The output of a solar system depends on which way your roof is orientated, and sizing the solar system correctly is the best way to save money and be efficient in the mean time, now we are getting into the specifics of maximizing the benefit of a solar power installation. The Solar Team will often advise people to go for a split array. Yes, having the panels facing south is best, if you are in Los Angeles however, this creates a rough bell-curve of output where you get a peak generation period during the middle of the day. Are you going to be able to use most of the solar power most of the time, 5kW system in summer, turning on as the sun comes up and turning off again at around 8 pm. As an aside, one of the most important points is the maximum output. sizing the solar system for a 5kW system almost never gets close to 5kW of output at any one time due to the angle and the orientation of the panels. This could be improved by sizing the solar system accordingly also with sun tracking, however, the cost of installing and maintaining an array that follows the sun does not pay for the increase you will get in output. It is much cheaper to just get a few extra panels. Look at google maps (or get out a compass) to see what roof sections you can install solar panels on. Anything south of west or east is usable. Panels facing east will output more power in the morning and panels facing west will output power in the afternoon. Compared to South, panels facing east or west will not output quite as much over the course of a year, however, losses are not that great, being more significant in winter when the sun is lower in the sky to the south.
Perhaps one of the most important points to consider is sizing the solar system accurately so you will know how much you pay for your power and when. If you have time of use billing, you are much better off generating solar power in the afternoon during the peak billing period. If your panels face west of south, you will push the output of your solar system into the afternoon, and during summer output will continue up until 8 pm. If we size the solar system accordingly and If you have time of use billing, That’s where you take an average of 30 cents per kWh when estimating the potential benefit to your power bill. Do you have shade? According to Renewable Energy World, shading of as little as 9% of a solar system connected to a central inverter, can lead to a system-wide decline in power output with as much as 54%. The below image is a great example of how micro inverters can significantly increase output. In this image, the system will be working at near maximum output, despite the sizing the solar system, patchy shade. With a string inverter, the system will be outputting almost no power because of the panels, I have heard a bit of talk about bypass diodes lately. It is important to state that bypass diodes are designed to help stop hot spots on panels from bird droppings and the like. They do not work in the same way as micro inverters and will not help maximize output in shaded conditions like micro inverters do. If you have patchy shade,
If sizing the solar system done in the right way and then if micro inverters or optimizers used then can significantly increase the output. the system will be working at near maximum output, despite the patchy shade. Summary We hope this information helps you cut through the sales talk. If it all gets too much, just keep it simple; solar can save you around $100 per kW per quarterly power bill and will output around 4 times its size, doing more in summer and less in winter.