Tucson Electric Power 8-K Regulation FD Disclosure

Exhibit 99.1

UniSource Energy Corporation UBS Natural Gas, Electric Power and Coal Conference March 2011 NYSE: UNS

2 Contact Information & Safe Harbor Paul J. Bonavia, Chairman, President and CEOKevin P. Larson, SVP, CFO and TreasurerInvestor Relations Contact Information M. Jo Smith, Director Chris Norman, Lead Analyst (520) 884.3650 (520) 884.3649 josmith@uns.com cnorman@uns.com Investor Information http://ir.uns.comSafe Harbor and Non-GAAP MeasuresThis document contains forward-looking information that involves risks and uncertainties, that include, but are not limited to: state and federal regulatory and legislative decisions and actions; regional economic and market conditions which could affect customer growth and energy usage; weather variations affecting energy usage; the cost of debt and equity capital and access to capital markets; the performance of the stock market and changing interest rate environment, which affect the value of the company's pension and other postretirement benefit plan assets and the related contribution requirements and expense; unexpected increases in O&M expense; resolution of pending litigation matters; changes in accounting standards; changes in critical accounting estimates; the ongoing restructuring of the electric industry; changes to long-term contracts; the cost of fuel and power supplies; performance of TEP's generating plants; and other factors listed in UniSource Energy's Form 10-K and 10-Q filings with the Securities and Exchange Commission. The preceding factors may cause future results to differ materially from historical results or from outcomes currently expected by UniSource Energy.The Company's press releases and other communications may include certain non-Generally Accepted Accounting Principles (GAAP) financial measures. A "non-GAAP financial measure" is defined as a numerical measure of a company's financial performance, financial position or cash flows that excludes (or includes) amounts that are included in (or excluded from) the most directly comparable measure calculated and presented in accordance with GAAP in the Company's financial statements. Non-GAAP financial measures utilized by the Company include presentations of revenues, operating expenses, operating income and earnings (loss) per share. The Company uses these non-GAAP measures to evaluate the operations of the Company. Certain non-GAAP financial measures utilized by the Company exclude: the impact of non-recurring items: the effect of accounting changes or adjustments; expenses that are reimbursed by third parties; and other items. The Company's management believes that these non-GAAP financial measures provide useful information to investors by removing the effect of variances in GAAP reported results of operations that are not indicative of fundamental changes in the earnings or cash flow capacity of the Company's operations. Management also believes that the presentation of the non-GAAP financial measures is largely consistent with its past practice, as well as industry practice in general, and will enable investors and analysts to compare current non-GAAP measures with non-GAAP measures with respect to prior periods.

2010 Financial Overview 3

2010 Highlights Reported diluted earnings per share of $2.82 vs. $2.69 in 2009Excluding Millennium, diluted EPS of $3.15 vs. $2.63 in 2009TEP's total retail kWh sales were 0.8% below 2009Weather, economy and energy efficiency negatively impacted retail sales volumesMining kWh sales increased by 1.4% as miners increased production in response to strong copper pricesUNS consolidated Base O&M of $265 million was 2.6% below 2009Lower generating plant maintenance and pension and postretirement medical expenseCapital markets supportive of refinancing effortsRefinanced over $750 million of credit facilitiesIssued $137 million of new debt at TEP; $37 million of which replaced higher coupon bondsRate increases at UNS Gas and UNS Electric2% base rate increase at UNS Gas effective April 20104% base rate increase at UNS Electric effective October 2010; ACC approved purchase of BMGSACC adopted decoupling policyUtilities can propose decoupling mechanisms in next general rate case TEP completed purchase of Sundt Unit 4TEP added 3.4 MW of company - owned solar facilities 4 (CHART)

2011- 2013 Financial Outlook ACC approval in mid-2011 of interim decoupling mechanismTEP's request included lost revenue recovery from incremental energy efficiency savings of up to $4 million in 2011 and $14 million in 2012 Potential increase in TEP's mining loadUp to 100 MW in the next 3-5 years from expansion of existing mining operations and re-opening of dormant mines At full production, 100 MW from the proposed new Rosemont Copper mineContinued O&M cost containmentUNS Gas case filed in 2011 with new rates effective in mid-2012Return on TEP and UNS Electric investments in solar projectsTEP rate case filed June 30, 2012 with new rates effective in mid-2013 2011 Factors 2011 - 2013 Opportunities 5 Pre-Tax ($ mil)UNS Consolidated Higher Base O&M $ (7) TEPHigher retail sales of 0.5% $ 3 Lower long-term wholesale margin $ (9) Higher depreciation expense $ (10)Higher interest expense* $ (7)Lower capital lease expense** $ 3* Interest expense on long and short-term debt**Includes capital lease interest (net of interest income) and amortization

2011 Key Earnings Sensitivities 6 6 (CHART) (CHART) 2011 Earnings Guidance: $2.60 - $2.90 per Diluted Share

Company Overview 7

Regulated Electric and Gas Utility Businesses UNS' Largest Subsidiary~ 77% of Operating Revenues~ 81% of Total AssetsVertically Integrated Electric Utility~ 403,000 Electric Customers Gas & Electric T&D Businesses~ 146,500 Gas Customers~ 91,000 Electric Customers 8

Utility Service Areas Valencia Tucson San Juan Four Corners Luna Phoenix Flagstaff Prescott NEVADA UTAH COLORADO CALIFORNIA NEW MEXICO Navajo Springerville Black Mountain MEXICO Sundt Generating StationSolar Station Service Areas TEP UNS Gas UNS Gas & ElectricUNS Electric 9

Compelling Long-Term Value Proposition Compelling Long-Term Value Proposition 10

Attractive Dividend Yield & Growth Potential In February 2011, the Board increased the dividend by 7.7% to an annual indicative level of $1.68Reiterated intent to reach a 60% payout level Signals confidence in UNS' continued strong operating performance and solid cash flows from operationsPayout is calculated using net income or basic earnings per share; not diluted earnings per share *Indicated annual dividend (CHART) Notes: UNS estimated payout based on 2011 indicated annual dividend and the net income associated with the mid-point of earnings guidance.Industry average taken from EEI Q4 Financial Update (CHART) (CHART) 16% Avg. Annual Growth Rate 11

UNS Consolidated - Cash Flows & Capital Expenditures Strong operating cash flows provides flexibilityOn average, operating cash flows fund capital expendituresAnnual dividend increases since 2000Bonus depreciation expected to increase cash flowsManageable level of capital expendituresEnvironmental upgrades to generating plants and expansion of transmission capability into Palo Verde hub driving higher capital expenditures in 2011-2014Rate base growth without regulatory lagPurchased Sundt Unit 4 in 2010 for $52 million$14 million invested in solar PV projects in 2010 with cost recovery through the renewable energy surcharge (RES) beginning in January 2011Anticipate investments in solar projects of $33 million per year in 2011 - 2014, with cost recovery through the RES surcharge Note: Capital expenditure estimates are from the 2010 Form 10-K 12 (CHART)

TEP - Diverse Retail Customer Base TEP - Diverse Retail Customer Base TEP - Diverse Retail Customer Base 2010 Retail kWh Sales Mix University of Arizona Davis Monthan Air Force Base Freeport McMoRan (CHART) Customer Sector Freeport McMoRan Copper Mining Asarco Copper Mining University of Arizona Education Fort Huachuca, US Army Intelligence Center Military Raytheon Defense IBM Technology Davis Monthan Air Force Base Military Arizona Portland Cement Construction Liquid Air Manufacturing Largest Retail Customers 13 2010 Retail Margin RevenuesTotal = $551MM (CHART)

TEP - Retail Customers Customer base continues to grow at a modest paceLong-term outlook positive with a customer growth rate of more than 1.5% by 2014Expect local economy to gradually improvePositive indicators in home sales and inventoriesEconomists at the University of Arizona consider the recession over in Arizona and expect growth to gradually resumeTucson unemployment rate 8.3% (as of Dec. 2010) vs. national average of 9.0% (as of Jan. 2011) Rate of Growth in Retail Customer Base 14 (CHART) (CHART) Weak economic conditions impacted salesRecession resulted in year-over-year sales declines since 2008In 2010, sales to mining customers increased 1.4% Modest growth expected to return in 2011Anticipate increase in sales to mining and commercial customers in 2011Retail sales in 2012 and 2013 expected to increase 1.5% - 2.5%

Long-Term Economic Outlook Remains Strong *According to University of Arizona Economic and Business Research Center as of Dec. 2010 (CHART) 15 (CHART)

TEP - Energy Resources Provide Optionality 2010 Resource Mix - GWh Generating Capacity - 2,245 MW Owned Coal - 1,061 MW(incl. 14% of Springerville Unit 1) Luna Combined Cycle Gas Turbine Purchased Power Simple Cycle Gas Units Gas CCCT190 MW - 9% Coal/Gas156 MW - 7% Simple Cycle Gas496 MW - 22% Solar6 MW - 0.3% Leased Coal - 86% of 387 MW Springerville Unit 1 Coal / Gas - Sundt Unit 4 Leased Coal334 MW - 15% 334 MW - 15% 334 MW - 15% Solar (CHART) Owned Coal1,061 MW - 47% Leased and duel fuel plants provide optionalitySpringerville Unit 1 lease (expires Jan. 2015) has fair market value purchase and lease renewal optionsNo near-term new base load generation requirementsSubstation and transmission line additions are expanding access to the Palo Verde hubCurrent resources and access to Palo Verde hub are adequate to serve potential increase in mining load in the next 3 to 5 yearsLimited commodity price exposure for retail fuel & purchased power costsLong-term coal contracts provide price and supply stability PPFAC allows for full recovery PPFAC allows for full recoveryProtection against carbon-related costsCarbon costs are a fuel-related cost and can be recovered through the PPFAC2008 Rate Order allows base rate & adjustor mechanism change in emergency conditions, subject to ACC approval 16

Strong Coal Plant Operating Performance Average Equivalent Availability Factor Baghouse- Low NOx Environmental Equipment Operator TEP's Share (MW) Coal Delivery In Service Dates TEP's Share (%) TEP 156 MW rail 1967 100% TEP 770 MW rail Unit 1 - 1985 Unit 2 - 1990 100% Arizona Public Service 110 MW mine mouth Unit 4 - 1969 Unit 5 - 1970 7% Salt River Project 168 MW mine mouth Unit 1 - 1974 Unit 2 - 1975 Unit 3 - 1976 7.5% Public Serviceof New Mexico 322 MW mine mouth Unit 1 - 1976 Unit 2 - 1973 50% Coal Supplier Contract Term Peabody 2020 BHP Billiton 2016 Peabody 2011 San Juan Coal 2017 Rio TintoChevron Mining 2009 Annual Expected Coal Usage 350 k tons 3.2 mil. tons 400k tons 500k tons 1.3 mil. tons BaghouseScrubbersLow NOx BaghouseScrubbers- PrecipitatorsScrubbers- BaghouseScrubbersLowNOxMercury removal Sundt Unit 4 coal/gas Navajo Units 1,2&3 coal Industry Avg. coal Four Corners Units 4&5 coal San Juan Units 1&2 coal Springerville Units 1&2 coal (CHART) 93% 87% 87% 83% 05 06 07 08 09 91.9% (CHART) 89.2% (CHART) 82.1% (CHART) 86.1% (CHART) 81.1% (CHART) 85.0% 06 07 08 09 10 17 06 07 08 09 10 06 07 08 09 10 06 07 08 09 10 06 07 08 09 10

UniSource Energy Services UNS GasT&D retail gas business146,500 retail customers2010 retail sales - 112 million therms$240 million net plant in-service at 12/31/10Rate Case Activity Base rate increase of $3.5 million effective April 2010Original cost rate base of $180 million @ 6/30/08Expect to file new rate case in 2011UNS ElectricT&D retail electric businessMore than 90,000 retail customers2010 retail sales - 1,857 GWh$220 million net plant in-service at 12/31/10Rate Case Activity Base rate increase of $7.4 million effective October 2010 (UNS Electric requested increase of $13.5 million)Original cost rate base of $169 million at 12/31/08Approved acquisition of Black Mountain Generating Station Approved investments of $5 million annually in company- owned solar projects from 2011-2014 UES Net Income($ millions) Estimated Capital Expenditures($ millions) 18 (CHART) (CHART)

Renewable Energy Leadership Arizona Renewable Energy Standard and Tariff RES requires 15% of all retail energy needs from renewable resources by 2025Customer surcharge funds above market cost renewable energyProposals to invest $146 million in solar photovoltaic projects over next 5 yearsTEPACC approved 2011 investment of up to $28 million for ~ 7 MWCost recovery, including ROI through RES surchargeUNS ElectricACC approved annual investments of up to $5 million for ~1.25 MW from 2011-2014Purchase Options Included in Solar PPAs136 MW of TEP's solar Power Purchase Agreements (PPA) include purchase options that can be exercised after the 5th year(CHART) (CHART) 19

TEP & UNSE Renewable Contracts and Projects PPAs 20 Owned / In Development Resource/ Counterparty Resource/ Counterparty Technology Location Operator Completion Date Term (Years) Purchase Option Capacity MW Solar Solar Amonix Concentrating PV Tucson, AZ Amonix 2011 20 On or after yr. 6 at FMV 2 Swan Solar Concentrating PV Tucson, AZ Amonix 2011 20 12 NRG Solar Fixed PV Tucson, AZ NRG Solar 2011 20 25 First Light Fixed PV Tucson, AZ CTC 2011 20 5 Emcore Solar Concentrating PV Tucson, AZ Emcore 2011 20 2 Solon SAT PV Kingman, AZ Solon 2011 20 5 Solon SAT PV Santa Cruz County Solon 2012 20 5 FRV Tucson Solar SAT PV Tucson, AZ Renewable Ventures 2012 20 25 FSP Solar One SAT PV Tucson, AZ Foresight Solar 2012 20 4 FSP Solar Two SAT PV Tucson, AZ Foresight Solar 2012 20 12 Avalon Solar Fixed PV Marana, AZ Avalon 2012 20 35 Renewable Fuel Solar Thermal Tucson, AZ Bell IPC 2013 20 5.5 Wind Wind Western Wind Energy US Corp Wind Kingman, AZ Western Wind 2011 20 None 11 Macho Springs Wind Deming, NM Element Power 2011 20 None 50 Landfill Gas Landfill Gas Sexton Energy Landfill Gas Tucson, AZ Sexton Energy 2013 15 None 2.2 Total 198.5 Fuel/ Plant Fuel/ Plant Technology Status Completion Date Net Capacity MW Solar Solar Springerville Solar Station Fixed PV Complete 2002 4.6 Springerville Solar Expansion Fixed PV Complete 2010 1.8 Univ. of Arizona Tech Park SAT PV Complete 2010 1.6 Tucson Airport Project SAT PV In progress 2011 5 TBD SAT PV Scheduled 2012 5 Total 18

TEP - Long-Term Wholesale Sales Margin on long-term wholesale sales benefits shareholdersGross margin on total long-term wholesale sales was $28 million in 2010Expect gross margin on 2011 long-term wholesale sales of $19 millionSalt River Project (SRP) 100MW TEP receives monthly demand charge of $1.8 million ($22 million annually) and provides energy at TEP's average fuel costContract modifications effective June 1, 2011No demand charge; energy charge based on slight discount to Palo Verde IndexSRP monthly purchase requirement of 73,000 MWhs (876,000 MWhs annually)Contract expires May 2016Navajo Tribal Utility Authority (NTUA)No demand charge; energy priced in mid - $50 per MWh rangeNo minimum purchase requirementContract modifications effective 2010Energy charge for 50% of sales (June-Sept) based on Palo Verde Index (~30 GWhs)Contract expires December 2015Long-Term Contracts Regulated by FERCApproximately $63 million of generation assets excluded from ACC rate base in TEP rate case (12/31/06 test year) 21 (CHART) (CHART)

Regulatory Overview 22

Regulatory Framework Arizona Corporation CommissionConstitutionally created branch of Arizona governmentFive commissioners elected state-wideLimited to serve two consecutive four year terms Commissioner Term Expires Gary Pierce (R)(Chairman) Jan. 2015* Brenda Burns (R) Jan. 2015 Bob Stump (R) Jan. 2013 Sandra Kennedy (D) Jan. 2013 Paul Newman (D) Jan. 2013 Federal Energy Regulatory Commission Transmission rates Long-term wholesale transactions 23 * Unable to run for re-election - two term limit

Good Regulatory Foundation 24

Energy Efficiency Standards and Decoupling ACC approved Electric and Gas Energy Efficiency Standards in 2010Designed to require TEP, UNS Electric, UNS Gas and other affected utilities to implement cost effective demand side management programsElectric EE Standards target total retail kWh savings in 2011 of 1.25% of 2010 salesTargeted kWh savings increase annually in subsequent years until they reach a cumulative annual reduction in retail kWh sales of 22% by 2020Gas EE Standards target total retail therm savings in 2011 of 0.5% of 2010 salesTargeted savings increase annually in subsequent year until they reach a cumulative annual reduction in retail therm sales of 6% b 2020ACC Decoupling Policy Adopted in December 2010Designed to encourage energy conservation by restructuring utility rates to separate the recovery of fixed costs from the level of energy consumedPolicy indicates that revenue per customer decoupling may be well suited for Arizona as it responds to customer growthUtilities can propose decoupling mechanism in next general rate case applicationTEP requested interim decoupling mechanism that would allow recovery of lost revenues resulting from the implementation of energy efficiency measuresRequested recovery of up to $4 million in 2011 and $14 million in 2012 25

2008 TEP Rate Order Key Provisions Methodology Cost-of-service Test year 12/31/2006 Rate base $1.02 billion 2006 Retail Sales (GWh) 9,320 Allowed ROE 10.25% Capital Structure 42.5% equity / 57.5% debt (Actual capital structure was 40% equity, excluding capital leases, and 60% debt) Non-fuel base rate increase 6% (approx. $47 million). Effective Dec. 1, 2008. Purchased Power and Fuel Adjustment Clause (PPFAC) Effective Jan. 1, 2009Forward lookingEnergy, capacity and transmission Springerville Unit 1 - 387 MW coal-fired plant leased by TEP. Lease expires Jan. 1, 2015. Non-fuel recovery of $25.67 per kW per month or approx. $117 millionApproximates levelized cost through the remainder of the term of the lease Average base retail rate 8.9 cents / kWh (base non-fuel rate of 6.0 cents) Rate case moratorium Cannot file new case before 6/30/2012 with a test year no earlier than 12/31/11 26

2008 TEP Rate Order - Rate Base $1.02 billion ACC jurisdictional rate base as of 12/31/2006Excludes FERC-regulated assetsHigh voltage transmission assets of $205 millionGeneration assets dedicated to long- term wholesale sales of approximately $63 millionExcludes adjustments of $134 million for deferred income taxes, working capital and other items and other items and other items and other items and other items and other items and other items and other items and other items and other items and other items and other items 27 Note: Capital expenditure estimates from 2010 10-K(CHART) $1.4B - $1.5B

TEP Rate Case & Springerville Unit 1 Timeline 2008 2009 2010 2011 2012 2013 2014 2015 12/1/2008Effective date of 2008 TEP Rate Order 12/31/2011Earliest test year 6/30/2012Earliest filing date 1/1/2013Earliest effective date of rate case 1/1/2015Expiration of Springerville Unit 1 Lease 28 9/1/2013Notify lessor of intent to purchase or renew Springerville Unit 1 Lease

2008 TEP Rate Order - Key Provisions 29 ACC Decision No. 70628II. Rate increase2.2 TEP's rates, including generation, will be determined using a cost-of-service methodology. ...TEP shall withdraw its proposed market and hybrid rate methodologies. Original cost rate base: $1.02B (net of $134M of adjustments, including deferred income taxes of $119M)Average base rate increase of 6% (avg. base retail rate of 8.9 cents/kWh)Includes base cost of fuel & purchased power of 2.8896 cents/kWhRevenue increase of $47.1MIII. Ratemaking treatment of generation assets 3.1 For ratemaking purposes, SGS Unit 1 and Luna shall be included in TEP's rate base at their respective original costs. All other generation assets acquired by TEP after December 31, 2006, but before December 31, 2012, shall be included in TEP's rate base at their respective original costs, subject to the Commission's subsequent regulatory and ratemaking review and approval. 3.2 Recovery of SGS Unit 1 non-fuel costs shall reflect a cost of $25.67 per KW per month which approximates the levelized cost of SGS Unit 1 through the remainder of the primary lease term for this generating facility. In addition, SGS Unit 1 leasehold improvements shall be included in TEP's original cost rate base at net book value as of December 31, 2006.3.3 Luna shall be included in TEP's original cost rate base at net book value as of December 31, 2006. 29

2008 TEP Rate Order - Key Provisions 30 X. Rate case moratorium10.1 TEP's base rates shall remain frozen through December 31, 2012.10.2 TEP shall not submit a rate application sooner than June 30, 2012. ...test year ending no earlier than December 31, 2011.10.2 Signatories agree to use their best efforts to have post-moratorium rates in place no later than thirteen months after TEP's rate application is filed with the Commission.XI. Emergency Clause11.1 ...TEP shall not be prevented from requesting a change to its base rates, or necessary changes to the PPFAC mechanism, the DSM or REST, that would take effect prior to January 1, 2013, in the event of conditions or circumstances that constitute an emergency. ...emergency is limited to an extraordinary event that is beyond TEP's control and that, in the Commission's judgment, requires rate relief in order to protect the public interest. This provision is not intended to preclude TEP from seeing rate relief pursuant to this paragraph in the event of the imposition of a federal carbon tax or related federal cap and trade system. 30

Supplemental Information 31

TEP Generation Portfolio Fuel/ Plant Fuel/ Plant Unit No. Location Date In Service Operator TEP's Share % TEP Share Net Capacity MW Coal Coal Springerville Station 1 Springerville, AZ 1985 TEP 100 387 Springerville Station 2 Springerville, AZ 1990 TEP 100 390 San Juan Station 1 Farmington, NM 1976 PNM 50 170 San Juan Station 2 Farmington, NM 1973 PNM 50 170 Navajo Station 1 Page, AZ 1974 SRP 7.5 56 Navajo Station 2 Page, AZ 1975 SRP 7.5 56 Navajo Station 3 Page, AZ 1976 SRP 7.5 56 Four Corners Station 4 Farmington, NM 1969 APS 7 55 Four Corners Station 5 Farmington, NM 1970 APS 7 55 Gas Gas Luna Energy Facility 1 Deming, NM 2006 PNM 33.3 190 North Loop Tucson, AZ 2001 TEP 100 95 Gas/Oil Gas/Oil Sundt Station 1 Tucson, AZ 1958 TEP 100 81 Sundt Station 2 Tucson, AZ 1960 TEP 100 81 Sundt Station 3 Tucson, AZ 1962 TEP 100 104 DeMoss Petrie Tucson, AZ 1972 TEP 100 85 Sundt ITCs Tucson, AZ 1972-1973 TEP 100 50 Coal/Gas Coal/Gas Sundt Station 4 Tucson, AZ 1967 TEP 100 156 Solar Solar Springerville Solar Station Springerville Solar Station Springerville, AZ 2001 TEP 100 6 Community Solar Projects Community Solar Projects Tucson, AZ 2011 TEP 100 2 Total 2,245 32

Credit Ratings Sufficient lines of creditTEP - $200 million; UES - $100 million; UNS - $125 million; mature in Nov. 2014Credit ratingsTEP received one notch upgrade from Fitch in Sept. 2010 TEP Fitch Secured BBB Unsecured BBB- Issuer BB+ Outlook S&P BBB+ BBB- BB+ Stable Moody's Baa1 Baa3 Baa3 Stable Stable UniSource Energy Moody's Ba1 Stable Secured Credit Facility Outlook UNS Electric Moody's Baa3 Stable Sr. Unsecured Notes(guaranteed) Outlook UNS Gas Moody's Baa3 Stable Sr. Unsecured Notes(guaranteed) Outlook 33

Long-Term Debt Summary Balances as of 12/31/10Rates as of 2/15/11 Interest Curr. Balance Issue Maturity Current Facilities Debt Issue Rate (in millions) Date Date Call Price Security Financed TEP Unsec. Ind. Dev. Bonds 2009 Pima A 4.950% 80 Oct-09 Oct-20 N/C Unsecured San Juan PC 2010 Coconino A 0.33% 37 Dec-10 Oct-32 100% Navajo PC 2009 Coconino A 5.125% 15 Oct-09 Oct-32 N/C 10 Navajo PC 1997 Pima A 6.100% 22 Sep-97 Sep-25 100% Local T&D 1998 Apache A 5.850% 84 Mar-98 Mar-28 100% SGS 1 PC 1998 Apache B 5.875% 100 Mar-98 Mar-33 100% SGS 2 PC 1998 Apache C 5.850% 16 Mar-98 Mar-26 100% Local T&D Subtotal $ 638 Var. Rate Tax-Exempt Bonds 1982 Pima A - Irvington 0.27% 39 Oct-82 Oct-22 100% Local T&D / Irvington 1982 Pima A 0.27% 40 Dec-82 Dec-22 100% Local T&D / 4 Corners PC 1983 Apache A 0.27% 100 Dec-83 Dec-18 100% SGS 2 1983 Apache B (Tranche A) 0.27% 80 Dec-83 Dec-18 100% SGS 2 1983 Apache C (Tranche A) 0.25% 50 Dec-83 Dec-18 100% SGS 2 1985 Apache A 0.25% 20 Dec-85 Dec-20 100% SGS 2 Subtotal $ 366 TEP TOTAL $ 1,004 2008 Pima A 6.375% 91 Mar-08 Sep-29 N/C 5 Local T&D UES UNS Gas Unsecured Notes 6.230% 50 Aug-03 Aug-11 MW + 50 Unsecured General Purpose UNS Gas Unsecured Notes 6.230% 50 Aug-03 Aug-15 MW + 50 General Purpose UNS Electric Unsecured Notes 6.500% 50 Aug-08 Aug-15 MW + 50 General Purpose UES TOTAL $ 200 UniSource Stand-Alone Sr. Unsec. Convertible Notes 4.500% 150 Mar-05 Mar-35 Par Unsecured General Purpose Revolving Credit Facility LIBOR + 3.00% 27 Nov-10 Nov-14 Par Unsecured General Purpose UNISOURCE STAND-ALONE TOTAL $ 177 UNISOURCE CONSOLIDATED TOTAL $1,410 2008 Pima B 5.750% 130 Jun-08 Sep-29 N/C 5 Local T&D UNS Electric Unsecured Notes 7.100% 50 Aug-08 Aug-23 MW + 50 General Purpose var. rate Secured UED Term Loan LIBOR + 3% 29 Feb-10 Mar-12 Par Black Mountain Mortgage Bonds 34 2010 Pima A (Tax-Exempt) 5.250% $ 100 Oct-10 Oct-40 N/C 10 Local T&D