Various technology and gadgets require power sources.
For simplicity, power sources are given tiers and are roughly equal to other sources in their tier.
Individual power sources also have an associated size that determines how portable they are.
Very weak power, suitable for handheld gadgets like torches.
Weak power, suitable for simple standing gadgets like lamps.
Stable power, suitable for complex standing technology like turrets.
Strong power, suitable for integrated technology like large computers.
Very strong power, suitable for a small building.
Substantial power, suitable for a large building or complex of buildings.
Immense power, suitable for a village or town.
Titanic power, suitable for a city or arcology.