Whenever researchers plot a graph for academic, research publication or hypothesis testing, a quality graph will always result a long-lasting impression and can make a huge difference in the impact it has on the viewers.

For drawing graphs in high resolution like 300/600/more dpi image, tiff/jpg etc format picture, we have OriginPro, KaleidaGraph, Grapher etc. Besides, Paint, MS Office Word, Ms Excel, MS Visio, OpenOffice Draw, AutoCAD, LibreCAD, skelion etc are widely used for the said purposes, and for drawing schematic diagrams as well. For instance,

I) Microsoft Visio software is for drawing a variety of diagrams including flowcharts, org charts, building plans, floor plans, data flow diagrams, process flow diagrams, business process modeling, swimlane diagrams, 3D maps, and many more.

II) Skelion is a Sketchup's plugin to insert solar photovoltaics and thermal components in a surface.

But,

Some of them are freely available whereas most of them are not, rather premium based. Again, some cannot be customised. In fact, we don't have colors that we we actually need.

For my works, I'd like to be able to include wires/metals/layers with their corresponding colors, sun, battereis, loads, inverters, textured ARC layer structure etc.

I would be grateful if anyone suggest me wheter there is any good free software available online to lay out a schematic diagram, specifically 3D image for solar PV cells and devices.