9 Tips to Increase Solar Power Generation｜Review Procedures to Prevent Losses

When you want to increase the energy output of a solar power system, the first thing to do is not to add more equipment but to verify that the existing plant is operating at the performance it should be expected to deliver. Generation fluctuates with weather, season, solar irradiance, and temperature, but even facilities in the same area and of the same size can differ depending on how daily management and inspections are carried out. Small amounts of dirt, shading, misaligned settings, deteriorating connections, and overlooked records can accumulate and result in annual generation losses that are hard to ignore.

This article outlines nine on-site improvement steps that operational staff searching for "how to increase power generation" can readily review. It does not discuss increasing generation capacity itself through special capital investments; rather, it summarizes an approach to isolate the causes of generation decline and to restore the power plant’s condition while minimizing losses.

Table of Contents

• Power Output Improvement Technique 1: First establish a baseline and visualize abnormalities in power output

• Power Output Improvement Technique 2: Check for dirt, fallen leaves, and bird damage, and clean/clear the panel surface

• Power Output Improvement Technique 3: Review shading occurrences for each season

• Power Output Improvement Technique 4: Check the panels' tilt, orientation, and mounting condition

• Power Output Improvement Technique 5: Compare differences between strings to narrow down faulty locations

• Power Output Improvement Technique 6: Inspect connections, wiring, and terminals for degradation

• Power Output Improvement Technique 7: Check the power conditioner (inverter) for shutdowns, control, and settings

• Power Output Improvement Technique 8: Manage weeds, drainage, and the surrounding environment to prevent generation losses

• Power Output Improvement Technique 9: Keep inspection records to continuously manage improvement effects

• Summary: Increasing power output comes down to the on-site review procedures

Power Generation Improvement Technique 1: First establish a baseline and visualize anomalies in power generation

To increase solar power generation, you first need to be able to determine whether the current output is low or reasonable given the weather and season. Because output varies with solar irradiance, temperature, season, installation orientation, tilt angle, and the surrounding environment, simply comparing it to yesterday or last month can lead to incorrect conclusions. Prolonged rain or cloudy weather will reduce output, and in summer, even with high irradiance, high temperatures can limit performance. In winter, temperatures may be more favorable, but output is affected by shorter sunlight hours and the sun’s lower angle.

Therefore, it is important to first establish the criteria for comparison. Combine past performance for the same month, solar irradiance trends in nearby areas, design-stage generation forecasts, and generation per unit of installed capacity to understand the typical condition of each power plant. Rather than looking only at generation output itself, examining how much generation is produced relative to solar irradiance can smooth out weather-related fluctuations to some extent. If days continue when solar irradiance is present but generation does not increase, it provides an opportunity to check whether there are factors causing degradation in the equipment or the surrounding environment.

When considering how to increase power output, what you should avoid is moving ahead with cleaning or parts replacement before identifying the cause. Cleaning and inspections are important, but if you perform work without checking where and to what extent losses are occurring, you may end up spending effort on areas that have little effect. Confirming whether the entire plant’s output is low, only some power conditioners or strings are underperforming, or the drop occurs only during specific time periods will change the order in which you prioritize reviews and actions.

When checking daily power generation, pay attention not only to monthly or annual totals but also to changes by time of day. If generation is low only in the morning, it may be due to shadows or dirt on the east side; if it’s low only in the afternoon, it may be caused by obstacles on the west side; if there is a sudden drop around midday, output control or equipment shutdowns may be involved. Observations such as whether the drop in generation occurs at the same time every day, whether it happens regardless of weather, or whether it improves only after rain can also provide clues to narrow down the cause.

The purpose of setting baseline values is not only to detect anomalies. They are also necessary to determine whether a decline in power generation has truly been remedied after corrective work. If you can compare power generation trends before and after cleaning, before and after weed control, and before and after checking settings, it will also help inform future management decisions. Improving power generation is not something that is completed with a single task; it is important to create a process that visualizes the condition, identifies the causes, implements improvements, and records the effects.

Power Output Improvement Tip 2: Inspect for Dirt, Fallen Leaves, and Bird Damage and Maintain the Light-Receiving Surface

One of the items easy to check on site to increase power generation is the condition of the solar panel surface. Because panels generate electricity by receiving sunlight, the amount of light they receive can decrease if the surface becomes covered with dirt, fallen leaves, soil, pollen, bird droppings, sap, sand dust, etc. Attention is required not only when the entire surface is lightly soiled but also when part of it is heavily soiled. Partial shading or uneven soiling can lead not only to reduced power generation but also to localized stress, so make sure not to overlook them during visual inspections.

Power generation losses caused by soiling vary depending on a plant’s location. Near farmland or newly developed land, soil dust is prone to become airborne; near forests or rivers, fallen leaves and bird damage are more likely. In locations close to the sea, soiling containing salt tends to adhere, and along roads with heavy traffic, dust may accumulate. If power output is gradually declining, it’s worth checking not only for equipment failures but also whether dirt has accumulated on the light-receiving surfaces.

Whether to perform cleaning is determined based on the type and extent of soiling, the impact on power generation, safety, and the risk of equipment damage from cleaning. Light dirt may be washed away by rain, but bird droppings, adhered mud, and deposits accumulated at the bottom edge of panels can remain. In particular, when soiling accumulates in a band along the lower edge, it can cause a persistent impact on parts of the cells. Soiling that remains after rain should be prioritized for inspection.

However, while cleaning can potentially improve power generation, incorrect work methods carry the risk of scratching panel surfaces or damaging mounting structures and wiring. Avoid excessively high-pressure water flows, hard tools, unsuitable cleaning agents, and unsafe scaffold work, and confirm the manufacturer's recommendations and on-site safety procedures. Working in wet conditions or at heights also carries risks of electric shock and falls. If operational staff find it difficult to judge on their own, it is safer to consult specialist contractors or maintenance managers.

When there is bird damage, we consider not only cleaning but also preventing recurrence. We inspect structures where birds tend to perch, the occurrence of nests, surrounding trees, and adjacent facilities to identify the causes of recurring soiling. Even if a one-off cleaning yields a temporary improvement, generation losses will recur if bird damage continues in the same location. To stably increase power generation, it is effective to consider cleaning work together with measures to create an environment in which soiling is less likely to occur.

Power Output Improvement Technique 3: Review the Occurrence of Shadows by Season

In solar power generation, the effects of shading should not be overlooked. Not only when a large shadow covers an entire panel, but even when only part of a panel is shaded, it can affect power output. Causes of shading include nearby buildings, utility poles, trees, fences, signs, mountain ridgelines, adjacent equipment, racking elevation differences, and weeds. Even if there were few issues when the plant was completed, over time trees can grow or new structures can appear nearby, causing shading to occur later.

The important point when checking for shading is to examine seasons and times of day separately. Because the sun’s altitude and azimuth change with the seasons, locations with little shade in summer can still receive long shadows on panels in winter. In the morning and evening the sun’s altitude is low and shadows tend to stretch long, so inspections conducted only during midday can miss them. If you see a pattern of lower power generation only in the morning, only in the afternoon, or a tendency to drop in winter, it is worth checking whether shading might be the cause.

When checking shadows on site, compare the times of power output drops under clear-sky conditions with the actual positions of the shadows. Power output shown on the management dashboard alone can make it difficult to determine whether the issue is shading or a problem with the equipment. By linking time-of-day power output with the on-site shadow conditions, it becomes easier to understand which obstructions affect which areas. If a shadow falls on only certain rows or specific strings, only the power output for those areas may be reduced.

Countermeasures against shading include pruning trees, removing weeds, checking the positions of obstacles, managing the area around panels, and reconsidering the placement of equipment that tends to cast shadows. Shading caused by existing buildings or terrain may not be easy to eliminate, but if you grasp the times and the extent when shading occurs, you are less likely to misidentify the cause of reduced power generation. When considering additions or renovations, it is also important to take into account not only existing equipment but future changes in shading.

Reviewing shading is an activity aimed at preventing unnecessary drops in power generation rather than forcibly increasing output. While shading may appear obvious when inspected on site, it actually changes with the seasons, time of day, weather, and the sun’s position. If you are targeting higher power output, it is advisable not to limit inspections to once a year, but to also check at seasonal transitions and after any changes in the surrounding environment.

Power Generation Improvement Tip 4: Check the Angle, Orientation, and Mounting Condition of the Panels

The angle and orientation of solar panels are factors that affect power generation. Even if azimuth and tilt are determined at the design stage and the panels are installed accordingly, ground settlement after construction, loosened mounting structures, strong winds, snowfall, and aging can cause tilts and misalignments. Large deformations are usually noticeable by eye, but differences in row heights and twisting of the panel surfaces can be overlooked from a distance. If you want to increase power generation, it is important to check that the panels are maintaining a state close to the design intent.

Angle and orientation issues affect not only power generation efficiency but also soiling and drainage. In areas with insufficient tilt, rainwater may not drain well and dirt can tend to accumulate at the lower edge of the panels. If part of the mounting structure has settled, puddles and mud splashing can occur in sections of a row, potentially leading to long-term generation losses and reduced maintainability. Also, if the panel surface is twisted, extra stress can be placed on the fastenings and frames. Focusing only on power output can delay noticing such structural problems.

During inspections, view the panel rows from the front, side, and at an angle to observe the alignment of the rows, tilt, level differences, and the condition of the mounting hardware. Also check the racking foundations, loose bolts, corrosion, settlement on slopes, and ground scour. In particular, on reclaimed sites or soft ground, changes may occur as the ground settles after installation. The larger the power plant, the more important it is to divide the site into areas and inspect them rather than trying to view the entire facility at once.

Changing the panels’ tilt or orientation does not necessarily increase power output. You need to consider design conditions, the racking structure, wind loads, snow loads, regulations, and maintainability. Therefore, rather than arbitrarily changing angles on an existing installation, it is realistic to first check whether it has deviated from the design state. If there are areas with low power generation and the racking shows tilting or settlement at the same time, it is worth prioritizing an inspection of the equipment.

In practical work to increase power output, attention tends to focus on electrical inspections, but it is also important that the structure supporting the panels is stable. If the orientation, angle, or mounting condition of the light-receiving surface is disrupted, it affects not only generation efficiency but also maintainability and safety. To operate a power plant stably over the long term, inspections of electrical equipment and of structures should be viewed together rather than separately.

Tip 5 for Increasing Power Output: Narrow Down Faulty Sections by Comparing Differences Between Strings

When you feel the power output is low, looking only at the total for the entire plant may not reveal the cause. A solar power plant is made up of multiple panels, strings, combiner boxes, and power conditioners, so even if there is no obvious large anomaly overall, only some circuits may not be generating or may be producing less power. If you aim to increase generation, it is important to break down the overall numbers one step further and check where the losses are occurring.

By examining differences between strings, you can more easily narrow down causes such as dirt, shading, poor connections, panel defects, broken wiring, loose terminals, or abnormalities on the equipment side. If there is a difference in power output or current between strings that should be under the same conditions, there is likely some reason for that difference. Of course, when installation orientation, number of panels, shading conditions, or equipment configuration differ, a simple comparison is not possible. The comparison assumes systems that are, by design, under almost the same conditions.

When verifying on-site, it is important to make comparisons during periods when solar irradiance conditions are stable. On days with frequent cloud movement or during morning and evening hours, values can fluctuate easily due to momentary changes in solar irradiance. Comparing multiple systems under the same conditions during a consistent time window on clear days makes it easier to identify systems with abnormalities. If monitoring data are available, looking at trends over several days to several weeks, rather than a single day, allows you to separate temporary fluctuations from persistent anomalies.

If a drop is found at the string level, sequentially inspect the panel surface, shading, wiring, junction boxes, terminals, fuses, and switches in that area. Rather than immediately considering part replacement, check for visually apparent abnormalities, looseness, dirt, damage, discoloration, burn marks, and animal damage. It is also important to correctly correlate the low‑generation circuit with its on‑site location. If drawings or labels do not match the actual wiring, you may inspect the wrong location and it will take longer to identify the cause.

Narrowing down the locations of faults helps not only to increase power generation but also to prevent wasted maintenance costs. Rather than inspecting everything uniformly, determining the inspection scope from data and then conducting on-site checks makes it easier to prioritize work. For power plants with low generation, it is especially important to first identify exactly where the output is low. Increasing power generation is easier to achieve by examining differences to narrow down the cause than by taking measures based on intuition.

Power Generation Improvement Tip 6: Inspect Connections, Wiring, and Terminals for Deterioration

The decrease in solar power generation is not caused only by the panel surface or shading. Electrical degradation in connection points, wiring, terminals, and junction boxes can prevent generated electricity from being transmitted properly. Loose wiring, terminal corrosion, poor connector contact, damaged cable sheathing, water ingress, animal chewing, and heat-related deterioration can lead not only to reduced power output but also to safety risks. If you are considering increasing power output, keeping the electrical pathways healthy is indispensable.

Connection problems don't necessarily appear initially as a major outage. As contact resistance increases, heat generation becomes more likely, and the condition can gradually worsen. If power output is gradually decreasing, the current in a specific system is unstable, or output fails to rise even on sunny days, wiring and connections should be checked. During visual inspection, check for discoloration, scorch marks, unusual odors, deformation of resin components, dirt or moisture around the terminal block, and sagging or chafing of cables.

Solar power systems installed outdoors are exposed to wind and rain, ultraviolet radiation, temperature fluctuations, humidity, small animals, grass-cutting operations, and other environmental influences. If cables are in contact with the ground, rub against corners of the mounting structure, or have their ties come undone and sag, they can suffer jacket or insulation damage over time. Also, if moisture enters junction boxes or panels, it can cause corrosion and reduced insulation. Regular checks of wiring routes should be performed not only to improve power output but also to protect long-term operational safety.

During inspections, sufficient caution is required when working on energized equipment. Since photovoltaic power systems generate electricity during the daytime, it is dangerous to casually touch connection points. Electrical measurements and terminal checks should be carried out only after the necessary qualifications, safety regulations, manufacturer procedures, and site procedures have been fulfilled. In the initial checks performed by operational personnel, it is important to detect signs of abnormalities and to escalate to specialist inspections. To prevent accidents during inspections intended to increase power output, clarify the scope of work and the scope of responsibility.

Inspecting wiring and connection points is useful not only when power output suddenly drops, but also after typhoons, heavy rain, snowfall, grass cutting, or nearby construction. External factors can pull on cables or allow water to enter the panel. If signs can be found on-site before anomalies appear in the power generation data, it is easier to minimize losses. Increasing power output is not just about generating more electricity; it also means maintaining a condition that safely transmits the generated power without loss.

Power Output Improvement Technique 7: Check Power Conditioner Shutdown, Control, and Settings

Even if the solar panels are generating normally, if the power conditioner experiences shutdowns or control actions, the power output will not increase. The power conditioner is an important device that converts DC power into AC and connects to the grid. When abnormal shutdowns, temperature rises, output control, configuration inconsistencies, or communication failures occur here, they manifest as reduced power generation. When considering increasing power output, it is essential to check the condition of the conversion equipment as well as the panels.

First, what I want to check are the shutdown and error histories. If there was a day with low power generation, check whether the power conditioner had stopped during that period or whether any warnings had been issued. Even short shutdowns, if repeated frequently, can lead to a loss of generated power. It is also important to distinguish whether a communication failure is merely preventing generation data from being acquired, or whether generation has actually stopped. Do not rely solely on monitoring data; compare it with on-site displays and records as necessary.

Temperature conditions are also important. Power conditioners may have their output limited or may shut down in high-temperature environments. Conditions such as poor ventilation at the installation site, objects placed nearby, dust or weeds in the intake and exhaust vents, and exposure to direct sunlight or reflected heat affect equipment temperature. If power generation plateaus on clear summer days, check not only solar irradiance but also equipment temperature and the installation environment. Removing factors that impede ventilation can reduce the risk of shutdowns or output limitations.

Restrictions due to output control or grid conditions can also cause reduced power generation. Even if there is no problem with the equipment, output may be suppressed by grid conditions or control instructions. In such cases, cleaning or replacing parts on-site will not increase generation. To avoid misidentifying the cause of low generation, it is important to check whether control is being applied, the time of occurrence, historical records, and the operating condition of the equipment. In particular, if output does not rise above a certain level on sunny days, consider the possibility of control actions or settings.

In configuration checks, verify the equipment capacity, input circuits, interconnection conditions, time settings, monitoring settings, communication status, and so on. If the clock is out of sync, comparing generation data and pinpointing the time of anomalies will be impaired. If communication is unstable, data may appear to be missing even though generation is occurring. To correctly judge increases in power generation, it is necessary to ensure not only the operating condition of the equipment itself but also the reliability of recording and monitoring.

Power Output Improvement Technique 8: Prevent Power Generation Losses by Managing Weeds, Drainage, and the Surrounding Environment

Stabilizing power generation requires not only solar panels and electrical equipment but also environmental management around the power plant. When weeds grow, they can cast shadows under panels and on lower-positioned panels. Especially at low-mounted installations or on sloped terrain, grass height can affect power generation. Weeds are related not only to shading but also to ensuring access paths, the safety of inspection work, the presence of pests and small animals, and contact with wiring. To sustain increased power generation, it is important not to treat weed management as merely an aesthetic issue.

In weed control, rather than responding after weeds have grown, it is effective to plan by anticipating seasonal growth. From the rainy season through summer, weeds grow quickly and can cause shading and pathway obstructions in a short period. Managing vegetation before power generation losses occur makes it easier to limit losses than mowing after output has already declined. However, during mowing operations, care is required to avoid panel damage from flying stones, cable damage, and contact with electrical panels or mounting racks. It is important to share the work area and points of caution in advance and to follow procedures that will not damage the equipment.

Drainage conditions should not be overlooked. In areas where puddles form after heavy rain, the ground around racking foundations can be scoured, cables can be submerged in muddy water, and inspection walkways can become difficult to use. If the muddiness persists, movement of work vehicles and personnel can churn up the ground and further worsen drainage. Poor drainage may not seem to immediately affect power generation, but over the long term it can lead to generation losses through equipment deterioration and reduced maintainability.

In the surrounding environment, check for tree growth, sediment inflow from neighboring land, fence damage, animal intrusion, and dust from nearby construction. The power plant is an outdoor facility and continuously subject to changes in its surroundings. The conditions that were in place at completion are not necessarily maintained thereafter. It is important not only to investigate causes after power generation has decreased, but also to detect changes that could lead to a decline as early as possible.

Managing the site environment may seem unremarkable, but it forms the foundation for increasing power generation. No matter how high-performing the equipment is, if weeds cast shadows, drainage is poor, and inspections are difficult, it becomes hard for it to continue delivering its intended performance. By viewing the goal of increasing power generation not as an issue for individual pieces of equipment but as creating the overall environment of the power plant, the priorities for daily management become clear.

Power Output Increase Technique 9: Keep Inspection Records to Continuously Manage Improvement Effects

An important part of efforts to increase power generation is the management of inspection records and improvement histories. Tasks such as cleaning, mowing, checking wiring, and reviewing equipment settings may be remembered at the time, but the details tend to become unclear after a few months. To determine whether power output has improved or changed due to other factors, you need to record the work date, scope of work, weather, changes in power generation, anomalies found, and actions taken.

At power plants where records are not kept, the same checks tend to be repeated and past abnormalities are easily overlooked. When personnel change, decision-making is delayed if the historical background is unknown. Conversely, if inspection records are organized, when a drop in power generation occurs you can check the last cleaning date, past fault locations, seasonal shading, timing of weed growth, and so on. This not only helps increase power output but also improves the overall efficiency of maintenance operations.

If records are too detailed, they won't be maintained; if they're too sparse, they're useless. In practice, it is important to record information related to power generation. Make it clear when, in which area, what was checked, what abnormalities were present, and how they were addressed. When keeping photographs, indicate the photo location and direction so they can be easily compared next time. Photographing the same spot from the same angle makes it easier to track changes in dirt, weeds, shadows, and the condition of the racking.

When assessing improvement, it is important not to judge based on only the single day immediately after the work. Because power generation can vary greatly with the weather, if the day after cleaning is cloudy the effect can be difficult to detect. It is preferable to look at trends over several days to several weeks and compare days with similar solar irradiance conditions. Judge by indicators appropriate to the cause — for example, whether the differences between strings narrowed before and after the work, whether drops during specific time periods improved, or whether error shutdowns decreased.

In ongoing management, we also review the frequency and priorities of inspections. There are periods when power output is likely to decline, times when weeds are likely to grow, and moments to watch for after typhoons or heavy rain, after snowfall, or after nearby construction—each power plant has specific timings that require attention. Rather than inspecting everything at the same frequency, focusing checks on higher-risk periods and locations makes management easier even with limited personnel. Increasing power output is not a one-off improvement task but an ongoing effort to improve management accuracy based on records.

Summary: Increases in power output depend on the site review procedures.

To increase the energy output of a solar power system, it is important to check whether the existing plant is performing as intended before adding equipment. Although energy generation fluctuates with weather and seasons, there are factors that can be improved through on-site management—dirt, shading, angle misalignment, faulty wiring, equipment outages, weeds, poor drainage, insufficient record-keeping, and so on. Reviewing these items one by one reduces unnecessary generation losses and makes it easier to prevent financial losses.

The important thing is not to judge solely by feel when you think generation is low. First, set a baseline, check the data by time of day and by system, and compare it with on-site conditions. Then, starting with items that are easy to inspect visually—such as dirt and shading—and proceeding in order to string mismatches, wiring, power conditioners, and the surrounding environment, it becomes easier to isolate the cause. The shortcut to increasing generation is not flashy measures but narrowing down the cause in the correct order.

Also, after carrying out improvement work, it is essential to always keep records and check for changes in power generation. Cleaning, mowing, settings checks, and inspections do not reveal their effects simply by being performed. If you can determine which tasks led to what degree of improvement, decisions will be made more quickly in the future and the quality of management will improve. By grasping trends for each power plant, you can detect declines in power generation early and move toward operations that keep losses to a minimum.

Increasing power generation is the result of accumulating small daily reviews. By keeping the light-receiving surface in good condition, reducing shading, protecting electrical pathways, checking equipment condition, and managing the surrounding environment, a power plant can operate more stably. By continuing on-site inspections, record keeping, and improvements, and by using professional inspections and management support tools as needed, you can create operations that are less likely to overlook the causes of power output declines.