7 Operational Improvements to Increase Power Generation｜Practical, Cost-Effective Measures

Table of Contents

• Prioritize operational improvements over adding equipment to increase power generation

• Operational improvement 1: Review power generation data by time of day and by equipment unit

• Operational improvement 2: Confirm the extent and impact of soiling before cleaning

• Operational improvement 3: Systematically manage shadows from weeds, trees, and structures

• Operational improvement 4: Detect abnormalities in strings, connections, and cables early

• Operational improvement 5: Check power conversion equipment for shutdowns, curtailment, and temperature conditions

• Operational improvement 6: Improve drainage, terrain, and inspection routes to prevent recurrence

• Operational improvement 7: Sustain improvement effects through inspection records and location data

• An approach to improving power generation while minimizing costs

• Summary

To increase power generation, prioritize operational improvements over adding equipment

When you want to increase the power output of a solar photovoltaic system, the first thing to consider is not adding new equipment but confirming whether the existing equipment is able to perform to its full potential. In solar power generation, you cannot increase the amount of solar irradiance on-site. You cannot increase the number of sunny days or change the seasonal solar altitude. However, you can move closer to a state where the received irradiance is converted into electricity with as little waste as possible. In practical terms, operational improvements to increase generation mean identifying the causes that are causing you to miss out on power that should be generated and working to reduce generation losses.

Many practitioners searching for "how to increase power generation" are looking for improvement measures that can be implemented on-site with as little additional burden as possible. In that sense, operational improvements are extremely important. Dirt on panel surfaces, bird droppings and fallen leaves, shading from weeds and trees, connection faults, cable damage, stoppages of power conversion equipment, output curtailment, temperature rises, poor drainage, and insufficient inspection records can potentially be detected early through daily management. If left unaddressed, these issues can accumulate to reduce power generation and lead to long-term losses.

One common pitfall when trying to increase power output through operational improvements is deciding the cause based only on how the site looks. Judgments such as cleaning the panels because they are dirty, removing grass because it has grown, or inspecting equipment because it appears to have stopped are sometimes necessary. However, if the main cause of the power drop lies elsewhere, carrying out those tasks may not yield the expected improvement. Even if dirt is conspicuous, morning and evening shading may actually be reducing output. Even if you cut the grass, daytime power generation will not increase if the power conversion equipment is experiencing repeated short stoppages.

To increase power generation while keeping costs down, it is important not to work blindly but to check the areas that have the greatest impact on generation first. First, look at the generation data to narrow down the time periods and the range of equipment where output has declined. Next, on-site, check for soiling, shading, connections, equipment, drainage, and inspection/maintenance access routes. Based on that, proceed in order with the countermeasures that are expected to be effective. The purpose of operational improvements is not to increase the amount of work, but to perform the necessary tasks in the correct order and reduce generation losses.

Also, improvements in power generation are not something that can be completed in a single operation. A solar power plant is an outdoor facility, and its condition changes with the seasons, weather, surrounding environment, and aging of equipment. Even if you clean it, dirt will return; even if you remove weeds, grass will grow; trees will grow; and drainage paths will change due to sediment and fallen leaves. That is why, for operational improvements, it is necessary to repeat assessing the current status, implementing countermeasures, verifying their effects, and updating records. From here, we will explain seven operational improvements that are easy to implement in practice to increase power generation while keeping costs down.

Operational Improvement 1: Review power generation data by time of day and by facility

The first operational improvement to increase power generation is to change how you view generation data. If you only look at monthly or annual generation, you cannot tell when, where, or how generation losses are occurring. Even if nothing looks abnormal on a monthly basis, generation may drop during certain hours of sunny days, or only specific equipment may continue to operate at a low level. For operational improvements, it is important not only to look at totals but to check generation by time of day, by equipment unit, by day, and by season.

If power generation is low in the morning, shadows from trees on the east side, slopes, nearby structures, or adjacent equipment may be involved. If it is low in the evening, check for shadows on the west side and the surrounding terrain. If the midday peak does not reach expected levels, candidates include dirt on the panel surface, temperature rise, limitations of power conversion equipment, output curtailment, or equipment shutdown. If the generation curve suddenly drops during a sunny day, it is necessary to correlate shutdown and alarm histories with the time. In this way, simply analyzing by time of day can greatly change the direction of on-site inspections.

When comparing individual units, it is important to compare units under the same conditions. If you simply compare equipment with different orientations, tilts, numbers of panels, shading conditions, or connection configurations, you may mistake normal differences for abnormalities. If a specific area is consistently lower compared with adjacent rows or units with the same orientation, suspect localized soiling, partial shading, connection faults, cable damage, or abnormalities on the converter side. Don’t rely solely on the overall figures for the power plant; detecting small differences is the quickest way to improve power generation.

Pay attention to how the power output is declining. If it drops suddenly, possible causes include equipment shutdown, a broken or disconnected cable, poor connections, or the emergence of obstructions. If it is declining gradually, potential factors include the accumulation of dirt, the growth of weeds or trees, deterioration of the site environment due to poor drainage, and aging of equipment or components. The places that need checking and the priority of countermeasures differ between a sudden drop and a gradual decline.

From the perspective of cost reduction, checking the data is highly effective. If you narrow down the periods of reduced output and the scope of equipment to be inspected before going on site, you can reduce wasted inspections. Instead of wandering aimlessly around a large power plant, you can concentrate on locations showing a drop in generation. If you start work without looking at the data, you may end up spending time on areas that have little impact on generation. For operational improvements aimed at increasing power generation, the basic principle is to review the data first to improve the accuracy of on-site work.

Operational Improvement 2: Confirm the Extent and Impact of Contamination Before Cleaning

Panel cleaning is a typical measure to increase solar power generation. Because solar panels generate electricity by receiving sunlight on their surface, dirt and deposits reduce the light reaching the cells. The type of soiling varies with site conditions, such as soil dust, pollen, yellow sand, bird droppings, fallen leaves, sap, dust from nearby construction, road-derived dust, and salt-containing dirt that easily accumulates in coastal areas. When soiling is related to a decrease in power generation, appropriate cleaning directly leads to improved output.

When implementing cost-conscious operational improvements, you should avoid the approach of cleaning immediately just because something appears dirty. Cleaning itself is an effective measure, but if the main causes of reduced power output are shading or equipment outages, cleaning alone will not lead to sufficient improvement. Before cleaning, confirm whether the equipment with low power generation corresponds to the areas where dirt is noticeable. If, compared with equipment under the same conditions, only a specific row shows lower output and that row has concentrated lower-edge soiling or bird droppings, then the priority for cleaning should be higher.

Particularly important to watch for are the band-like stains that remain at the lower edge of panels and around the frames. It is often assumed that rain will wash them away naturally, but in reality the flow of rainwater can gather dirt at the bottom edge and leave it there. Panels with a shallow tilt do not drain well, making dirt more likely to accumulate. Even dirt that is not noticeable from a distance can affect power generation if it covers part of a cell. During on-site inspections, you need to carefully check not only the overall coloration of the panels but also the lower edges, corners, and areas around the frames.

Localized deposits such as bird droppings and fallen leaves should not be overlooked. Unlike dirt that spreads thinly across the entire surface, these cover specific spots more heavily and act as partial shadows that hinder power generation. Rows near trees, around structures where birds tend to perch, rows that are often downwind, and areas near unpaved walkways are more prone to accumulations of dirt and deposits. Understanding the types of dirt and the locations where they are likely to occur can be used to inform future inspection and cleaning plans.

When cleaning, it is essential to avoid damaging the equipment. Avoid vigorously scrubbing with hard tools, performing sudden work during times when panels are hot, or working without having checked electrical safety. Cleaning to increase power output is not a cosmetic task; it is maintenance intended to restore the panels’ light‑receiving condition and to keep the equipment operating stably for a long time. Recording before‑and‑after photos, the area cleaned, changes in power output, and weather conditions makes it easier to verify the effectiveness of the cleaning.

Operational Improvement 3: Systematically Manage Shadows from Weeds, Trees, and Structures

In operational improvements to increase power generation, shadow management is indispensable. Because solar panels generate electricity by receiving sunlight, even a shadow on part of a panel can reduce power output. Causes of shadows vary and include weeds, trees, fences, utility poles, surrounding buildings, mounting racks, adjacent rows of panels, monitoring equipment, and more. Shadows move with the time of day and season, so just because a shadow wasn't visible at the time of inspection doesn't mean there's 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 to summer and cast shadows on the panel lower edges and on front rows. Even when the vegetation does not touch the panels, shadows lengthen when the sun is low in the morning and evening. Furthermore, when weeds become overgrown, airflow deteriorates, inspection paths become blocked, and it becomes harder to carry out checks around equipment. Because this affects not only power output but also maintainability and safety, weed management is a high-priority item for cost-effective operational improvement.

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

When checking shadows, it is important to align with the time periods when the power output data shows a decline. If output is low in the morning, check the on-site conditions in the morning; if it is low in the evening, inspect the evening shadows. Even if there is no problem at noon, large shadows can appear in the morning and evening. Also, even if there are no issues in summer, shadows can lengthen in seasons when the sun’s altitude is lower. Shadows need to be managed not as a single moment but as something that changes with time and season.

Planning weed control and pruning can reduce the need for ad-hoc interventions. If vegetation grows in the same spot at the same time every year, you can inspect before power output declines. If there are trees that cast shadows in the morning and evening, recording how the shadows change with the seasons makes decisions easier. For cost-saving operational improvements, it is important to anticipate the locations and times where problems are likely to occur rather than responding to each issue after it has grown.

Operational Improvement 4: Detect abnormalities in strings, connection points, and cables more quickly

To increase power output, you need to check not only the panel surface and shading but also the pathways that extract the electricity. Even if solar panels are receiving sunlight normally, faults in the strings, connection points, or cables can prevent you from fully extracting the generated electricity. Loose terminals, poor contact, damage to cable insulation, moisture ingress, animal damage, damage during grass-cutting work, and deterioration due to aging are all significant causes of reduced power generation.

When checking for anomalies at the string level, compare strings that are under the same conditions. If you simply compare systems that differ in the number of panels, orientation, tilt, shading conditions, or connection configuration, you may mistakenly interpret normal differences as abnormalities. Check whether any are consistently lower compared with adjacent rows or installations with the same orientation. If only a particular string is low, possible causes include soiling, partial shading, poor connections, cable damage, or equipment-side problems.

Pay attention to how anomalies manifest. If the output is consistently lower than the surroundings even on sunny days, dirt or connection problems may be suspected. If it is only lower in the morning and evening, check for the effects of shading. If anomalies tend to appear after rain, moisture ingress or the condition of the connection points may be involved. If instability occurs 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.

When inspecting electrical equipment, safety must be the highest priority. Even if there is a desire to increase power output, on-site personnel should avoid forcing connections or opening up equipment internals to make a judgment. Organize information on the equipment showing abnormalities, the time they occurred, changes in power generation, on-site photographs, and the surrounding environment, and, if necessary, arrange for specialized inspections. At the stage of identifying the cause, it is important to clarify where and what kind of anomaly is suspected.

From a cost-saving perspective, it is important to detect abnormalities early. Even small differences in power generation can lead to large losses if they persist over a long period. Furthermore, faults in connection points or cables affect not only power output but also safety. By spotting small discrepancies in the data before abnormalities grow and focusing inspections on the areas that need attention, it becomes easier to improve generation while keeping operational burdens down.

Operational Improvement 5: Verify Shutdown, Suppression, and Thermal Environment of Conversion Equipment

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

When checking stoppage histories, confirm which equipment stopped, when it stopped, and for how long. Even short stoppages can cause large losses if they occur during the daytime when power generation is high. If equipment repeatedly stops and restarts during the day, it may not be noticeable in the monthly totals, yet can still lead to lost generation. The suspected causes vary depending on whether only a specific piece of equipment stops or multiple pieces stop simultaneously.

If output curtailment is occurring, power generation may plateau even under clear-sky conditions. When the top of the generation curve looks flat, check operational data and history. However, a flat curve does not necessarily mean output curtailment. Similar shapes can be caused by equipment capacity limits, temperature rise, dirt, shading, or measurement anomalies. Do not judge based on the generation curve alone; it is important to verify by comparing equipment records with on-site conditions.

Temperature conditions are also a point to reconsider. Solar power generation is generally easier when sunlight is stronger, but output can become less responsive as temperatures rise. If generation does not increase as expected on a clear summer day, check not only the irradiance but also the panel temperature and the temperature around the equipment. If weeds are growing under the panels, there is grass or obstacles around the equipment, or dust and deposits are inhibiting heat dissipation, these can affect the increase in generated output.

Environmental maintenance around equipment is a relatively easy operational improvement to implement. By making the area around the equipment easier to inspect, reducing vegetation and debris that obstruct ventilation, and keeping the equipment in a condition where abnormal indicators and external appearance can be easily checked, stoppages and abnormalities can be detected more quickly. To avoid confusing equipment-side malfunctions with panel-side problems, it is important to correlate the time of the power output drop with the equipment history and to isolate the cause based on sound evidence.

Operational Improvement 6: Adjust Drainage, Terrain, and Inspection Routes to Prevent Recurrence

Operational improvements to increase power generation must consider not only the panels and equipment, but also the plant-wide drainage, terrain, and inspection access routes. Areas where water tends to accumulate, places where sediment can flow in, mud-prone paths, slope failures, scour around mounting structures, and locations where cables are likely to be exposed can directly or indirectly cause reductions in power generation. Poor drainage and changes in terrain may at first seem unrelated to power output, but they are important factors that lead to soiling, weeds, connection faults, and reduced accessibility for inspections.

Areas where puddles remain after rain tend to promote weed growth. When weeds grow they cast shade, reduce ventilation, and make inspections more difficult. Muddy walkways can slow work and may reduce the frequency of cleaning and weeding. Where sediment flows in, it can accumulate under panels and around cables, causing soiling and damage. If cleaning or weeding repeatedly fails to prevent problems in the same locations, drainage or terrain issues should be suspected.

When checking topography and drainage, on-site inspections after rain as well as during sunny weather are effective. Determine where water flows in, where it accumulates, and where it drains away. Recording puddles, sediment deposits, vegetation overgrowth, walkway subsidence, and changes to slope faces will reveal locations prone to recurrence. Leaving poor drainage unaddressed causes repeated soiling and weed growth, resulting in the same power generation losses occurring repeatedly.

Maintaining clear inspection routes is also important as a practical measure to reduce costs. Areas that are difficult to inspect tend to delay the detection of abnormalities. If grass has overgrown and paths are impassable, if it is too muddy to approach, if equipment numbers are hard to identify, or if abnormal locations are difficult to share, on-site responses take longer. Even if equipment with low power output is identified from the data, if it takes time to reach the relevant location on site, improvements will be delayed.

Improvements to drainage, topography, and inspection access routes may not immediately show up as an increase in power generation. However, over the long term they help reduce soiling, weed growth, poor connections, and inspection delays. To increase power generation while keeping costs down, it is essential not only to perform immediate cleaning and weeding but also to create site conditions that make the same problems less likely to recur.

Operational Improvement 7：Sustaining the Effects of Improvements through Inspection Records and Location Information

Keeping inspection records is essential to sustain operational improvements that increase power generation. Even if dirt, shading, abnormalities, or poor drainage are found on site, if the exact location is not accurately shared, it takes time to implement countermeasures or to reconfirm. Especially at large power plants, where similar rows and equipment are lined up, it can be difficult to identify locations from photos alone. By linking inspection results with location information and managing them, the practical work of improving power generation can be greatly streamlined.

What you should record are the locations of equipment with low power output, rows prone to soiling, spots where shadows occur, places where water accumulates, locations where connection failures happened, repaired areas, and the ranges where cleaning or weeding was performed. Leaving photos, date and time, equipment numbers, work performed, details of abnormalities, response status, and whether re-inspection is required will be helpful at the next inspection. If you add too many items to record it won’t be sustainable in the field, so it’s important to start by making sure that, when you look back later, you can tell what happened and where.

Linking power generation data with on-site photographs makes it easier to determine causes. If the locations of low-performing installations overlap with areas where shadows occur or where drainage is poor, the rationale for countermeasures becomes clear. If the power output at a cleaned location improves, you can conclude that dirt had a significant impact at that site. If morning and evening power output improves after weeding, it is likely that shadows from weeds were the cause. Keeping records speeds up decision-making for future cases.

If inadequate record-keeping is left unaddressed, the same problems will be repeated. Even when there are clear patterns — grass growing in the same spots every year, dirt accumulating in the same rows, the same passageways getting muddy after rain, the same equipment causing stoppages — without records the next response will be ad hoc. To reduce costs, instead of investigating the cause from scratch each time, it is important to use past records to narrow down where to check.

After implementing countermeasures, verify how the power generation has changed. After performing cleaning, weeding, repairs, equipment checks, and drainage checks, record the pre- and post-work power generation, site photos, work scope, and weather conditions. It is difficult to completely eliminate the influence of weather, but by comparing clear-sky days or comparing with facilities under the same conditions, you can identify certain trends. Prioritize measures that showed a large effect for future work, and if an effect is not apparent, suspect other causes. Repeating this cycle is the basic approach to prevent power generation improvements from being only temporary.

Approach to Improving Power Generation While Keeping Costs Down

To increase power generation while keeping costs down, it is important not to start small but to focus on measures that deliver high impact. Cleaning, weeding, repairs, equipment inspections, and drainage measures may all be necessary, but if you implement them in order of smallest impact on power generation, the workload will merely increase and the improvement effects will be hard to see. First, narrow down the areas of decline using power generation data, identify the causes through on-site inspection, and address the locations with the greatest impact first.

Also, always perform a before-and-after comparison of the work. If power generation does not change significantly after cleaning, you should suspect causes other than dirt. If morning and evening generation improves after weeding, you can conclude that shading had a large effect. If the history of equipment shutdowns corresponds with the decrease in power generation, inspection of the equipment should take priority. By linking countermeasures with results in this way, future decisions can be made more quickly.

When it comes to reducing costs, preventing recurrence is also important. If the same spot becomes dirty repeatedly, grass grows in the same area, the same pathway becomes muddy after rain, or the same equipment experiences repeated shutdowns, superficial measures alone will be inefficient. You need not only to deal with problems as they arise but also to determine why they occur in the same place and to record them. If you identify locations prone to recurrence, you can respond next time before power generation drops significantly.

To continue improving operations, it is also important to keep information in a state that is easy to share among responsible personnel. In large power plants, photos alone may not convey the location. If equipment numbers, location information, photos, and work histories are recorded together, on-site staff, managers, inspectors, and maintenance personnel can more easily identify the same location. As a result, redundant inspections and missed checks are reduced, making it easier to improve power generation.

Summary

In operational improvements aimed at increasing power generation, it is important to correctly identify the causes of generation losses and to address them starting with the areas that have the greatest impact on output. In solar power generation, the site cannot increase the amount of solar irradiance itself. However, you can improve output by bringing the system closer to a state in which the received sunlight is converted into electricity with minimal waste. To do so, it is necessary to check, in order, generation data, dirt on panel surfaces, shadows from weeds and trees, strings and connection points, conversion equipment, drainage and terrain, and inspection records.

To increase power generation while keeping costs down, rather than taking large measures all at once, it is important to first look at the data separately. Identify when output is low, which equipment has low output, and whether there are differences compared with equipment under the same conditions. By then inspecting the site, the places that need cleaning, the areas that need weeding, the connection points that need inspection, the devices that need checking, and the drainage or access routes that should be reviewed become clear. To maximize the effectiveness of generation improvements, it is important to make decisions by linking data with on‑site conditions rather than relying on intuition.

Also, improving power output is not something that can be completed with a single action. Even if you clean, dirt will return; even if you remove weeds, grass will grow back; trees will continue to grow; and equipment and wiring will change or deteriorate over time. By comparing power output before and after countermeasures, keeping on-site photos and work records, and using them for the next inspection, the precision of improvements increases. To achieve a stable increase in power output, it is essential not only to eliminate the causes but also to create a site environment and management system that make the same causes less likely to recur.

In particularly large power plants, a system for accurately sharing problem locations is essential. If you record dirt-prone rows, shadowed areas, places where water accumulates, abnormal strings, repair locations, cleaning coverage, and inspection photos together with location information, stakeholders can more easily verify the same spot. Combining power generation data with on-site location information makes it easier to explain the priorities for cleaning, weeding, and repairs, and also streamlines follow-up checks for recurrence.

If you want to continuously implement operational improvements to increase power generation based on on-site data, leveraging LRTK can also be effective. As an iPhone-mounted GNSS high-accuracy positioning device, LRTK is useful for recording inspection locations within a solar power plant, areas prone to soiling, locations where shadows occur, drainage failure points, abnormal equipment, repair locations, cleaning ranges, and on-site photos together with high-accuracy location information; by keeping records of operational improvements with location information, it becomes easier to pursue power generation improvements based on field data rather than intuition.