Alternatives to Wind TP Preface Wind TP integrates

Alternatives to Wind. TP

Preface Wind. TP integrates energy storage into a powertransmission system for wind turbines. Of course there alternatives. . . 2

Contents • Just do without energy storage • Use standalone energy storage • Integrate storage with Wind in other ways • WINDTP review in light of the above 3

Contents • Just do without energy storage • Use standalone energy storage • Integrate storage with Wind in other ways • WINDTP review in light of the above 4

Who needs Energy Storage? To operate well, the electricity system needs flexibility. Energy storage is only one of several possible ways to provide this flexibility. Massive interconnection of power systems will help, for example. Smart Meter Water Heater So, too, would extensive demand-side response. http: //www. power-technology. com/features/featurecontinentalpower-operating-the-super-grid-4512977/ 5

Who needs Energy Storage? Time-zones and weather patterns span distances of thousands of km! Interconnection over these distances has a high cost. The occurrence of daylight tends to cause us to synchronise our 6

Contents • Just do without energy storage • Use standalone energy storage • Integrate storage with Wind in other ways • WINDTP review in light of the above 7

Standalone Energy Storage? Standalone energy storage takes electricity from the grid and puts it back there. Wind variation is slow! Slow variation => large amounts of stored energy for a given power. Irish wind power and demand recorded in 2011 Energy storage is expensive! Batteries >$200/k. Wh until at least 2022(? ) Example: 1 MW wind turbine, 2 days storage ~ 50 MWh ~ $10 M.

Standalone Energy Storage? Apart from batteries, there is also … • • • Pumped hydro energy storage, PHES Compressed air energy storage, CAES Pumped thermal energy storage, PTES Liquid air energy storage, LAES Flywheel energy storage Varieties of gravitational energy storage other than PHES Issues: • • Location dependence (PHES and CAES) Costs of power-conversion machinery (affects all) Cost effectiveness can depend on huge scale (PHES, CAES) Round-trip losses can be large (20% 50%) (LAES, PTES esp)

Contents • Just do without energy storage • Use standalone energy storage • Integrate storage with Wind in other ways • WINDTP review in light of the above 10

GIES with Wind Install a compressor in wind turbine nacelle ? Gearbox still needed because natural speeds so different. Blade ‘Costs extremely high. Hub Gearbox Compressor Blade e. g. WO 200713675 Eric Ingersoll (behind General Compression) (Early patent from GC). GC now diverted to EIEO storage and merged. . Direct drive air compression in nacelle is impossible – huge swept volume. 11

GIES with Wind Direct air compression – but not in nacelle ? 12

GIES with Wind Pump water directly? Great idea – except for 2 things: (1) limited to 10 m of “suction” (2) Wind is typically strongest at the top of a hill, not at the bottom! Long mechanical transmissions quite expensive. There are some indirect possibilities with cable drives or hydraulics. You still need a large natural pumped-hydro type resource 13

GIES with Wind Convert rotor work directly into heat? ? (US 2012/0326445 A 1) Filed June 2011. Concept study of wind power utilizing direct thermal energy conversion and thermal energy storage Toru Owned by APPLE Corporation. Okazakia, Yasuyuki Shiraib, Taketsune Nakamurab Renewable Energy, 83, 332 -338. Nov. 2015 Mr. Carnot teaches why this has limited possible efficiency 14

GIES with Wind Use “spare” rotor work to drive a reversible heat pump? Hub Differential Gearbox Blade Differential Gearbox Generator Blade Generator 15

Contents • Just do without energy storage • Use standalone energy storage • Integrate storage with Wind in other ways • WINDTP review in light of the above 16

Wind. TP Review Now review what Wind. TP does! • Can be integrated with any new wind farm - anywhere • Uses one direct-drive machine to absorb all power from the wind turbine rotor – the primary compressor • Uses one (shared) expander-generator set to deliver electrical output power. • Uses one (shared) secondary-compressor (rated at 65% of collective power of primary compressors) • Has very low marginal cost for power-conversion kit • Only passes energy through storage that should pass through storage. • Has a high effective round-trip efficiency. 17

Thank you for listening Sincere thanks to EPSRC for funding the work from which Wind. TP emerged. info@Wind-TP. com An Open Lecture, Nottingham, June 15, 2010