Investor Relations Earnings Release

Business Wire, May 1, 2008

SPS 2008 wholesale rate case - On March 31, 2008, SPS filed a wholesale power base rate case in the full-requirements customers' base rates. SPS is seeking an annual revenue increase of $14.9 million or an overall 5.14 percent increase, based on 12.20 percent requested ROE. A motion for dismissal and protest was filed by the four eastern New Mexico Cooperatives on April 21, 2008. A FERC decision is expected later in 2008.

SPS formula transmission rate case -- In December 2007, SPS submitted an application to implement a transmission formula rate for the SPS zone of the Xcel Energy Open Access Transmission Tariff. The proposed rates would be updated annually each July 1st based on SPS' prior year actual costs and loads plus the revenue requirements associated with projected current year transmission plant additions. The proposed ROE on common equity is 12.7 percent, including a 50 basis point adder for SPS' participation in the SPP RTO, consistent with FERC precedent. The proposed rates would provide first year incremental annual transmission revenue for SPS of approximately $5.5 million.

In February 2008, the FERC issued an order accepting the proposed rates, suspending the effective date to July 6, 2008, and setting the rate filing for hearings and settlement procedures. The FERC granted a 50 basis point adder to the ROE on common equity that it will determine in this proceeding, as a result of SPS' participation in the SPP regional transmission organization. In March 2008, the FERC accepted the companion SPP rate change filing subject to the outcome of the SPS rate filing. The rate filings are now in settlement procedures. The ultimate outcome of the rate filings is not known at this time.

Wisconsin electric fuel cost recovery - On April 7, 2008, we filed an application with the Public Service Commission of Wisconsin (PSCW) for an electric fuel surcharge. The forecast in the application shows NSP-Wisconsin will under-recover 2008 fuel costs by $19.7 million without a surcharge. If the surcharge is approved as filed, we estimate it would recover approximately $12.8 million through December.

Note 5. Xcel Energy Earnings Guidance

Xcel Energy's 2008 diluted earnings per share and key assumptions are detailed in the following table.

[TABLE OMITTED]

Key Assumptions for 2008:

* Normal weather patterns are experienced during the year.

* Various riders, associated with MERP, Minnesota and Colorado transmission and Minnesota renewable energy, are expected to increase revenue by approximately $55 million to $65 million over 2007 levels.

* Reasonable regulatory outcomes in the New Mexico electric rate case, North Dakota electric rate case, the PSCo and SPS FERC wholesale electric rate cases and the interim rate recovery of capacity costs in the upcoming Texas electric rate case.

* No material incremental accruals related to the SPS regulatory proceedings.

* Weather-adjusted retail electric utility sales grow by approximately 1.8 percent to 2.2 percent.

* Weather-adjusted retail firm natural gas sales grow by approximately 0.0 percent to 1.0 percent.