10 Measures to Reduce Waste in Power Generation｜Explaining How to Boost Solar Power Output

Table of Contents

• Approach to Reducing Waste in Power Generation

• Item 1: Check generation data by time of day

• Item 2: Compare with equipment under the same conditions to locate performance drops

• Item 3: Separate variations caused by weather and sunlight conditions

• Item 4: Check panel surfaces for dirt and deposits

• Item 5: Manage shading from weeds and trees

• Item 6: Do not overlook abnormalities at the string level

• Item 7: Check connection points and cables for faults

• Item 8: Check for shutdowns and output curtailment of power conversion equipment

• Item 9: Review temperature rise and inadequate ventilation

• Item 10: Organize drainage, terrain, and inspection records

• How to sustain operations that reduce wasted power generation

• Summary

Approaches to Reducing Waste in Power Generation

When considering how to increase solar power generation, the first thing to be aware of is that you cannot increase the solar irradiance itself on-site. You cannot increase the number of sunny days, nor can you change the sun’s elevation by season. However, you can move closer to a state in which the received solar irradiance is converted into electricity with as little waste as possible. In practical terms, increasing generation is not just about adding equipment; it involves finding the causes of lost potential generation and taking steps to reduce wasted output.

Losses in power generation are not caused only by large visible failures. Dirt on panel surfaces, bird droppings and fallen leaves, shading from weeds and trees, faults in connections, cable damage, stoppage of conversion equipment, output curtailment, temperature increases, poor drainage, and insufficient inspection records—small factors like these accumulate and reduce power generation. Especially at solar power plants, even if the total generation does not appear to show a major anomaly, only some equipment may be underperforming. Quickly detecting those small losses is the first step to improving generation.

For practitioners searching for "how to increase power output", the important thing is not to decide on countermeasures based only on the fact that output is low. Whether output is low only in the morning, only in the evening, the midday peak fails to rise, it becomes unstable after rain, or only certain rows or strings are underperforming will change which causes need to be checked. Cleaning because panels are dirty and weeding because vegetation has grown are valid actions, but if the power output data aren't linked to on-site conditions, you may end up prioritizing tasks with little effect.

To reduce wasted power generation, it is important to link and review power generation data, on-site photos, inspection results, and work histories. Determine where generation losses are occurring, prioritize countermeasures by their impact, and verify changes in generation after the measures are implemented. By repeating this cycle, generation improvement becomes not a one-time task but a continuous operational improvement. Below, we explain 10 items you should check to increase solar power generation, presented in the order that is most practical for on-site use.

Item 1: Check power generation data by time of day

The first thing you should do to reduce wasted power generation is to check the power generation data by time of day. Looking only at monthly or annual generation totals won’t tell you when generation losses are occurring. Even if the outcome is the same—low generation—the cause can vary greatly depending on whether it’s only low in the morning, the midday peak doesn’t extend, it drops in the evening, or there are sudden dips during the daytime.

If power generation is low in the morning, shadows from trees on the east side, slopes, surrounding structures, or adjacent equipment may be involved. If it is low in the evening, check for shadows on the west side and the surrounding terrain. If the midday peak does not develop, candidates include dirt on the panel surfaces, temperature rise, limitations of conversion equipment, output curtailment, or equipment shutdowns. If the generation curve suddenly drops during a sunny day, you need to correlate shutdown histories and alarm logs with the timestamps.

When checking by time of day, be careful not to judge based only on cloudy or rainy days. On days when power generation rises and falls with the movement of clouds, it becomes difficult to distinguish that from equipment abnormalities. Whenever possible, check the generation curve on clear days and look for similar dips at the same times each day, which makes it easier to spot patterns of shading or equipment stoppage. To increase power generation, it is important not only to know that output is low but also to identify the times when drops occur.

Checking data by time of day will also improve the accuracy of on-site inspections. If generation drops in the morning, check the site conditions in the morning; if it drops in the evening, look for evening shadows. If it doesn’t increase at midday, focus on checking soiling, equipment, and temperature conditions. Walking the site without looking at the data tends to make inspections broad and superficial. To reduce wasted generation, it is essential to first narrow down the time periods when generation losses occur.

Item 2: Identify areas of degradation by comparing with equipment under the same conditions

Wasted power generation does not necessarily appear uniformly across an entire power plant. Even if the overall output does not look significantly abnormal, the output of some rows, some strings, or some conversion devices may be reduced. Such partial reductions, if left unaddressed, will continue to produce generation losses over long periods. Therefore, to increase power output, it is important to compare equipment under the same conditions.

When comparing, select installations with similar azimuth, tilt, number of panels, shading conditions, and connection configurations. Simply comparing installations with different conditions may cause you to misinterpret normal differences as anomalies. For example, if the azimuth or tilt differs, energy output will vary even under the same solar irradiance. The purpose of the comparison is to identify, within the power plant, installations that should normally have similar values but are consistently lower.

If only part of the installation shows lower output compared with equipment under the same conditions, localized dirt, partial shading, poor connections, cable damage, or equipment-side faults may be suspected. Even if the difference in power generation seems small, if it continues every day it becomes a large loss. If the difference is especially clear on sunny days, it is more likely to be caused by on-site factors rather than the weather. In improving power generation, it is important not to overlook such small differences.

The comparison results serve as the basis for determining priorities for on-site inspections. Identify the locations of equipment with low power output and check for dirt, shading, wiring, devices, and drainage conditions around them. If locations with low power output coincide with on-site problems, the rationale for countermeasures becomes clear. Conversely, if a visual inspection suggests an issue but a drop in power output cannot be confirmed, other areas may need to be prioritized. Finding areas of decline through comparison rather than by intuition helps reduce wasted power generation.

Item 3: Separate variations due to weather and solar irradiance conditions

When you feel power generation is low, what you should check before suspecting an equipment fault is the impact of weather and solar irradiance conditions. Solar power generation is highly dependent on the amount of sunlight, so during stretches of cloudy or rainy weather output can fall even if the equipment is fine. If you judge that output has deteriorated based solely on comparing monthly generation with the same month last year or with the previous month, the primary cause may in fact be differences in the weather.

On the other hand, you must avoid overlooking a real anomaly by attributing it to the weather. If the entire plant is declining in the same way consistent with local weather, you can consider that solar irradiance conditions have a major impact. However, if only part of the plant is performing lower while other equipment at the same plant is operating normally, or if there is a clear difference compared with equipment under similar nearby conditions, the weather alone cannot explain it. In such cases, you need to check for soiling, shading, poor connections, equipment shutdowns, and output curtailment.

To distinguish between weather-related and equipment-related causes, it is effective to compare clear days with other clear days or days with similar weather. On cloudy or rainy days, power generation fluctuates greatly due to cloud movement, making it difficult to discern the characteristics of anomalies. By selecting and checking power generation curves from clear days, trends such as shading, shutdowns, curtailment, and string anomalies are easier to find. Rather than looking only at days with low power generation, it is important to compare them with days that have similar conditions.

Seasonal differences are also taken into account. In winter, the solar altitude is lower, and shadows from surrounding trees and terrain tend to extend longer. In summer, while solar radiation is stronger, panel temperatures and temperatures around equipment rise, which can make it harder for output to increase. During periods with frequent rain, monthly power generation tends to be lower, and after strong winds or heavy rain attention must be paid to deposits, sediment, poor drainage, and the condition around cables. Understanding natural variability and then looking for onsite waste that can be improved is the basic approach to increasing power generation.

Item 4: Check for dirt and deposits on the panel surface

Dirt and deposits on panel surfaces are a common cause of reduced power output. Because solar panels generate electricity by receiving sunlight on their surfaces, when dirt accumulates the amount of light reaching the cells is reduced. The way panels become dirty varies with the site environment: soil dust, pollen, yellow sand, bird droppings, fallen leaves, tree sap, dust from nearby construction, road-borne dust, and salt-containing deposits that readily adhere in coastal areas.

Particularly concerning are the bands of dirt that remain at the lower edge of the panels and around the frame. It is often assumed that rain will wash them away naturally, but in reality the flow of rainwater can collect the dirt at the lower edge, where it then remains. Panels with a shallow tilt do not drain water easily, making dirt more likely to accumulate. Even dirt that is not noticeable from a distance can affect power generation if it covers part of a cell.

Local deposits such as bird droppings and fallen leaves should not be overlooked. Unlike dirt that spreads thinly across the entire surface, these cover specific spots densely and act as partial shadows that impede power generation. If only some installations show reduced output, concentrate on inspecting the panel surfaces around those installations. Rows near trees, areas around structures where birds are likely to perch, rows that are often downwind, and locations near unpaved walkways are more prone to dirt and deposits.

When cleaning is carried out, it is practical to prioritize locations that have the greatest impact on power generation. Instead of cleaning all panels at the same frequency, focus on equipment where a decline in power generation has been confirmed, rows where dirt is concentrated, areas where soiling at the lower edge is conspicuous, and places with heavy bird damage or fallen leaves. By comparing photos and power generation before and after cleaning, it becomes easier to judge how much the soiling at that site had been affecting power generation.

However, cleaning must be carried out in a way that does not damage the equipment. Avoid vigorously scrubbing with hard tools, performing sudden work during periods when panels are at high temperatures, and working without verifying the electrical safety of the equipment. Cleaning to increase power output is not a cosmetic task to improve appearance but a maintenance task to restore the light-receiving condition and to ensure long-term, stable use of the equipment. If you find dirt, it is important to record its location, extent, and the likely causes.

Item 5: Manage shading from weeds and trees

Managing shading is essential to reducing wasted power generation. Because solar panels generate electricity from sunlight, even a small amount of shade on part of a panel can reduce its output. Sources of shading include weeds, trees, fences, utility poles, nearby buildings, racking, adjacent rows of panels, and monitoring equipment. Shadows move with the time of day and the seasons, so the fact that shading was not visible at the time of inspection does not necessarily mean there is no problem.

Weeds are a common cause of power generation loss at sites. Even if they are not a problem in winter or immediately after installation, they can grow rapidly from spring to summer and cast shadows on the lower edge of panels and on the front row. Even if the vegetation does not touch the panels, the low solar altitude in the mornings and evenings causes shadows to extend far. Furthermore, when weeds become overgrown they reduce ventilation, block inspection walkways, and make it difficult to check around equipment. Because they affect not only power output but also maintainability and safety, weed management is fundamental to improving power output.

Shadows from trees are a factor that tends to become problematic during long-term operation. Trees that had little impact at the time of installation can grow over several years and reduce power generation. Trees located to the south, east, and west in particular cast shadows on the panels at different times of day. At power plants near forests or slopes, the height of the terrain combined with the height of trees can create long shadows in winter. If generation is low only in winter, or there are large drops in the morning and evening, it is necessary to check the trees and the terrain together.

When checking shadows, aligning the power generation data with the time of on-site inspection makes it easier to find the cause. If power output is low in the morning, check on-site conditions in the morning; if it is low in the evening, look at the evening shadows. Even if there is no problem when checked at noon, significant shadows can appear in the morning and evening. Also, even if there is no problem in summer, shadows can lengthen in seasons when the solar altitude is low. Shadows should be managed as something that changes over time and with the seasons, not as a single point in time.

When performing weeding or pruning, prioritize areas that have the greatest impact on power generation. Rather than aiming only to uniformly tidy the entire site, focus on checking the front of the panels, around equipment, inspection walkways, and directions where shadows are likely to extend. After work, record whether shadows have actually been eliminated, whether inspections have become easier, and whether ventilation has improved. If you record the sources of shadows, it will be easier to determine the timing of future weeding or pruning.

Item 6: Don't overlook string-level anomalies

Generation losses can occur at the string level. Even if the plant’s total output doesn’t appear to show a major problem, some strings may have reduced generation. Such partial reductions, if left unaddressed, will continue to cause generation losses over a long period. To increase output, don’t be reassured by the overall average; you need to detect anomalies at a finer unit level.

When checking for anomalies at the string level, the basic principle is to compare items under the same conditions. If you simply compare systems that differ in the number of panels, orientation, tilt, shading conditions, or connection configuration, you may mistakenly interpret normal differences as anomalies. Compare with adjacent rows or installations with the same orientation to see if any are consistently lower. If only a particular string is lower, candidate causes include soiled panels, partial shading, poor connections, cable damage, or equipment-side issues.

Pay attention to how the anomaly appears. If it is consistently lower than the surroundings even on clear days, dirt or connection problems may be suspected. If it is lower only in the morning and evening, check for shading effects. If anomalies tend to occur after rain, moisture ingress or the condition of the connections may be involved. If it becomes unstable during high-temperature periods, poor contacts or the temperature environment around the equipment are also possible causes. Combining the power output waveform with on-site conditions makes it easier to narrow down the cause.

Even small differences in power output can result in significant losses if they persist over a long period. Furthermore, when poor connections or cable damage are involved, the issue can pose safety risks in addition to reducing generation. For locations suspected of abnormalities, recording the equipment ID, position, photos, and the time of occurrence makes it easier to hand over information for subsequent inspections or specialist assessments. Reducing wasted generation requires the habit of focusing on details rather than the whole.

Item 7: Check connectors and cables for faults

In solar power generation, even when panels are receiving sunlight properly, faults in connections or cables can reduce power output. Loose terminals, poor contact, damaged cable sheathing, moisture ingress, animal damage, damage during grass-cutting operations, and deterioration from aging are among the many causes that can impede the flow of electricity. Because these issues can be difficult to detect from appearance alone, it is necessary to narrow down the abnormal range using power generation data and make a judgment by cross-checking with on-site conditions.

You should suspect faults in connections or cables when only specific equipment shows low power output, when abnormalities tend to appear after rain, when power generation suddenly drops, or when output fluctuates unstably. If a section is underperforming despite no visible dirt or shading, electrical faults should also be considered. If there is a persistent difference compared with a string under the same conditions, prioritize inspecting the connections and cables.

Cables are parts that are easily affected by site conditions. In areas with heavy weed growth, it becomes difficult to check the condition of cables. There is also a risk of cables being contacted during grass cutting operations. In locations with poor drainage, moisture and puddles can affect connection points. At power plants where animals can easily enter, cable damage can also occur. It is important not to view connection issues in isolation, but to inspect them together with the surrounding environment.

Verification of electrical equipment must be carried out with safety as the highest priority. Rather than having on-site personnel forcibly touch equipment to make judgments, document and organize the equipment showing abnormalities, the time of occurrence, changes in power generation, on-site photographs, and the surrounding environment, and, if necessary, arrange for a professional inspection. You should avoid performing work that skips safety checks simply to increase power generation. Even after repairs, confirm background factors such as moisture, vegetation, exposed cables, and animal intrusion so that the same problem does not recur at the same location.

Item 8: Confirm shutdown of conversion equipment and output suppression

The causes of low power generation are not limited to the panels and wiring. Even if solar irradiance is sufficient, generation will not increase if the equipment that converts the generated electricity is stopped or its output is being limited. To reduce wasted generation, it is essential to check the operating status of the conversion equipment, shutdown history, alarm history, and whether there is any output curtailment.

When reviewing outage history, confirm which equipment stopped, when it stopped, and for how long. Even a short downtime can cause significant losses if it occurs during the daytime when power generation is high. If stops and recoveries recur during the daytime, they may not be noticeable in the monthly total but could still mean lost generation. Whether only a specific device stops or multiple devices stop at the same time will change which causes you should suspect.

When output curtailment occurs, power generation can plateau even under sunny conditions. If the upper part of the generation curve appears flat, check operational data and history. However, a flat curve does not necessarily indicate output curtailment. Similar shapes can result from equipment capacity limits, temperature rise, soiling, shading, or measurement anomalies. Do not judge based on the generation curve alone; it is important to verify equipment records together with on-site conditions.

When checking the equipment side, it is important to match the time of the drop in power generation with the time of shutdown. If the time the power generation fell matches the time of an alarm or shutdown, it becomes easier to narrow down the possible causes. If there are no abnormalities in the equipment records, check other causes such as panels, wiring, shading, dirt, and solar irradiance conditions. Addressing issues based on data and history rather than speculation is the key to preventing failures in corrective actions.

Item 9: Reassess temperature rise and inadequate ventilation

Temperature rise and poor ventilation are often overlooked causes of lost generation. While solar power systems generally produce more electricity under stronger solar irradiance, output can fail to increase when panel temperatures or the temperatures around equipment rise. If, on a clear summer day, generation does not reach expected levels, you should check not only the solar irradiance but also the thermal environment.

Panels outdoors are exposed to strong solar radiation, so their surface temperature rises. If the surrounding airflow is poor or weeds are overgrown beneath the panels, heat can easily accumulate. Temperature-related power loss may appear not as a sudden shutdown but as a slowdown in the increase of power output. At sites where generation tends to plateau around noon in summer, it is worth checking the ventilation conditions.

Conversion equipment is also affected by temperature. If grass or other objects around the equipment obstruct heat dissipation, this can lead to reduced efficiency or activation of protective functions. The area around the equipment needs to be kept accessible for inspection, well ventilated, and in a condition where any abnormalities can be checked immediately. A situation in which weeds or accumulated debris make it hard to see around the equipment is undesirable not only for power generation but also for ease of inspection and safety.

It is not possible to completely eliminate the decrease in power generation caused by temperature rise. However, unnecessary heat buildup can be reduced. Managing weeds under the panels, ensuring ventilation around equipment, maintaining inspection walkways, and checking for dust and deposits are measures that can be implemented on site. From the perspective of increasing power generation, it is necessary to review not only direct causes such as dirt and shading but also indirect factors like the thermal environment.

Item 10: Organize drainage, topography, and inspection records

To reduce losses in power generation, it is necessary to check not only the panels and equipment but also the plant’s overall drainage, topography, and inspection routes. Places where water tends to accumulate, where sediment can wash in, paths that easily become muddy, slope collapses, scouring around racking, and areas where cables are likely to be exposed can directly or indirectly cause reductions in power output. Poor drainage and changes in terrain may at first seem unrelated to power output, but they are important factors that lead to soiling, weeds, connection faults, and reduced accessibility for inspection.

In places where puddles remain after rain, weeds tend to grow more easily. When weeds grow, they create shade, reduce ventilation, and make inspections more difficult. Muddy walkways can slow down work and may reduce the frequency of cleaning and weeding. Where sediment flows in, it can accumulate beneath panels and around cables, causing dirt and damage. If problems repeatedly occur in the same location even after cleaning and weeding, drainage or topography issues should be suspected.

During terrain and drainage inspections, on-site checks after rain as well as in fair weather are effective. Identify where water flows in, where it accumulates, and where it drains away. Recording puddles, sediment deposits, vegetation overgrowth, pathway settlement, and changes in slopes helps pinpoint locations prone to recurrence. If poor drainage is left unaddressed, dirt and weeds will recur, resulting in the same power generation losses occurring repeatedly.

Inspection records are also important. If you record the locations of underperforming equipment, rows that tend to get dirty, areas where shadows occur, places where water accumulates, points where connection faults have occurred, repaired spots, and the areas where cleaning or weeding was carried out, it will be clear which places should be checked at the next inspection. When records are insufficient, even if the same problems recur you cannot learn their causes, and responses tend to be ad hoc. To reduce wasted generation, it is essential to retain inspection results as information that can be used for future improvements.

How to Sustain Operations That Reduce Wasted Power Generation

Efforts to reduce wasted power generation cannot be completed by a single cleaning, weeding, or repair. Solar power plants are outdoor facilities, and their condition changes with the seasons, weather, surrounding environment, and the aging of equipment. Even after cleaning, dirt will accumulate again; after weeding, grass will regrow; trees will grow; and drainage routes will change. Because equipment and wiring also change condition over long-term operation, continuous inspection is necessary.

First, it is important to compare power generation before and after the measures. After performing cleaning, weeding, repairs, equipment checks, and drainage checks, confirm how the power generation has changed. It is difficult to completely eliminate the influence of weather, but by comparing clear days with each other or comparing installations under the same conditions, you can identify certain trends. Prioritize measures that had a large effect for next time, and if an effect is hard to see, suspect another cause.

Next, designate areas prone to recurrence as management targets. If you record rows where dirt tends to accumulate, time periods when shadows are likely to occur, places where water pools, walkways prone to damage, and equipment likely to show abnormalities, you can inspect them before power generation drops significantly. To stably increase power output, it is important not only to respond after output falls but to identify conditions that tend to cause declines in advance and implement countermeasures.

When multiple people are responsible for management, it is also important to be able to share the exact same location. In a large power plant, rows and equipment that look similar are lined up, so a photo alone can make it hard to identify a location. If you record the equipment number, location information, photos, and work history together, on-site personnel, managers, inspection staff, and maintenance personnel can more easily confirm they are referring to the same place. Operations to reduce wasted power generation also involve building systems that turn observations made on site into the next improvements.

Summary

To reduce wasted power generation, it is important to identify the causes of generation losses in sequence and address them starting with the areas that have the greatest impact on power output. In solar power generation, you cannot increase the incident solar irradiance at the site itself. However, you can improve output by bringing the system closer to a state that converts the received irradiance into electricity without waste. To do this, it is necessary to check, in order, power generation data, equipment comparisons, weather conditions, panel surface soiling, shade from weeds and trees, string abnormalities, connection points, conversion equipment, the temperature environment, drainage, and inspection records.

When you feel that power generation is low, rather than immediately carrying out cleaning or repairs, it is important first to break down and examine the data. Identify when output is low, which equipment is underperforming, and whether there is a difference compared with equipment under the same conditions. By then inspecting the site, the places that need cleaning, the areas that need weeding, the connections that need inspection, the equipment that needs checking, and the drainage or traffic flow that should be reviewed will become clear. To maximize the effectiveness of improving power generation, it is important to make decisions by linking data with on-site conditions rather than relying on intuition.

Also, efforts to reduce waste in power generation cannot be completed in a single action. Even if you clean, dirt will reaccumulate; even if you remove weeds, grass will regrow; trees will grow; and equipment and wiring will change condition with age. By comparing power generation before and after countermeasures, keeping on-site photos and work records, and using them for the next inspection, the accuracy of improvements increases. To raise power generation consistently, it is essential not only to eliminate the causes but also to create a site environment and management system that make the same causes less likely to occur.

In particularly large power plants, a system to accurately share problem locations is essential. If rows prone to soiling, shadowed areas, places where water accumulates, abnormal strings, repair locations, cleaning extents, and inspection photos are recorded together with location information, stakeholders can more easily confirm the same locations. By combining power generation data with on-site location information, it becomes easier to explain the priority for cleaning, weeding, and repairs, and to streamline verification of recurrence in future inspections.

If you want to continuously reduce wasted power generation based on field data, using LRTK is also effective. As an iPhone-mounted GNSS high-precision positioning device, LRTK is useful for recording inspection locations, areas prone to soiling, locations where shading occurs, poor drainage spots, abnormal equipment, repair locations, cleaning areas, and on-site photos within solar power plants together with high-precision positional information. By managing how solar output is improved not by intuition but with on-site records that include location information, it becomes easier to continuously reduce wasted power generation.