Power Plants

You need electricity for your facilities. There are several different buildings that generate electricity.

Most cost-efficient growth plan
From this we can conclude that the most cost-efficient way to acquire electricity is:
 * 1) Buy 5 Wind-driven generator (You pay $12.5 for each Electrical Unit)
 * 2) Upgrade each of the Wind-driven generators to first upgrade (You pay $31.2 for each new Electrical Unit)
 * 3) Upgrade each of the Wind-driven generators to second upgrade (You pay $37.5 for each new Electrical Unit)
 * 4) Upgrade each of the Wind-driven generators to third upgrade (You pay $51.2 for each new Electrical Unit)
 * 5) Upgrade each of the Wind-driven generators to fourth upgrade (You pay $60.3 for each new Electrical Unit)
 * 6) Buy 5 Generator (You pay $62.5 for each new Electrical Unit)
 * 7) Upgrade each of the Wind-driven generators to fifth upgrade (You pay $74.5 for each new Electrical Unit)
 * 8) Buy 5 Solar Power Plant (You pay $125.0 for each new Electrical Unit)
 * 9) Upgrade each of the Generators to first upgrade (You pay $156.2 for each new Electrical Unit)
 * 10) Upgrade each of the Generators to second upgrade (You pay $194.0 for each new Electrical Unit)
 * 11) Upgrade each of the Generators to third upgrade (You pay $248.2 for each new Electrical Unit)
 * 12) Upgrade each of the Generators to fourth upgrade  (You pay $301.3 for each new Electrical Unit)
 * 13) Upgrade each of the Solar Power Plants to the first upgrade  (You pay $312.5 for each new Electrical Unit)