This document discusses Ocean Gravity Energy Storage (OGRES), a proposed gravity-based energy storage system. It provides details on: - Assumptions and technical questions around the OGRES system. - A cost structure analysis showing estimated costs for system components like weights, floats, anchoring systems, and electricity cables. - Prototype scenarios to demonstrate and validate the system at various scales from 1 ton to 5 MW. - The potential OGRES market in mini-grids and macro-grids for renewable energy storage.

1. Sink Float Solutions
Christophe STEVENS
April 27th 2016
Ocean Gravity Energy Storage
(OGRES)

2. OGRES
Assumptions
Simple
Low cost
Demonstration
Cost structure
Technical questions
Sink Float Solutions
IP
Prototype
Partnership
Market

3. OGRES video
How the energy storage system works
https://www.youtube.com/watch?v=EzdQAnDJjfg

4. Christophe Stevens – April 27th 2016
100
Tesla
Batteries
1 MWh
Theory
« Low cost energy storage »
320 k€

5. Reality
« Other components are necessary … »
« … all of them are proven technology at an industrial scale»
Standard components
Barge, ballasts, pulleys, gearbox, brake, motor/generator, transfo, converter, control, cables (lifting,
anchoring), floats, lanyards, hooks, ROV’s, compressor, heave compensators, etc

6. Cost structure
« 50 €/kWh? … we need to present some figures ! »
0
50
100
150
200
250
300
350
Seuil de compétitivité Très dévaforable Exemple détaillé Favorable
Opérations (10 ans)
Câble électrique (HVDC ou AC)
Barge et son câble ascenseur
Système d'ancrage
Flotteurs des lests
Lests
(€/kWh)
FavorableCompetitor
Average
(Example)
Unfavorable
Operations (10 years)
Electric cable
Barge and lifting cable
Anchoring cables
Floats
Weights

7. 0
20
40
60
80
100
120
WEIGHTS
FLOATS
ANCHORING
ELECTRIC
CABLE
BARGE
OPERATIONS 600 k€/year during 10 years, 50 MW, MWh/MW=12h
Hypothesis
Power 50 MW
Distance 100 km
Cable + installation +
converters = 3 k€/km/MW
Trenching 90 k€/km
Included
Barge
Mechanics (pulleys, cable, gear reducer)
Electricity (motor/generator, transfo. converter, etc.)
Other (propulsion, steering, other …)
See details on next page
Anchors (concrete block), edge floats, etc.
Wire rope (breaking strength 2000 N/mm2 - coef séc 5 -
2,5 €/kg)
equivalent
20 €/kg PVC
…
Lower floats + ….
Upper floats + …
Reinforced concrete: 200 €/m3, density 2,3
Design: cylinders H/D = 4, v 20 km/h, drag. losses <15%
Other …
Depth:
4000meters
Storage capacity investment
(€/kWh)

8. 0
5
10
15
20
25
30
35
40
46 €/kW
€/kWh  €/kW (x12h)
Converter DC/AC
(option)
Transformer
Motor/generator
Gearbox (reducer, 3
speed)
Brake
Pulleys
Lifting cable (+l,
hooks, lanyards, etc.)
Other …
Barge
(Float capacity)
Ballasts (option)
Propulsion, etc
Dead time
46 k€/MW
Hypothesis
33 k€/MW
32 k€/MW
96 k€/MW
12 k€/MW
The best existing machine for the OGRES purpose are wind
turbines electromechanical components (gearbox ratio and
generator with variable speed: torque/speed variation). The
référence for cost structure, is a 2 MWC DFIG machine with
15 rpm (650 kN.m/MW).
18 k€/MW
0,15 €/N.m
150 €/ton(CMU)/pulley
(ratio D/d = 85)
Continuous cycle => 1 cable (length = 2x4000 mètres)
Wire rope breaking point 2000 N/mm2 - coef sécu 5 - 2,5 €/kg
650 €/ton
Total capacity = 3,3 x weight
Hypothesis: cost + 10%. Several options can solve the « dead time »
during the hanging/dropping phases: Several barges (N+1) can operate
together + speed increase, ancilliary storage systems: flywheels, super
capacitors, batteries, unique weight OGRES, etc.
Sources
BARGE
* … and certified connectable to the grid

9. 200 €/m3
(concrete)
30 m3
(180 €/m3)
2 to 5 MW
> >100 kgf
(thruster)
Barge < 650 €/ton
(load capacity)
(230 k€/MW)
Standard components for
5 MW barge
1 MWh weights (20 km/h)
16 barge modules
Cable = 5 cm
Pulley = 2 m
Ratio = 40

10. ROV with simple tool
(no need articulated arm)
Each weight includes 2 lanyards with 1 hook and 1 float each and each
side of the lifting cable includes 1 lanyard with 1 hook
Swell impact on
hooks movement

11. Container ship
(capacity 200 kT)
OGRES 500 MW barge
(total capacity 30 kT)
Standard components for
500 MW barge
100 MWh weights (20 km/h)
Autonomous weights
(no anchoring)
10 kT
D 13 m
H 45 m
Height 150 m
Upper float (barge) = 5% total
capacity
10 kt = 200 x 50 m3
= Leak hazard resilience
100 t = 3 x 30 m3
= capex destruction if leak
16 barge modules

12. Cable lifting systems don’t have « max load » limitations
Capacity = 10 kT (500 MW)
Diam. pulley = 4 m
diam. cable = 5 cm
Ratio D/d= 80
Sea bed

13. 290
150
35
Investment
(€/kWh)
Scale economies
Physical law
Electricity
Hydrodynamics
Industrial
Large series quotation
Electricity transport cost
Engineering, optimization
Solutions and spec. choice (best combinations)
Automation
Reinforced concrete calculation (ref 200 €/m3…)
Levelized cost
(LCOE)
For more information about LCOE and sensitivity study, a tool is available on our website www.sinkfloatsolutions.com
cost = f (RE+SE combination, power, location)
Batteries OGRES
1
0
Life time Dismantling cost
Batteries < 10 years Yes
OGRES Barge >> 30 ans
Transport >> 60 ans
Other ±20 ans
Negative
(barge steel price =
150 €/ton)

14. Technical questions
« Heavy swell is patent friendly »
Not exhaustive list (2 years of challenges with experts in different sectors)
Swell movements impact the hooks and lanyards
- Hanging operations (death time)
- Dropping operations (shock with seabed)
- Torque fluctuation
- Resonance frequency and cable strength
- Sea state percentage vs operation rate (best economical
choice). Eg Bay of Biscay different from Mediterranean Sea
Kinetic energy impact on cable strength
Temperature (and volume) variation due to
compression/expansion
Cable elasticity, power/speed/torque control, etc.
Constant power (death time, acceleration, deceleration, kinetic
energy impact on cable strength, PV=constant, …)
Animals curiosity, HVDC power cable weight (4000 m),
operation cost, heavy lanyards, heavy hooks, 4000 m depth
seabed hook accuracy. Freeboard, certification, etc
Main solutions
7 patent solutions necessary for
economical viability (all of them Sink
Float perimeter, 3 patents including 2
with 100% A category research report)
Secondary solutions
Different solutions can be developed for
each problem, and might improve
slightly the economical performance
(Sink Float > 40 claims)
Other solutions (free)
Solutions
Frequent comments and asked questions
More information is available in appendix

15. A B C
D
E
F G
H, I ?
Sink Float Solutions
Energy storage (Sink Float) Délivrance
Technologies Other Gravity 3 patents deliveries are guaranteed for Sink Float (until
2032)Inventor Christophe Autre
Patents G F D E H? I?
7 main solutions Each main solution can be developed independently of one
to an other and could be « sold » as different licenses (even
inside the same patent). Each one of the main solutions
(used as unique) is necessary to develop a competitive
storage solution.
Solution 1 v
Solution 2 v
Solution 3 v
Solution 4 v
Solution 5 v
Solution 6 v
Solution 7 v v
Secondary solutions In different situations, secondary solutions can be combined
(independantly of the patent), they do not solve the same
technical problems.
None of these secondary solutions is absolutely
indispensable for the financial viability of OGRES. However
they allow to improve the economical performance in many
situations.
Solution 21 v
Solution 22 v v
Solution 23 v v
Solution 24 v
Solution 25 v
Solution 26 v
Solution 27 v
Solution 28 v
… v
… v
Solution 31 v
Solution 32 v
Solution 33 v
…

16. Prototype scenarios
« Improving the perceived value with proofs »
PROTOTYPE SCENARIOS DEMONSTRATION CONSEQUENCES
Budget Size OGRES
availability
(meteo)
Economics Validation
level
1 million € Barge = 1 ton/weight
(max for crowd funding
budget)
/ 50% of cost
structure
assumption
validation*
40% Increase the value
of the project**
5 millions € Barge = 500 to 1 MW
(20 tons/weight)
+ anchoring system
resistance trials
50 to 90%
(Mediterranean
Sea)
Cost <
competitor*
80% First customers
x millions €
***
Barge = 5 MW
Grid connection
> 75% Cost RE + ES <
market price
95% Market 10 Mds €
Optimisation
(autonomous weights, >
50 MW units, etc.
> 90% Market > 100 Mds €
* Transport and operation are not taken into account (since theoretical validation is acceptable)
** For new fund raising and/or first IP licensing
*** It depends on site location
A
B
C

17. Possible
contributions
If Sink Float If …the industrial partner…
Prototype financing Via crowd funding (only scenario A),
and/or private and/or industrial
partnership (suppliers). Several options
identified, co investment possible
Scenario A possible, but it would
make sense to go directly to
scenario B or C in order to create
value faster
Prototype assembly
and trials
Project management by SFS possible if
scenario A (can be fast) and B. Scenario
B, C => subcontracting experts. Possible
partnership for PV grid project
Project management for proto > 1
MW with grid connection
Additional engineering Subcontracting all Electromechanics and transport (+
marine energy?)
Suppliers We got quotation from at least one
supplier for each component. Several
suppliers want to invest (apport en
industrie)
It would make sense in order to
reduce the prototype cost (supplier
base) and "make or buy" strategy
integration
Market Product could be IP licenses or storage
system (both can be sold by project or by
geographic perimeter)
Global strategy, energy mix strategy
(renewable + storage combo)
Possible partnerships
We can manage all but it would make sense to be associated soon with a
major of energy sector. Several partnership combinations seem possible.

18. Market
2 MARKET
DYNAMICS
MINI GRIDS MACRO GRIDS
New PV or wind farm will be developed
together with OGRES, for a particular
customer (industry, municipality)
A progressive deployment of OGRES will
follow the progressive replacement of
conventional power plants by renewable
energy facilities.
MWh/MW ratio 12h to 48 h 3h to 18h
Power 5 to 100 MW > 20 MW
Electricity market > 10 c€/kWh < 15 c€/kWh
Customer location Close to the sea Far from the sea
Additional backup capacity factor = 0 to 30% /
PRODUCT STRATEGY
Patent licenses
(royalties €/kWh a/o €/kW)
By project
By geographic perimeter
Storage systems Industrial (make)
Business (buy)
Turnover = benefit*
2017 – 2020 > 1 bn €
2021 – 2030 > 100 bn €
* Patent licensing scenario

19. Christophe STEVENS
Sink Float Solutions
Email: christophe.stevens@sinkfloatsolutions.com
Tél: +33.6.74.12.96.75
Web: www.sinkfloatsolutions.com
Thank you for your attention

20. APPENDIX

21. Solution 1
Solution 2
Solution 3
Solution 4
Solution 5
Solution 6
Solution 7
Main solutions (Sink Float Solutions IP)
presented in the video
Inventor C Stevens
Capex + 15%, energy losses + 2%, operation
ratio 100%
Cost constant in all locations (for a given depth) :
eg Mexico Gulf cost = Mediterranean cost
Possible to build a prototype with only very
standard additional components (by comparison
to solution 1, 2)
100% A
(research report)
Synergies with the 2 main challenges:
More difficult the technical challenges (state of the sea) = more value of the IP solutions

22. Anchoring cable
concrete
Upstream reservoir dam: 600
kg/kWh
Tunnel excavation volume,
turbine/pump infrastructure
are not included
PVC 1 kg/kWh
Reinforcement (for concrete)Concrete 75 liters
Barge
Mechanics
Lifting cable
Barge
Anchoring
Weights
steel
20 kg/kWh
Lead 35 kg/kWh
Lead 35 kg
Lead 35 kg
Lead 35 kg
Lead 35 kg
Lithium 10 kg Lithium 10 kg
Downstream reservoir dam:
130 kg/kWh
150 x 5 = 750 €/kWh
320 x 2 = 640 €/kWh
How much raw material for 1 kWh of storage capacity?
With pumped storage hydro
(eg Bath County)
With batteries
(for 20 years lifetime)
With OGRES
Copper (submarine electric cable HVDC 100 km, 50 MW)
91 €/kWh (prototype maturity)

23. Barge 1 Barge 2 Barge 3
20 MW 20 MW 20 MW
HVDC Cable (60 MW)
Mothership
(crew: ROV,
maintenance, etc)
ROV
ombilical
Etc.
Switch on the number of barge as
function of the power need (optimal
speed for better energy efficiency)

24. Why OGRES solutions was not economically viable earlier?
Market evolution:
Intermittent energies cost reduction
Technology improvement:
Submarine HVDC
ROV
Power electronics (generator)
Dynamic positioning (GPS)
Offshore engineering (oil, gas, RE)