The Gas Power Plant is an Investor-Tier building. It is fueled by consuming Gas delivered from a Warehouse at a rate of 1,33 per minute, which allows the building to produce Electricity. This equals to 6 gas wells at 100% per power plant. This electricity will spread out from the Gas Power Plant at a maximum of 59 tiles across paved roads. Powerline masts will line the streets where it does.
It's worth pointing out that while the Gas Power Plant might look the same as its Oil counterpart, it is slightly larger and has a larger range of effect (10 tiles more than the Oil Power Plant). Its range can be extended up to 134 tiles by taking advantage of the Palace or Local Department of Welfare bonus at maximum prestige level (+60 tiles of range from Passive Effect and +15 tiles from Welfare Policy).
Gas Power Plant doesn't have specific Trade Union items and doesn't seem to be affected by items for all Production Buildings. However, while being placed in the range of a Trade Union its borders will light up.
The electricity produced by the Gas Power Plant is used in two ways. Electricity is a basic need for Engineers and Investors. When in range of the Gas Power Plant's influence, their residences will gain +2 Engineers/+8 Investors per house.
Production buildings gain an additional +100% productivity when in range of the Gas Power Plant and will upgrade their cargo transports from horse-drawn carriage to early model trucks. Some buildings even require electricity. These are: