7 Ways to Increase Solar Power Generation｜Practical Measures to Reduce Waste in Solar Power

Table of Contents

• Basics to address before increasing power generation

• How to increase power generation 1: Reduce soiling and deposits

• How to increase power generation 2: Manage shading from weeds and surrounding trees

• How to increase power generation 3: Detect abnormal strings and connection faults early

• How to increase power generation 4: Check power conditioner stoppages and curtailment

• How to increase power generation 5: Compare inspection data to isolate causes

• How to increase power generation 6: Review terrain and drainage to reduce degradation factors

• How to increase power generation 7: Identify shading and layout inefficiencies through on-site surveys

• An operational approach to ensure power generation improvements are not a one-time effort

• Summary

Basics to Know Before Increasing Power Generation

When aiming to increase the energy output of a solar PV system, the first thing that matters is not to immediately add more equipment. At many sites, causes remain that prevent the system from delivering the output it should be capable of. Dirt on the panels, shading from weeds, deterioration at connection points, equipment stoppages, overlooked generation data, poor drainage, insufficient surveying accuracy, and other small losses can accumulate to create large differences in annual energy production.

The point operational staff should focus on is not so much simply increasing generated power as on reducing generation losses. Solar power cannot increase the solar irradiance itself, but it can be brought closer to a state in which as much as possible of the received irradiance is converted into electricity. To do that, it is essential to understand what is happening on site and to isolate and verify the causes.

Even when power generation has decreased, the cause is not necessarily a single one. For example, if generation is low only in the morning, shading on the east side or orientation issues may be suspected. If some generation drops after rain, connection points or drainage can be factors. If output falls short of expectations in summer, high-temperature-induced output reduction, equipment shutdowns, or weed growth may be related. Looking at the problem by season, time of day, weather, and individual equipment units makes it possible to see which countermeasures should be prioritized.

Also, measures to increase power generation, if implemented haphazardly, make it difficult to understand their effects. If cleaning, weeding, inspections, equipment adjustments, surveying, and repairs are carried out at the same time, it becomes hard to determine which work contributed to the improvement in power generation. In practice, it is effective to first grasp the current power generation, then organize the causes as hypotheses, and afterward compare the data again following the countermeasures. When improving power generation, rather than proceeding by intuition, it is important to make decisions by linking on-site conditions with the data.

How to Increase Power Generation 1: Reduce Dirt and Deposits

When dirt accumulates on the surface of solar panels, it makes it harder for sunlight to reach the cells and leads to reduced power generation. The causes of soiling vary by site. Along roads, dust and exhaust-related deposits tend to accumulate, while near farmland or forested areas, soil dust, pollen, fallen leaves, and bird droppings become problems. At sites close to the sea, deposits containing salt can also adhere. Even if these contaminants appear thin at first glance, if they spread over a wide area they can affect power output.

Particular attention should be paid to the banded soiling that accumulates along the lower edge of the panel and near the frame. When it rains, surface dirt will wash away, but residues that don’t fully flow off can remain at the edges. If those areas cover part of a cell, it can affect the power generation efficiency of the entire circuit, not just cause a loss proportional to the covered area. During on-site inspections, it is important to check whether the entire panel is uniformly soiled or whether dirt is concentrated in specific rows or only at the edges.

When performing cleaning, it's efficient to prioritize areas that have the greatest impact on power generation. Instead of cleaning all panels at the same frequency, focus on areas with a gentle slope, downwind areas where dust easily accumulates, areas with frequent bird damage, and areas with poor drainage. Cross-check power generation data with on-site photos, and if strings with heavy soiling correspond to reduced generation, their cleaning priority should be high.

However, cleaning, if done incorrectly, can damage the panel surface. Scrubbing with hard tools or carrying out rapid washing during times of large temperature differences can place stress on the surface and frame. In practice, it is necessary to plan the work to include the timing, the water to be used, scaffolding, safety measures, and post-work inspections. Cleaning to increase power generation should be considered not merely as an improvement of appearance but as an operation to restore the panels' light-receiving condition without damaging the equipment.

After cleaning, compare the power generation before and after the work. Because it is difficult to compare under exactly the same solar irradiance conditions, it is realistic to compare on days with similar weather, at the same time of day, and for the same equipment unit. Looking at the difference between cleaned and uncleaned areas makes it easier to understand how much dirt affected power generation. By accumulating these checks, you can determine the appropriate cleaning frequency for each site.

How to Increase Power Generation 2: Manage Shading from Weeds and Nearby Trees

One of the common factors that reduces power generation is shading. In solar power generation, even when it appears that sunlight is hitting the entire panel, just grass, branches, utility poles, fences, or parts of the mounting structure casting shadows on the cells can cause output to fall significantly. Because shadows lengthen especially during periods of low solar altitude, checking for shading is indispensable at sites where generation in the morning and evening is lower than expected.

Weeds may not be a problem immediately after a solar power plant begins operation, but they can grow rapidly depending on the season. From spring through summer growth is fast, and grasses that posed no problem at inspection can cast shadows on the lower edge of the panels just a few weeks later. Even partial shading from weeds can cause generation losses. Furthermore, they reduce airflow and raise panel temperatures, become habitats for pests and insects, and hinder inspection work, affecting not only power generation but overall operations and maintenance.

Shadows from trees are another factor that is easy to overlook. Because nearby trees grow gradually, there may be no problem at the time of installation but effects can appear several years later. In particular, trees to the south, east, and west cast shadows depending on the time of day. At power plants near forested areas, trees on slopes can cast long shadows during periods when the sun's altitude is low. At sites where power generation drops significantly only in winter, it is necessary to check the changes in solar altitude together with the surrounding terrain and the positions of trees.

For shadow mitigation, a single site visit is not sufficient. Shadows change with the time of day and the seasons, so conditions differ in the morning, around noon, and in the afternoon. Even if there is no problem in summer, shadows can lengthen in winter. In practice, it is effective to check the power generation data for time-of-day dips and then search on site for the sources of those shadows at those times. Recording drone photos and ground-level photos makes it easier to decide on weeding or tree removal.

Weed control is not simply shortening the grass; it is important to plan with regrowth in mind. Weed growth varies with the site’s slope, soil type, water flow, and surrounding vegetation. Prioritize work where drops in power generation are noticeable, and after work confirm whether shadows have disappeared, inspection walkways have been secured, and drainage flow is not being obstructed. Shadow management is a fundamental measure for increasing power generation, yet it varies greatly from site to site. Regular monitoring and record keeping determine its effectiveness.

How to increase power generation 3: Detect abnormal strings and connection failures early

In a solar power plant, not all panels necessarily generate the same amount of electricity. Even if the total output doesn't appear to show a major anomaly, some strings may be underperforming. If abnormal strings are left unattended, the power loss in those sections will continue and, over a year, become a non-negligible difference. To increase power generation, you need to look for anomalies at the finest possible granularity rather than relying on the overall average.

Connection faults are a common cause of reduced power output and should be routinely checked in the field. Loosened terminals, damaged cables, poor connector contact, moisture ingress, and damage caused by animals can all produce abnormalities in current and voltage. These issues can be difficult to detect from appearance alone, but when measurement values are compared they may show behavior different from the surrounding system. If you observe trends such as only a particular string producing lower power, anomalies occurring more frequently after rain, or output becoming unstable during periods of high temperature, the connections should be inspected.

To detect anomalies, it is important to know what the normal condition is. Even within a power plant, power generation varies depending on orientation, tilt, the number of panels, and shadow conditions. Therefore, rather than simply deciding something is abnormal because the numbers are low, compare equipment under the same conditions. If there is a persistent difference compared to adjacent strings under the same conditions, it becomes a higher-priority inspection target.

Also, the causes to be suspected differ between cases where power generation suddenly drops and those where it gradually decreases. Sudden drops can be caused by equipment shutdown, broken wiring, poor connections, or the emergence of obstructions, among other things. Gradual declines may be related to dirt, degradation, growth of trees, or insufficient weed management. When considering how to increase power generation, it is important to interpret the pattern of the decline.

Inspections combine measurements, visual checks, verification of thermal imbalances, and inspection of cable routes, all on the premise of safety management. If an abnormality is found, record why it occurred rather than performing a one-off repair. Understanding whether the location has poor drainage and tends to retain moisture, whether the cable layout makes cables prone to damage during grass-cutting operations, or whether animals can easily enter helps prevent recurrence. Improving power generation is not just about fixing abnormalities but also about making the site less likely to experience them.

How to Increase Power Generation 4: Check Power Conditioner Shutdowns and Curtailment

The cause of low power generation is not necessarily limited to the panels. If the equipment that converts the generated direct current into alternating current is stopped or is limiting output, the actual power generation will be low even when the panels are able to generate sufficiently. Operational personnel need to check the operating condition of the equipment as well as panel soiling and shading.

The first things to check are the shutdown history and alarm history. If short interruptions are recurring, they can be overlooked when looking only at daily or monthly aggregates. For days with low power generation, compare which time periods the equipment was stopped and whether other equipment was operating during those same periods. If only specific equipment has stopped, the cause may lie with that equipment or its connection scope. If multiple pieces of equipment have stopped simultaneously, consider influences from the grid side, environmental conditions, settings, and surrounding equipment.

Next, check whether output curtailment is occurring. During periods when output curtailment is in effect, power generation will level off even if solar irradiance is sufficient. On a graph, the top of the generation curve can appear flat even on sunny days. However, curtailment is not the only cause of a flattened plateau. Similar shapes can result from equipment capacity limits, temperature effects, shading, faults, or measurement anomalies. It is important to cross-check with curtailment records and equipment operation data when making a determination.

The effects of high temperatures should not be overlooked. While solar panels tend to generate more power under stronger sunlight, their output decreases as temperature rises. If generation does not increase as much as expected on a sunny summer day, panel temperature or the equipment’s heat-dissipation environment may be affecting it. If there is grass or other obstacles around the power conditioner causing poor ventilation, this can lead to protective operation of the equipment or reduced efficiency. It is useful to check the surrounding ventilation, direct sun exposure, accumulated debris, and the condition of any filters.

Because equipment-side measures often require specialized inspection, we proceed by clearly defining the scope of responsibility. What on-site personnel can do is organize the time of shutdown, alarm details, visual appearance, surrounding environment, and power generation data. If that information is organized, the decision on specialist inspection can be made more quickly. To increase power generation, it is necessary to view the entire power plant flow, including not only the panels but also power conversion, protection, monitoring, and grid connection.

How to Increase Power Generation 5: Isolate Causes by Comparing Inspection Data

A common reason for failure when trying to improve power generation is deciding on the cause based only on impressions from the site. If you think that panels are dirty so you should clean them, that grass has grown so you should remove it, or that equipment is old so you should replace it, the actual magnitude of generation losses and the priority of countermeasures can become misaligned. To increase power generation, it is important to compare inspection data and isolate where the major inefficiencies are.

The basics of comparison are comparison with the past, comparison with the surroundings, and comparison with expected values. For comparison with the past, compare the same month or the same season with the previous year. For comparison with the surroundings, compare equipment under similar conditions within the same power plant. For comparison with expected values, check whether the results deviate significantly given the solar irradiance and installation conditions. By combining these approaches, it becomes easier to determine whether a discrepancy is simply due to weather differences or a problem on the equipment side.

For example, if the entire power plant is declining in the same way as the surrounding area's weather, the influence of irradiance conditions is likely significant. Conversely, if only part of the same power plant is performing poorly, local shading, soiling, poor connections, or equipment outages are suspected. If output is lower than the same month of the previous year but nearby meteorological conditions were also poor, you should consider weather correction before concluding there is an equipment fault. Misinterpreting the data can lead to unnecessary work.

Inspection records become more useful when photos are combined with numerical data. Site photos alone make it hard to assess the impact on power generation, and numbers alone make it difficult to identify the cause. Record and link information such as which row and which position has soiling, what times of day shadows occur, and which equipment triggered alarms to the power generation data. This makes it easier to check the same locations at the next inspection and to track the effectiveness of any improvements.

Also, decreases in power generation should be considered as either temporary or persistent. If output is low for only one day, weather or a temporary shutdown may be the cause. If it continues for several days, dirt, shading, or equipment malfunction is suspected. If it is gradually declining over several months, it is necessary to check for degradation and environmental changes. Countermeasures to increase power generation should be chosen based on the duration and extent of the decline.

By making data comparison a habit, improving power generation becomes a reproducible operation. Rather than relying solely on the experience of personnel, by accumulating power generation, inspection results, on-site conditions, and the history of countermeasures, it becomes clear what to look at next. This is particularly important when managing multiple power plants. If you understand trends at each site, you can focus limited inspection time on areas that have a large impact on power generation.

How to Increase Power Generation 6: Review Terrain and Drainage to Reduce Degradation Factors

A decrease in power generation can arise not only from the panels and equipment but also from the condition of the land. Terrain, drainage, slopes, access paths, and movement of soil around the mounting structures can affect the long-term stable operation of the power plant. In areas where water tends to accumulate, weeds are likely to proliferate, and moisture increases the risk of deterioration around connections and mounting structures. Where sediment flows in, it can lead to soiling under the panels, uneven access paths, and exposed cables.

Poor drainage, while not always seen as a direct cause of reduced power generation, can be the starting point for various problems. In areas that become muddy after rain, inspections and weeding are more difficult. If work is delayed, weeds and dirt increase, which in turn affects power generation. Also, if water flow concentrates in one area, the ground around the racking foundations can be eroded, potentially leading to tilting or sinking of equipment. Changes in panel angle or the conditions between rows can also affect shading and light-receiving conditions.

When examining the terrain, we grasp the overall elevation differences and the flow of water across the power plant. We check where water enters, where it collects, and where it exits. Subtle undulations that are difficult to discern on drawings become easier to identify through on-site inspections and surveying after rainfall. Puddles, sediment accumulation, topsoil erosion, pathway settlement, slope failures, and uneven vegetation growth are clues that indicate drainage problems.

From the perspective of increasing power generation, drainage measures themselves do not necessarily lead to an immediate rise in output. However, by mitigating soiling, weeds, equipment degradation, and reduced ease of inspection, long-term generation losses can be reduced. If you only look at short-term improvements, cleaning and weeding stand out, but at sites where the same problems recur repeatedly, a reassessment of terrain and drainage is necessary. To sustain improvements in power generation, it is important not to stop at surface-level causes but to delve into the on-site environment.

Particularly at power plants on slopes or on developed land, pay attention to ground changes after installation. Rainwater flows, sediment movement, inflow from surrounding roads, and springs emerging from the mountainside all change over time. During periodic inspections, recording the condition of the ground from the same spot as well as the panels and equipment makes it easier to notice changes. To stabilize power generation, equipment management and land management should not be separated; an integrated approach is required.

How to Increase Power Generation 7: Identify Inefficiencies from Shadows and Layout Through On-site Surveys

To increase power generation, it is important to accurately understand the site. Without knowing panel layout, row spacing, tilt, surrounding terrain, and the locations of trees and structures, you cannot correctly assess issues related to shading, drainage, and inspection access routes. Rather than judging by visual inspection alone that "there might be shade" or "the slope seems bad," organizing on-site data with positional information clarifies the priority of improvements.

Especially for shading issues, information on location and height is important. If you can determine where the object casting the shadow is, how tall it is, and in which direction it lies relative to the panel rows, it becomes easier to assess impacts by time of day and season. By recording trees, fences, surrounding structures, and terrain undulations through on-site surveying, you can more easily correlate drops in power generation data. This makes decisions on weed control, pruning, layout adjustments, and inspection planning more concrete.

Surveys are useful not only for improving existing power plants but also for evaluating expansions and renovations. Even if an area appears to be empty space, there are actually constraints such as shading, walkways, maintenance space, drainage, slopes, and safety clearances. Planning a layout without accurate positional information can result in poor workability later or in adverse effects from shading. When considering layouts to increase power generation, it is important not simply to increase the number of panels but to design a layout that minimizes waste over long-term operation.

Data obtained from on-site surveys integrates well with inspection records. If the locations of abnormal strings, heavily soiled areas, spots where weeds tend to grow, places where water accumulates, and zones with frequent equipment stoppages can be managed on a map, site issues can be visualized. Relationships that cannot be discerned by simply viewing a list of low-generation assets become easier to understand when overlaid with location information. For example, if a low-generation area coincides with a poorly drained spot or the shadow of trees, the rationale for countermeasures becomes clear.

In practical work, balancing survey accuracy with ease of use is also important. Carrying out extensive surveys every time may not be realistic. Therefore, having a system that can efficiently record the positions of required points during regular inspections and on-site checks is useful. Improving power generation requires leaving observations made in the field in a form that can be reviewed later. Photos with location information, inspection notes, and simple current-site diagrams make it easier to share within the company and to develop countermeasures.

The advantage of incorporating surveying as a way to increase power generation is that it reduces subjective judgment. If you can describe by location where shadows occur, where water pools, and which rows are more susceptible to the influence of surrounding conditions, it becomes easier to share the prioritization of countermeasures with stakeholders. Accurately recording on-site conditions leads not only to improved power generation but also to higher quality operation and maintenance.

Operational mindset to ensure power generation improvements are not a one-time event

Measures to increase power output are not a one-time action. A solar power plant is an outdoor installation, and weather, seasons, the surrounding environment, and equipment condition are constantly changing. Even if you clean it, it will get dirty again. Even if you remove weeds, they will grow back. Trees grow, drainage paths are altered by sediment, and equipment becomes increasingly prone to faults with age. Therefore, improving power output should not be treated as a single, isolated task but as part of ongoing management.

For ongoing operation, it is important to have criteria for detecting declines in power generation. Merely feeling that output is slightly low will delay decisions on countermeasures. By reviewing performance on a daily and monthly basis, by equipment, and by time of day, and by deciding in advance how large a deviation should prompt an investigation, you can detect anomalies earlier. This is especially true when managing multiple power plants, where relying solely on staff intuition makes it easy to overlook issues. It is important to standardize the indicators to monitor and the procedures for verification.

Next, it is important to keep a record of the measures taken. If you log when cleaning was performed, where weeding was done, which equipment was inspected, and which connection points were repaired, you can evaluate them by linking them to changes in power generation. Without such records, when the same problem occurs you will have to investigate the cause from scratch. To make improvements in power generation more efficient, it is necessary to accumulate on-site responses as knowledge.

Furthermore, it is important to consider improving power generation within the annual plan. Each site has seasons that require attention—when weeds grow, after typhoons or heavy rains, during periods with high pollen or yellow sand, and when winter shadows are long. Rather than scrambling to respond after a problem occurs, carrying out inspections and countermeasures before periods when generation tends to drop makes it easier to reduce losses. In particular, managing weeds and shading before they occur is more effective than dealing with them after a decline in generation appears.

Measures to improve power generation may not be completed by the on-site personnel alone. Multiple stakeholders—owners, management companies, inspection companies, design personnel, construction personnel, and others—may be involved. What is important in such cases is documentation that can explain the problem concretely. If a graph showing the decline in power generation, on-site photographs, location information, inspection results, and potential countermeasures are organized, decision-making will be faster. Conversely, even if the on-site team senses a problem, if explanatory materials are lacking, countermeasures may be postponed.

In operations aimed at increasing power generation, it is more realistic to tackle the largest loss points first rather than aiming for perfection. Trying to solve all problems at once makes it difficult to assess cost-effectiveness and workload. Start by prioritizing issues that have a large impact on generation—shading, shutdowns, abnormal strings, soiling, and weeds—and then expand to measures for drainage, layout, and long-term degradation. Even small improvements, if continued, will contribute to raising annual power generation.

Summary

When considering how to increase power generation, the important thing is not to add equipment but to identify and reduce on-site losses. Solar power generation output is not determined solely by solar irradiance conditions. Dirt on panel surfaces, shadows from weeds or trees, poor connections, equipment shutdowns, output curtailment, poor drainage, layout and terrain issues, and multiple other factors combine to reduce generation. Operations personnel must isolate these issues one by one and address them in order of their impact on power generation.

First, check the power generation data to see whether the decline is occurring across the entire system or only in parts. Next, compare by time of day, season, weather, and equipment unit to sort out possibilities such as shading, soiling, shutdowns, and abnormal strings. Then inspect the site and record photos, measurement results, and location information. After countermeasures, compare how the power generation changed and reflect that in the next management plan. By establishing this process, power generation improvement becomes continuous operational improvement rather than ad hoc work.

In particular, issues such as shading, drainage, and layout can be difficult to assess by visual inspection alone. Accurate on-site data is useful for understanding where and what kind of problems exist and how they relate to reduced power generation. If inspection results can be organized with location information, decisions about weeding, cleaning, repairs, and layout revisions become more concrete and easier to share with stakeholders.

To stably increase the power output of a solar power plant, it is important to accurately measure the site, record the data, and have a system that leads to improvements. LRTK, as a smartphone-mounted GNSS high-precision positioning device, can be used to streamline confirmation of inspection points within the plant, locations where shadows occur, areas with poor drainage, and equipment layout. To reduce waste in power generation, if you want to record on-site conditions together with location information and improve the accuracy of maintenance and improvement decisions, using LRTK is also an effective option.