energy Corporation of India. The scheme allows system sizes from 100kW to 500kW and aggregation of capacity from smaller roofs. Under the scheme, 30 percent of the cost is provided as subsidy and 70 percent is to be met by the consumer, with surplus solar power to be fed into the grid. India has decided to follow the dual path approach by provisioning schemes and programs that encourage development of large scale grid-connected projects as well as small and medium ground-mounted and rooftop-based projects. Although national and state policies have successfully kick-started the development of utility scale solar power projects in India, the small-scale segment is still in a nascent stage of development.

Lack of monitoring caused problems for solar panel users. Most systems had a simple fix that a monitoring system would have caught. Low-income areas have huge demand for reliable, long- lasting energy generation, but most cannot afford the monitoring systems currently on the market.

Rooftop-solar-panel

Potential failures or damages that can occur on a solar farm due to lack of monitoring facility :

1. Perimeter Fence Damage: Damage caused to the perimeter fence can immediately have a negative effect on facility operations.  Not only people can get injured due to the high voltage produced by the system, but the expensive equipment is at risk if intruders enter the area with intent to destroy or steal items.  Regular inspection and quick response to this is crucial for all solar farms.

2. Ground Erosion: Soil and ground erosion are caused by water and wind. But a sudden erosion can have a deleterious effect on a PV plant.  Loss of topsoil can lead to reshaping of the ground and the creation of channels, holes and slopes in earth.  This could cause racking to shift affecting the ability of panels to generate the energy and also lead to flooding and destruction of equipment. Proper and frequent site monitoring will alert asset managers to anything out of the ordinary happening that could put operations at risk.

3. Transformer Leakage: A transformer leak can cause land contamination and other safety risks.  Knowing if a leak is present and planning for maintenance to repair or replace it can be key in keeping energy generation at a maximum. Monitoring transformer oil temperature, pressure and level to prevent a transformer from leaking in the first place is the best way to avoid down time issues. To prevent fatal errors, a parameter range is set and automatic alarms can be issued to check on site before the problem scales.

4. Various Inverter Damage: Monitoring of inverters is of high importance, since changes to voltage and frequency may occur that affect performance as well as the safety of those in proximity. Inverter damage may lead to the complete failure of the PV plant or partial string outages as a result of defective inverters. Inverter failures are responsible for roughly 80% of PV system downtime.

5. Broken Conduit: Broken conduit can cause a cable to break or damage the insulation which can cause a fire and personal hazards.

6. Cell Browning/Discoloring: In addition to providing power, UV radiation will lead to aging in panel cells, seen as browning and discoloration.  This degradation in the film leads to impaired output and productivity.

7. Unclean Panels:  Dust, snow, pollen, leaf fragments, and even bird droppings – all can absorb sunlight on the surface of a panel, reducing the light that reaches the cells.  Clean surfaces result in increased output performance over the lifespan of the equipment. Routine cleaning is necessary in this case.

8. Defective Tracker:  Defective trackers can contribute significantly to lowered performance output and should be serviced as soon as detected.

9. Shorted Cell: A shorted cell can impact productivity if not addressed in a timely manner. Identifying these defects through testing via infrared imaging is an  efficient, cost-effective test and measurement methods for characterizing a cell’s performance and its electronic structure help ensure maximum energy production.

10. Combiner Box Damage:  With the ability to simplify wiring, combiner boxes combine inputs from multiple strings of solar panels into one output circuit.  Normally 4 to 12 strings are connected to a combiner box.  If damaged, they pose a safety risk as well as a major decrease in productivity.

Rooftop solar is a budding business stream in India. The installed capacity has been rising steadily over the last few years. However, the industry needs more support to grow at the same rate as the ground-mounted segment. It has been estimated that with conducive environment India’s rooftop solar capacity could touch 1.5 GW in 2018, as compared to the current 285 MW. Rooftop systems are sustainable and much more cost effective in the longer run. Given conventional fuel sourcing challenges and rising energy demand, solar can give a strategic push to combat India’s energy deficit. Installing rooftop project accompanied by smart metering solutions can help the cities in accessing clean energy while helping the grid manage energy flow efficiently. While industrial units and organisations are realizing that solar based captive power generation is more sustainable. Energy generated from these systems will help lower their diesel and grid-connected consumption, thereby reducing operating expenses.

Keleno is going to provide just the right kind of solution at lowest cost fixing all the key challenges that simultaneously need attention offering a positive turn for the industry.

Stay tuned for more details.

Please write to info@keleno.com to know more about us.

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