An historic pact on Climate Change signed by 195 countries during the last COP 21 in Paris 2015 established elements to deal with emission reductions and global temperature rise, which will take effect by 2020. Therefore, renewable energy sources are essential to reach these new targets, like the world area’s abundant solar resources that can be developed in order to contribute partially to the fossil fuel reduction, increasing the energy efficiency of O&G plants and reducing the emissions level at the same time.

Solar PV (photovoltaic) is the most widely used solar energy technology to date and secondly, CSP (Concentrated Solar Power). While PV converts sunlight directly into electricity by using panel arrays based on semiconductor materials, the CSP make use of mirrors to concentrate the sun’s energy and produce steam that can be used in the oil and gas industry in different ways:

To drive steam turbines and produce the electrical power to supplement the oil and gas facilities demand.

For thermal technologies in enhanced oil recovery systems or generally for plant process units steam use.

omancsp

All of the aforementioned CSP applications have the possibility to add thermal energy storage systems needed to overcome night time or for topping off during non-ideal solar conditions.

oman06

Nowadays the photovoltaic cells have evolved technologically being very affordable with decreasing price trends and an increasing interest in standalone application at medium to large-scale capacity, nevertheless the CSP is shyly appearing in the oil and gas industry in specific geographical areas basing its attractiveness as a source of steam generation.

The present paper refers to a case study of a combined-cycle power plant which benefits of the integration with a solar field (Integrated Solar Combined Cycle – ISCC) for oil and gas production facilities use sited in the North Africa region. This geographical area offers appropriate solar DNI (Direct Normal Irradiance) for CSP technologies. The selected configuration for this case, exploit the CSP heat in the same heat recovery steam generator (HRSG) of the combined cycle. Solar heat is integrated at the evaporation section, with an efficient heat exchange coming from the CSP system.

In this study, it is presented a fuel saving configuration, in which constant power is produced. Therefore gas turbine electric load decreases up to 80% and the remaining electricity is produced in the steam cycle exploiting the heat coming from the solar field, which thermal load is decided as an overall compromise solution for the CSP field size. Results from the life cycle cost analysis showed that investment payback in order to be inside project operational life limits is largely driven from two market variables remaining a barrier: fuel gas price and CO2 shadow price; other limitation that might be an issue is water scarcity in the area for steam cycle or make up and also any permitting for connection to the grid unless the plant will be operated standalone.

 

Bruce Kelly., Ulf Herrmann, Mary Jane Hale: “Optimization Studies For Integrated Solar Combined Cycle”, National Renewable Energy Laboratory – Golden, Colorado, Proceedings of Solar Forum 2001, 2001 Washington, DC

Randall C. GEE, David WHITE / SkyFuel, Inc., Arvada, CO (US) “Solar/Gas Hybrid Power System Configurations And Methods Of Use”, United States Patent Application, Publication Pub. No.: US 2014/0223906 A1

Authors
Carlos Tommasi (eni SpA) | Roberto Zennaro (eni SpA) | Marco Ferrari (eni SpA) | Lino Carnelli (eni SpA – Istituto eni Donegani) | Tamara Passera (eni SpA – Istituto eni Donegani) | Carla Lazzari (eni SpA – Istituto eni Donegani) | Paolo Silva (PoliMI) | Marco Lamberti (PoliMI)
DOI
http://dx.doi.org/10.2118/183517-MS
Document ID
SPE-183517-MS
Publisher
Society of Petroleum Engineers
Source
Abu Dhabi International Petroleum Exhibition & Conference, 7-10 November, Abu Dhabi, UAE