Solar Shading Analysis provides an important resource for designing energy-efficient buildings and enhancing solar panel performance. Shading occurs when sunlight is blocked by factors around a building (other buildings, trees, topography, etc.). Understanding the effects of shading on a building and a solar panel system is important for optimizing energy generation and reducing energy consumption in today's building design.
In the case of solar panels, the main focus of the solar shading analysis is to quantify the shading impact on energy generation. The results of the shading analysis can then be used to adjust the positioning and orientation of the panels or consider measures that can counter the shading impact. Calculating shading impact is important information to use in the design process to maximize solar system output throughout the year.
In reference to buildings, solar shading analysis is also important for the design of buildings, establishing indoor conditions and balance of energy needs for heating or cooling or daylighting purposes. For building design, engineers use shading analysis to find passive solar design opportunities by providing maximum natural daylight while limiting solar heat gain and glare. Understanding and evaluating solar shading greatly contributes to more energetically and thermally comfortable environments as well as sustainable design goals.
Basics of Solar Shading
Understanding Shading and Sun
Solar shading analysis for sunlight assesses how sunlight potentially impacts outdoor areas and building envelopes. In order to understand the importance of solar shading, one must first understand the role sunlight and shading play in the built environment.
Sunlight is important for human health, visual comfort, and a resource for natural heating. Humans are even using sunlight in the form of solar radiation to exploit renewable resources to power their homes. Sunlight is certainly a good thing; however, too much sunlight could also result in glare, overheating, and inefficiencies of energy.
Shading, is in fact, necessary for the visual and thermal comfort. Shading can be supplied through many mechanisms of landscape such as trees, as well as built mechanisms such as awnings, overhangs, and louvres. Because of the desired interaction of sunlight and shading, a precise balance of each is required to achieve spaces that will provide comfort, as well as energy efficiency.
Importance of Solar Shading Analysis
Solar shading analysis is simply a full study that incorporates various instruments and methodologies that quantify the performance of shading of a structure or site over a 12 month period of a year. This analyses measures the interaction of sunlight with adjacent structures, vegetation, and topography each year.
There are many reasons for performing solar shading analyses:
Energy Efficiency: A solar shading analysis shows locations that may be receiving too much amount of sunlight potentially causing overheating and discomfort for the occupants and actually causing the increased use of cooling and ventilation energy. In contrast, it also shows areas that do not receive any natural light, and must receive artificial lighting.
Visual Comfort and Thermal Comfort: A solar shading analysis enables designers to consider deliberately what sun control devices one would use, sun orientation of windows, and building façade materials, to ensure visual and thermal comfort for occupants.
Sustainability: The use of solar shading approaches contributes to the to the overall sustainable design of a building; minimizing environmental impact while improving energy utilization.
Code Compliance: Various building codes/jurisdication levies and sustainability certifications set a base solar radiation threshold, hence, assessing for solar shading is paramount for compliance.
Solar shading analysis allows designers and planners to develop and utilize easily maintainable spaces. Sunlight and shade analysis are essential for energy efficiency, occupant comfort, and sustainable design.
Shading analysis technologies
Tools and software
There are several types of technology for generating solar shading reports, with unique pros and cons for their use. One type of technology is 3D models, these specialized softwares use 3D models for accurate and reliable solar shading assessments and are known as software programs. One such tool in this category is Solmetric SunEye, known as it allows for the generation of a 3D shading analysis by means of digital photographs and GPS tagging to provide accurate and verified ASHRAE solar shading predictions. As a result of a shading analysis, including but not limited to:
Annual solar access
Total solar resource fraction
Shade reduction on energy output
Another widely used software is EagleView, which offers aerial imagery and data analytics for solar installations. This software combines high-resolution aerial images with 3D models to provide precise solar shading analysis. Key features of EagleView include:
Accurate roof geometry measurements
Solar access and shading reports
System design and layout optimization
Imagery and Data Sourcing Approaches
Besides applications like EagleView, there are still many further image and data sourcing approaches we use for solar shading analysis to enhance the accuracy of solar shading analysis i.e. aerial and satellite images, data like those obtained from aerial images, and using drones or aerial drones for high resolution images of the site. Aerial images can then generate an avenue for locating shading objects which could be trees and neighboring buildings. Somes aerial images could be integrated with 3D building models for shading representations of the site.
Another means of data sourcing could use locating GPS and digital compasses, in-site assessment of data using GPS and compasses location integrated devices. Such as a Solmetric SunEye would provide very accurate locations and orientation for shading analysis.
All of these tools, technologies, and data sourcing methods go into enabling the shading analysis with useful and reliable shading analysis data for solar PV designs. Solmetric SunEye, EagleView and 3D models are among various other types of data to generate a realistic system design that will seek to optimize performance.
Solar PV System Design
Solar PV system design includes many prospects of system design they include the position of the sun, panel angle and orientation modeling, and shading effects on array performance. In this paper we will highlight and discuss the respective prospects and recommend possible designs to develop the Solar PV system design.
Shade in System Design
Shade is an important design consideration in UV solar energy system design because shade can move energy output by completely covered to partially covered. The designer must analyze the area around the environment for shading from buildings, trees and any objects that may be placing shade on the solar panel.
Specific practical considerations for shade in the system design:
Conduct a solar shade analysis to determine shading options. This can assist in determining the best location, orientation and tilt of the solar panel to minimize shade.
Use microinverters or power optimizers for better performance in the shade. Micro-inverters or power optimizers allow each solar panel to operate independently so shading may cause a smaller impact on the overall system performance.
Solar Panel Orientation and Positioning
The orientation of your solar panel will directly affect the harvest of solar energy. The position of the solar panels can be placed in the following categories.
Latitude: Install the panel tilt angle at the site latitude so the panel can be utilized year around.
Orientation: Work the solar panels to point dead south (in northern hemisphere) or dead North (in the southern hemisphere) to absorb the most sunlight.
Azimuth angle: Utilize an azimuth angle base on geographical location to achieve the most output.
In any general location of your solar PV system, note the following criteria:
Select a maximum shadow-free area for the least amount of shading.
Leave enough room for maintenance and periodic cleaning.
Use ground-mounted systems where the rooftop cannot accommodate the system or where the best orientation is not possible.
You can best optimize energy production and improve your system performance of your solar PV system design by considering shading, panel orientation, and position.
Shade analysis and simulating
Simulating Sunlight and Shadows
One of the important parts of analyzing solar shading is making the shadows realistic, which means we need to calculate sunlight angles, positions, and how they interact with surrounding surfaces. Shadowmap is a tool that is useful in defining the location of the shadows, where, the date, and the time to generate accurate 3D shadows.
Solar Access Analysis and TSRF
After the shadows are calculated, the next step is to analyze the solar access values (SAV). The SAV is the total amount of direct sunlight received on a specific surface for different periods of time. It is important to note that the higher the SAV, the more potential energy will be from the sun.
Finally, Total Solar Resource Fraction (TSRF) is an important factor that takes into consideration both direct sunlight and diffuse radiation received at the location. It measures how much of the total available solar energy a solar collector can receive by including the shadows and anything obstruction that affect it.
A basic Total Solar Radiation Formulation will look like:
Total Solar Radiation = Direct Solar Radiation + Diffuse Solar Radiation
TSRF = (Actual Solar Radiation on Site) / (Total Solar Radiation)
With the materials and methods you now have, Academics or Practitioners of solar energy can write a complete shade report with the systems advantages, and site viability for solar. Shade reports will typically include shading patterns, any potential solar access values, TSRF, and extras if other metrics can score or help quantify solar energy performance.
The way of combining slope angles of the shading and solar access analysis allows for the design, placement, and spend on solar technologies to be built ordered to maximize efficiency and returns on investment.
Influence on solar Energy Production
Energy Conversion Loss
Shadows on PV systems impact solar energy production. In places with very high solar irradiance (sun), very small amounts of shading can create a great loss of energy production. If you want to assess the impact on energy production of shadows you would do a solar shading analysis.
Solar shading analysis is designed to measure the percentage of time PV system was in shadow, it is summarized as a clearance value meaning, the percentage of sky that is open for shading. The higher the clearance the less shading will be by PV array for energy production.
There are a number of ways and methods that the amounts of power loss can be assessed. Some ways include site visits (walk around and look on site), drone images, 3D models, and solar irradiance sensors. These are a technical approach to understand the consequences to PV energy production.
Maximizing Solar Panel Production
Energy loss could be reduced, and solar efficiency maximized with:
Adequate PV design: PV should be installed in an orientation, inclination, and spacing that limits the shading impacts from site condition such as buildings, trees or nearby PV.
Bypass diodes: Utilizing bypass diodes in a PV will help mitigate the shading PD impacts on the PV. Bypass diodes allow current to move around a shaded cell, optimizing the maximum power output of the non-shaded cells. The remaining cells are able to function at their maximum efficiency; while non-shaded others are limited and loss energy production.
Monitoring and maintenance: There should be regular monitoring of PV that identifies shaded PD impact, maintenance such as trimming trees or cleaning panels can happen to address the shading impact.
Micro-inverters and power optimizers: micro-inverters or power optimizers will intervene or recover energy generation at the PV level when the array is unevenly shaded.
Establishing and measuring shading energy loss and capacity of solar panel production will help PV provide usable energy and sustainable future.
Environmental and Physical Considerations
When considering a solar shading analysis, it is also important to consider some environmental and physical conditions that could affect solar energy systems. Vegetation and trees and the built environment and obstructions will be discussed in this section of the solar shade analysis.
Vegetation and Trees
Vegetation and trees are important elements in solar shading analysis because trees can provide shade and block light from the solar panels. There are multiple considerations for the effect of vegetation and trees:
Type of vegetation: Different vegetations and trees will grow in different synonyms, heights and densities that can cause solar shading. Deciduous trees lose their leaves at least once a year while evergreen trees provide dense foliage year round.
Placement and Distance: The location of trees and vegetation around the solar panels area will dictate how much shade they shade. There are multiple considerations for a solar shading analysis that will use the distance of vegetation and solar panels and the angle of solar shading.
Growth and Maintenance: Over time, as trees increase their shade level may be affected. Maintenance, such as pruning tree limbs, can reduce shading effects.
Built Environment and Blockage
Off of the built environment and blockage structures, such as buildings, billboards, and other mounted obstructions, may also affect solar shading. When considering these factors, it is important to consider:
Building height and orientation: A greater height of the building will increase the size of shadow on solar panel arrays; building orientation could make that shadow longer or shorter.
Material reflectivity: Some building materials have high reflectivity properties that would increase sunshine and solar energy production. Materials without reflectivity would increase shading from the building creating lower energy output.
Future development: The possibility of future expansion or alteration to the site must be weighed in the decision process for shading from buildings and their perceived obstruction, as this could be another consideration for shading.
It is critical to sensitive all the environmental and physical shading (obstruction) factors in solar shading analysis for proper evaluation of viability and performance of solar energy systems. Understanding and managing for vegetation, trees, and built environment obstructions to blocks of solar energy, solar energy projects can achieve the potential energy generation.
Economic Factors
Feasibility and ROI
In assessing solar shading, feasibility and return on investment (ROI) aspects will be the primary things for a building owner or facility manager. The main indicators related to feasibility in the solar shading applications are; site location, building orientation, type of shading, and a potential savings associated to energy cost. Sites having lower solar intensity, shorter solar days will result in lower potential savings from solar shading.
From assessing feasibility and potential ROI, a complete solar shading analysis; the situation of the site solar latitude, type of shading, and energy use pattern throughout the annual would have to be performed. Understanding the upfront costs versus estimated energy savings is a means to identify the economic feasibility of the project. The ROI for solar shading systems can be very inconsistent depending on the project installation context, but for quality commercial shading 3-7 years is an acceptable return on investment.
Operational Life & Maintenance
In addition to energy savings, the value of solar shading systems provides additional savings through the support of the HVAC system through an increased operational life and reduced maintenance cost. A well designed solar shading system should ideally have a lifespan of 15-25 years depending on material selection and installation environment.
Another consideration that can be included in the feasibility analysis is maintenance costs as it is relative to the performance efficiency and lifespan of the solar shading system. Maintenance is cleaning and lubricating all moving parts and checking representative debris or any damage. Maintenance costs will vary with the complexity of system and material selection; however, is often negligible with the majority of solar shading systems. Suggested maintenance intervals and procedures from the manufacturers would improve the efficiency and lifespan of the system.
In summary, economic considerations for solar shading assessment requires a feasibility and ROI analysis, operational life and maintenance costs. A thorough solar shading assessment will provide enough data for decision makers to evaluate projected savings, environmental impact, and viability of solar shading systems in commercial buildings.
New Trends and Innovations
Photovoltaic (PV) Technology Advancements
Solar shading analysis plays a very important role to the degree that they want to get maximize to the solar energy potential that a site can provide. However, optical convexity to sunlight and the respective advances in PV technology there are continual improvement in the efficiency and overall performance of solar systems. Here are the latest advances in PV technology.
Perovskite Solar Cells. These thin solar film cells have been gaining attention for being able to greatly increase power conversion efficiency, due to their full spectrum absorption of light.
Bifacial Solar Panels. Bifacial solar panels are able to collect sunlight on both panels, one with direct solar radiation and the other will utilize the reflected light on the back side. Both processes add-up to increase total efficiency producing up to 30% more energy.
Transparent Solar Panels. These new PV panels are transparent and retrofit as PV that generate usable electricity with almost no visible effect. This technology works for windows or as a building skin.
Future of Shading Analysis
The future of solar shading analysis is really based on renewable energy goals, smarter technologies, and public education/mindset. Future trends that may influence the focus of shading analysis:
BIM Integration: As solar didd and (of course) in the future become adatypes step for design, BIM integration would help with the storage of shading analysis into design process. This will create energy efficient/sustainable buildings.
Innovations in Smart Shading Systems: Shading systems that adjust dynamically based on the change of the sun angle or local weather events to optimize energy generation and reduce the overall cost of the system.
Public Awareness: As renewable energy goals continue to remain in the spotlight, solar potential analysis is in the spotlight. This will lead to more requests for solar shading analysis, and more robust methods of shading analysis.
By recognizing these trends and innovations, solar shading analysts will pivot, and afterwards utilize their report to explore how to optimize the solar systems' renewable energy potential.
Best Practices for Solar Shading Analysis
Accuracy and Precision
The accuracy and precision of your solar shading analysis is paramount importance from both an architect and client perspective. Reliable precision has to do with making impactful decisions regarding the ultimate siting and installation of a project.
Data sources: Use verifiable and recent data on solar radiation and weather data.
Software tools: Use solar shading analysis software that has been proven precise and reliable.
Validation processes: Routinely validate your accuracy with on-site verification.
As a side note, consider the idea of sharing the data reported to the project stakeholders to get transparency and confirm everyone is working from the same data.
Best basis for Siting and Installing
Investing time and energy to identify the best basis for siting / installation will have a huge impact on performance and economics of the project.
Site analysis: Conduct a thorough site analysis to figure out where the optimal placement of solar shading devices will be, taking into account sun path, adjacent buildings, and site climate.
Orientation and angle: Optimize the orientation and angle of solar shading devices to block a maximum of the sun, along with glare.
Material and design: Select materials and design that are highly reflective and low thermal conductance.
Keeping these practices in mind for accuracy and reliability as well as optimal locations and placement of your solar shading improvement the designers and client will ensure that your solar shading work will be efficient and effective and achieves the maximum solar energy management possibilities.
Frequently Asked Questions
What are the best methodologies to conduct solar shading analysis?
There are various methods to conduct solar shading analysis. Manual calculations, software, and on site. Out of these methods software and on-site are the best reliability & accuracy. Software modeling relies on either 3D modeling, satellite images, or both for the shading analysis. On-site works uses tools up from Solar Pathfinder or SunEyes for direct shading measurements on-site.
Do you have any free tools for shadow analysis for solar PV installations?
There are free tools available including Sketch Up, PVGIS, and the Solmetric Sun Eye Mobile. These calculators allow users to design a 3D model of a solar installation and assess shading effects over time. Each calculator has its own specific features and capabilities, so be sure to use the one that meets your requirements.
How do I use software to analyze solar site shading accurately?
To analyze solar shading using software accurately, here are the steps to follow:
Use site data, for a place's latitude and longitude, roof plan view, and relative problems nearby.
Utilize a software, input that data, and check to make sure the model represents accurate site data.
Run shading simulations at various times of the day, or year, to look at it's shadow effects.
Inspect the results, and decide if the panel design needs to be adjusted if the shading affects it.
What are some benefits to using solar shading calculator for designing a photovoltaic system?
Using a solar shading calculator, provides many benefits to designing a photovoltaic system. Some advantages are below:
They assist engineers, or designers in optimizing the solar layout for maximizing energy generation.
They help prevent issues shading issues, prior to the panel installation.
They give the user an accurate estimates of energy generation, which allows the financial estimation to be longer being based on guesswork.
They indicate areas of the property having better solar access when determining prospective sites for installations.
How does the Solar Pathfinder Supports a solar shading analysis?
Solar Pathfinder is a portable tool for shading analysis, and it acts as a visual representation of shadowing on a specific site. The Solar Pathfinder method is via reflection of the sky onto a curved dome, providing a supposed image overlay of the solar path. That can be quantified for shadowing for throughout the day and year. Also, the Solar Pathfinder can be used along with software that assists in creating a shading profile for a site.
How do I couple the shade analysis, with Google Earth, for a total solar project?
To couple shade analysis with Google Earth to get a total picture of a final solar project allows the following:
3D modeling using SketchUP, or other such software programs for the project site.
Export in the form of KML/KMZ, compatibility of a Google Earth file.
Import to Google Earth for letting users utilize the sun and shadows analysis for a shading effect.
Together use Google Earth shadow study in conjunction, or other software shadowing analysis, or as measured in person shadow measurements.
Using the shade analysis within the Google Earth allows us to have a more complete view to give a sense of solar potential for that entire space, and the solar installation may be optimized efficiently.