Source Bill Mead from Unsplash
As we approach Spring and Summer, and days have longer daylight, I see our solar installation producing more and more every day and I keep looking at ways to increment production and to store energy with batteries.
Usually, when ppl go for their first installation, they check their house roof to decide how many panels they can fit in the area facing South (at least in the northern hemisphere). If the surface is not too big, they just place as many panels as they can and dimension their project according to that. Most companies do not recommend placing panels in areas of the roof facing other directions as the yield you get is not good enough. Once the number of panels is defined and their peak production calculated by adding the total of them, you decide the inverter you need to transform the DC current generated by the panels into AC for the house.
Some people decide to extra dimension the inverter in the event they want to increase the number of panels in the future but that may not be possible as there are other factors you have to consider as the empty connection streams in the inverter, the orientation of the new panels compared to the old ones and their model. Every stream of panels connected to the inverter has to be the same brand and model and keep the same inclination and orientation, so it is quite possible you may not be able to find the same model of panels in the market by the time you decide you want to increase your production nor have a chance to place them in the exact same orientation and inclination to be able to use the same inverter.
What you can do instead is set up some additional panels in a completely new installation but with microinverters which allow you to have two different flows connected to the house. We may be considering that option in the future as we have a porch in the garden that could be covered with 4 additional panels.
As I mentioned, another important aspect to consider is the orientation and inclination you place your panels. There are some nice online tools to help you check the productivity you may get when considering different locations and positions.
One interesting tool is PVGIS (PHOTOVOLTAIC GEOGRAPHICAL INFORMATION SYSTEM) site from the EU, where you place your location in the map, the azimuth angle and tilt of your panels and it gives you a simulation of the production you may get. If you play with those two variables you may see if it is worth installing your panels with an aluminum structure to get a bigger tilt.
Although is offered to European consumers, I believe you can place a location anywhere in the world. Add your city and country, select if your installation will be connected to the grid or if you will be off-grid, select your PV panel type or leave the default one, the peak of installed power, or leave just the default 1 if all you want to do is compare. Finally, play with the slope and azimuth degrees (0 is South) and hit the visualize results button.
You will get a nice report with the monthly expected production together with the simulated outputs.
