Image: Folsom Labs
Many software tools are available to help renewable energy engineers evaluate a location and design a photovoltaic system. Of the current options, PVSyst has become the industry standard, estimating energy production that accounts for losses due to weather and climate, shading, wiring, component efficiencies, panel mismatches, and aging, and providing recommendations for equipment and array layout. But HelioScope, a new program introduced by Folsom Labs, includes all the features of PVSyst and adds the design functionality of AutoCad, allowing designers to do a complete design with one package. Folsom Labs’ founder Paul Grana was kind enough spend an hour on the phone with me and answer my questions about HelioScope.
HelioScope is a web-based tool, so there’s no software to download and you can use it from any connected computer. Instead of buying the program, you pay a monthly or annual fee. (Click the Read More… link at the end of this article to go to their web site.)
When using HelioScope, the user enters the location’s address, selects the roof area for the array, specifies a PV module, and chooses an inverter model. You can use Google Earth to find the location and import its 3D layout into SketchUp, a free drawing program. Based on that 3D model, HelioScope will perform its shading analysis. With this method, one can do a complete site assessment and design without setting foot on the actual property. This saves considerable travel time and expense.
In addition to giving a recommended PV panel layout, HelioScope provides a detailed wiring diagram, including the exact placement of panels, inverters, and other equipment. It then produces a complete bill of materials. Grana estimates that integrating the simulation and CAD into one package reduces design time by a factor of four.
HelioScope uses the same state-of-the-art mathematical models that PVSyst uses, so they’re not reinventing the wheel with the simulation algorithms. (Want to see the models? Click here.) It uses weather files, shading analysis, physics of solar modules, wire resistance, and other factors do run its simulation. Where PVSyst estimates wire losses based on simplified models, HelioScope uses actual wire models and lengths based on the layout to calculate wire resistance, and hourly sunlight/electrical production values to determine current levels. Knowing how much current flows in each string, it can calculate I2R losses more accurately. You can select different components and run multiple simulations for the same location to compare the results and choose the best design configuration.
The “soft costs” associated with solar, including site assessment and system design, have remained steady even as hardware costs continue to plummet. HelioScope could be the tool that brings down the overall cost of designing PV systems. Will it unseat PVSyst as the industry standard?
HelioScope was developed with help from a SunShot Initiative grant.
Watch Paul Grana perform a four-minute design and simulation using HelioScope:
Video: Folsom Labs