2011 Transmission Customer Meeting October 12, 2011

 Agenda ◦ Minnesota Power and MISO Rates Structure ◦ 2010 True Up ◦ 2012 Rates ◦ Supporting Documentation ◦ Questions

◦ ALLETE Attachment O to the MISO Tariff  Develops rates for the AC system  Schedule 7 Firm Point to Point Transactions  Schedule 8 Non Firm Point to Point Transactions  Schedule 9 Network Transmission Service  Develops rates for the HVDC system  Schedule 7 Firm Point to Point Transactions  Schedule 8 Non Firm Point to Point Transactions  Schedule 9 Network Transmission Service

◦ ALLETE Attachment GG to the MISO Tariff  Develops rates for the AC system  Schedule 26 Network Upgrade Charge  Develops rates for the HVDC system  Schedule 26Network Upgrade Charge

◦ Minnesota Power is required to perform a true up of the 2010 forecasted rates to actual cost during ◦ This true up has been completed based on the 2010 FERC Form 1. ◦ Any adjustments as a result of the true up will be included as part of the 2012 forward looking test year. These adjustments will also include an interest calculation.

MISO Attachment O True Up Calculation Annual Transmission Revenue Requirement True Up AC System DC System Historic Year Actual RR $ 29,913,575$ 15,754,008 Historic Year Projected RR$ 32,028,415$ 15,985,088 Historic Year True Up$ (2,114,840)$ (231,080) Divisor True Up (KW Peak) Historic Year Actual Divisor 1,488, ,000 Historic Year Projected Divisor 1,445, ,000 Difference in Divisor 42,900 0 Historic Year Projected Annual Rate ($/kw/yr) $ $ Divisor True Up (Rate * Difference) $ 950,549 Summary Revenue Requirement True Up$ (2,114,840) $ (231,080) Divisor True Up$ 950,549 $ 0 Total 2010 True Up Before Interest$ (1,164,291) $ (231,080) Interest Calculation $ ( 75,679) $ (15,020) Minnesota Power Average Prime Interest Rate Interest for 24 Months (Jan-10 to Dec-11) 3.25% 3.25% Total True Up $(1,239,970) $ (246,100)

MISO Attachment GG True Up Calculation Annual Attachment GG Revenue Requirement True Up AC System DC System Historic Year Actual RR for GG $ 4,770,799 $ 0 Historic Year Projected RR for GG $ 3,801,425 $ 0 Historic Year True Up $ 969,354 $ 0 Interest Calculation $ 9,965 $ 0 Minnesota Power Short Term Interest Rate Interest for 24 Months (Jan-10 to Dec-11).514% Total True Up $ 979,319 $ 0

AC System DC System Gross Plant in Service (13 month avg.) $291,453,512$127,421,467 CWIP (13 month avg.) $ 33,078,662 Rate Base $ 168,002,502$ 60,274,065 Attachment GG Credits( $ 16, ) Net Revenue Requirements $ 38,753,394$ 16,329,538 (Before True Up Credits) True Up Credits ($,1,239,970) ( $ 231,080) Net Revenue Req. $ 37,513,424 $ 16,098, Projected Peak (MW) 1, Annual 2012MISO Transmission Rate $24,677 $32,197 ( Net RR / Peak = $/MW Yr)

AC System DC System Annual Rates $24,677 $32,197 Monthly Rates (Annual rates / 12) Schedule 7 (Firm) $2,056 $2,683 Schedule 8 (Non Firm) $2,056 $730* Schedule 9 (Network) $2,056 N/A * HVDC Non Firm Transactions are charged $ 1 per MW/Hr due to non firm losses being incremental

Comparison of Monthly Rates 2011 compared to AC System $2,223 $2,056 DC System $2,482 $2,683

◦ AC Load up from DC Load steady ◦ AC Plant Balances up due to completion of the Phase 1 of the Essar Steel Project, the St. Cloud to Monticello CAPX Line and the Boswell to Bemidji CAPX Line. ◦ CWIP Balances are up to reflect the continuation of the St. Cloud to Fargo CAPX project ◦ AC Revenue Requirements have been offset by $16,192,567 in Attachment GG Credits

Schedule 26 Network Upgrade Charge Until MISO publishes 2012 allocations from all MISO TO’s a complete rate can not be projected. The 2012 allocations will be posted by MISO in December Minnesota Power will be collecting revenue requirements for the following projects through Schedule 26 in KV Badoura Area Upgrades In Service $ 5,930,346 (Includes 2010 True Up Amount) 230 kV Boswell to Bemidji CAPX Project In Service Sept 2012 $ 2,231, kV St Cloud to Monticello CAPX Project In Service Dec 2011$ 2,770, kV St Could to Fargo CAPX ProjectCWIP$ 4,503, kV 9 Line Upgrade In Service Dec 2012$ 1,736,007

◦ A revised Attachment O and GG were posted to the MP page of the MISO OASIS earlier this week ◦ A complete set of working papers can also be found at the same location ◦

 Questions

Contacts: Mike Donahue (218) Jeanne Kallberg (218) Kara Henderson (218)