AN INNOVATIVE PUMPED-STORAGE PROJECT IN AN UNDERGROUND MINE. Ernst Zeller November 2017

Transcription

1 AN INNOVATIVE PUMPED-STORAGE PROJECT IN AN UNDERGROUND MINE Ernst Zeller November 2017

2 AGENDA Pump storage technology Battery vs. Pump storage technology Why in Pyhäsalmi Ore Mine? Pyhäsalmi Project 2

3 PUMP STORAGE TECHNOLOGY Pumped storage facility is made by two water basins, connected by a pressure pipe, with the water running through a pump-turbine rotating motor-generator Load MW מתח תדר יציבות PSP Production Upper Reservoir Demand Pumping Straightened curve Pumping Pump mode איזור התועלות הדינמיות Lower Reservoir Turbine mode Storing potential energy by pumping the water from the lower basin to an upper one and using that energy by releasing the water back when required 3

4 PROVEN MATURE TECHNOLOGY World Energy Council 2015: 99% of world s operational electricity storage is in hydropower (pump storage) IEC 2016: PSP is a significantly cheaper energy storage alternative compares to batteries, answering all national grid dynamic benefits needs 4

5 PUMPED STORAGE HYDRO WORLDWIDE 5

6 O&M Cost [$/kw] PUMPED STORAGE VS BATTERIES (PSP VS BAT) LIFE TIME PSP BAT > 50 years vs. ~15 years Batteries Lifetime is years* Batteries storage capacity decreases substantially after 3 years TECHNOLOGY Pumped storage hydro Batteries Li-ion* Compressed air Hydrogen ~40% ~68 % ~65 % ~77 % * According to NREL Predictive Models of Li-ion Battery Lifetime CAPEX According to EPRI Energy Storage Project A PSP * Average Efficiency, which declines over the years for Batteries OPEX PSP Batteries According to Energy Storage Screening Study For Integrating Variable Energy Resources within the PacifiCorp System July 9,

7 BENEFITS OF PUMPED STORAGE POWER PLANTS Storing Energy Provide a substantial contribution towards a balance between electricity generation and consumption Absorb excess power in the grid particularly when balancing energy produced by wind and solar plants wind and solar erratic through 24 hour period Increase of Wind capacity in many emerging countries Solar power starts Balancing Services Provide required regulatory functions contributing to grid stabilization and frequency regulation at primary and secondary levels in generating mode Black Start services able Increasing Effectiveness of Renewables Diversify the energy mix Absorb base load production particularly from nuclear and coal plants at night and release during peak hours in morning and evening Lower the dependency on non-renewable fuels Combining the generation of Wind- Solar- and Hydro Energy with Pumped Storage Power plants Reducing Transmission costs Installing PSPP close to Demand and Generation of Wind Power November

8 PYHÄSALMI MINE Provides 1400 m of head! Perfectly investigated geology with best rock conditions Infrastructure on ground and in 1400 m depth including access tunnel Excavated open pit for a upper reservoir, 110 kv connection and substation Good location in balancing the Finnish power grid Mine operation will run until

9 GEOLOGY GEOTECHNICAL CONDITIONS Very good knowledge from existing mine operation Mafic volcanites are preferred for underground structures Parameters: Very good rock mass quality Small plasticisation around excavation expected, but high risk of rock burst High elastic modulus low level of deformations expected Temperature conditions constantly around 22 C in 1400 m depth. Groundwater: High chloride concentration (level of marine water) corrosion risk! Hydraulic conductivity very low Rock is very dry at lower levels 9

10 ALTERNATIVE STUDY HYDRAULIC HEAD Elevation -700 m Preferred location Higher head / reduced flow rate Reduced underground storage size main cost driver Elevation m 10

11 ALTERNATIVE STUDY - MAIN PLANT CHARACTERISTICS 50 MW 100 MW 200 MW 300 MW 400 MW Number of units 1x50 1x100 2x100 2x150 2x200 Q [m³/s] Shaft Velocity [m/s] Required area [m²] Number of shafts or 2 1 or 2 Diameter [m] 1.8 (1.3) or 2x or 2x2.6 Cavern Volume [m³] 30,375 45,000 70,000 78,300 86,550 Storage size [m³] 6 h 90, , , , ,200 8 h 119, , , , , h 148, , , ,500 1,162,000 11

12 INITIAL ECONOMIC EVALUATION Expected revenues from day-ahead market are relative modest Revenues from ancillary services are limited due to market size Outcome from generation benefit analysis (Pöyry s BID3 market model) suggests that the most feasible configuration is around 75 MW and 6 hours storage size. Due to current challenging market conditions an implementation in stages appears favourable. 2 options have been studied further: MW MW wide range from 75 MW to 200 MW is covered within the feasibility study 12

13 MAIN PLANT SECTION 75MW 13

14 MAIN PLANT LAYOUT 75MW 14

15 LOWER RESERVOIR Layout of final tunnels optimized in respect to geological conditions (joint systems, primary state of stress) and existing tunnel system Aeration tunnel can be used for construction, partly as reservoir and for later access in case of maintenance Active storage of 162,000 m³ and 21,000 m³ for dewatering of power waterway 15

16 POWER SHAFT - UNLINED Unlined pressure shaft (based on experience from Norway) Design criteria: Sufficient distance to existing tunnels (based on rock condition / hydraulic gradient < 18 distance min. 70m Reduced flow velocity < 2.5 m/s Include a rock trap before cavern Raised boring method constructed in 2 sections Treatment of fracture zone 16

17 ES PYHÄSALMI - CAVERN DESIGN 75MW 17

18 PROJECT IMPLEMENTATION - EXPANDABLE DESIGN 18

19 TERNARY UNIT SET ARRANGEMENT - VERTICAL M.O.L. Alternative 1 Alternative 2 Alternative 3 hs MG T T MG MG P P P Legend Motorgenerator Turbine Pump T 19

20 TERNARY UNIT SET - DESIGN CHALLENGE MG Motorgenerator F.S.L. hf T Pelton-Turbine with mandatory free board ~11 m M.O.L. Shaft length! hs P Multistage Pump with mandatory suction head 20

21 TERNARY UNIT SET - 75 MW UNIT SET Motorgenerator Pelton Turbine Converter Multistage Pump 21

22 CYCLE EFFICIENCIES AT RATED OPERATION POINT 22

23 TRANSPORT LOGISTICS Transport of large E&M equipment to depth level of m is considered as critical Existing decline tunnel has steep gradient, narrow curve radius and restricted crosssection Transport study showed that curves have to widened by about 1,5 m. 23

24 CONCLUSION Preferred location at m depth in order to utilise the full head and to minimise related storage volume. No technical show stoppers have been identified. Technical and construction advantages due to excellent geological conditions. Ternary unit set with pressured turbine-tailwater chamber is the preferred arrangement. Specific costs are in the lower range compared to other PS projects. Economic evaluation (Pöyry s BID3 market model) showed challenging conditions for PS in Finland. If realised it will likely be the pumped -storage plant with the highest head worldwide. 24

25 WE ARE PÖYRY THE CONNECTED COMPANY Delivering consulting, engineering, project execution and operational services. Global community of talented people working closely with clients locally. Inspiring new solutions by connecting deep expertise and profound insight. Contributing to projects that make a difference. 70 nationalities 150 offices 70% with higher academic degree 45 countries CLIENT FOCUS 10,000 projects delivered annually 6,000 experts 50 languages spoken ENERGY INDUSTRY INFRA 25

26 ENERGY EMPOWERING YOUR BUSINESS Thermal power & Renewable energy Hydropower Transmission & distribution Nuclear energy * RANKED # 8 CONTRIBUTED TO 10% OVER 60 GW DELIVERED 200+ in power generation globally * total hydropower capacity globally total combined capacity of thermal power plant projects wind power projects Consulting. Engineering. Projects. Operations. * source: ENR

27 INFORMATION 27

28 Contact: Ernst Zeller Consulting. Engineering. Projects. Operations.