Smart phones and tablets have become a tool of choice for innumerable purposes. The simplest Apps contain ready construction references and the most sophisticated apps make use of onboard hardware: GPS, compass, camera, and accelerometer / inclinometer for use in site surveys. There are apps that calculate annual energy output based on local information with some even doing it in real time as the device is moved around. A number of apps perform financial calculations such as system payback time.
Usually not exceeding $30 in price, mobile apps are far less expensive than some of their branded cousins. The Solmetric App (IOS), for instance is about $900 less than the standard Solmetric hardware / software system.
Solmetric iPV, IOS ($39.99) measures shade and evaluates potential energy output of a solar PV system; all of the information you need for a site evaluation is stored on the phone including world-wide hourly weather data and a wide range of PV panels and inverters. It then produces an estimate of the monthly solar energy at a location, taking into account an approximation of the local shading.
PV Master, IOS ($11.99) The application is divided into 5 sections: Data (insolation and weather information), Guide (general information), Panel Calculator, Battery Calculator, and a Glossary.
Solar Tools, IOS ($8.99) is a solar site-assessment tool gathering information in the form of text, photos and calculations resulting in a PDF solar survey.
Solar Panel Installer, IOS ($5) by New Jersey Solar Consulting, has a step-by-step interface to collect geometry and budget data. It calculates how many panels are required to produce a certain amount of energy annually. A good-looking UI, but a pretty low user rating of only 2.5 stars.
Solmetric iSV, IOS ($4.99) Sun Viewer application uses the iPhone camera to provide an “augmented reality” view of the sun paths at a specific location. This allows a quick assessment of the timing and impact of shading obstructions.
PV Solar Calculator, IOS ($3) takes system information in terms of one parameter—either DC or AC power output, annual energy production, system cost, or surface area—and calculates the other parameters.
Solar Checker, IOS (free) by SMA, estimates a system’s annual and lifetime energy production and comes up with the rate of return on investment – this is one of the best rated free apps.
Solar Friend, IOS (free), by Bosch, calculates the total lifetime energy output for a PV system. Limited to a few Bosch modules.
Solar Panel Advisor, IOS (free) provides instantaneous power output at your location, given the time of day. It’s a handy way to see whether a solar array is working as advertised.
Solar PV Payback, IOS (free) calculates how long an array will take to pay itself off based on its size, installation cost, government rebates, and electricity rate.
What about Balance of System (BOS)?
The previous apps were all IOS (Iphone / IPad) and directly related to PV design and site survey. Searching for those apps will also lead to Apps for wire size, ampacity, conduit depth, and a multitude of electrical design apps. Let’s shift to the Android OS in order to list a couple of great BOS apps:
Electrical Pro, Android ($2), by Comoving Magnetics, a hugely useful app for estimating BOS costs. It includes: Bury depth, Fault calcs, Fill Calcs, Wire ampacity and voltage drop – all critical items in estimating system costs. The only drawback to this great app is that it must have internet access.
Elec Ref, Android ($4) by Trunnion, Inc., adds transformer sizing, wire colors, and a number of other handy items to the above list, plus it works off-line.
Many more apps are available either free or at very low cost, so it might be worthwhile to simply download a few and put them through their paces to decide how useful they are. The few that have a more substantial price tag might warrant more careful research of online reviews and features before making an investment. But even the most expensive of these apps still constitutes a small price to pay to have a variety of PV design tools in one’s pocket.
Check out the itunes store or android market for more information about the solar PV design and calculation apps.