Solar Asset Failures during Summers & its Solutions

Energy generation is the highest during summers which is advantageous to the solar plant stakeholders. But the summers bring in their own set of challenges & it is still a major misconception that the stronger the sunlight, it will lead to more power generation by modules.

This is not always true & it is often observed that solar plant assets are more likely to fail during the summers due to several factors.

Here are some major faults & failures that can occur in the summer season: –

PV Module Losses

It may seem counter-intuitive, but solar panel efficiency is affected negatively by temperature increases.

Photovoltaic modules are tested at a temperature of 25 degrees C (STC) – about 77 degrees F., and depending on their installed location, heat can reduce output efficiency by 10-25%.

Heat can severely reduce the solar panel’s production of power, as the temperature of the solar panel increases the voltage output is reduced linearly, this voltage drop can further lead to your PV module system not performing to its desired and advertised capacity.

If the PV module losses are not paid attention to, they lead to higher O&M costs, unpredicted downtime, and degradation of the PV module.

Apollo’s Approach

Apollo’s ‘Asset Performance Benchmarking’ Application:

• Make use of Apollo’s digital twin technology which helps create a digital replica by the PV module. Through this, the plant stakeholders can compare the direct effects of over-heating on the PV module and can measure generated vs observed output.
• O&M managers can get real-time PV Module performance-related notifications and carry out daily benchmarking of industry-standard KPIs.

Apollo’s ‘Asset Health Diagnosis’ Application:

• Enables, machine learning-based decision-making support to assist engineers and diagnostic teams with fault prediction.
• Operations & Maintenance teams can discover PV module health degradation using Key Health Indicators (KHIs) and Insights

Cable Losses

Cable losses are majorly dependent on ohmic losses, and the ampacity of power cables strictly depends on the ambient conditions. It is very important to check whether a cable is buried in soil, installed in the air, or placed in ducts to determine the impact of temperature on the cable.

For instance, when a cable is installed in free air, potential solar radiation has the dominant impact on the prospective ampacity. These losses lead to a loss of voltage & in case of a large voltage loss, under certain circumstances, the cable is no longer fully able to function as desired. Hence a predictive tool that helps understand the effects of temperature on the cable is always beneficial.

Nevertheless, extended monitoring of the temperatures along cable lines is a necessity to avoid failures that could appear at any location and ensure that the operational cost is kept minimum.

Apollo’s Approach

Apollo’s ‘Fault Detection’ mechanism:

• Helps identify high power loss faults, and sensor malfunctioning in DC and AC cables.
• Applies, streaming analytics-based event discovery using single or multiple observed parameters and/or KPIs to identify cable losses.
• The event discovery can be achieved using a time-based value threshold or absolute value-based threshold (Time rolling window of 10-60 mins)

Soiling Loss

A major concern for solar plant O&M managers during summers is an increase in the amount of soiling and the adverse effects it has on the solar outcomes which result in both short-term performance reduction and long-term health degradation.

Accumulation of such dust particles & soil patches such as vegetation, leaves, bird droppings, and dirt patches block some cells in a PV module & has a severe effect on the performance, and reduces the overall energy delivered by up to approximately. 0.5-1% daily and within 30 days the soiling loss can reach up to 5-10%.

Apollo’s Approach

Apollo offers – the ‘PV Module Soiling Loss Optimization’ application:

• Is an automated digital technology based on AI/ML that assists in the optimization of cleaning schedules, which adds to improving solar module generation and lowering O&M expenditures over some time.
• The application has an algorithm that can take input from PV module cleaning schedules from the site, weather conditions, and raw data from the inverter or CB.
• The algorithm learns from historical soiling patterns to generate accurate results on Plant-Level Soiling Levels (%), Plant Level Energy Loss (kWh) & CB Level Soiling Loss (%).
• The application also calculates the amount of soiling at the end of the day and generates the cleaning schedule for the O&M site team.

Transformer Losses

The power transformer is a vital component in the power system, and it must be protected against the various core and winding faults. In summers transformers experience a higher frequency of Turn-to-turn fault (TTF). Traditional transformer differential protection is frequently insufficiently sensitive to identify such winding turn-to-turn faults before they develop into more serious and costly to repair ground faults. Sudden Pressure Relay relays, on the other hand, can detect such problems just as well. However, these relays detect such low-level faults with a delay typically 50 ms – 100 ms which often allows the fault to evolve into a more serious one.

Apollo’s Approach

Apollo’s Health Diagnosis Application & Stream Analytics Engine will help you tackle transformer losses and improve the asset’s health. Click here to know-how.

Inverter Losses

Inverters, like all semiconductor-based equipment, are sensitive to overheating and, in general, perform best at colder temperatures, with higher internal temperatures resulting in power losses and damage.

The inverter generates heat as it converts DC power to AC power. This heat, plus the hot summer temperature, is added to the ambient temperature of the inverter enclosure, and the inverter dissipates the heat through fans and/or heat sinks.

The heat needs to stay below a certain level otherwise the materials in the inverter start to degrade.  Insulation becomes brittle, solders expand, and crack & metal components in capacitors start to fatigue.

Apollo’s Approach

Watch this space to know more!

If you are interested in digitizing your plants or solar assets using IoT, solar digital twin, data science and analytics, or are looking for an energy analytics solution, Contact us today.