How big is Allete?

Pretty big. And growing.

The Minneapolis/St. Paul Business Journal recently put out its Top 25 Minnesota-based utilities list. The annual ranking is based on total plant investment over the years.

Allete, Inc., based in Duluth, came in No. 3, same as last year. The company had $2.5 billion in total plant investment as of Dec. 31. That’s the cumulative amount over time.

Sounds like a lot. And it is. But it pales in comparison to utility king, Minneapolis-based Xcel Energy Inc., which had total plant investments of $29.1 billion.

To get an idea how big Xcel is, it serves 3.8 million consumers in eight Western and Midwestern states. In comparison, Allete serves 171,000 consumers in Northeastern Minnesota (as Minnesota Power) and Northwestern Wisconsin (as Superior Water, Light & Power).

But Allete is the fastest growing utility, according to this report.

While every utility reported total plant growth in 2009, with the average being 6 percent, Allete led the pack with 17.1 percent growth.

No. 2, by the way, was Great River Energy based in Maple Grove, Minn. Serving southwestern Minnesota, suburban Twin Cities and parts of the Arrowhead region, the utility had 14.8 percent plant growth and nearly $3.3 billion in plant investment.