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To get the most out of a self sufficient complex consider using 2 medium stations instead of a large station if it would allow the 0.5x productivity in Energy Cells demand to go to another small product producing factory. In the case of Crystal Fabs and Solar Power Plants having 3 Medium instead of 1 Large can sometimes make better use of available silicon resources. Also do not just aggregate the asteroids with the highest yields into a complex as excess mining capacity also results in a higher drain on Energy Cells which could go into other product producing factories that work closer to a balance instead. Use https://joelbfant.bitbucket.io/x3/x3apocc.html for an online complex calculator.
Worked Example
To demonstrate how to plan a simple self sustaining complex lets turn Harmony of Perpetuity into a parking lot. The sector contains 3 Silicon asteroids (18, 19 and 20 yields) and 2 Ore asteroids (16 and 18 yields) and the only hostiles are the odd Yaki or Pirates fighter or Duke's TS so it is safe to build near the Jump Gate.
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