Complex sentence: This may cause a problem where it's cheaper to buy electricity than to burn fuel, therefore many engines are used in CHP (Combined Heat and Power) configurations that can be small enough to be integrated into portable container configurations.
Split into simpler sentences: This may cause a problem in which it is cheaper to buy electricity than to burn fuel. Therefore many engines are used in CHP (Combined Heat and Power) configurations that can be small enough to be integrated into portable container configurations.