Xcel cites four reasons for its request to raise Minnesota electric rates by $285 million, or 10.7 percent overall. The biggest reason is its investment in various nuclear power plant upgrades. The effects of slack demand are the second-biggest reason.Prairie Island and Monticello nuclear plants: $114 million40% share of increase
Effect of slack demand: $75 million, 26% share of increase
Electricity grid, power plant upgrades: $56 million, 20%
Higher property taxes*: $40 million, 14%
* mostly due to increased investment
Source: Xcel Energy