How to Increase Power Generation? 7 Checks to Review First

Table of Contents

• Visualizing the causes is the first priority for increasing power generation

• Check 1: Verify power generation data by time of day

• Check 2: Distinguish drops caused by weather and solar irradiance conditions

• Check 3: Inspect the panel surface for dirt and deposits

• Check 4: Check for shading from weeds and trees

• Check 5: Inspect strings and connection points for abnormalities

• Check 6: Verify shutdowns or output curtailment of conversion equipment

• Check 7: Verify drainage, terrain, and inspection routes

• Management methods to sustain efforts to increase power generation

• Summary

Visualizing the Causes Is the First Priority for Increasing Power Generation

To increase solar power generation output, it is important first to visualize where generation losses are occurring. When you feel the power output is low, you may be tempted to immediately consider adding equipment or carrying out major renovations. However, in many real-world cases, the existing equipment is simply not able to deliver its full intended generation capacity. Dirt on panel surfaces, shading from weeds or trees, faults at connection points, equipment shutdowns, output curtailment, poor drainage, and site conditions that make inspections difficult — small factors like these can accumulate and reduce power output.

The first concept that practitioners searching for "how to increase power generation" should grasp is not so much increasing generation as preventing the loss of the electricity that should be generated. In solar power generation you cannot increase the amount of solar irradiance at the site itself. On the other hand, you can manage how the received sunlight is converted into electricity so that as little as possible is wasted. In other words, the basis of improving generation is to look for where waste occurs in the flow of receiving sunlight, converting it into electricity, transmitting it, and recording it.

The causes of low power generation are not necessarily limited to a single factor. If output is low only in the morning, east-side shading may be responsible; if it is low only in the evening, west-side shading may be the cause; if the midday peak does not reach expected levels, dirt, temperature, or equipment limitations may be involved. If only certain pieces of equipment show low output, connection faults or string-level anomalies are suspected. If output becomes unstable after rain, it is necessary to check connection points, drainage, and the areas around cables. In this way, by changing your perspective—looking at time of day, location, weather, season, and equipment unit—the causes of reduced power generation become easier to identify.

Also, measures to increase power generation should be implemented in a way that allows before-and-after comparisons. If cleaning, weeding, repairs, and equipment inspections are done simultaneously, it becomes difficult to tell which action was effective even if generation recovers. Even when simultaneous work is necessary due to site constraints, recording before photos, the work area, generation data, abnormal locations, and post-work changes will help inform future decisions. To increase power generation, an attitude of improving by connecting data with on-site conditions is essential, rather than taking ad hoc measures.

From here, we explain the seven checkpoints you should examine first to increase power output. Each is easy to verify on site and important for isolating the causes of generation losses. When you feel the power output is low, rather than only inspecting obvious areas, checking in this order will make it easier to organize the points that need improvement.

Check 1: Verify power generation data by time of day

The first thing to check to increase power generation is the generation data by time of day. If you only look at monthly or daily generation, you cannot tell when generation losses are occurring. Even if the outcome is the same—low generation—the likely causes differ greatly depending on whether it is low only in the morning, the midday peak fails to develop, it suddenly drops only in the evening, or there is an unnatural dip during the daytime.

If morning generation is low, shadows from east-side trees, slopes, nearby structures, or adjacent equipment may be involved. If evening generation is low, check for shadows on the west side and the influence of surrounding terrain. If generation plateaus around noon, suspect soiling, temperature rise, power conversion equipment capacity limits, output curtailment, or equipment shutdowns. If the generation curve suddenly drops partway through the day even on a sunny day, it is necessary to cross-check shutdown history and alarm logs with the timestamps.

When checking by time of day, it is effective to use data from clear days whenever possible. On cloudy or rainy days, power output can fluctuate greatly due to passing clouds, making it difficult to distinguish those fluctuations from equipment faults. On clear days, the shape of the generation curve is relatively stable, making it easier to identify features such as shading, shutdowns, curtailment, or abnormal strings. Comparing generation curves of equipment under similar conditions within the same plant also makes it easier to identify areas where only part of the output has decreased.

When reviewing power generation data, it is also important to distinguish between abrupt drops and gradual declines. Abrupt drops are often caused by equipment shutdowns, wire breaks, poor connections, the emergence of obstructions, and similar issues. On the other hand, when output declines gradually over the course of several weeks to several months, factors such as the accumulation of dirt, the growth of weeds or trees, aging-related deterioration, and site condition degradation due to poor drainage may be involved. By looking at the pattern of the decline, you can narrow down the locations that should be prioritized for on-site inspection.

To increase power output, the starting point is not to act only on the fact that output is low, but to determine when it is low. By checking data by time of day, on-site inspections become more efficient. If output is low in the morning, check for morning shadows; if it does not rise at midday, check for dirt, equipment issues, or temperature; and if it is low in the evening, check for shadows on the west side—this makes the inspection focus clear.

Check 2: Separate declines caused by weather and solar irradiance conditions

When you feel the power output is low, what you should check before suspecting an equipment fault is the weather and solar irradiance conditions. Solar power generation is greatly affected by solar irradiance, so during periods with many cloudy or rainy days the output will decline even if there is no problem with the equipment. If you judge that monthly output has “decreased” only by comparing it with the same month last year or the previous month, the main cause may actually have been differences in weather. To increase power output, it is necessary to distinguish declines that can be remedied from natural variations caused by the weather.

When assessing weather-related differences, rather than a simple month-to-month comparison, it is helpful to compare sunny days with other sunny days, days with similar weather, and power generation trends within the same region. If you manage multiple power plants, check whether plants in the same area are experiencing similar declines. If nearby plants are also showing similar declines, the impact of solar irradiance conditions may be significant. Conversely, if other equipment in the same region or within the same plant is operating normally but only some units are underperforming, you should suspect equipment- or site-related causes.

To separate weather-related factors from equipment-related ones, the shape of the power output curve is also useful. Cloud-induced variations often show similar rises and falls across multiple pieces of equipment. In contrast, equipment shutdowns or connection faults may cause only certain equipment to suddenly drop or to be near zero for a period. Shadowing can produce similar dips at the same times each day even on clear-sky days. To determine whether a decline is due to weather or to an on-site issue, it is important to overlay multiple data sets.

When checking solar radiation conditions, seasonality should also be taken into account. In winter, the sun’s elevation is lower, and shadows from nearby trees and terrain tend to extend farther. In summer, even when solar radiation is strong, panel temperatures rise and output may not increase as much. During the rainy season and typhoon periods, overcast and rainy weather can persist, reducing monthly power generation. Rather than immediately assuming a drop in generation indicates a fault, it is important to check while taking seasonal characteristics into account.

However, you must not let weather be used as an excuse to overlook equipment abnormalities. If you dismiss low power generation as “because the weather was bad,” dirt, shading, poor connections, and equipment shutdowns may be left unaddressed for long periods. The purpose of isolating weather-related differences is not to stop checking for abnormalities, but to correctly focus on causes that can be improved on site. To increase power generation, you need to understand weather-driven variations and actively seek generation losses on the equipment side.

Check 3: Inspect the panel surface for dirt and contaminants

When aiming to increase power generation, dirt and deposits on panel surfaces are items you should always check. Because solar panels generate power by receiving solar radiation on their surface, when dirt adheres the light reaching the cells is reduced. Examples include soil dust, pollen, yellow sand (Asian dust), bird droppings, fallen leaves, sap, dust from nearby construction, road-borne dust, and salt-containing dirt that tends to adhere in coastal areas; the type of soiling varies depending on site conditions. Even light soiling spread over a wide area can affect power output, and localized deposits can act as a strong shading effect even if they cover only a small area.

One area that is particularly easy to overlook is the band-like dirt that remains along the lower edge of the panel and near the frame. It is often assumed that surface dirt will be washed away when it rains, but in reality the flow of rainwater can carry dirt to the lower edge, where it accumulates and remains. Panels with a shallow tilt do not drain well, making them prone to dirt buildup. Even dirt that is not noticeable from a distance can affect power generation if it covers part of a cell.

Pay attention to deposits such as bird droppings and fallen leaves. Unlike uniform soiling, these adhere heavily in specific spots and create localized shading. If only some installations are showing reduced power output, check the panel surfaces in that area. Rows near trees, around structures where birds tend to perch, rows that are often downwind, and areas near unpaved walkways tend to be more prone to dirt and deposits.

When cleaning, it is practical to prioritize areas that have the greatest impact on power output. Rather than cleaning all panels at the same frequency, focus on rows where dirt is concentrated, equipment where a drop in power output has been observed, areas where soiling along the lower edges is noticeable, and locations with heavy bird damage or fallen leaves. Comparing photos and power output before and after cleaning makes it easier to understand how much soiling was affecting generation at that site.

However, cleaning must be carried out in a way that does not damage the equipment. Avoid scrubbing vigorously with hard tools, performing sudden work during periods when panels are at high temperature, or working without confirming electrical safety of the equipment. Cleaning to increase power output is not merely an operation to improve appearance; it is maintenance work to restore the panels’ light-receiving condition and to keep the equipment operating stably over the long term. By identifying the causes that make soiling likely and reviewing access paths, surrounding vegetation, and places where birds tend to gather, it becomes easier to prevent recurring declines in power generation.

Check 4: Check for shadows cast by weeds and trees

To increase power generation, checking for shadows is essential. Solar panels generate electricity by receiving sunlight, so even a portion of a panel being shaded can reduce output. Causes of shading include weeds, trees, fences, utility poles, surrounding buildings, mounting racks, adjacent rows of panels, monitoring equipment, and various other factors. Because shadows move with the time of day and season, the absence of visible shading at the time of inspection does not necessarily mean there is no problem.

Weeds are a common cause of on-site power generation losses. Even if there is no problem in winter or immediately after installation, they can grow rapidly from spring through summer and cast shadows on the lower edges of panels and the front rows. Even if the vegetation does not touch the panels, the low solar altitude in the morning and evening causes long shadows. Furthermore, when weeds become dense, ventilation worsens, inspection walkways become blocked, and it becomes harder to check around equipment. Because they affect not only energy production but also maintainability and safety, weed management is a basic measure to increase power generation.

Shading from trees is 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 panels depending on the time of day. At plants near forests or slopes, the height of the terrain and the height of the trees can overlap, creating long shadows in winter. If generation is only low in winter or there is a large drop in the mornings and evenings, it is necessary to check both the trees and the terrain together.

When checking shadows, matching the power generation data with the time of the on-site inspection makes it easier to find the cause. If generation is low in the morning, check the on-site conditions in the morning; if it’s low in the evening, inspect the shadows in the evening. Even if there is no problem at noon, large shadows can appear in the morning or evening. Also, even if there is no problem in summer, shadows can lengthen in seasons with lower solar altitude. To increase power generation, shadows need to be managed not as a single point in time but as something that changes with time and season.

When performing weeding or pruning, prioritize the areas that have the greatest impact on power generation. Rather than simply leveling the entire site uniformly, focus specifically on the area in front of the panels, around equipment, inspection walkways, and directions where shadows are likely to extend. After work, record whether the shadows have actually been eliminated, whether inspections have become easier, and whether ventilation has improved. Because shadow issues tend to recur, do not treat it as a one-time operation; annual management that assumes the growth of grasses and trees is important.

Check 5: Inspect strings and connection points for abnormalities

To increase power generation, it's important to check for anomalies at the finest possible granularity, not just by looking at plant-wide figures. Even if total generation doesn't seem to indicate a major problem, only some strings may be underperforming. If left unaddressed, these partial declines will continue to cause generation losses over a long period. To boost power generation, don't be reassured by the overall average; identify differences at the equipment level and the string level.

When comparing at the string level, it's fundamental to compare like with like. If you simply compare systems that differ in the number of panels, azimuth, tilt, shading conditions, or connection configuration, you may mistakenly interpret normal differences as abnormalities. Check whether any string is consistently lower than adjacent strings or installations with the same orientation. If only a particular string is low, possible causes include dirty panels, partial shading, poor connections, cable damage, or equipment-side issues.

Pay attention to how anomalies manifest. If output is consistently lower than the surroundings even on sunny days, dirt or connection problems are 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 connection points may be involved. If it becomes unstable during periods of high temperature, poor contact 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.

Faults in connections and cables are also an important cause of reduced power generation. There are many causes that can impede the flow of electricity, such as loose terminals, poor contact, damage to cable sheathing, ingress of moisture, damage caused by animals, damage during mowing operations, and deterioration with age. Because these can be difficult to detect from appearance alone, it is important to narrow down the abnormal range using power generation data and make a judgment by cross-checking with on-site photos and work history.

Inspections of electrical equipment are conducted with safety as the top priority. Rather than having on-site personnel forcefully handle equipment to make judgments, we compile information on the equipment showing abnormalities, the time of occurrence, changes in power output, on-site photographs, and the surrounding environment, and, when necessary, refer these to specialist inspections. Even if connection points are repaired, recurrence is possible if conditions remain, such as water pooling in the same place, overgrown vegetation, cables that are easily exposed, or easy access for animals. To increase power output, it is necessary not only to fix abnormalities but also to reassess the environment so that abnormalities are less likely to occur.

Check 6: Confirm shutdown and output suppression of conversion equipment

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

When reviewing downtime history, check which equipment stopped, when it stopped, and for how long. Even short outages can cause large losses if they occur during daytime when generation is high. If stops and recoveries are repeatedly occurring during the day, they may not stand out in the monthly totals but can still result in lost generation. Whether only a specific piece of equipment stops or multiple pieces stop simultaneously will change which causes you should suspect.

If output curtailment is occurring, power generation can plateau even on sunny days. If the top of the generation curve appears flat, check curtailment records and operating information. However, a flat curve does not necessarily mean output curtailment. Similar shapes can result from equipment capacity limits, temperature rise, dirt, shading, or measurement anomalies. Do not judge based only on the generation curve; it is important to isolate causes by combining equipment records with on-site conditions.

The surrounding environment of the conversion equipment is also a point that should be checked. Conditions such as weeds growing around the equipment, poor ventilation, excessive dust and deposits, or heat buildup can affect operating efficiency and increase the risk of shutdown. While solar power generation is easier when solar irradiance is strong, output tends to decrease if panel temperature or the temperature around equipment rises. If, on a clear summer day, generation falls short of expectations, check for temperature increases and poor ventilation.

When checking the equipment, the important thing is to correlate the drop in power output with the shutdown time. If the time the output fell matches the time of alarms or a shutdown, it becomes easier to narrow down the cause. Conversely, if there are no anomalies in the equipment logs, suspect other causes such as the panels, wiring, shading, dirt, or irradiance conditions. To increase power generation, it is important to choose countermeasures based on data and history, not on guesswork.

Check 7: Confirm Drainage, Topography, and Inspection Access Routes

To increase power generation, not only the panels and equipment but also the site's overall drainage, topography, and inspection routes need to be checked. Locations where water tends to pool, places where sediment can flow in, pathways prone to becoming muddy, slope failures, scour around the mounting racks, and spots where cables are likely to become exposed can directly or indirectly cause reductions in power output. Poor drainage and changes in terrain may at first seem unrelated to power generation, but they are important factors that lead to soiling, weeds, connection faults, and reduced accessibility for inspections.

In areas where puddles remain after rain, weeds are more likely to grow. When weeds grow, they create shade, reduce airflow, and make inspections more difficult. Muddy walkways can slow work and may lead to less frequent cleaning and weeding. In places where sediment washes in, it can accumulate beneath panels and around cables, causing dirt and damage. To increase power generation consistently, it is important to manage the site environment as well as the generation equipment.

When checking terrain and drainage, it is effective to inspect the site not only in fine weather but also after rain. Determine where water flows in, where it accumulates, and where it drains out. Recording puddles, sediment deposits, dense vegetation, settlement of pathways, and changes in slopes will reveal locations prone to recurrence. If dirt and weeds repeatedly appear in the same place despite cleaning or weeding, you should suspect drainage or topography problems rather than rely on superficial measures alone.

Inspection routes also affect power generation improvement. Locations that are difficult to inspect tend to delay the detection of anomalies. If grass has overgrown so you cannot pass, the ground is too muddy to approach, equipment numbers are hard to read, or it is difficult to share the location of an anomaly, on-site response takes longer. Even if data identifies equipment with low output, improvements will be delayed if it takes time to reach the relevant location on site.

Reviewing drainage, site topography, and access routes may not immediately appear to yield a large increase in power generation. However, reducing soiling, weeds, poor connections, and inspection delays can help curb long-term generation losses. To ensure efforts to increase power output do not end as temporary improvements, it is essential to create a site environment that is less prone to problems, easy to inspect, and easy to implement countermeasures.

Management Methods to Sustain Efforts to Increase Power Generation

Efforts to increase power generation cannot be completed with a single action. Solar power plants are outdoor installations, and seasonal conditions, weather, the surrounding environment, and equipment condition are constantly changing. Even if you clean them, dirt will return; even if you remove weeds, grass will grow back; trees will grow; and drainage channels are altered by sediment. Equipment and cables also change condition with age. Therefore, to consistently increase power generation, it is necessary to establish a continuous management approach rather than rely on one-off tasks.

First, the important thing is to establish criteria for checking power generation. Decide how frequently to review generation data, what degree of decline will trigger an on-site inspection, and to what equipment unit comparisons will be made; doing so enables faster detection of anomalies. Relying solely on the intuition of staff leads to oversights and inconsistent judgments. By standardizing the generation curve on sunny days, comparisons with equipment under the same conditions, checks of outage history, and the recording of on-site photographs, the accuracy of power output improvements becomes more consistent.

Next, perform a before-and-after comparison of the measures. After cleaning, weeding, repairs, equipment inspections, and drainage checks, verify how the power output changed. It is difficult to completely eliminate the effects of weather, but by comparing sunny days with each other or comparing installations under the same conditions, you can identify consistent trends. Measures that produced large improvements should be prioritized in the future, and if an effect is not apparent, consider other causes. By continuing these comparisons, you will identify which measures tend to be effective at each site.

Keeping records is also important. If you record the date of work, scope of work, before-and-after photos, abnormalities, actions taken, and whether reinspection is necessary, the next inspection can be made more efficient. If you can identify trends—such as weeds growing in the same spot every year, dirt accumulating in the same row, the same walkway becoming muddy after rain, or the same equipment causing shutdowns—you can take proactive measures before problems occur. To increase power generation, it is important not only to respond after output declines but also to understand the conditions that make declines more likely and manage them to prevent problems in advance.

In particularly large power plants, a system for accurately sharing problem locations is indispensable. If you record the locations where shadows occur, rows prone to soiling, places where water accumulates, abnormal strings, repair locations, and inspection photos together with location information, stakeholders can more easily confirm the same spots. Combining power generation data with on-site location information makes it easier to explain the prioritization of countermeasures and streamlines subsequent inspections and checks for recurrence.

When managing multiple power plants, it is important to standardize management methods. If each site differs in how inspection photos are taken, how equipment numbers are labeled, and the format of anomaly records, sharing information takes time. Managing power generation data, on-site photos, location information, and work histories with a consistent approach makes it easier for stakeholders to share the situation. Efforts to increase power generation lead not only to improvements at individual sites but also to overall quality improvement in management operations.

Summary

To increase power generation, it is important to check the key points in order and isolate the causes of generation losses. In solar power generation, you cannot increase the amount of solar radiation itself on site. However, you can bring the system closer to a state that converts the received solar radiation into electricity without waste. To do that, you need to check power generation data by time of day, separate weather and irradiance conditions, and sequentially review panel surface soiling, shading from weeds and trees, abnormalities in strings and connections, stoppages or output curtailment of conversion equipment, drainage and terrain, and inspection access routes.

When you feel the power output is low, rather than immediately considering major renovations, it is important to first break down and examine the data. Confirm when it is low, which equipment is underperforming, and whether there is a difference compared with equipment under the same conditions. Then, when you inspect the site, it becomes clear which areas need cleaning, which zones require weed removal, which connection points need inspection, which pieces of equipment need checking, and which drainage or access routes should be reconsidered. Improving power output should be driven by linking data with on-site conditions, not by intuition.

Also, efforts to increase power generation cannot be completed in a single operation. Even if you clean, dirt will return; even if you weed, grass will regrow; trees will grow; drainage routes will change; and equipment and wiring will change condition with age. Comparing power generation before and after countermeasures, keeping on-site photos and work records, and using them for the next inspection increases the precision of improvements. To stably increase power generation, it is essential not only to remove the causes but also to establish a site environment and management system that are less prone to decline.

By leveraging on-site records and location information, it becomes easier to further improve power generation. If you record the locations where shadows occur, rows prone to soiling, areas where water accumulates, abnormal strings, repair locations, and inspection photos together with location information, stakeholders can more easily confirm the same locations. Combining power generation data with on-site location information makes it easier to explain the priority of countermeasures and streamlines checks for recurrence.

If you want to strengthen on-site management to increase power generation with more accurate records and location information, using LRTK is also effective. As an iPhone-mounted GNSS high-precision positioning device, LRTK is useful for recording inspection locations within solar power plants, locations where shadows occur, areas of poor drainage, abnormal equipment, repair locations, and on-site photos together with high-precision location information. To increase power generation, it is important to accurately identify causes and have management that allows the same locations to be continuously rechecked. By using LRTK, it becomes easier to carry out the practical on-site management necessary for improving power generation—from recording the initial check items to post-improvement verification.