This website provides tools to solve some common problems for rooftop solar systems. If you are planning to install a new system or if you are analyzing the performance of an existing system it is very likely that you have faced some of the following problems:

• Predicting the amount of electricity a solar system will generate in a year.
• Predicting the monthly generation of a rooftop solar system.
• Choosing the size in kW of the system for a particular location and application.
• Choosing the angle of tilt for solar panels.
• Predicting the return on investment.
• Analyzing the effect of geometry of rooftop and surrounding structures.
• Choosing the best placement of solar panels for the given rooftop geometry.
• Finding the root cause for poor performance of an existing system.
• Finding the root cause for poor return on investment of an existing system.

The Solar Generation Calculator on this website calculates the monthly and yearly generation of a solar system. Generation depends on the size of system in kW, the location, and the tilt to horizontal at which the panels are installed.

The Solar System Size Calculator calculates the size in kW for the system that will generate the required amount of electricity at a given location. This calculator also allows the user to choose the tilt for the panels.

These calculators work for almost all locations in the world. It provides the user a choice to specify either the name of the location or the coordinates in terms of latitude and longitude. Barring the extreme northern and southern latitudes, almost all locations are supported. The calculators use publicly available data from NASA along with proprietary algorithms to make the calculations.

Another useful tool is the Shadow Calculator. This tool allows the user to specify rooftop geometry along with placement of solar panels and shadow-causing objects. Given this data, the tool calculates shadows for a specified date and time span. This tool too works for almost any location in the world.