1. RENEWABLE ENERGY VS DECOMMISSIONING
A new life cycle to the Adriatic offshore platforms to be decommissioned:
Renewable energy production
Authors:
A.Rubiu,
N. Mondelli

2. INDICE Introduction Purpose of the Paper
Scouting of the Available Resources
Use, Conversion and Storage of the Produced Energy
Business Cases
Conclusions

3. 1. INTRODUCTION
The costs for the decommissioning of the offshore platforms at reaching the oil reservoir end of life requests the need to identify different solutions other than the dismantling of the offshore existing structures.
According to the «Blue Economy» business model, such existing infrastructures should be evaluated to exploit alternatives energy generation solutions.
Rosetti Marino Group has recently acquired significant know-how in the field of the renewable energy and in studying the associated new technologies
Rosetti Marino Group may guarantee a deep knowledge of the Adriatic offshore background as well as of the renewable and smart energy generation systems through partnerships and cooperation agreements with technology providers, research centres and Italian Universities

4. 2. PURPOSE of the PAPER The main purpose of the study is as follow:
to identify how reusing the Adriatic offshore infrastructures may advantage the exploitation of the local resources different from the oil reservoires for which they have been designed
To identify the local resources as well as their potential duties
To verify through different business cases the preliminary feasibility of such innovative approach

5. 3. SCOUTING of the AVAILABLE ENERGY RESOURCES
Only well proven resources have been investigated within wind and solar energy
Solar Energy
The most suitable available technology for the North Adriatic application is the photovoltaic. The site available radiation levels make the Concentrated Solar Power (CSP) and Concentration Photovoltaic (CPV) not suitable . PV
CSP
CPV
Assuming an electric power yeld of about 1100 kWh/year/kWp at the North Adriatic latitudes over an availbale area of 500 m2 it will be possible to produce about kWh/year by about 310 modules

6. 3. SCOUTING of the AVAILABLE ENERGY RESOURCES
Wind Energy – average wind velocity map and energy production
By an average wind velocity of 6.2 m/s and a velocity stochastic distribution with a Weibull coefficient k=2, it is possible to run the turbine at full rated duty for about 2500h/year 
With N. 1 turbine x 1 MW rated power, the electric power production is circa kWh/year

7. 3. SCOUTING of the AVAILABLE ENERGY RESOURCES
Wind Energy: 2 MW turbine installation example

8. 3. SCOUTING of the AVAILABLE ENERGY RESOURCES
Wind Energy: Turbine installation check
8 legs platforms provided with skids ways designed for 1200÷1500 t drilling towers have no constrains for 2,3 MW turbine, 250 t total weight
Fatigue life of the legs can be extended by increasing the inspection frequencies according to the API RP 2A
It will be possible to define the tower height and duty according to the jacket design and characteristics,

9. 4. USE, CONVERSION AND STORAGE OF THE PRODUCED ENERGY
Proposed use of the produced renewable energy
to utilize the produced electric power at the adjacent platforms still in operation
to convert and store the produced energy by the use of the existing infrastructures
New dedicated infrastructures connecting the produced energy to the inland electric grid have been excluded since too expensive with very low return on the investment
Energy conversion: Power to Gas (P2G) – H2 generation
An innovative energy conversion and storage solution using electrolysis that integrates renewable sources of generation, converts surplus electricity to produce hydrogen and leverages the attributes of the existing natural gas infrastructure.

10. 5. USE, CONVERSION AND STORAGE OF THE PRODUCED ENERGY
Proton Exchange Membranes (PEM) may couple wide range of load, fast response to transient conditions and H2 production at higher pressure
100% of the electric power produced by photovoltaic and/or turbine systems may feed the electrolyzer and may be converted to produce H2
the system power consumption is in the range of 4.5 to 7.5 kWh/Nm3 H2 and about 1 lt of demineralized water is required
the electric power yearly production of N.1 turbine x 1 MW rated power will generate about Nm3/year H2
Energy conversion: how to best utilize the produced H2
Three different solutions have been envisaged:
Direct H2 injection into the existing gas sealine of the nearby platforms in operation and sold at the same price of the natural gas
Inland transportation through abandoned sea line and sold as H2 technical gas
Inland transportation as above and used by the methanation process to convert CO2 and H2 into methane (not evaluated in this study)

11. 6. Business Cases
Case 1 - Hybrid electric power generation to integrate the power requirement with the nearby platform in operation
Case 2 - Hybrid electric power generation to produce H2 on the platform and to inject the H2 into the existing natural gas sea lines of the nearby platforms still in operation
The produced H2 is sold at the same price of the natural gas
Case 3 – Power generation and conversion to H2 as per above Case 2, but the H2 is injected into an abandoned sea line and stored onshore before to be sold as technical gas or utilized for CO2 abatement through the methanation process

12. 6. Business Case 1
Hybrid electric power generation integrated into the power system of the nearby platforms in operation
Photovoltaic: Modules and rqd. Area: x 330Wp / 500 m2
Electric power yeld : kWh/year/kWp
Total installed peak power: 100 kWp
Electric Power Production: 110 MWh/year
Investment Costs: 0,2 MM€
Wind Turbine: Installed Power: 1 MWp
Running hours at peak: h/year
Electric Power Production MWh/year
Investment Costs :Turbine: 2,0 MM€
BOP el ,3 MM€
TOTAL Equipment INVESTMENT COSTS: 2,5 MM€

13. 6. Business Case 2
Hybrid electric power generation, H2 conversion and injection into the existing natural gas sea lines
Hybrid Power Generation: Photovoltaic + Wind Turbine (see previous slide)
Total Electric Power Production: MWh/anno Power Generation Investment Costs: 2,5 MM€
H2 Conversion : Electrolyzer Installed Power: 500 kWp
Electolyzer Yeld: ,9 kWh/ Nm3 H2 H2 Production: Nm3/year
kg/anno
Investiment Costs: - Electrolyzer: 1,5 MM€ Auxyliaries: 0,5 M€
TOTAL Equipment INVESTMENT COSTS: ,5 MM€

14. 6. Business Case 3
Hybrid electric power generation, H2 conversion, inland transportation through existing sea lines and onshore storage before distribution to users
Hybrid Power Generation and H2 Conversion: as per Business Case 2
Total Electric Power Production: MWh/anno
H2 Production: Nm3/year, or
kg/anno
- Total Investment Costs for 4,5 MM€ Power Gen and H2 Conversion:
H2 Storage Case a) : N˚5 modules, 12 bottles x 1,6 m3 each
Storage capacity/ Pressure: m3/ 200 bar
Storage and auxiliaries Investment Costs: 4,0 MM€
H2 Storage Case b) : by existing sea lines : 20 km, DN: 200 mm vol: 630 m3
Auxiliaries Investment Costs: ,5 MM€
TOTAL INVESTIMENT COSTS: Case a) 8,5 MM€
Caso b) 6,0 MM€

15. 7. CONCLUSIONS
The results of the study highlight that the existing offshore infrastructures may provide added value in exploiting renewable energy
The proposed Business Cases demonstrate how the integration of the existing offshore infrastructures with the new hybrid power generation systems is feasible and can be envisaged as a positive example of “Blue Economy”
The return on the investment may be accelerated by including:
the financial benefit from the delay of the decommisioning costs, and
the benefit from the White Certificate or the Energy Efficiency Credits (EEC) that could grant additional benefits proportional to the tonne of oil equivalent (TOE) saved
4. ……and the indirect benefit in term of image that moves the focus on the offshore platforms from the oil processing to the renewable energy