What has happened since 2015? Preesall Underground Gas Storage Scheme What has happened since 2015? Market drivers Technical Development Contract Strategy Legacy Brinewell Management

Market Drivers Renewable generation continues to expand 20% and rising Preesall Underground Gas Storage Scheme Market Drivers Renewable generation continues to expand 20% and rising Intermittent generation need expanding UK gas storage depleted by Rough closure 70% of UK storage lost 13 days down to 4 days GREATER NEED FOR FAST CYCLE STORAGE

Technical Development Preesall Underground Gas Storage Scheme Technical Development Surveys have been undertaken and continue Operational requirements modelled in detail DCO compliance commenced SECTION 106 Regulatory authorities engaged

Construction Strategy Preesall Underground Gas Storage Scheme Construction Strategy Delivery strategy developed Contracts for advanced works being let Haul road Brine pipeline Construction starting in 2018 (Q1)

Way Forward Preesall Underground Gas Storage Scheme DCO Decision July 2015 Project Delivery Planning Jan-Dec 2016 Liaison, Surveys, Design and Consents 2017-2018 Phase 1 Construction 2018-2021 First Gas 2020      Brine outfall Electricity supply NTS connector Gas compound Wellhead compounds etc Cavern washing Approvals & operation Preesall Underground Gas Storage Delivery 5

Legacy Brinefield Management Preesall Underground Gas Storage Scheme Legacy Brinefield Management Halite has continued to manage legacy brinefield Monitoring Maintenance Blow out risk Collapse risk Subsidence Well pressures

Legacy Brinefield Management Preesall Underground Gas Storage Scheme Legacy Brinefield Management Meeting the HSE annually Meeting other interested parties Repairing wellheads Maintaining fences & tracks Since 2015 >£250,000 spent

In the UK gas is stored underground in: Caverns Depleted reservoirs Preesall Underground Gas Storage Scheme SAFETY In the UK gas is stored underground in: Caverns Depleted reservoirs Pipelines (Linepack)

Preesall Underground Gas Storage Scheme SAFETY

Preesall Underground Gas Storage Scheme SAFETY Normal Rock Salt

At least 300m below the ground surface Shaped for stability Preesall Underground Gas Storage Scheme The Caverns Up to 19 caverns 100m diameter 50m to 200m tall At least 300m below the ground surface Shaped for stability Roof cone Main chamber Sump

Preesall Underground Gas Storage Scheme How the Caverns are constructed

Salt has a very low porosity Salt has a very low permeability Preesall Underground Gas Storage Scheme SAFETY Why is salt safe? Salt has a very low porosity Salt has a very low permeability Salt is self healing therefore does not fracture like normal rocks Salt is strong Gas has been stored in caverns for more than 50 years and there is no case of gas leakage from salt caverns

Salt Cavern Fast Cycle Gas Storage Preesall Underground Gas Storage Scheme SAFETY Salt Cavern Fast Cycle Gas Storage ‘huff ‘n puff’ Its most distinguishing characteristic is deliverability (mcm/d), not working gas volume or space Carbon – shallow salt strata, rapid volume in and out of storage means low energy costs and low CO2.

Way Forward Preesall Underground Gas Storage Scheme DCO Decision July 2015 Project Delivery Planning Jan-Dec 2016 Liaison, Surveys, Design and Consents 2017-2018 Phase 1 Construction 2018-2021 First Gas 2020      Brine outfall Electricity supply NTS connector Gas compound Wellhead compounds etc Cavern washing Approvals & operation Preesall Underground Gas Storage Delivery 16