Simulating photovoltaic power plants with Energy3D

Modeling 1,000 PV panels in a desert
Solar radiation simulation
We have just added new modeling capacities to our Energy3D software for simulating photovoltaic (PV) power stations. With these additions, the latest version of the software can now simulate rooftop solar panels, solar parks, and solar power plants. Our plan is to develop Energy3D into a "one stop shop" for solar simulations. The goal is to provide students an accessible (yet powerful) tool to learn science and engineering in the context of renewable energy and professionals an easy-to-use (yet accurate) tool to design, predict, and optimize renewable energy generation.

Users can easily copy and paste solar panels to create an array and then duplicate arrays to create more arrays. In this way, users can rapidly add many solar panels. Each solar panel can be rotated around three different axes (normal, zenith, and azimuth). With this flexibility, users can create a PV array in any direction and orientation. At any time, they can adjust the direction and orientation of any or all solar panels.
PV arrays that are oriented differently


What is in the design of a solar power plant? While the orientation is a no-brainer, the layout may need some thinking and planning, especially for a site that has a limited area. Another factor that affects the layout is the design of the solar tracking system used to maximize the output. Also, considering that many utility companies offer peak and off-peak prices for electricity, users may explore strategies of orienting some PV arrays towards the west or southwest for the solar power plant to produce more energy in the afternoon when the demand is high in the summer, especially in the south.

Rooftop PV arrays
In addition to designing PV arrays on the ground, users can do the same thing for flat rooftops as well. Unlike solar panels on pitched roofs of residential buildings, those on flat roofs of large buildings are usually tilted.

We are currently implementing solar trackers so that users can design solar power plants that maximize their outputs based on tracking the sun. Meanwhile, mirror reflector arrays will be added to support the design of concentrated solar power plants. These features should be available soon. Stay tuned!

3D model of Ulm Minster created in just one day using Energy3D

Although our Energy3D software is billed as a piece of building simulation and engineering software, it has also become a powerful tool for constructing 3D models of buildings. With even more enhancements in the latest version (v 5.3.2), users can create incredibly complex structures in a short time.

Guanhua Chen, a graduate student from the University of Miami in Florida who joined my team this week as a summer intern, created an unbelievably detailed model of Ulm Minster -- in JUST ONE DAY. In total, his model has 373 elements.

Considering that he is very new to Energy3D (though he previously had some experiences with Maya and Unity3D), this somehow indicates just how easy Energy3D may be for 3D modeling, especially for novices. (As a matter of fact, I must confess that we cheated a bit because, as he was working on it, I rushed to add new features to the software on the fly to address his complaints. Then he just restarted the program and got onto a more performant version).


This capability will be extremely useful for engineering design, which must address both structure and function and their relationship. Being able to create complex structures rapidly and then study their functions based on the building simulation and solar simulation engines of Energy3D allows users to explore many design options and test them immediately, a feature that is critically important to engineering education.







Energy3D makes designing realistic buildings easy

The annual yield and cost benefit analyses of rooftop solar panels based on sound scientific and engineering principles are critical steps to the financial success of building solarization. Google's Project Sunroof provides a way for millions of property owners to get recommendations for the right solar solutions.



Another way to conduct accurate scientific analysis of solar panel outputs based on their layout on the rooftop is to use a computer-aided engineering (CAE) tool to do a three-dimensional, full-year analysis based on ab initio scientific simulation. Under the support of the National Science Foundation since 2010, we have been developing Energy3D, a piece of CAE software that has the goal of bringing the power of sophisticated scientific and engineering simulations to children and laypersons. To achieve this goal, a key step is to support users to rapidly sketch up their own buildings and the surrounding objects that may affect their solar potentials. We feel that most CAD tools out there are probably too difficult for average users to create realistic models of their own houses. This forces us to invent new solutions.

We have recently added countless new features to Energy3D to progress towards this goal. The latest version allows many common architectural styles found in most parts of the US to be created and their solar potential to be studied. The screenshots embedded in this article demonstrate this capability. With the current version, each of these designs took myself approximately an hour to create from scratch. But we will continue to push the limit.

The 3D construction user interface has been developed based on the tenet of supporting users to create any structure using a minimum set of building blocks and operations. Once users master a relatively small set of rules, they are empowered to create almost any shape of building as they wish.

Solar yield analysis of the first house
The actual time-consuming part is to get the right dimension and orientation of a real building and the surrounding tall objects such as trees.
Google's 3D map may provide a way to extract these data. Once the approximate geometry of a building is determined, users can easily put solar panels anywhere on the roof to check out their energy yield. They can then try as many different layouts as they wish to compare the yields and select an optimal layout. This is especially important for buildings that may have partial shades and sub-optimal orientations. CAE tools such as Energy3D can be used to do spatial and temporal analysis and report daily outputs of each panel in the array, allowing users to obtain fine-grained, detailed results and thus providing a good simulation of solar panels in day-to-day operation.

The engineering principles behind this solar design, assessment, and optimization process based on science is exactly what the Next Generation Science Standards require K-12 students in the US to learn and practice. So why not ask children for help to solarize their own homes, schools, and communities, at least virtually? The time for doing this can never be better. And we have paved the road for this vision by creating one of easiest 3D interfaces with compelling scientific visualizations that can potentially entice and engage a lot of students. It is time for us to test the idea.

To see more designs, visit this page.

5 Reasons to Vote in STEM For All Video Showcase

We’re thrilled to present five videos in the National Science Foundation STEM for All Video Showcase from May 17 to 23! We invite you to view the videos and join the conversation about the latest research in STEM and computer science teaching and learning. Please vote for our videos through Facebook, Twitter, or email!

CODAPCODAP

Data are everywhere, except in the classroom! Learn how our Common Online Data Analysis Platform (CODAP) is bringing more rich experiences with data to more teachers and students.

Watch Now

Teaching TeamworkTeaching Teamwork

Collaboration is highly valued in the 21st century workplace. Our Teaching Teamwork project is measuring how effectively electronics students work in teams.

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GeniverseGeniConnect & GeniGUIDE

Geniverse engages students in exploring heredity and genetics by breeding virtual dragons. GeniConnect connects afterschool students with biotech scientists to play Geniverse together. In GeniGUIDE, we’re adding an intelligent tutoring system to Geniverse, supporting students and relaying information to the most intelligent tutor in the room – the teacher.

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Teaching Environmental Sustainability with Model My WatershedTeaching Environmental Sustainability
with Model My Watershed

Teaching Environmental Sustainability with Model My Watershed is developing place-based, problem-based, hands-on set tools aligned to NGSS to promote geospatial literacy and systems thinking for middle and high school students.

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GRASPGRASP

GRASP (Gesture Augmented Simulations for Supporting Explanations) is investigating how middle school students use body movement to build deeper reasoning about critical science concepts.

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Making sense of non-optimal solar panel orientations seen on Google Maps


Figure 1: Google Map
If you are thinking about putting solar panels on your roof, the conventional wisdom is that your house probably would be automatically disqualified if its roof does not have a large south-facing side for installing solar panels. If you have no idea about this, the sales representatives from solar companies would probably tell you this based on their training.

While it might be a smart strategy to target houses with most promising returns at the beginning of the solar energy industry back a decade ago, the old rules may not hold any longer. With the solar cell efficiency of commercial panels climbing above 20% and, more importantly, the environmental awareness of homeowners increasing, the solar energy market has changed a lot.

Thanks to Google Map, it is just a few mouse clicks away to get an idea about the current status of the market. So I surveyed my neighborhoods in eastern Massachusetts and was surprised to find that a significant amount of rooftop solar panel arrays do not actually face south (Figure 1). This is understandable because a significant percentage of buildings do not have a roof that has a south-facing side. So if homeowners living in those houses want to contribute to solving the environmental problems, they do not have any other choice except putting solar panels wherever they can be mounted. If you take a look at your own neighborhood in Google Map, you should spot a lot of west- and east-facing (or even north-facing!) solar panels.

Figure 2. Solar simulation in Energy3D
Figure 3: South-facing vs. west-facing
I have heard some solar installers accusing competitors of coaxing homeowners into this kind of less effective configurations in order to increase their profits at the expense of the homeowners' running cost. Before we start pointing fingers at one another, let's stop and think: Is it really such a horrible idea to put solar panels on a non-south-facing side? The problem is that few people really have an idea about how much less energy those non-ideal configurations would entail compared with the optimal south-facing situation. An estimate of this is critically important to helping homeowners make up their mind whether to go solar or not. And, by the way, it also demonstrates your business ethics and technical capability as well. Unfortunately, in reality, you cannot re-orient people's houses or roofs to figure that out.

Thanks to the funding from the National Science Foundation, this kind of estimation can be easily done using our Energy3D software, which has a decent crystal ball when it comes to solar modeling and prediction (Figure 2). I have been blogging about this capacity of the software for a while. It is time to finally put this tool into practice to help people evaluate their solar options.


Let's start with a very simple house and a 5kW solar panel system (Figure 3). The first step is to get a sense of how accurate Energy3D's prediction may be. In situations similar to the standard test conditions (STC), this system -- when oriented to the south -- should generate about 6,000 kWh per year in Boston, Massachusetts and about 8,000 kWh per year in Los Angeles, California. The results from Energy3D agree exactly with these widely-cited numbers, as shown in Figure 4.

Figure 4: BOS vs. LAX
With this validity, we can then ask the following question: What if we have only a west-facing roof? This can be easily done by rotating the model house in Energy3D 90° and then redo the calculation. It turns out that the homeowner in Boston will get about 80% of the maximal output (when the panels face south), as illustrated in Figure 5. The folks in LA will fare slightly better -- about 82%.

Figure 5: South-facing vs. west-facing outputs
I believe a large number of homeowners, if informed by the results of this simulation-based analysis, may consider 20% performance reduction as acceptable. Yes, their panels will generate less electricity than those on the roofs of houses with the optimal orientation, but many would like to do whatever they can to help reduce carbon emission. To them, doing it at a pace that is 20% slower is infinitely better than doing nothing at all, letting alone that many houses do not face exactly west and the actual performance reduction will be less than 20%.

The results of this study should give you a sense about how simulations may be useful in fostering the growth of the solar energy market. Even better, through years of development, we have made solar simulation in Energy3D so easy that anyone can do it. As an experimental step, we are now collaborating with high schools in Massachusetts to pilot-test the feasibility of engaging students to evaluate the solarization potential of their own houses. Our goal is to create an integrated education-business model that benefits both sides. We hope that the success of this project will help the world reach the goals set by the Paris Agreement.

Personal thermal vision could turn millions of students into the cleantech workforce of today

So we have signed the Paris Agreement and cheered about it. Now what?

More than a year ago, I wrote a proposal to the National Science Foundation to test the feasibility of empowering students to help combat the energy issues of our nation. There are hundreds of millions of buildings in our country and some of them are pretty big energy losers. The home energy industry currently employs probably 100,000 people at most. It would take them a few decades to weatherize and solarize all these residential and commercial buildings (let alone educating home owners so that they would take such actions).

But there are millions of students in schools who are probably more likely to be concerned about the world that they are about to inherit. Why not ask them to help?

You probably know a lot of projects on this very same mission. But I want to do something different. Enough messaging has been done. We don't need to hand out more brochures and flyers about the environmental issues that we may be facing. It is time to call for actions!

For a number of years, I have been working on infrared thermography and building energy simulation to knock down the technical barriers that these techniques may pose to children. With NSF awarding us a $1.2M grant last year and FLIR releasing a series of inexpensive thermal cameras, the time of bringing these tools to large-scale applications in schools has finally arrived.

For more information, see our poster that will be presented at a NSF meeting next week. Note that this project has just begun so we haven't had a chance to test the solarization part. But the results from the weatherization part based on infrared thermography has been extremely encouraging!

Listen to the data with the Visual Process Analytics


Visual analytics provides a powerful way for people to see patterns and trends in data by visualizing them. In real life, we use both our eyes and ears. So can we hear patterns and trends if we listen to the data?

I spent a few days studying the JavaScript Sound API and adding simple data sonification to our Visual Process Analytics (VPA) to explore this question. I don't know where including the auditory sense to the analytics toolkit may lead us, but you never know. It is always good to experiment with various ideas.


Note that the data sonification capabilities of VPA is very experimental at this point. To make the matter worse, I am not a musician by any stretch of the imagination. So the generated sounds in the latest version of VPA may sound horrible to you. But this represents a step forward to better interactions with complex learner data. As my knowledge about music improves, the data should sound less terrifying.

The first test feature added to VPA is very simple: It just converts a time series into a sequence of notes and rests. To adjust the sound, you can change a number of parameters such as pitch, duration, attack, decay, and oscillator types (sine, square, triangle, sawtooth, etc.). All these options are available through the context menu of a time series graph.

At the same time as the sound plays, you can also see a synchronized animation of VPA (as demonstrated by the embedded videos). This means that from now on VPA is a multimodal analytic tool. But I have no plan to rename it as data visualization is still and will remain dominant for the data mining platform.

The next step is to figure out how to synthesize better sounds from multiple types of actions as multiple sources or instruments (much like the Song from Pi). I will start with sonifying the scatter plot in VPA. Stay tuned.

What’s new in Visual Process Analytics Version 0.3


Visual Process Analytics (VPA) is a data mining platform that supports research on student learning through using complex tools to solve complex problems. The complexity of this kind of learning activities of students entails complex process data (e.g., event log) that cannot be easily analyzed. This difficulty calls for data visualization that can at least give researchers a glimpse of the data before they can actually conduct in-depth analyses. To this end, the VPA platform provides many different types of visualization that represent many different aspects of complex processes. These graphic representations should help researchers develop some sort of intuition. We believe VPA is an essential tool for data-intensive research, which will only grow more important in the future as data mining, machine learning, and artificial intelligence play critical roles in effective, personalized education.

Several new features were added to Version 0.3, described as follows:

1) Interactions are provided through context menus. Context menus can be invoked by right-clicking on a visualization. Depending on where the user clicks, a context menu provides the available actions applicable to the selected objects. This allows a complex tool such as VPA to still have a simple, pleasant user interface.

2) Result collectors allow users to gather analysis results and export them in the CSV format. VPA is a data browser that allows users to navigate in the ocean of data from the repositories it connects to. Each step of navigation invokes some calculations behind the scenes. To collect the results of these calculations in a mining session, VPA now has a simple result collector that automatically keeps track of the user's work. A more sophisticated result manager is also being conceptualized and developed to make it possible for users to manage their data mining results in a more flexible way. These results can be exported if needed to be analyzed further using other software tools.

3) Cumulative data graphs are available to render a more dramatic view of time series. It is sometimes easier to spot patterns and trends in cumulative graphs. This cumulative analysis applies to all levels of granularity of data supported by VPA (currently, the three granular levels are Top, Medium, and Fine, corresponding to three different ways to categorize action data). VPA also provides a way for users to select variables from a list to be highlighted in cumulative graphs.

Many other new features were also added in this version. For example, additional information about classes and students are provided to contextualize each data set. In the coming weeks, the repository will incorporate data from more than 1,200 students in Indiana who have undertaken engineering design projects using our Energy3D software. This unprecedented large-scale database will potentially provide a goldmine of research data in the area of engineering design study.

For more information about VPA, see my AERA 2016 presentation.