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Ivanpah SEGS:Case Study for Hybridization

Binyamin KoretzDirector, Strategic Planning & IP

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What is Ivanpah SEGS? What were we trying to accomplish? What kind of hybrid system did we build? What can we do in the future?

Outline

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The Ivanpah SEGS Project

Equity owners:NRG, Google, BrightSource

Debt: $1.6B DOE Loan Guarantee

EPC Contractor: Bechtel

STGs: Siemens

SRSGs: Riley Power

Solar field supply chain mgmt:BrightSource

377 MW net electricity generation

20+ year contracts with PG&E (2 units) and SCE (1 unit)

Start of construction – October 2010

$2.2B project financing – April 2011

commercial operations – 2013

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The Ivanpah SEGS Project

Forced-recirculation drum-type boilers with SH to 560°C @ 160 bar and RH

140m towers173,500 heliostats, each 15m2

Photo taken April 2013

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Photo taken April 2013

Ivanpah SEGS

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Photo taken April 2013

Ivanpah SEGS

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Photo taken April 2013

Ivanpah SEGS

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Ivanpah SEGS – last week

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Full-size gas-fired boiler justified by a 15% gas allowance and the PPA tariff

Our message to regulators was: Higher gas allowance can provide network reliability

benefits to facilitate integration of solar thermal plants in the California grid, with lower carbon and other emissions than system power from incremental reserves and peaking units

What were we trying to accomplish?

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The California regulatory system still does not support hybrid solar-gas plants There has been no framework for procurement of

renewable energy and ‘resource adequacy’ in the same PPA Very difficult public permitting processes Environmental opposition to adding gas to renewables

2% de minimis use with incidental electricity generation (up to 5% under certain conditions)

Overnight/startup use without incidental electricity generation not counted in the 2%

5% overall limit on fossil input as % of all heat inputs

What did we accomplish?

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A ‘light’ hybrid (like the first Prius cars) We installed package boilers with output equivalent to

~17MWe at poor heat rate We use gas-fired steam for:

Preheating SH and RH panels to accelerate morning startup Cooling-down SH and RH panels for pre-shutdown cooldown Night preservation boiler ‘Solar boost’ at IP inlet IP-only turbine mode

What kind of hybrid did we build?

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Optimal hybrid configuration will depend on many factors Availability and cost of gas Public policy Site characteristics

With little or no gas then MS tower could be more cost-effective if storage is required

With limited gas (15-25%) direct steam towers with MS storage can provide an optimal solution with boiler or storage plus independent (gas-fired) superheater

With enough gas there is no need for storage, and a gas-solar hybrid can be the lowest-cost solution for completely dispatchable power with a high renewable component – which may also be achieved with solar augmentation of fossil-fueled plants

What can we do in the future?

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Thank you