Electricity providers have been competing for business in Illinois for more than a decade and a half. But residents have had a choice in their electricity company for only five years and there has been serious competition only fairly recently.

But Spark Energy reports that only in the last year, when the competition between electricity suppliers really began to grow, its customers have already saved more than $2 million on electricity bills.

"Spark Energy was one of the leading choices for the more than 200,000 residential consumers who switched away from ComEd last year – and I attribute that not only on our ability to offer very competitive pricing plans, but also on our focus on delivering unbeatable customer service and being very active and relevant in the communities we serve," Phil Tonge, president of Spark Energy, said in a statement.

Part of this was the introduction of the "Empower What Matters" campaign that allows customers to direct the company's donations in the region through their electricity bills.

PlugInIllinois reports that more than 225,000 ComEd customers had chosen to switch electricity providers at the end of last year, with nearly 262,000 across all of Illinois.