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The nuclear fleet : a decisive enablerto integrate a share of Renewables.

(in the framework of a comprehensive system solution)

ATOMS FOR THE FUTURE

SFEN - october 21 - 2013

H. GRARD (CEA), J.-B. THOMAS (CEA)

V- 6 : 18/10 – 13h30

1 - System effects; production & storage back-up2 - Flexible base-load fleets (coal, nuclear) + storage & cogeneration as

IREN integration enablers : a win-win deal3 - Yes, NPP are flexible enough, if system effects are dealt with in a

synergistic system solution framework4 - An overview of storage back-up contribution 5 - Going on with NPP improvements : some innovation and R&D issues

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Summary (1/2)

• An efficient and clean base-load production fleet complemented with a powerful, 6 to 12 h. (typically) discharge duration storage back-up, isthe backbone of the mix.

• The IREN are a (disruptive) « winger », up to 20% of total power production. They need a large flexible baseload protecting the grid, the consumer, the production fleet itself.

• Baseload generation plants need a high capacity factor (low variable cost/ high capital cost). A « win–win » deal is thus mandatory.

Flexible but lower merit order fleets(gas, excepting domestic shale gas) are receding (Spain, Germany) becauseof a pincer movement made by IREN on one side and by coal or by nuclearand hydro on the other side, and thusof a letal fall-back of their capacityfactor.

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• Intermittency is a system issue and will be dealt with using system solutions, involving primarily storage back-up.

• Beyond the ultimate grid and plants adaptation effort, toxic surplusesmust be « stored or dumped » by the producer (detrimental production of a commodity : no value).

Summary (2/2)

• Baseload plants (coal, nuclear) need to keep a large installed power to deliver the required power ramping capacity (LF + IREN). This requirement would be contradictory with a high kp if smart storagecould not help (in France, currently, hydro dams and PumpedHydropower Storage (STEPS)).

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The main IREN Drawbacks

1 - Week-long, “pan-European” failure : winter solar hibernation, wind “naps”

� IREN can’t remove more than 3 to 4 % of their installed power(for a typically balanced fleet). France – 2030 : ~ 3 GW (not 20)4% of the installed power means ~ 20% of their mean power.

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The main IREN Drawbacks

2 – Threatening thermal commercial plants (gas, coal, nuclear) kp and flexibility

France–2030 : Prod # 550 TWh; Pi (IREN) = 70 GW, Pmean ~14 GW Power prod. (IREN) # 120 TWh (not all dispatchable), “Commercial thermal Production back-up” kp decrease : • little Pi reduction (3 to 4% Pi IREN),• But minus 100 to 120 TWh production (under “fatal” IREN assumption).

From Wagner :

capacity factor as a function of IREN energy production/annual demand

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The main IREN Drawbacks

3 – Summer “pan-European” solar flares (even without DESERTEC)

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Le solaire Allemand, préfiguration du solaire Français de 2030 ?

L’Allemagne possède un parc de production d’énergies intermittentes avec en puissance

installée, 33000 MW de solaire et 30000 MW d’éolien.

Production

solaire

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16/06 Pic de production de la

journée : 20000 MW

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16/06/2013 : consommation vs, solaire et éolien "20 30"

Consommation

éolien 2030

solaire Ge

Transposing to the French 2030 prospective

base résiduelle en été en 2030 (données du 16 06 20 13 Fce et Ge)

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QSP base

Killing the base-load fleet “softly”Threatening the grid

Flexible base-load (N/C)PP

Flexible hydropower dams

Cogeneration

Smart* (see below) Storage back-up

Reducing drastically the need for “production back-up”

Making solar and wind energy useful, by IREN production time-shift, at the right location

Plus air conditioning and efficient heat pump winter heating growth

Remedies ?

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“It’s the air conditioning, stupid !”

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Typical anticipated German patterns (with storage) - Wagner

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“The power flows from North to South through lines of least resistance, causing parallel flows in Benelux countries in the West (2006) and in Poland and the Czech Republic in the East”.

+ Limitless exchanges between Germany and Austria.

Europhysics News (2013)

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The main IREN Drawbacks

4 – The “regular” wind intermittency

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The main IREN Drawbacks

5 – Challenging the multi-scale space – time control of frequency and voltage, supported by the patiently built consistency : production,

transmission and distribution.

The breaking down threshold is probably lower than in the previous sections devoted to “scalar” issues

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The main IREN Drawbacks6 - Intermittency induced volatility

Towards restored margins through (much) higher prices for the consumer. Challenging the availability + affordability criteria (WEF)

A panel of helpers (to be coupled with a power production fleet), including P2G

There is no clear cut between storage and cogeneration, either.

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“Wind Dumping” from “The limits of wind penetration” (USA).“Excessive wind dumping imposes an upper economic limit on wind power”.Toxic surpluses call for a dedicated regulation : “store or dump”.Taking off around 20/30%. (see Wagner : 30/40% : “optimized” IREN mix)

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Yes, NPPs are flexible enough. Implementation level variable, depending on past needs, culture, improvements (hard, soft).

Related Requirements : EUR ; ALWRs : URD from EPRI.

Supporting (any time - any location) : frequency, voltage, through :• Contracts (down to a few hours);

• Automatic control on flexible reserves

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New “ramping” challenges from massive IREN penetration

LF requires fast and deep ramping up/down. In winter, between 6h and 7h(a.m.), + 7 GW can be required in 1 h., and the total ∆∆∆∆P can be ~ +18 GW

in 3 h.The present French mix can deal with such steps and ramping rates, everymorning.

The IREN hibernation (solar) and “naps” (wind) make it impossible to shrinkthe nuclear base-load component (at most – 2 to GW around 2030).Moreover, due to the intermittency, keeping a large nuclear installed poweris necessary. Dedicating 40% of the fleet to a 50% of its rated power“step” at 1%/mn means + 12 GW in 1h. Adding 25% interruptiblecogeneration (long term energy time-shift : G2P ?), leads to + 18GW in 1h.

Supported by hydro dams and STEPS, this “enabler” can withstand asignificant level of IREN penetration before coming in trouble. Anyway, thistime might come sooner than expected.The toxic system effects from intermittency are highly non-linear withIREN installed power (see above : “dumping take-off point”).

A system solution involving a broader synergy between flexible production,cogeneration and storage capacities, must be devised before over-investingin the grid (but strengthening some transport lines will be unavoidable).

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STORAGE Who ? How ? When ? Where ?

Electric Energy Storage Applications (SANDIA report)

Renewables Integration :• Renewables Energy Time-shift ; (in the US : “buy low, sell high”)• Renewables Capacity Firming;

Players : • Solar and wind power producers (farms; residential & commercial)• “utilities”;• “grid”;• “Consumers”;• Private investors

Main parameters • The discharge duration : excepting Short Term wind support (10 s. to

15 mn.), the typical discharge duration of interest ranges from 1 to 6 h Obvious as for solar; helps also for wind.

• The unit power capacity involved. “Smart storage” will probably be modular / distributed (1 MW to 100 MW), with a few high concentration sources (~ 0.5 / 1GW).

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STORAGE Who ? How ? When ? Where ?

Where ? Close to :

• Some wind (solar) farms : at the source of the intermittent supplies, for various reasons : upstream grid protection; “capacity firming”, “polluter/payer” or “pirate/corsair” mode; depending on the global regulation framework and on the game played by the main actors;

• The main base-load plants, as auxiliary tools;

• The main consumption sites;

• The most fragile locations on the grid.

• The only locations where the implementation is easy, accepted, efficient and low cost.

How (and how much – money - ?). Highly dependent on the way it is used, as well as on potential synergies with other applications.

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Direct use (simplified)

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16 GW : 40% (Pinst.)

Pumped

½ welcome / ½ undesirable ���� creative solutions (cogeneration)

Store or dump

~ 10 TWh Turbined ~ 7 TWh

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Solaire et STEP

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15 GW : 50% (Pinst.)

Direct use (incl. Air Cond.)

Mean value (kp # 14%)

Pumped ~ 5 TWh

Turbined ~ 3.5 TWh

More Air Conditioning ? (with HP – power – heating in winter and a leverage ratio of 2.5 to 3 ?)

Start from typical patterns of cooperation between a flexible production fleet and an auxiliary storage “pool” dedicated to the grid optimisation.

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CAES

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STORAGE Who ? How ? When ? Where ?

For solar, peak storage during “summer sonny afternoons” means about the same capital cost than building the solar plant. It makes solar power dispatchable and useful, thus defining its very value.

Massive air conditioning : a profitable opportunity given by solar “pushers”Compressed Air Energy Storage, High Temperature Stimulated Geothermal

Storage (with cogeneration) : specific SWOTs; a limited but valuable potential.

The best suited tool seems to be the extension of Pumped Hydropower Storage. France disposes of around 5 GW of STEP power productionpotential (efficiency : about 70%), less than Germany, and Japandisposes of around 25 GW.

In Germany, about 50 GWh are installed and about 20 GWh are in construction. In France, a few more GW (before 2025) could be beneficial to the grid.

In summary, storage increases the value of IREN by energy time-shift and it curtails the LF burden for base-load workhorses. Up to 20% of IREN power production (?), it enables :

• IREN firming by “filling” the dips during the production drop; • Protecting the grid from failure or from huge irrational over-costs (grid

wizard); • protecting nuclear and coal from over-ramping (up/down) as well as of

shutting down during wind storms and solar flares. • avoiding (partly) dumping toxic surpluses.

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The continuous improvement process is going on. Application to Gen-2, Gen-3, Gen-3+; to the SMR, then to Gen-4 prospective.Specifications and related R&D topics

1 – Defining the “flight envelope” ���� useful improvement criteria

2 – Some related R&D topics could be :

• Improving the knowledge of the physical state of the core, of the fuel : coupling the instrumentation to “numerical core simulation”, plus real time optimisation of core control “planning” by advanced algorithms.

• Ageing : technology, materials; anticipation thanks to the “virtual reactor” monitoring and to extended operation feedback knowledge bases

• Flexible, interruptible cogeneration : open questions about operation and compatibility, about cogeneration process ramping rate capability, about capacity factor (kp) and capital cost balance, etc.

3 – SMR; small core control, without boron; dedicated fuel …

4 - Gen-4.