8 Ways to Increase Solar Power Generation | On-site Measures You Can Implement

Table of Contents

• Basics to check before increasing solar power generation

• Method 1: Check generation data by time of day and by individual equipment

• Method 2: Remove dirt and deposits from panel surfaces

• Method 3: Manage shading from weeds and trees

• Method 4: Detect string-level anomalies early

• Method 5: Check connections and cables for faults

• Method 6: Check for stoppages of power conversion equipment and output curtailment

• Method 7: Review temperature rises and inadequate ventilation

• Method 8: Use topography, drainage, and location information to prevent recurrence

• Management framework to sustain improvements in power generation

• Summary

Basics to Check Before Increasing Solar Power Generation

When you want to increase solar power generation, the first important step is not to add more equipment but to verify that the existing equipment is able to perform at its intended level. With solar power you cannot increase the amount of sunlight at the site. However, you can move the system toward a state in which the received sunlight is converted into electricity with as little waste as possible. In other words, in practical terms, increasing generation means finding the causes of lost potential power and implementing measures to reduce generation losses.

The causes of low power generation are not necessarily limited to a single factor. Dirt on the panel surface, shadows from weeds or trees, faults at connection points, cable damage, shutdown of conversion equipment, output curtailment, temperature increases, poor drainage, and a lack of inspection records are examples of multiple factors that can combine to reduce generation. Even if there appears to be no major visual problem, looking at power generation data by time of day or by individual equipment can reveal that only some units show a significant drop. Conversely, what feels like low generation may not be an equipment fault once weather and solar irradiance conditions are taken into account.

Therefore, to increase solar power generation, you must first accurately understand the current situation. Rather than judging based only on monthly generation totals, check the generation curve on sunny days, the drops in the morning and evening, the midday plateau, differences between installations, alarm history, and the site's shading and soiling conditions together. With only the result that generation is low, you cannot determine whether you should clean, remove weeds, inspect equipment, or review drainage. Isolating the causes is the first step in selecting improvement measures.

Improving power generation is not a one-time task. Panels become dirty again, grass grows, trees mature, and equipment conditions change with age. At outdoor solar power plants, seasonal and weather changes and shifts in the surrounding environment continually affect power generation. By continuously implementing on-site countermeasures, comparing power generation before and after work, keeping records, and using them for the next inspection, the accuracy of power generation improvements increases.

This article outlines eight measures that operational staff can easily check on-site. The important point is not to try to do special things all at once to increase power generation, but to eliminate causes of generation loss in order, starting with the largest. By combining data checks, cleaning, weeding, wiring inspections, equipment inspections, temperature control measures, drainage checks, and record management using location information, it becomes easier to steadily raise the power output of solar power plants.

Method 1: Check power generation data by time period and by equipment unit

The first step you should take to increase solar power generation is to review the data. When you feel the generation is low, judging only by the monthly or daily totals can lead to misidentifying the cause. Monthly generation is heavily affected by the weather, so during periods with many cloudy or rainy days it will be lower even if there is no problem with the equipment. Conversely, even if the monthly totals do not show a large difference, there may be ongoing generation losses during certain hours on sunny days or in specific equipment.

What you need to check is when, where, and how the power generation is low. If power generation is low only in the morning, shadows from trees or structures on the east side are suspected. If it is low only in the evening, check for shadows on the west side and the influence of the surrounding terrain. If the midday generation peak does not reach its expected level, candidates include soiling of the panel surface, temperature rise, inverter shutdowns, output curtailment, and capacity constraints. If the generation curve suddenly drops midway even on sunny days, it is necessary to cross-check shutdown logs and alarm histories.

Comparisons at the equipment level are also important. If you only look at the generation output of the entire power plant, anomalies in some equipment can be obscured. Compare units that have, as much as possible, the same orientation, the same tilt, the same number of panels, and similar shading conditions, and check whether any particular unit is consistently lower. If only some units are lower compared to units under the same conditions, it is more likely that the cause is on-site—such as dirt, shading, poor connections, cable damage, or equipment faults—rather than the weather.

When reviewing power generation data, it is important to distinguish between sudden drops and gradual declines. A sudden drop in generation may indicate equipment shutdown, a broken wire, poor connections, or the appearance of an obstruction. A gradual decline may be related to the accumulation of dirt, the growth of weeds or trees, aging-related degradation, or deterioration of site conditions due to poor drainage. Interpreting the pattern of the decline allows you to narrow down the locations that should be inspected on site.

Verifying data greatly affects the efficiency of on-site work. Rather than aimlessly inspecting the entire power plant, entering the site after identifying the times and equipment showing declines allows you to find the cause more quickly. On-site measures to increase power generation are often assumed to start with cleaning and weeding, but in reality they begin with interpreting the data. If you make a habit of segmenting the data, you can reduce unnecessary work and focus on measures that have the greatest impact on power generation.

Method 2: Remove dirt and buildup from the panel surface

Dirt on the surface of panels is a common cause of reduced solar power output. Because solar panels generate electricity by receiving sunlight on their surface, dirt and deposits reduce the light reaching the cells. The types of soiling vary with site conditions, including soil dust, pollen, yellow sand (Asian dust), bird droppings, fallen leaves, tree sap, dust from nearby construction, road-borne dust, and deposits containing salt in coastal areas. Even light soiling can affect power generation if it is widespread.

What you should pay particular attention to is the banded dirt that remains along the panel's lower edge and around the frame. It's often assumed that rain will naturally wash away dirt, but in reality runoff can carry it to the edges, where it then remains after the rain. On panels with a shallow tilt, water does not drain easily, making dirt more likely to accumulate. Although localized dirt may appear small in area, it can cast shadows on some cells and affect power generation efficiency.

Don’t overlook bird droppings and fallen leaves. These don’t form a thin film over the entire surface but rather heavily cover specific spots, acting as localized shading. Even if they aren’t noticeable from a distance, they can be found on panel edges and corners when inspected up close. If power generation data shows only some installations are underperforming, it is important to focus on inspecting the panel surfaces in that area.

When cleaning, rather than cleaning all panels at the same frequency, it is more efficient to prioritize the areas that are more prone to soiling. Focus on rows near unpaved walkways, rows on the downwind side, places where birds tend to gather, areas where fallen leaves accumulate, spots where rainwater drains poorly, and equipment where a drop in power output has been observed. By comparing before-and-after photos and power output, it becomes easier to determine how much soiling at that site is affecting power generation.

However, cleaning, if done incorrectly, can place a strain on the equipment. You should avoid actions such as scrubbing hard with rigid tools, performing sudden operations during periods with large temperature differences, and working without confirming electrical safety of the equipment. Cleaning to increase power generation is not simply a task of making the surface clean, but a task of restoring the light-receiving condition without damaging the equipment. It is important to plan the work method, timing, safety measures, and post-work inspections.

When addressing soiling, it's also necessary to focus on reducing its causes. If dust is rising from nearby walkways, review vehicle routes; if there are many fallen leaves, check the surrounding vegetation; if bird damage is frequent, identify places where birds tend to gather. Rather than just removing soiling, understanding the conditions that make soiling likely makes it easier to prevent a recurrence of reduced power output.

Method 3: Manage shading from weeds and trees

Managing shading is essential for increasing solar power generation. Solar panels generate electricity from sunlight, so even partial shading of a panel can reduce its power output. Sources of shading include weeds, trees, fences, utility poles, surrounding buildings, mounting structures, adjacent rows of panels, and monitoring equipment. Because shading moves with the time of day and the seasons, a single inspection can cause problems to be overlooked.

Weeds are a particularly common cause of power generation losses on site. Even if they are not a 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 on the front rows. Even if the grass does not touch the panels, shadows can extend far at the low sun angles in the morning and evening. Furthermore, when weeds become overgrown they reduce ventilation, block inspection walkways, and make it difficult to inspect around equipment. Because they affect not only power output but also maintenance and safety, weed management is fundamental to improving power generation.

Shading from trees is a factor that tends to cause problems during long-term operation. Even trees that had little impact at the time of installation can grow over several years and reduce power generation. Trees located on the south, east, and west sides, in particular, cast shadows depending on the time of day. At plants near forests or slopes, the height of the terrain and the height of trees can overlap, producing long shadows in winter. If generation is low only in winter, or if there is a large drop in the mornings and evenings, both the trees and the terrain need to be checked.

When checking shadows, it is effective to match the power generation data with the times of on-site inspections. If generation is low in the morning, check the on-site conditions in the morning; if it drops in the evening, observe the evening shadows. Even if an inspection at noon shows no problems, large shadows may appear in the morning and evening. Also, even if there is little shadow in summer, shadows can lengthen in seasons when the sun's altitude is low. When taking measures against shading, it is important to be aware of the time of day and the season.

When performing weeding or pruning, prioritize areas that have the greatest impact on power generation. Rather than simply making the entire site uniform, focus especially on the fronts of panels, around equipment, walkways, and directions where shadows are likely to extend. After work, record whether shadows were actually eliminated, whether inspection accessibility has improved, and whether ventilation has improved. Because shadows tend to recur, it is important not only to record that the work was done but also to predict and manage when shadows are likely to reappear.

Method 4: Early detection of string-level anomalies

To increase power output, it is important to look for anomalies not only at the plant-wide level but also at the smallest possible units. Even if the total generation does not appear to show a major problem, only some strings may have reduced output. Such partial declines, if left unaddressed, will continue to cause generation losses over long periods. If detected early and addressed, you can reduce lost generation.

When checking at the string level, it is essential to compare strings under the same conditions. Simply comparing strings that differ in number of panels, azimuth, tilt, shading conditions, or connection configuration can lead to mistaking normal differences for faults. Check whether any string is consistently lower compared with adjacent rows or installations with the same orientation. If only a specific string is low, possible causes include panel soiling, partial shading, poor connections, cable damage, or equipment-side problems.

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

When an anomalous string is found, it is important to be able to accurately pinpoint its location on site. If the management drawings do not match the equipment numbers in the field, row numbers are hard to read, or photos alone do not convey the location, inspections and repairs will take longer. Even if a drop in power generation is detected quickly, if the team cannot reach the relevant location on site, the time until remediation will be extended.

String-level anomalies should not be overlooked even if they appear as small differences. Daily generation losses may be minor, but if they continue over a long period they become significant losses. Moreover, when poor connections or cable damage are involved, the issue can lead not only to reduced output but also to safety risks. To increase generation, don’t be satisfied with the overall average alone; management that detects anomalies at a finer unit level is necessary.

Method 5: Check connection points and cables for faults

In solar power generation, even if panels are receiving sunlight normally, faults in connections or cables can reduce power output. There are many causes that impede the flow of electricity, such as loose terminals, poor contact, damage to cable sheathing, moisture ingress, damage caused by animals, damage during grass-cutting operations, and deterioration with age. Because these issues can be difficult to detect from appearance alone, it is necessary to make judgments by combining power generation data with on-site inspections.

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

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

Inspection of electrical equipment must be carried out with safety as the highest priority. Instead of having on-site personnel forcibly handle equipment to make judgments, organize the affected equipment, time of occurrence, changes in power output, on-site photos, and the surrounding environment, and, when necessary, arrange for professional inspections. To increase power output, it is important not only to respond quickly but also to identify the cause safely using the correct procedures.

A perspective focused on preventing recurrence is also indispensable. Even if you repair the connection points, if conditions remain—such as water pooling in the same spot, rampant vegetation growth, cables being easily exposed, animals gaining access, or difficulty inspecting the area—faults can occur again. Recording where a fault occurred and its cause, and reviewing the surrounding environment, leads to management that is less likely to experience repeated drops in power generation.

Method 6: Confirm Shutdown of the Converter and Output Suppression

The causes of low power generation are not limited to the panels and wiring. Even with sufficient solar irradiance, generated electricity will not increase if the equipment that converts it is stopped or if its output is being limited. To raise solar power generation, it is essential to check the operating status of the conversion equipment, 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 downtimes can cause large losses if they occur during the daytime when generation output is high. If stops and recoveries are repeatedly occurring during the day, they may not stand out in the monthly total, but in reality you could be missing a significant amount of generated power. Whether only a specific piece of equipment stops or multiple pieces stop simultaneously changes the causes you should suspect.

If output curtailment is occurring, power generation can plateau even on sunny days. If the upper part of the generation curve looks flat, check curtailment records and operational data. However, a flat curve does not necessarily mean output curtailment. Similar shapes can result from equipment capacity limits, temperature rises, soiling, shading, or measurement anomalies. It is important not to judge based on the generation curve alone, but to isolate causes by comparing it with equipment records.

You should also check the surrounding environment of the conversion equipment. Conditions such as overgrown weeds, poor ventilation, excessive dust and deposits, or exposure to direct sunlight and heat buildup can affect the equipment’s operation. If the equipment is operating in a high-temperature environment, it may trigger protective actions or lead to reduced efficiency. When power generation is low, check not only the panel surfaces but also the space around the equipment, ventilation, access routes, and cleanliness.

What is important when checking the equipment side is to correlate the drop in power output with the shutdown time. If the time when the power output fell coincides with the time of an alarm or shutdown, it becomes easier to narrow down the cause. Conversely, if there are no abnormalities in the equipment records, suspect other causes such as the panels, wiring, shading, soiling, or solar irradiance conditions. To increase power output, it is important to choose countermeasures based on data and history rather than on guesses.

Method 7: Review temperature rise and poor ventilation

Solar power generation tends to produce more power with stronger solar irradiance, but output also tends to decrease as temperature rises. If, on a clear summer day, the generated power does not increase as expected, you need to check not only the irradiance but also the panel temperature and the temperature around the equipment. Because temperature rises often do not manifest as clearly as a malfunction, they are frequently overlooked as a cause of reduced power generation.

Because panels are exposed to strong sunlight outdoors, their surface temperature rises. If the surrounding airflow is poor or weeds are growing densely under the panels, heat can become trapped. Temperature-related output reductions may manifest not as a sudden shutdown but as a slowing in the increase of power output. At sites where power output tends to plateau around noon in summer, it's worth checking the ventilation.

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

It is not possible to completely eliminate the loss of power generation caused by temperature increases. However, it is possible to reduce unnecessary heat buildup. Managing weeds under the panels, ensuring ventilation around equipment, keeping inspection walkways clear, 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 or shading, but also indirect factors like the thermal environment.

Consider seasonal differences as well. If generation is lower than expected only in summer, temperature and ventilation effects are likely candidates. If it is low only in winter, check for the reduced solar altitude, shading, snow accumulation, and the influence of surrounding terrain. Methods for increasing generation are not the same year-round. It is important to adjust the inspection items on the assumption that the causes of reduced generation change with the seasons.

Method 8: Leverage topography, drainage, and location information to prevent recurrence

To increase power generation, it is necessary to check not only the panels and equipment but also the terrain and drainage of the entire power plant. Locations where water tends to pool, spots where sediment can wash in, pathways that easily become muddy, slope collapses, scour around mounting racks, 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 generation, but they are important factors that lead to soiling, weeds, connection failures, and reduced inspectability.

In areas 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 slow down work and can reduce the frequency of cleaning and weeding. In places where sediment flows in, it accumulates under panels and around cables, causing dirt and damage. To stably increase power generation, it is important to improve not only the generation equipment but also the site environment.

When checking topography and drainage, on-site inspections after rain as well as during clear weather are effective. Determine where water flows in, where it accumulates, and where it drains away. Recording puddles, sediment deposits, vegetation overgrowth, subsidence of access routes, and changes to slopes will reveal locations prone to recurrence. If power output is low and you only carry out cleaning or weed removal, the same problem may recur if poor drainage remains.

A key point here is management that leverages location information. If you can record, together with location data, where shadows appear within the power plant, where dirt tends to accumulate, where water pools, and which equipment is prone to abnormalities, the priorities for countermeasures become clear. Even on large sites where photos alone make it difficult to identify locations, having location information makes it easier for stakeholders to share the same place.

When power generation data is linked with location information, causal relationships become easier to see. If the locations of low-producing installations coincide with areas where shadows occur or with sites of poor drainage, the rationale for countermeasures becomes clear. If abnormal strings, repair histories, cleaning areas, weeding areas, and poor-drainage locations can be managed on a map, the next inspection and recurrence checks can also be streamlined. To increase power generation, it is important not to treat problems found on site as one-offs, but to retain them as information that can be used for the next improvement.

Management System for Sustaining Power Generation Improvements

Measures to increase solar power generation are not something you do once and then finish. As outdoor installations, the seasons, weather, surrounding environment, and equipment condition are constantly changing. Even if you clean, dirt will return; even if you remove weeds, grass will grow; trees will grow; and drainage paths will change due to sediment. Equipment also becomes more prone to faults as it ages. To stably increase power generation, a continuous management system is required rather than one-off measures.

First, decide on the criteria for checking power generation. If you determine how frequently to review the data, at what level of decline to carry out on-site inspections, and down to which equipment unit to make comparisons, anomalies will be detected more quickly. Relying solely on the intuition of personnel causes oversights and variations in judgment. Standardizing the sunny-day generation curve, comparisons with equipment under the same conditions, checks of outage histories, and on-site photographic records stabilizes the accuracy of power generation improvements.

Next, perform a before-and-after comparison of the countermeasures. After cleaning, weeding, repairs, equipment inspections, and drainage checks, confirm how power generation has changed. It is difficult to completely remove the effects 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 produced large effects for future work, and if an effect is not apparent, suspect other causes.

The quality of records is also important. If you record the work date, scope of work, before-and-after photos, abnormal locations, actions taken, and whether a recheck is necessary, the next inspection will be more efficient. If you can identify trends such as weeds growing in the same place each year, dirt accumulating in the same rows, the same walkway becoming muddy after rain, or the same equipment causing stoppages, you can take proactive measures before problems occur.

When managing multiple power plants, it is also important to standardize management methods. If the formats of inspection records and the criteria for decisions differ by site, differences will arise in the timing of detecting drops in power generation and taking countermeasures. If power generation data, on-site photos, equipment numbers, location information, and work histories are managed using the same approach, sharing among stakeholders becomes easier. Efforts to increase power generation lead not only to improvements at individual sites but also to overall improvements in the quality of management operations.

When working to improve power generation, it is also important not to try to solve all issues at once. There are many challenges on site, such as dirt, shading, equipment, wiring, temperature, drainage, and traffic flow. If everything is treated with the same priority, the workload can become large and highly effective measures may be postponed. Start by identifying the causes that have the greatest impact on power generation, then address the factors that are prone to recurrence; proceeding in that order makes it easier to sustain the work in practice.

Summary

Raising solar power generation is not just about adding more equipment. On-site measures include checking generation data, cleaning panels, managing shading, checking for abnormalities at the string level, inspecting connections and cables, checking for inverter shutdowns or output curtailment, reviewing temperature and ventilation, and improving site conditions including terrain and drainage. By checking these items in order, it becomes easier to identify the causes of potential generation being lost.

When you feel the power generation is low, don’t immediately jump to major countermeasures; first separate and examine the data. Check when the output is low, which units are underperforming, and whether there is a difference compared with units under the same conditions. Then inspect the site for soiling, shading, wiring, equipment, temperature, and drainage—this will make it easier to isolate the cause. Improving power generation should be based on linking data with on-site conditions rather than proceeding by intuition.

Moreover, efforts to increase power generation depend more on continuous management than on the individual tasks. Dirt returns after cleaning, weeds regrow after weeding, and equipment and cables change condition with age. Comparing power generation before and after countermeasures, recording on-site photos and any abnormal points, and applying those records to the next inspection will improve the accuracy of improvements. To prevent repeated declines in power generation, it is necessary not only to temporarily remove the cause but also to create a site environment that is less likely to allow recurrence.

Especially at large power plants, accurately sharing where problems are located is essential. By recording shaded areas, rows prone to soiling, places where water accumulates, anomalous strings, repair locations, and inspection photos together with location information, stakeholders can more easily verify the same spots. Combining power generation data with on-site location information makes it easier to explain the priority of countermeasures and streamlines future inspections.

If you want to strengthen improvements in power generation at a solar power plant using on-site records and location information, using LRTK is also effective. As an iPhone-mounted GNSS high-precision positioning device, LRTK is useful for recording inspection points within the plant, locations where shadows occur, poor drainage spots, abnormal equipment, repair locations, and on-site photos together with high-precision location information. To increase solar power generation, it is important to accurately identify causes and have a management system that can continuously verify the same locations. By utilizing LRTK, you can more reliably record on-site countermeasures and make it easier to practically advance improvements in power generation.