Origin Energy Not for Distribution or release in the United States of ...

Sydney15 December 2010Origin EnergyAcquisition of Integral EnergyRetail, Country Energy Retail andEraring GenTrader arrangementsNot forDistribution orrelease in theUnited States ofAmerica or to anyUnited Statesperson

2Important NoticeThis presentation has been prepared by Origin Energy Limited (ABN 30 000 051 696) (Origin) in relation to the acquisition of retail assets and liabilities ofCountry Energy and Integral Energy Australia and the entry into of GenTrader arrangements with Eraring Energy. This has been done pursuant to variouscontracts entered into with the State of New South Wales and a number of State-owned corporations on 14 December 2010. The transactions arescheduled to complete on 1 March 2011.This presentation includes references to a possible pro rata equity offering to subscribe for new ordinary shares in Origin to be made to shareholders inOrigin. This presentation is not a prospectus, disclosure document or offering document under any law. If any such pro rata equity offering is conducted ina manner for which a disclosure document is required under the Corporations Act 2001, then a disclosure document will be made available following itslodgement with ASIC. Any investor interested in participating in any such offer should read and consider the disclosure document in deciding whether todo so and will only be able to participate in the offer in accordance with an application form provided in, or accompanying, any such disclosure document.Not for distribution or release in the United States of America or to or for the account of US persons. This presentation does not constitute an offer,invitation or recommendation to subscribe for or purchase any shares and neither this presentation nor anything contained in it will form the basis of anycontract or commitment. In particular, this presentation does not constitute an offer to sell, or a solicitation of an offer to buy, shares in the UnitedStates or to, or for the account or benefit of, any "US person" (as defined in Regulation S under the Securities Act 1933). Securities may not be offered orsold in the United States absent registration under the Securities Act or an exemption from registration. This document may not be distributed or releasedin the United States or to or for the account of any US Person.This presentation does not constitute investment advice (nor financial product, tax, accounting or legal advice), or an inducement or recommendation toacquire or dispose of any securities in Origin, in any jurisdiction (including the USA). This presentation does not take into account the investmentobjectives, financial situation or particular needs of any investor, potential investor or any other person. No investment decision should be made inreliance on this presentation. Independent financial and taxation advice should be sought before making any investment decision.No representation or warranty, express or implied, is or will be made in relation to the accuracy, reliability or completeness of the information in thispresentation and no responsibility or liability is or will be accepted by Origin or any of its respective subsidiaries, affiliates and associated companies (orany of their respective directors, officers, employees or agents) (the "Relevant Persons") in relation to it. In particular, Origin and the Relevant Persons donot endorse, and are not responsible for, the accuracy, reliability or completeness of any information in this presentation relating to or provided by a thirdparty, including Country Energy, Integral Energy Australia and Eraring Energy.Certain statements in this presentation are in the nature of forward looking statements, including statements of current intention, statements of opinionand predictions as to possible future events. Such statements are not statements of fact and there can be no certainty of outcome in relation to thematters to which the statements relate. These forward looking statements involve known and unknown risks, uncertainties, assumptions and otherimportant factors that could cause the actual outcomes to be materially different from the events or results expressed or implied by such statements.Those risks, uncertainties, assumptions and other important factors are not all within the control of Origin and cannot be predicted by Origin and includechanges in circumstances or events that may cause objectives to change as well as risks, circumstances and events specific to the industry, countries andmarkets in which Origin and its related bodies corporate, joint ventures and associated undertakings operate. They also include general economicconditions, exchange rates, interest rates, the regulatory environment, competitive pressures, selling price, market demand and conditions in thefinancial markets which may cause objectives to change or may cause outcomes not to be realised.None of the Relevant Persons makes any representation, assurance or guarantee as to the accuracy or likelihood of fulfilment of any forward lookingstatement or any outcomes expressed or implied in any forward looking statements. In addition, statements about past performance are not necessarilyindicative of future performance. The forward looking statements in this presentation reflect views held only at the date of this presentation. Subject toany continuing obligations under law or the ASX Listing Rules, Origin and the Relevant Persons disclaim any obligation or undertaking to disseminate afterthe date of this presentation any updates or revisions to any forward looking statements to reflect any change in expectations in relation to any forwardlooking statements or any change in events, conditions or circumstances on which such statements are based.

Outline1) Transaction Overview2) Integral Energy and Country Energy Retail Businesses3) Eraring GenTrader Arrangements4) Business Strategy5) Appendix3

1) Transaction Overview

Through the NSW Government’s Energy Reform Process, Origin has agreed toacquire the Integral Energy and Country Energy retail businesses, and theEraring GenTrader arrangements for $3,250 million 1The transaction secures Origin’s position as the leading Australianintegrated energy company - becoming Australia’s largest energy retailerwith 4.6 million customers and owning one of Australia’s largest and mostdiverse generation portfolios in excess of 5,800 MW Increased scale and incumbency results in a competitive cost to serve Greater diversity lowers cost of risk management GenTrader arrangements provide long term competitive cost of energy Creates further opportunities for growth across OriginThe transaction is expected to be materially accretive to underlyingearnings per share 2 at completion5(1) Acquisition price includes $136 million for stamp duty in NSW and excludes $15 million of stamp duty outside of NSW. Itexcludes GST and a conditional amount of up to $198 million which will be payable if certain payments under theGenTrader arrangements are ruled to be tax deductible. An ATO tax ruling will be sought.(2) Based on underlying EPS, excluding non-recurring integration costs and changes in fair value of financial instruments.

The Integral Energy and Country Energy retail businesses deliver Origin alarge scale incumbent market position in NSW, Australia’s largest energymarketIntegral Energy + Country Energy retail businessesAcquisition Price:Customer accounts as at30 June 2010:Annual Sales Volumes andRevenuesyear ended 30 June 2010:Eraring GenTrader arrangementsAcquisition Price:$2,300 millionElectricity:Natural Gas:LPG:Electricity:Natural Gas:Revenues:1.6 million33 thousand9 thousand27 TWh4.5 PJ$3.8 billion$950 million(excluding a deferred and contingent payment of up to $198 million)Power Station Contracts: Eraring Power Station 2,800 MW Black CoalShoalhaven Scheme 240 MW Pumped Hydro• Eraring Power Station is currently upgrading the capacity of each unit from 660 MW to 720 MW by 2012,which Origin can dispatch up to a plant total of 2,800 MWThe GenTrader arrangements increase the scale and diversity ofOrigin’s generation portfolio making Origin the owner of one of thelargest portfolios of generation capacity and generation contractualrights in Australia6

The Integral Energy and Country Energy customer bases have been acquiredfor $1,282 per customer account which is consistent with previousacquisitions …Retail Segment Price Key MetricIntegral Energy and Country Energy retailcustomer accounts1.6 million customer accountsWholesale Portfolio27 TWh$2,108 million $1,282/customer account$192 million $0.35/MWh 1Generation Segment Price Key MetricEraring GenTrader arrangements - 3,040 MW $950 million $313/kWIncluding contingent consideration $1,148 million $378/kW• The Country Energy and Integral Energy retail businesses will be reported throughOrigin’s Retail Segment. This segment has historically earned EBIT margins of 8% - 9%• The GenTrader will be reported in the Generation Segment and will receive a tollingcharge from Retail commensurate with a pre-tax cash-flow return on productive capital… while the GenTrader arrangements have been acquired for$313/kW to $378/kW, well below new entrant cost7(1) Value across Origin’s entire post-acquisition wholesale electricity portfolio of 57 TWh, represents an annual equivalent

The acquisition will be funded through new debt facilities which areexpected to be partly refinanced with a pro-rata equity offering to beconducted within 12 months …• The acquisition is currently scheduled for completion on 1 March 2011• The acquisition is fully financed via underwritten debt facilities 1– $2.2 billion 1 to 2 year bridge facility to be refinanced via equity and long termdebt– $1.1 billion 3 to 5 year fully underwritten bank facility to be syndicated in early2011• Following the transaction Origin is expected to have cash and committed undrawndebt facilities in excess of $2 billion• A pro-rata equity offering is expected to be conducted within 12 months with thesize and structure of the offering to be determined• After the equity raising it is expected that Origin’s credit ratings will be reaffirmedas BBB+ by S&P and Baa1 by Moody’s… providing Origin with the financial flexibility to pursue additionalgrowth projects8(1) Excludes $198 million of deferred consideration not expected to be payable on completion

2) Integral Energy and Country EnergyRetail Businesses

The acquisition of the Integral Energy and Country Energy retail businessesincreases Origin’s customer accounts by over 50% to 4.6 million …• Origin’s electricity, natural gas and LPG customer base will increase to around 4.6 millioncustomer accounts post acquisition• The retail transaction structure does not involve acquisition of legal entities• Included in the transaction are:- electricity, natural gas and LPG customer contracts and data- hedge contracts, power purchase agreements and greenrights contracts- gas & LPG wholesale supply contracts, gas transportationagreements- Transition Services Agreements for the provision of customerservices- certain intellectual property and brand, including businessnames, domain names and trademarks- certain working capital10• Accounting standards require hedge contracts to be valued on completion and to the extentnecessary a provision will be made in the accounts at that time• Excluded from the transaction are property, plant & equipment; network, metering and watersupply assets; IT systems, licences and permits• Employees will not be transferring to Origin as part of the transaction, however Origin mayoffer employment to retail business employees using an agreed employee offer protocol… and provides Origin with a leading retail base across easternAustralia

Integral Energy holds NSW’s second largest electricity customer base with anincumbent position in NSW growth corridors …Customer Accounts – 30 June 2010 (‘000)Electricity – Mass Market 840Electricity – Commercial and Industrial 8Total 848Energy ConsumptionFY ended 30 June 2010Electricity – Mass Market (TWh) 7.2Electricity – Commercial and Industrial (TWh) 3.8Retail Revenue ($ billion) 1.611… while Integral’s electricity-only customer base represents anopportunity to provide dual fuel offering with natural gas which isavailable across the area

Country Energy is the incumbent retailer in regional NSW and has a stablecustomer base with a large portion of customers having not chosen to switchretailer …Customer Accounts – 30 June 2010 (‘000)Electricity – Mass Market 749Electricity – Commercial and Industrial 6Natural gas 33LPG 9Total 797Energy ConsumptionFY ended 30 June 2010Electricity – Mass Market (TWh) 6.6Electricity – Commercial and Industrial (TWh) 9.2Natural Gas (PJ) 4.5Retail Revenue ($ billion) 2.212… while its wide geographic spread brings a flatter load profile

IPART’s determination of regulated energy price caps has effectively set NSWtariffs to 30 June 2013 giving relative pricing certainty to mass marketcustomers on regulated tariffs in the near term• In December 2007 the Government committed to extend energy retail priceregulation until it is satisfied there is sufficient competition in the NSW market• The Independent Pricing and Regulatory Tribunal (IPART) has determined themaximum weighted average price cap that can be charged in NSW for mass marketelectricity and natural gas customers on regulated tariffs over the period 1 July2010 to 30 June 2013– The determination provides for annual reviews of energy costs– Prices are not regulated for customers who sign market contracts, howevermass market customers can elect to convert back to regulated tariffs, andmost market contracts are benchmarked to regulated standard contracts– Both Integral Energy and Country Energy have a high proportion of theircustomer base on regulated standard contracts• The NSW Electricity Tariff Equalisation Fund (ETEF), which reduces wholesalepurchase price risk for regulated load, is currently being phased out and will end on30 June 201113Origin expects that over time the east coast energy market willreach a long term sustainable margin that is consistent acrossstates and reflects the increasingly competitive nature of themarket

After completion, Transition Services Agreements will be in place underwhich core retail services will continue to be provided by the distributionnetwork businesses• Origin will enter into Transition Services Agreements (TSAs) with the distribution networkbusinesses to continue to provide services such as billing, collections and debtor management andcustomer service including call centres• The TSAs will continue through the development phases of Origin’s existing Retail Transformationproject and as such, will not impact the progress of the project, which remains on schedule forcompletion during 2011• The scheduled end dates for the TSAs will be staggered, allowing sufficient time to ensure asmooth integration into Origin systems from both the Integral Energy and Country Energy systems• These services are at a cost which is higher than Origin’s current cost to serve and consequently aprovision will be raised on acquisition that will be unwound to offset this effect• The Retail Transformation project will also deliver improved customer service functionality• Origin has a successful track record of integrating systems and migrating data as evidencedthrough the Energy 21, Powercor, CitiPower and Sun Retail acquisitionsOn integration into the Origin retail systems, scale and incumbencyenables the most competitive cost to serve across Origin’s 4.6million customers14

3) Eraring GenTrader Arrangements

Eraring Power Station is situated on the western shore of Lake Macquarie,30 km south-west of Newcastle on the NSW Central Coast• Eraring Power Station is a coal fired powerstation located 30 km south-west ofNewcastle• The power station’s capacity is currentlybeing expanded to 2,880 MW and Origin willhave the right to dispatch up to 2,800 MW• Historically it has consumed around six toseven million tonnes per annum of coal• Fuel is supplied from local and remotemines delivered by conveyor, rail andprivate road, with coal storage capacity onsite• The power station has access to coolingwater supplies from Lake Macquarie which isocean-fed and has flexible watermanagement protocols• The Shoalhaven Scheme is a pumped storagehydro electric power scheme with 240 MWof capacity located south of Sydney16Eraring Power Station and the Shoalhaven Scheme currently supplyapproximately 7% of the annual energy requirements of the NEM

Eraring Power Station has proven to be a highly reliable and flexible plant,with the ability to generate efficiently at as low as one third of its ratedcapacity, enabling it to respond to periods of peak demand and high prices• Past operations have regularly demonstrated aminimum continuous operating load of 210 MW perunit – or around 32% of its rated capacity• In recent years, the thermal efficiency of EraringPower Station has been stable, averaging 35.6%• Eraring’s Equivalent Forced Outage Factor 1 hasaveraged 1.9% over the last 16 years• Eraring’s average emissions intensity for calendaryear 2009 was 0.91 tCO 2e per MWh sent out 2Eraring Power StationThe power station is currently undergoing major capital upgradeswhich will improve its reliability and efficiency17(1) Equivalent Forced Outage Factor represents the percentage of total energy lost by the unit in a given period due toall forced outages(2) Source: Eraring Energy and ACIL Tasman

The Shoalhaven Scheme provides generation in peak demand periodsFitzroy FallsReservoirHead607m664 m10 GL80 ML/hr100 ML/hrKangaroo ValleyPumping and PowerStation2 x 80 MW4GL capacity isallocated to Eraringfor storage andgeneration purposesBendeelaPondage183 m1 GL160 ML/hrBendeelaPumping andPower Station2 x 40 MWShoalhaven SchemePumped Storage HydroPower200 ML/hrLake Yarrunga56 m35 GL• Shoalhaven is a pumped storage hydroscheme which serves as a duel purposewater transfer and hydro-electricpower generation scheme• Water is pumped to the holdingreservoir of Fitzroy Falls during periodsof low electricity prices and thenreleased to produce electricity duringtimes of high prices• In addition to electricity generation,water is also pumped for off-take tosupply Sydney and Wollongong,particularly during drought periods• Eraring Energy has allocated waterreserves sufficient to provide 200 MWof generation capacity for up to 28hours with an extra 40 MW for up to 6hours continuously• The power stations have fast startcapability, requiring only 10 minutesfrom start to full load18Its fast start capability and ability to store water enables it torespond rapidly and efficiently to market prices

The Eraring GenTrader arrangements provide Origin with contractualrights over a significant portfolio of power generation …Power StationEraring EnergyCommissioningDateGTAExpiryFuel Units Units Size(MW)• Eraring Power Station has typically operated at an average capacity factor of between 55% - 75%• The GenTrader agreements for Eraring and Shoalhaven expire in 22 and 28 years respectively, representingbroadly half of the plants’ operational lives• Eraring Power Station is currently undergoing major capital improvements designed to increase itscapacity, and improve reliability and efficiency– each unit will be upgraded from 660 MW to 720 MW; Origin can dispatch up to a plant total of 2,800 MW– upgrades for 1 unit are complete, and the remaining units are due for completion in late 2012– these upgrade costs are included in the GenTrader arrangements and Origin has no exposure tomovements in these costs• The Eraring Power Station also includes a 40 MW diesel-fired gas turbine which is intended to provideBlack Start ancillary services to the Australian Energy Market OperatorGTA TotalContractCapacity (MW)Eraring Power Station 1982 – 1984 2032 Black Coal 4 660 - 720 2,800Shoalhaven SchemeBendeela Power Station 1977 2038 Pump/Hydro 1 2 40 80Kangaroo Valley Power Station 1977 2038 Pump/Hydro 1 2 80 160Total Generation Trading Agreement Contract Capacity (MW) 3,04019… and support Origin’s fuel, plant and geographically diversifiedgeneration portfolio(1) Pumped storage hydro power cannot earn renewable energy certificates

Under the GenTrader arrangements, Origin supplies the fuel, pays the agreedoperating and maintenance charges, and has the right to sell the electricityoutput …Origin’s Rights and ObligationsRIGHTS• Entitlements to the electricity outputof the power stations• Provide instructions to Eraring Energyfor dispatch of the power station• Assume existing electricity hedge bookOBLIGATIONS• Purchase and supply fuel for thepower station• Bear the cost of auxiliary powerrequirements• Assume the costs and benefits of allcarbon regulations• Bear the cost of capital improvementsand change events• Dispatch plant at or above min-genlevels• Maintain certain insurances for thebenefit of Eraring EnergyDelivery of plantoutput• Capacity Charges• Fixed Charges• Variable Charges• Pass Through CostsEraring’s Rights and ObligationsRIGHTS• Retain legal title to the power stations• Retain all employeesOBLIGATIONS• Operate and maintain the powerstation• Maintain connection of the powerstation to the transmission network• Receive deliveries of and handle,manage, store and burn coal• Supply and treat water for use at thepower stations• Manage spares for use at the powerstations• Bear the risk of variability in stay inbusiness capex and operating andmaintenance expenses20… while Eraring Energy will own, operate and maintain the powerstations

The payment structure for the GenTrader arrangements includes a number offixed and variable fees and charges payable by Origin to Eraring EnergyPayment Structure• Annual Capacity Charge- for the supply of the Total Contract Capacity to Origin over the life of the agreement- at completion Origin has agreed to place funds on security deposit for the term of theGenTrader arrangements to cover the annual capacity charge payment• Ongoing Payments- Fixed Charges: for operating and maintenance costs payable monthly. These charges arefixed for the life of the contract subject to index escalation- Variable Charges: costs per unit of energy produced to reflect the cost of consumablesincluding chemicals, lubricant and hydrogen and is payable monthly- Pass-Through Costs: including water, transmission connection charges, licence fees, landtaxes and auxiliary power purchasesOutages and Availability Liquidated Damages (ALDs)• The structure of the GenTrader arrangements is intended to incentivise Eraring Energy tomaintain availability by having ALDs which are payable (subject to certain conditions) byEraring Energy to Origin where availability is below specified annual targets• ALDs are higher in peak than off peak periods intending to maintain availability during keytimes, however are not linked to NEM spot prices21Power station outages are managed through a planned maintenanceschedule and Availability Liquidated Damages which incentiviseEraring Energy to maintain availability

Excluding the Cobbora contract, Eraring Power Station has a substantiallycontracted coal position until 2012, after which it gradually declines, withno fuel supply contracts currently extending beyond 2022 …22• Eraring Power Station has historically consumed between six and seven million tonnes ofcoal per annum• At completion Origin will purchase all stock of coal and fuel oil at the power station• Eraring Energy will retain its existing coal supply agreements but will on-sell the coal toOrigin• A large proportion of Eraring’s fuel requirements from 2015 are expected to be met bythe supply of coal under the Cobbora Coal Supply Agreement with the State of NSW• The remaining uncontracted coal requirements will be met through Origin-sourced fuelsupply arrangements• The quantity of coal consumed going forward will depend on how Origin chooses tooperate the power station• The operational flexibility of Eraring Power Station allows Origin to be guided by marketconditions when sourcing its fuel, enabling Origin to meet operational requirementswithout assuming onerous take or pay obligations• Eraring Power Station owns and operates its own flexible coal handling infrastructure,which has inbuilt redundancy and historically has experienced high availability• There are various take or pay obligations in the coal supply agreements which are in linewith historical capacity factors… providing Origin with the opportunity to source appropriatequantities of coal to meet its operational requirements for theEraring GenTrader arrangements

The Cobbora coal resource is expected to provide Eraring Power Station withan additional and substantial supply of competitively priced coal …• The NSW Government is retaining ownership of the Cobbora coal resource andwill progress its development to commence coal deliveries from 2015• The Cobbora contract contains a specified contract price and quantity, whichextends for the remaining term of the Eraring GenTrader Agreement• The contract, including price and commencement date, is subject torenegotiation under limited conditions around the mine development approvalprocess• Origin is responsible for procuring appropriate haulage of the coal to the powerstation. The Cobbora coal mine is located approximately 380 km from EraringPower Station, and coal will be transported to the power station by rail• Origin believes that track upgrades will be required to provide sufficient capacityfor the transport of coal to the power station• If development of the Cobbora coal mine is delayed, Origin may need to procureadditional coal to meet mid-term requirements… and is currently planned to commence deliveries in 201523

4) Business Strategy

The National Electricity Market was established in 1998 in response to movesto privatise and deregulate energy markets in Australia …• In the mid 1990s energy markets in Australia werecharacterised by State based ownership ofelectricity generation and distribution assets,while each capital city was supplied by gas fromone major supply source• Differences in each state or region led to uniquerequirements for billing and customermanagement in each region• The process of deregulation and privatisationinitiated at that time has seen the development ofsophisticated, interconnected gas and electricitymarkets across eastern and southern Australia• Greater interconnection of markets has facilitatedcompetition and results in price and marginconvergence• The emergence of new customer systems and thirdparty service providers is also leading toconvergence in customer systems25Source: AEMO• This has resulted in highly competitive energymarkets with churn rates amongst the highest inthe world… and commenced a process of convergence of electricity and gasenergy markets across southern and eastern Australia

Customer Accounts ('000s)Origin has grown from a market share of around 4% of gas and electricityaccounts in the late 1990s to a market leading position of around 33% and anincumbent position in each mainland region of the NEMElectricity and Gas Market Share in theNational Electricity Market regions1998Origin 4%5,0004,5004,0003,5003,0002,500LPGGasElectricityOrigin Customer Accounts 1Citipower264,000 customersSun Retail896,000 customersIntegral Energy (IE) &Country Energy (CE)1,644,000 customers2,0001,5001,0005000Powercor580,000 customersEnergy 21540,000 customers26Post-Acquisition 1Origin33%(1) Market data as at 30 June 2010; Percentagesare based on Origin-estimated customer accountsnumbers using publicly available data• Market convergence and increasing competition makeincumbency in each region desirable and capability in bothelectricity and natural gas essential• Notwithstanding high levels of churn, Origin has essentiallymaintained its customer base following each majoracquisitionOrigin believes that further significantconsolidation by acquisition is nowunlikely for leading market participants

The acquisition of the Integral Energy and Country Energy retail businessesincreases Origin’s peak demand from around 7,000 MW to 12,000 MW …MW14,00012,000Peak Demand and Generation CapacityAnnual Demand and GenerationPeak Demand vs Generation CapacityAnnual C&I Demand Annual vs EnergyTWh Demand vs Annual GenerationPeak Demand vs Generation Capacity14,0007070Before AcquisitionAfter Retail AcquisitionBefore Acquisition After Retail Acquisition12,000606010,0008,00010,0008,000C&I PeakDemand50405040Annual C&IDemand6,0004,0002,0000C&I PeakDemandMass MarketPeak DemandOriginPlant6,0004,0002,000Mass MarketPeak DemandOriginPlantOriginPlant000Demand Generation Demand Generation Demand Generation Demand Generation302010Annual C&IDemandAnnual MassMarketDemandOriginPlant302010Annual MassMarketDemandOrigin has the choice of covering these requirements with investment in new generation,long term contractual rights or financial instruments such as swaps or caps27… and increases annual electricity sales from 30 TWh to around57 TWh

Increased scale and diversity of the combined position reduces the cost of riskmanagement relative to the three stand-alone businesses …Capacity (MW)Coincident loadis lower thanthe sum of thetwo loadsIntegral Energy +Country Energy +Origin LoadCapacity (MW)capscaps+ =Reduced CapRequirementcapsswapsswapsOrigin LoadswapsOriginHedge BookAcquired HedgeBooksCombinedHedge BookFor illustrative purposes only. Not to scale.• The geographic diversity and broad customer base of the combined portfolios for Origin,Country Energy and Integral Energy means that the combined portfolios increase salessubstantially while increasing peak requirements by a lesser amount… providing a competitive advantage in wholesale energy supply28

Due to allowances for plant age and various risks associated with the GenTradercontractual arrangements, the Eraring GenTrader was purchased at $313/kW,representing a significant discount to the new entrant cost to build14,00012,00010,0008,0006,0004,0002,000MW&I Demand vs Energy0Supply/Demand balance post Retailerand GenTrader acquisitionsTWhGenTrader Capacity Charge versus New Entrant costsPeak Demand vs Generation Capacity70Peak DemandAnnual Energy DemandBrown CoalC&I PeakDemandMass MarketPeak DemandContractedPlant6050403020Annual C&IDemandAnnual MassMarketContractedPlantOrigin 10DemandPlantOriginPlant0Demand Generation Demand GenerationBlack CoalCombined Cycle GTOpen Cycle GTEraring GenTrader0 500 1,000 1,500 2,000 2,500 3,000Capital Cost ($/kW)Source: ACIL Tasman: “Fuel resource, new entry and generationcosts in the NEM”, April 2009; and Origin GenTrader estimate• The Eraring GenTrader arrangements provide Origin with flexible baseload andpeaking generation capacity at a significantly lower price than the equivalent newentrant cost to build29Origin expects that electricity prices in the long run will reflect newentrant capital and operating costs which means the GenTraderarrangements represent a competitively priced long term hedge

The Eraring GenTrader represents a competitively priced long term hedge,and also provides Origin control of the dispatch of this generation capacityNEM Market Share of Generation Capacity 1OriginMacquarie GenerationSnowy HydroInternational PowerSource: Originand AEMOTRUenergyAGLDelta CoastDelta WestTarongCS EnergyLYMMCoTas Hydro***6%5%5%5%5%5%5%6%7%9%10%12%0% 2% 4% 6% 8% 10% 12% 14%* GenTrader arrangements other than Eraring being sold by NSW Government. Noassumption has been made on the outcome of the sale of these GenTraderarrangementsOwnedTRU without GenTraderSource: Origin and AEMODispatchRightsAfter completion Origin will either own or hold contractual rights fordispatch of over 5,800 MW, representing one of the largest and mostdiverse generation portfolios in the NEM30(1) Post acquisition; Includes scheduled generation only; Includes Mortlake Power Station which is currently under constructionand contracted generation; excludes Cullerin Range Wind Farm as it is non-scheduled generation

MW18,00013,5009,0004,500-MW18,00031Origin has built a position in the four largest regions of the NEM and is wellplaced to compete in energy retailing in each region and continue to deepenits integration in these markets13,5009,0004,500-QLDPeakDemandSAPeakDemandInstalledGenerationInstalledGenerationNEMOriginNEMOriginMW18,00013,5009,0004,500QLDMW18,00013,5009,0004,500-MW18,00013,500Post acquisition; Origin’s generation capacity in Victoria includes Mortlake Power Station which is under construction.Source: Origin load data and AEMO generation data9,0004,500NEM-OriginNSWPeakDemandVICPeakDemandInstalledGenerationInstalledGenerationNEMOriginNEMOrigin

The additional demand of Integral Energy and Country Energy is partly metthrough the Eraring GenTrader arrangements. Origin will need to acquire ordevelop further supply including Renewable Energy Certificates under theMandated Renewable Energy Target …&I Demand vs Energy14,00012,00010,0008,0006,0004,0002,000MW0Peak DemandC&I PeakDemandMass MarketPeak DemandContractedPlantTWhPeak Demand vs Generation Capacity70MWAnnual Energy Demand14,0006050403020Annual C&IDemandAnnual MassMarketContractedPlantOrigin 10DemandPlantOriginPlant0Demand Generation Demand GenerationOrigin has the choice of covering these requirements withinvestment in new generation, long term contractual rightsor financial instruments such as swaps or caps12,00010,0008,0006,0004,0002,00002,250Origin's Generation Portfolio5503,130351Mortlake2,6703,44332… providing the opportunity for Origin to invest in further gasand renewable energy generation from Origin’s extensive winddevelopment portfolio or other options

Origin has a higher proportion of gas-fuelled power stations compared withthe NEM and a lower average carbon intensity …Carbon Intensity by Generator TypeBrown CoalBlack CoalNEM averageintensity0.92t/MWhOwnedDispatchRightsOCGTCCGTRenewables0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4Carbon Intensity (CO 2 tonnes/MWh)Source: ACIL Tasman; based on FY10 energy consumption(Origin estimate for Darling Downs)Source: Origin and AEMO• The Australian electricity market is predominantly fuelled by coal, and has an averageemissions intensity of around 0.92 tonnes of CO 2e per MWh• Through the Eraring GenTrader arrangements Origin has obtained dispatch rights to anexisting generator at a similar emissions intensity to the NEM. Origin believes any carbonprice will be recovered in the market at the average emissions intensity of the NEM• Through the Integral Energy and Country Energy retail businesses Origin has increased itsshare of GreenPower customers in the NEM from 48% to 56%… and Origin’s portfolio provides a hedge against carbon outcomes33

This transaction secures Origin’s position as the leading Australianintegrated energy company … Australia’s largest energy retailer with around 4.6 million customer accounts One of Australia’s largest generators with capacity and contractualarrangements in excess of 5,800 MW Increased scale enables a competitive cost to serve Greater diversity of load lowers cost of risk management GenTrader arrangements ensure long term competitive cost of energy Creates further opportunities for growth... and is expected to be materially accretive to underlying earningsper share at completion34

5) Appendix

Origin’s Generation Capacity and Contractual RightsGeneratorCapacity(MW)Type Fuel Status Ownership%NEMScheduledLadbroke Grove 80 OCGT Gas Merchant Plant 100 YQuarantine 216 OCGT Gas Merchant Plant 100 YRoma 74 OCGT Gas Merchant Plant 100 YMt Stuart 414 OCGT Liquid Fuel Merchant Plant 100 YUranquinty 640 OCGT Gas Merchant Plant 100 YDarling Downs 630 CCGT Gas Merchant Plant 100 YCullerin Range 30 Wind Farm Wind Merchant Plant 100 NMortlake 550 OCGT Gas Under Construction 100 YOsborne 180 Cogeneration Gas PPA 50 YBulwer 32 Cogeneration Gas Externally Contracted 50 NWorsley 120 Cogeneration Gas Externally Contracted 50 NEraring 2,800 Subcritical Coal Black Coal GenTrader n.a. YShoalhaven 240 Pump/Hydro n.a. GenTrader n.a. Y36“Merchant Plant” refers to power stations that Origin contracts internally to assist with risk management of its retailelectricity requirements“PPA” refers to Purchase Power Agreements from third party generation“Externally Contracted” refers to plants whose output is sold under contract to third parties“GenTrader” refers to power stations that operate under GenTrader arrangements with NSW State Owned Corporations

Acquisition of Integral Energy Retail, Country EnergyRetail and Eraring GenTrader arrangementsSydney15 December 2010Origin EnergyFor further informationAngus GuthrieGroup Manager, Investor RelationsEmail: angus.guthrie@originenergy.com.auOffice: +61 2 8345 5558Mobile: + 61 417 864 255Websitewww.originenergy.com.au