5 Steps to Understand How to Increase Power Generation｜What to Check First

When you want to increase the power output of a solar power plant, the first important step is not to immediately replace equipment or undertake large-scale renovations. Multiple factors can make output appear low, including weather, season, solar irradiance, shading, soiling, vegetation, wiring, equipment settings, outage history, and missing or misinterpreted monitoring data. If you implement countermeasures without isolating the causes, you may spend time on tasks whose effects are hard to verify and risk misprioritizing on-site responses.

This article organizes, in 5 steps, the points that practical personnel searching for "how to increase power generation" should first check at a solar power plant. By "increasing power generation" we mean finding and reducing loss factors to bring equipment closer to a state where it can more easily deliver its originally intended performance. To be usable for daily inspections, monthly checks, investigations when anomalies occur, and the development of improvement plans, the explanation is practical and covers both on-site verification and data review.

Table of Contents

• Approach to isolate causes before increasing power output

• Step 1 Review power output data against solar irradiance and seasonal conditions

• Step 2 Check on-site losses such as shading, dirt, and vegetation

• Step 3 Check for abnormalities in panels, wiring, and connections

• Step 4 Check equipment downtime history and settings

• Step 5 Record improvement work and continuously verify effectiveness

• Decisions to avoid when trying to increase power output

• Summary: Increasing power output starts with on-site verification and data management

Approach to isolating causes before increasing power generation

The first step in increasing power generation is to determine whether the output has actually declined or only appears to have declined. Solar power output is not determined solely by installed capacity. Even at the same plant, generation fluctuates daily depending on the season, weather, temperature, solar irradiance, and the surrounding environment. If cloudy or rainy conditions persist, output will drop, and in winter generation is more affected by shorter daylight hours and lower solar elevation. Therefore, you should avoid judging output as "low" based on a single day's generation.

In practice, it is important to be clear about the baseline against which power generation is being compared. Whether you compare yesterday with today, the same month of the previous year, different sections within the same plant, or similar nearby facilities will change what issues become visible. In particular, when aiming to increase generation, you need to look not only at total output but also at how much is being generated relative to solar irradiance. It is natural for generation to be low on days with little irradiance, but if irradiance is sufficient and generation does not increase, there may be some losses occurring on the equipment side or the site side.

Measures to increase power generation should be prioritized according to the cause. For example, if shadows from weeds are the cause, weed removal or weed-control measures are candidates. If dirt on the panel surface is the cause, cleaning or checking the drainage condition are candidates. If wiring or connection faults are suspected, electrical inspections or confirmation by a specialist contractor are necessary. If equipment shutdowns are the cause, reviewing shutdown histories and recovery procedures is important. In this way, rather than choosing countermeasures without identifying the cause, narrowing down the location, time, and conditions of the power output decline is the starting point for improvement.

Also, a drop in power generation is not necessarily caused by a single factor. Shadows, dirt, vegetation, equipment outages, and missing measurement data can overlap. On site, you naturally want to address problems that are visible, but judging by appearance alone can lead you to overlook other losses that have a greater impact on power generation. To increase power generation, it is essential to combine on-site inspections with data checks and to systematically verify, in order, which losses are affecting the generation.

Step 1 Review power generation data against solar irradiance and seasonal conditions

The first step is to calmly review the power generation data. When you notice the output seems low, the first thing to check is whether the generation was reasonable given the solar irradiance conditions. Because solar power generation is influenced by solar irradiance, you cannot make an accurate judgment by looking at generation alone. You should verify the conditions that affect generation together — clear skies, thin clouds, rain, snow cover, yellow dust, periods after strong winds, etc.

In practice, arranging generation by day, by month, and by time of day side by side makes it easier to grasp trends. Check whether output is suddenly dropping on a daily basis, gradually declining month by month, or whether generation is failing to rise only during specific time periods. If it is low only in the morning, east-side shading or morning dew may be suspected; if it is low only in the afternoon, west-side shading or the effects of rising temperature may be suspected. If it falls sharply around midday, it is necessary to check for output control, equipment temperature rise, equipment shutdowns, problems with the connection system, and so on.

Comparing with the same month of the previous year is useful, but caution is needed with simple comparisons. Weather differs between last year and this year, and solar irradiance can change even in the same month. Therefore, instead of judging based solely on a year-on-year comparison for the same month, check solar irradiance, operating days, downtime, and changes in the surrounding environment together. Even if generation is lower than the previous year, if solar irradiance was similarly low, it does not necessarily indicate an equipment anomaly. Conversely, if solar irradiance is similar but only generation has decreased, one should suspect site-side or equipment-side losses.

To increase power generation, it is important not only to look at the total for the entire plant but also to examine differences by section, by circuit, and by equipment. Even if the overall plant shows only a small drop, some sections may experience a much larger decrease. In such cases, relying only on the overall average delays detection of anomalies. Conversely, if all sections decline similarly, weather, grid-side conditions, plant-wide settings, or widespread soiling may be involved.

Be careful of missing monitoring data and communication failures. Even if power is being generated, if the monitoring system does not correctly reflect the data, the generated output may appear to be low. Before considering measures to increase generation, confirm that the measurements themselves are being recorded correctly. Gaps in the records, time misalignment, differences in aggregation units, and configuration differences after equipment replacement can cause comparison results to deviate from reality.

The important thing at this step is to translate the feeling that “power output is low” into information you can verify. Organizing when it started being low, which time periods it is low in, which sections are affected, and whether it is low relative to solar irradiance conditions will clarify where to inspect next on site. Tasks to increase power output can be narrowed down considerably by checking the data before going to the site.

Step 2 Check for on-site losses such as shading, soiling, and vegetation

What should be checked next are the on-site factors that are impeding power generation. At a solar power plant, it is fundamental to keep the panels exposed to sufficient sunlight. Therefore, shadows, dirt or soiling, vegetation, debris buildup, snow accumulation, standing water, and changes to surrounding structures can all affect power output. Checking the site environment is a high-priority measure for increasing power generation.

When checking for shadows, it is important to observe how they change with the time of day. Even if there are no issues in the morning, shadows from trees, utility poles, fences, neighboring equipment, slopes, or mounting structures may be cast in the afternoon. Because the sun’s altitude changes with the seasons, shadows are less likely in summer and can lengthen in winter, reducing power output. If output drops only during a specific time of day, checking the shadow positions on-site at that time makes it easier to identify the cause.

Shadows from vegetation are an often-overlooked cause of reduced power generation. Even if there is no problem immediately after site development, over time weeds and nearby trees can grow and cast shadows on the bottom edge of panels or on some rows. Especially during periods when the sun is at a low angle, even small plants can produce long shadows. If vegetation is touching the panel surfaces, it can also lead to soiling, moisture buildup, and obstructions to inspection walkways. When performing weeding operations, it is efficient to prioritize checking the rows and orientations that have the greatest impact on power generation.

Dirt is also an important item to check. Soil dust, bird droppings, fallen leaves, pollen, yellow sand, dust from nearby construction, rain-streak stains, and the like, if remaining on the panel surface, can reduce the amount of light received. Dirt may accumulate uniformly across the entire surface or concentrate at the lower edge or near the frame. Even partial soiling can affect power generation depending on the circuit configuration. Some dirt will wash off naturally with rain, but on gentle slopes or in areas with poor drainage, dirt tends to remain.

When considering cleaning, it is important to check the relationship between the degree of soiling and the reduction in power generation. Even if a surface appears dirty, the impact on generation can be small, and conversely, dirt that looks minor may be affecting a specific circuit. To make it easier to judge next time, record the cleaned area, the date of the work, the weather, and the affected sections so you can compare power generation before and after cleaning.

Seasonal factors such as snowfall and fallen leaves also affect power generation. In snowy regions, power generation may drop significantly during periods when snow remains on panel surfaces. In locations with many fallen leaves, deposits can remain on some panels from autumn into winter. These are not necessarily equipment failures, but to increase power generation it is necessary to identify when and where losses are likely to occur and incorporate that into inspection plans.

Photographic records are useful for on-site loss checks. If you keep photos taken from the same position and orientation, and at times as close as possible, you can compare vegetation growth, changes in shadows, and the accumulation of dirt. Relying only on memory of the site makes differences from the previous inspection unclear. To increase power generation, it is important not only to temporarily fix problems you find but also to keep locations that are prone to recurrence on your management list.

Step 3 Check for abnormalities in the panels, wiring, and connections

If no major problems are found in the site environment, check the equipment—panels, wiring, and connection points—for abnormalities. In a solar power plant, many panels and lengths of wiring work together to generate electricity. Therefore, a fault in one part can appear as an overall drop in power generation. To increase power output, it is important to narrow down which unit is experiencing the abnormality.

First, determine the extent of the low power generation. Check whether the entire plant is producing low output, only certain sections are low, or only specific circuits are low. If only specific circuits have low output, suspect panel defects, loose connections, wiring damage, deterioration of terminal parts, tripped/disconnected breakers, open circuits, or poor contact. If multiple circuits are similarly low, inspect common equipment, junction boxes, and wiring routes.

During visual inspection, check the panel surface for cracks, discoloration, burn marks, frame deformation, abnormalities on the rear, cable sagging, damage to the sheath, loose connectors, animal damage, and the effects of rainwater. Some abnormalities cannot be judged by visual inspection alone, but obvious damage or connection failures can sometimes be detected early. In particular, after grass cutting, strong winds, heavy rain, snowfall, or suspected lightning strikes, it is important to check wiring and connection points for abnormalities.

Connections must be handled carefully because they affect not only power output but also safety. Looseness or deterioration can lead to overheating or poor contact. During inspections, checks should be carried out only after taking the necessary safety measures and in accordance with qualifications, the manufacturer's instructions, internal rules, and the scope of any maintenance contracts. Even if the aim is to increase power output, avoid forcing connections, touching them unnecessarily, or performing work while the system is energized.

Panel-level anomalies can be difficult to detect from generation data alone. Differences that look small in the overall plant figures may reflect a clear drop in output in some panels or circuits. During inspections, we combine generation trends by section, equipment-level output, and past anomaly records to narrow down suspicious locations. Once an anomaly is pinpointed, it becomes easier to proceed with concrete corrective actions such as replacement, repair, connection adjustments, cleaning, or shading countermeasures.

Also, conditions during design and construction can affect power generation. If the orientation, tilt, racking height, spacing between panel rows, wiring routes, or combinations of connections are not suited to the site conditions, actual power output may be lower than expected. Major changes can be difficult for plants already in operation, but identifying where losses occur can inform repairs, expansions, or improvements in future projects.

When inspecting panels and wiring, it's important not only to detect abnormalities but also to record normal conditions. If photos, measurements, connection status, and inspection results from normal conditions are kept, they can be used for comparison when an abnormality occurs. Inspections aimed at increasing power generation should be regarded not as one-off tasks but as management work that tracks changes in condition.

Step 4 Verify the equipment shutdown history and settings

Equipment shutdowns and settings are also important causes of reduced power generation. In a solar power plant, even if the panels are producing electricity, the actual output will drop if conversion equipment, protective devices, communication equipment, or equipment related to grid interconnection are offline. To increase power generation, it is necessary to check not only the on-site environment but also whether the equipment is operating correctly.

The first thing to check is the downtime history. Confirm when the stoppages occurred, which equipment stopped, how long they were down, and whether recovery was automatic or manual. Even short downtimes can affect monthly power generation if they occur frequently. If a downtime history is available, check whether the same error is recurring and whether it happens at specific times of day or under particular weather conditions.

For example, if there are more stoppages during periods of high temperature, it is necessary to check for equipment temperature rise and ventilation conditions. If stoppages increase after rain, it is necessary to check for flooding, moisture, insulation condition, and the condition of connection points. If errors occur during morning startup, it is necessary to check the startup conditions and the status of the input side. In this way, stoppage history is not merely a record of errors but a clue as to what to look for on site.

Checking the settings is also essential. If a device’s settings do not match the site conditions or system configuration, output may be curtailed during periods when generation should be possible, or the device may stop due to a fault. Output control, protection settings, voltage range, communication settings, time settings, recording intervals, and so on also affect how generation data appears. You should also check whether settings have changed after equipment replacement or maintenance work.

Communication failures are another issue that can easily be mistaken for decreased power generation. Even when generation is actually occurring, if data does not reach the monitoring side, the generated power may be displayed as low. Check the power supply of communication equipment, connection status, antenna placement, condition of the recording device, time synchronization, and whether there is any data loss. Before considering measures to increase power generation, it is important to distinguish whether it is not generating power or the generation is simply not being recorded.

Also, power output may be curtailed due to grid-side conditions. Because inspecting only the power plant’s internal equipment may not reveal the cause, check the time periods when output dropped, the condition of surrounding equipment, voltage fluctuations, and any operational constraints. However, matters related to the grid or protection settings require specialist judgment, so it is important to verify them in accordance with in‑house responsibilities and maintenance arrangements.

Equipment shutdowns and settings have a large impact on power generation, but you can often form reasonable hypotheses from monitoring data and history without going to the site. To increase power output, it is important to reduce downtime, shorten the time to recovery, and prevent recurrence of the same causes. Rather than simply restoring operation and stopping there, recording the reasons for the shutdown, the actions taken, and measures to prevent recurrence makes it easier to improve the overall availability of the plant.

Step 5 Record improvement activities and continuously monitor their effectiveness

Measures to increase power output are not complete once implemented. After carrying out tasks such as weeding, cleaning, repairs, setting checks, and equipment restoration, it is necessary to verify whether those actions actually improved power output. If you proceed to the next task without confirming the effect, you will not know which measures were effective. As a result, you will end up merely repeating similar inspections each time, and the precision of improvements will not increase.

In work records, clearly document when, where, what, and to what extent the work was performed. For example, record whether the entire power plant was cleaned or only certain rows, how much vegetation was cut and over what area, which connections were inspected, and which equipment settings were checked. Keeping photos, power generation before and after the work, weather, solar irradiance conditions, and shutdown history together makes later verification easier.

When verifying effectiveness, simply comparing power output before and after the work is not sufficient. If sunny weather continues after the work, power output will increase, and if cloudy weather continues after the work, it may appear that power output has not increased. Therefore, where possible, compare days with similar solar irradiance conditions or compare the sections within the same power plant that were worked on with sections that were not. By matching conditions, the improvement effect of the work becomes easier to observe.

When the effectiveness of a measure becomes apparent, we incorporate it into regular maintenance. For example, if shadows from vegetation appear every year in a particular section, rather than responding after power output drops, we schedule weeding before the shadows extend. If a row is known to retain dirt easily, we prioritize inspections after rain or during specific seasons. If equipment outages recur, we review the shutdown conditions and recovery procedures to shorten response times.

On the other hand, there are cases where power generation hardly improves even after taking measures. In such cases, the hypothesis about the cause may have been wrong. For example, if you thought soiling was the cause and cleaned but saw no improvement, recheck other possible causes such as shading, wiring, equipment shutdowns, settings, or missing data. When working to increase power generation, it is important not to cling too tightly to the initial hypothesis. If you have records, you can use which measures were tried and what did not improve to inform your next decisions.

During continuous monitoring, it is effective to look not only at monthly power generation but also at the frequency of anomalies, time to recovery, the number of defects found during inspections, and items that have recurred. Although power generation is affected by the weather, downtime and the number of recurrences are trackable indicators of management improvement. The goal of increasing power generation is not simply to temporarily boost output, but to maintain the plant in a state where it can consistently deliver its expected capacity.

Decisions to Avoid When Trying to Increase Power Output

When trying to increase power output, what you should avoid is proceeding with major measures without first confirming the cause. Simple judgments such as "adding equipment will increase output," "cleaning will surely improve it," "mowing the grass will be sufficient," or "replacing equipment will solve it" are dangerous. In reality, the causes of a decline in power output differ from site to site, and even at the same power plant they change depending on the season and time of day.

What you should be particularly careful about is assuming that any decline in power generation is entirely due to equipment degradation. Photovoltaic systems are operated over long periods, so aging cannot be ignored. However, the causes of reduced output are not necessarily all degradation. There are many factors that can be checked relatively quickly, such as shading, soiling, vegetation, shutdowns, communication failures, and aggregation errors. Before proceeding to a degradation assessment, it is important to organize the basic inspection items.

Also, you should avoid judging power generation by a single number. A low monthly generation figure alone does not identify the cause. Breaking the data down by day, time of day, section, and equipment makes measures to increase generation more concrete. The more granularly you examine the numbers, the easier it is to narrow the scope of on-site inspections and reduce unnecessary work.

Be careful about trying to solve everything with on-site work alone. Visual inspections are important, but if you only check the site without looking at power generation data, you can miss problems that have a large impact. Conversely, if you only look at the data and do not check the site, you will not notice vegetation, soiling, damage, or changes in the surrounding environment. To increase power generation, you need to make decisions by going back and forth between the data and the site.

Failing to keep work records is also a significant loss. When responding to decreases in power output, similar problems can recur. If there is no record of where you did what last time and how much improvement was achieved, you will have to investigate from scratch the next time. Keeping records is the foundation for increasing power generation and the basic practice for stabilizing inspection quality.

Summary: Increasing power generation starts with on-site inspections and data management

When considering how to increase power generation, it is important to first identify and isolate the causes of low output. Power generation is affected by many factors, including solar irradiance, season, weather, temperature, shading, dirt, vegetation, panel condition, wiring, connection points, equipment shutdowns, settings, and communication status. If you implement countermeasures without confirming the causes, you may spend time on tasks that have little effect.

The first thing to do is review the power output data together with solar irradiance and seasonal conditions. By organizing when, where, and at what times the power output is low, you will be able to identify the areas on site that should be checked. Next, check for on-site losses such as shading, soiling, vegetation, snow accumulation, and fallen leaves. Furthermore, by sequentially checking for abnormalities in panels, wiring, and connections, equipment downtime history, settings, and communication status, you can pinpoint the specific causes of the power output decline.

After carrying out improvement work, it is essential to always verify the effects and record the work performed. If you keep a record of how power generation changed as a result of weeding, cleaning, repairs, setting checks, and equipment restoration, you will be able to make faster decisions in the future. Efforts to increase power generation are not completed by a single inspection; their accuracy is improved through continuous management.

To steadily increase power generation, it is necessary to accurately grasp on-site conditions and have a system for making improvements while cross-checking with data. If shadows, terrain, panel layouts, inspection histories, and work records for each power plant can be checked centrally, early detection of anomalies and verification of improvement effects become easier. How to increase power generation is not determined by special measures alone. Monitoring generation relative to solar irradiance, reducing on-site losses, and continuously managing operations to prevent the recurrence of stoppages and faults are the fundamentals for maintaining a power plant’s performance.