Month: November 2020

Owning solar panels is a valuable investment that not only reduces your electricity bill, it also reduces your carbon footprint by providing you with renewable energy for the next 20-25 years. Even though solar panels require comparatively less maintenance when compared to other power electronic devices installed in your residence or factory due to lack of moving parts, regular maintenance is still required to ensure that your investment is reaping the maximum long-term benefits.

Understanding what kind of maintenance is required is an important thing to consider before scheduling a visit with your solar pv service provider. There are two kinds of maintenance activities that can be carried out on your solar pv system, namely, Preventive Maintenance and Corrective Maintenance. Preventive Maintenance refers to activities undertaken to keep the generation losses to a minimum. On the other hand, Corrective Maintenance corresponds to returning the PV system back to a functioning state once a failure has occurred.

Preventive Maintenance mainly consists of the cleaning of solar panels and the management of vegetation surrounding the panels.

Even though rains clear off debris and dust to a certain extent, dust and particles collect on the solar panel limiting the amount of sunlight directly hitting your solar panel. Therefore, it is suggested to clean the panels at least twice an year in rural areas and up to four times an year in areas of high dust accumulation.

Every once in a while, it is important to check if nearby trees have grown to such an extent that they cast a shadow on the panels, or if the near by branches are now lying on top of the panels. This can reduce generation drastically as the panels can be covered almost completely, bringing the output from these panels to almost zero. Solutions such as the SolarEdge Power Optimizer ensures maximum generation even from partial generation, but prevention is always better than cure. Ask your service team to check for shading from vegetation and have it cleared just enough to ensure that the panels will not be affected for the next year or so.

It is recommended to carry out preventive maintenance at regular pre-determined intervals so that the reduction in generation is kept at a minimum.

Corrective Maintenance on the other hand requires a team to visit your system only when a fault occurs. Failures of the solar pv system can be identified through the remote monitoring system provided by the inverter manufacturer or through onsite inspection during a panel service. The fault may occur on the panel, optimizer, inverter or grid connection point.

Onsite inspection, electrical system testing, fault diagnosis and part replacement are not usually covered by the OEM Equipment Manufacturer, but the replacements parts are usually covered if the warranty conditions are met.

At the end of the day, if you notice any irregularities on your electricity bill or an anomaly on your monitoring portal, contact your service provider to have a look and make sure everything is as it should be.

Increment of shortage of energy resources such as fossil fuels and environmental related concerns such as increment of carbon footprint have motivated humans to develop and utilize renewable energy sources to produce electricity. Moving into power generation through solar photovoltaic energy has become a nowadays trend in the electricity market. A rapid growth in solar PV technology and the industry is seen over the past several years due to less installation and maintenance costs, less pollution nature and enormous support and promotions given from the government. However, the intermittency, variability and randomness of PV power also cause huge grid fluctuations which limit its integration in the system. An accurate forecasting of solar power generation is essential and significant in order to optimize the operation and maintenance (O&M) schedules to manage the O&M activities properly as appropriate. Due to the uncertain nature of power output, accurate forecasting of power generation is very important in economic perspectives too. Solar power generation depends on various factors hence the necessity to forecast production is more critical. Due to PV power output showcase variability at all timescales, it is challenging and difficult to do predictions and forecasts accurately.

Solar PV generation forecast is simply based on solar irradiance which a particular location is receiving. PV production forecasting is mainly affected by the variability of the meteorological and climatological conditions which are varying throughout the day.

Forecasting can be done referring to a single PV system or to the aggregation of a number of solar PV systems spread over an extended geographic area. Forecasts can be focused either on the output power of solar systems or on its rate of change which is called as ramp rate. Accordingly, different forecasting methods are available. Forecasting methods also depend on the mechanisms and information available such as data from weather stations and satellites, PV system statistical data and results from numerical weather prediction (NWP) models.

Forecasting methods can be broadly classified as physical or statistical. The physical methods of forecasting use solar PV models to generate PV forecasts while the statistical methods are basically based on past data to train models which are having only a little or zero dependency on solar PV models.

Two basic methods of forecasting are in presence when considering intra – day forecasts. First approach is used for short-term (up to 6 hours) forecasts and the other is for the prediction of future generation from a solar power plant for a day or less than a day. Solar PV forecasting is more critical and challenging when it comes to day‐ahead forecasting which output power generated by PV systems within an area is forecasted for each hour of the next day or even up to few days ahead.

Variety of resources are used to perform solar PV forecasts which range from measured weather and PV system data to satellite and sky imagery observations of clouds, to numerical weather prediction (NWP) models that introduce modern weather forecasting.

It is very significant to review about the accuracy of the results of the forecasting. Possible maximum achievable accuracy is determined mainly by the factors such as local climate and weather conditions, single site or regional forecast, forecast horizon and accuracy metric used.

After analyzing all the forecasting approaches, the practical experience shows that the best method for predicting the solar PV power generation is to combine the forecasts obtained from different models of numerical weather forecasting. Thus, it is a fact that accurate forecasting leads more economically viable and reliable delivery of electrical energy to the consumers.

References

[1] Wang, Guochang, Yan Su, and Lianjie Shu. “One-day-ahead daily power forecasting of photovoltaic systems based on partial functional linear regression models.” Renewable Energy 96 (2016)

[2] Report IEA PVPS T14‐01:2013

[3] Seul-Gi Kim, Jae-Yoon Jung and Min Kyu Sim, Department of Industrial & Management Systems Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yonginsi, Gyenggi-do 17104, Korea

[4] avenston.com

Plant Audit is a service designed and developed around the requirement to identify, record and locate the primary source of anomalies. It is requested for Photovoltaic power plants to stick to a range of strict guidelines, regulations and safety standards. The installation of a photovoltaic power plant is carried out to the precise specifications and meets all existing standards and regulations. it can be ensured by quality inspection services for PV plants.

System Quality Audit is useful to; verify that the installation of a plant has been carried out according to the precise specifications, comply with a range of international standards including IEC 62446 and IEC 60364-7-712 and assure the relevant authorities that a photovoltaic power plant is operating safely and according to the relevant local guidelines.

It is imperative to study the active performance of the system in reference with designed energy output to understand the health of the plant because it achieves optimum generation and maintain a higher performance ratio. Plant Audit Scan assists in determining the root cause of decline in generation, accelerated degradation of modules, frequent equipment breakdowns, abrasion of structures among many other activities and recommend necessary corrective actions. Thorough inspection ensures that the plant cohere to quality installation, code compliance and conformance to design and safety criteria.

Plant Audit service encloses all segments of the project from review of design and engineering drawings, to visual checks of the equipment and materials, running specialized tests at site on individual components like thermography and IV-Curve test on modules, verifying O&M records, understanding the fault patterns and spare part consumption. Furthermore, to in-depth review of the condition of the equipment to test critical components and measure key plant performance indicators, advanced tools and techniques can be used. A techno-commercial analysis is derived to evaluate the true-life expectancy of the plant and highlight the investment risk based on the audit report.

Better performance of Solar PV power plants is essential in terms of escalated revenue generation to the asset owner. The performance audit of the plants on regular interval will indicate the space for performance improvements on continuous basis as the saying goes “you can’t manage what you can’t measure “.

References

[1].  https://www.eprmagazine.com/green-zone, Oct.2020

[2].  https://www.sgs.com/en/energy/energy-sources, Oct.2020

[3].  https://solarpost.in/technology, Oct.2020