A power generation industry is evolving very fast nowadays. A lot of modern technologies have become available recently for a product development process. Also new types of fuels have appeared on the market. All these factors have caused significant changes in a power generation approach. New products enabling more environment-friendly technologies have been introduced by many key-players on the market. This paper describes briefly needs and directions of gas engines development in modern power generation industry. It also presents shortly history of Wärtsilä gas engines together with present gas engine portfolio covering products like: spark ignited gas engine, conventional dual-fuel one and a dual-fuel engine equipped with high-pressure direct gas injection system. The paper focuses on the most important aspects of the recent Wärtsilä gas engines development process explaining also achieved benefits. It covers main features and new fuels introduced during development of specific engine which are key factors for customers willing to use the most modern technology in this field.