Sacred Solar Geometry: The Mathematics behind PV Booster, Rooftop Tracker
Since the dawn of time…
humanity has looked to the stars for solutions when faced with uncertainty. Channeling the hard sciences of astrology and various sacred texts, we at Point Load Power bring you - Sacred Solar Geometry.
Designed to help you See the Power in Energy and provide clarity amidst the myriad of questions faced by commercial real estate owners and solar developers, Point Load Power has put together this comprehensive series to guide you through these decisions. Throughout, we will divulge some of the universe's most well-kept secrets about how you can reach Maximum Energy yields that will eclipse all forms of ordinary rooftop solar.
Follow along with our weekly Sacred Solar Geometry series, look for new posts every Thursday as we help you and your client’s realize the rooftop’s true potential.
At Point Load Power, our purpose is to help you See the Power in Energy and bring our clients renewable solutions that harness the full, abundant power of solar rooftops, significantly reduce commercial building's energy costs, and generate unprecedented returns on investment.
In pursuit of this purpose we created PV Booster, the first ever rooftop tracking system. PV Booster can generate 70% more revenue per solar panel than any other rooftop system. In this 5-part series, we will explore:
We invite you to rethink rooftop solar and open your third eye to the natural power of tracking the sun. By the end of this series you will be armed with the information you need as an energy expert to add a high efficiency product offering and further enrich your clients’ commercial real estate.
Peak Performance - Energy Curve
As energy expert ourselves, we aim to enlighten our clients to the secrets of reaching peak solar energy production performance. Though these secrets are as old as time, no solar mount has been able increase the solar panel energy production to the degree PV Booster has achieved. In this Sacred Solar post, we review the mechanics that differentiate PV Booster from other solar panel mounts and what that means for your solar project economics.
Tracking systems are used on more than 70% of all ground-mounted solar projects in the US. Why? Because utility scale investors know that the advantages of using a tracking mount over a fixed mount are significant and bankable. The National Renewable Energy Laboratories (NREL) has also documented decades worth of data showing that tracking the sun throughout the sky results in much more solar energy production than if a panel is fixed.
In the past, mechanical barriers regarding solar mounts’ weight and wind resistance has prevented building owners from installing tracking solar mounts on the roofs of their C&I buildings. PV Booster solves this problem as the first tracking mount specifically designed for rooftop installation, allowing building owners to take advantage of otherwise unused potential of their solar panels. Not only is the ability to utilize this space a benefit for building owners, but the height advantage paired with sun tracking abilities, results in 40% more energy per panel than the standard 5-degree fixed-tilt system.
For a one-time, tax-advantaged CAPEX premium, your client produces a lifetime of higher solar yield per panel. This was good news even before time-of-use rates started spreading across the country. In fact, PV Booster produces more “super-peak” kWhs than most fixed-tilt rooftop systems, 56% more than a 5-degree fixed-tilt, southern facing system the topic of our webinar with Helioscope and Energy Toolbase.
PV Booster is bringing utility scale solar energy yields to rooftops, real estate’s last frontier. These underutilized spaces offer the next big development opportunity. Warehouses, distribution centers, single story offices, schools, financed projects, utilities with capacity limits or TOU rates are all scenarios where PV Booster shines every time. Customers want peak performance.
Tracking Geometry
Our Sacred Solar campaign is about honoring the sun and energy it emits, so naturally we created PV Booster, the first smart rooftop tracking system guaranteed to maximize solar energy production.
PV Booster is a distributed tracking system. Like optimizers, each module functions on its own self-contained tracker unit. This approach provides granular production and operational information unprecedented on rooftops or ground-mounted tracking projects. The health of the array, down to the panel level, is provided real-time remotely. This is a new level of intelligence from your solar mounting rack as energy generation and consumption systems grow in complexity. During O&M visits, service techs know exactly which modules require attention and what kind of attention they require.
PV Booster is made up of three major subsystems: the tri-pod base, the actuator gearbox, and the h-frame module support. The tri-pod base sits balanced on any roof surface providing incredible stability and support for each module. Weighing in at 30 pounds, PV Booster adds less than two pound per square foot additional dead-load to the roof, much less than ordinary fixed racking systems. The tri-pod base is extremely strong and can handle up to 110 mph wind speeds. This stout tracking system is driven by a proprietary, self-contained actuator which ensures up-time and functionality in all weather conditions.
The module tilt angle is 30 degrees, perfect for most of North America for most of the year, producing additional energy yields much higher than ordinary and inefficient fixed racking.
Finally, if it breaks, it’s fixed. If a unit is driven off course, it can easily be reset manually or remotely to face due south and still produce as much energy as a 30-degree fixed tilt module until the next routine maintenance site visit. No need to roll a truck on a distributed system.
Foundation of Strength
Sacred Geometry is the study of shapes and patterns and how they relate to the world around us. Sacred Solar Geometry is how these shapes relate to the sun, and when it comes to geometry and solar energy, we are experts.
A tetrahedron, also known as a triangular pyramid, is the simplest of all the ordinary convex polyhedrons and is the perfect foundation for a stand-alone tracker. Although they are referred to as flat roofs, if you’ve been on one, you know, most commercial and industrial rooftops are anything but flat. That is no problem for PV Booster as the trip-pod finds balance on any rooftop with a slope of less than 10 degrees. Just like the three-legged barstool, PV Booster remains stable throughout the life of your project.
This was the principle behind the design that our engineers used to ensure the longevity of our rooftop tracker. Each foot distributes down forces through non-penetrating contact with the roof material. Often roof membrane manufacturers require slip-sheets which easily attach to the underside of our feet to resist membrane wear overtime. Additionally, the center post mechanical attachment is lag-bolted to the roof support structure to resist uplift forces. Bottom line: this four-point tracker foundation is built to last and will remain stable through the entire life of the system. PV Booster had no problems in our load tests prior to production, handling over 1,200 lbs or downforce pressure and over 1,600 lbs of uplift pressure. Now that is strength!
Our support extends beyond the rooftop with a talented team of industry experts available to assist you.
Simple Spacing
PV Booster needs space. Shading is the enemy of solar power production and we’re in the business of high efficiency energy yield. When every kWh matters, PV Booster allows you to get the most out of the panels you purchase. This means the single-axis rooftop trackers need to be spaced appropriately to produce peak power no matter the hour or season. That spacing can also be informed by the roof support structure of the building that hosts your solar project. Our strategy is to avoid shade at all cost, but this design can be modified to suit your project. Sometimes the tradeoff between performance and capacity can be a worthwhile modification, we can help you model the impacts of these design decisions.
Since most flat roof commercial and industrial buildings have a support member at least every 8 feet, this is a good starting point for PV Booster’s center post mechanical attachments. These center posts will be lag bolted to either the roof support beams or roof support joists to resist as much as 110 mph winds. For this reason, a good rule-of-thumb is to space PV Booster rooftop trackers 8’ on center effectively. This gives each unit the space to execute a full range of motion without shading the array or coming into contact with adjacent PV Boosters. For more design specifications see our Design Guide.
Bottom line: Space PV Booster rooftop trackers eight feet on center for most applications.
Exponential Gain with Bifacial Modules
Bi-facial modules are all the buzz in the solar industry right now. Major manufacturers and industry new-comers alike are promoting the benefit of back-side gain in energy production, and it makes sense. Reflective solar energy, or albedo, is everywhere – thanks to the diffuse light reflecting off of surfaces of all-kinds. The lighter the material, the higher the albedo. Especially commercial and industrial rooftops, which are often covered in white, reflective membranes, the albedo can be tremendous. This is why PV Booster and bi-facial modules go together like AC & DC.
This past fall, we completed a rooftop test for bi-facial modules and found an additional 70% gain over ordinary 5-degree fixed racking. As energy consumption efficiency and energy management becomes a priority for real estate investors and time of use tariffs become more prevalent, rooftop project efficiency is going to be many times more important than solar capacity. High solar energy yields are a major driver of a lower levelized cost of energy (LCOE) which greatly improves your solar return on investment.
Combine the massive boost from closely tracking the sun with the additional bi-facial boost from albedo collection and you have a serious efficiency boost all day long. This combination is going to change the game for flat rooftops as they become the new utility scale solar projects.