George N PRODROMİDİS, Leonidas KİKAREAS, Panagiota STAMATOPOULOU, Grigoris TSOUMANİS, Frank A COUTELİERİS

Modelling and Experimental Study on Renewable Energy Based Hybrid Systems

In this paper a Renewable Energy Sources (RES) based hybrid system was designed and implemented. It has to cover several electric loads each one corresponds to the annual demands of a typical house, a typical country house and a small company. Experimental process reveals the efficient satisfaction of the desirable electric demands. These scenarios were also simulated by using HOMER software to determine time step results (over 95% load coverage). Moreover, it was found that the served power cannot meet the primary load when simulations take place at HOMER environment. These results are in contradiction with experimental observations that indicate the nearly uninterruptable coverage of the selected annually loads. In order to fill the gap between the real life operation and the simulation process of a hybrid RES project, an Innovative Theoretical Model Simulation (ITMS) based on a mathematical strategy plan, which incorporates the battery bank’s State of Charge (SOC), has been developed to accurately predict an autonomous system operation, found in excellent agreement with the experimental results.

Keywords:

Autonomous systems; Homer; Modelling; Renewable energy; Storage,

PDF

___

Conclusion
Initially, in the present study a laboratory scale off-grid RES based power project was built in Agrinio, Greece to examine the feasibility of such systems under real life conditions. PVs and WT were used as primary energy sources, and a deep cycle battery bank was chosen for intermediate energy buffering. The correlation between SOC and the voltage of the battery bank in each time step was determined in an experimental way in order to be incorporated in a new theoretical simulation tool being therefore an innovative evolution and approach on hybrid systems’ modelling.
J. Vera Gutierrez, Options for rural electrification in Mexico, IEEE Transl. Energ. Convers, vol. 7, pp. 426- 430, 1992. (Article)
M. Muselli, G. Notton, and A. Louche, Design of hybrid- photovoltaic power generator, with optimization of energy management, Solar Energ, vol. 65, pp. 143-157, 1999. (Article)
M.A. Elhadidy, Performance evaluation of hybrid (wind/solar/diesel) power systems, Renewable Energ, vol. 26, pp. 401-413, 2002. (Article)
F. Fazelpour, N. Soltani, and M.A. Rosen, Feasibility of satisfying electrical energy needs with hybrid systems for a medium-size hotel on Kish Island, Iran Energ, vol. 73, pp. 856-865, 2014. (Article) [5] J.G. McGowan, and J.F. Manwell,
Hybrid wind/PV/diesel system experiences, Renew. Energ, vol. 16, pp. 928-933, 1999. (Article)
J.G. Castellanos, M. Walker, D. Poggio, M. Pourkashanian, and W. Nimmo, Modelling an off-grid integrated renewable energy system for rural electrification in India using photovoltaics and anaerobic digestion, Renew. Energ, vol. 74, pp. 390-398, 2015. (Article)
O. Hafez, and K. Bhattacharya, Optimal planning and design of a renewable energy based supply system for microgrids, Renew. Energ, vol. 45, pp. 7-15, 2012. (Article)
S.M. Shaahid, and M.A. Elhadidy, Opportunities for utilization
(photovoltaic+diesel+battery) power systems in hot climates, Renew. Energ, vol. 28, pp. 1741-1753, 2003. (Article) stand-alone
hybrid [9] Y. Chang, M.Xianxian, Z. Yanfang, F. Shaoli, C. Hongyu, and D. Finlow, Lead-acid battery use in the development of renewable energy systems in China, J. Power Sourc, vol. 191, pp. 176-183, 2009. (Article)
J. Leadbetter, and L.G. Swan, Selection of battery technology to support grid-integrated renewable electricity, J. Power Sourc, vol. 216, pp. 376-386, 2012. (Article)
N.C. Nirmal-Kumar, and N. Garimella, Battery energy storage systems: Assessment for small-scale renewable energy integration, Energ. Buildings, vol. 42, pp. 2124- 2130, 2010. (Article)
J.H. Peter, and J.B. Euan, Energy-storage technologies and electricity generation, Energ. Policy, vol. 36, pp. 4352-4355, 2008. (Article)
A.M. Abdilahi, M. Yatim, M.W. Mustafa, O.T. Khalaf, A.F. Shumran and F.M. Nor, Feasibility study of renewable
Somaliland’s urban centers, Renew. Sust. Energ. Reviews, vol. 40, pp. 1048-1059, 2014. (Article)
in [14] R. Sen, and S.C. Bhattacharyya, Off-grid electricity generation with renewable energy technologies in India: An application of HOMER, Renew. Energ, vol. 62, pp. 388-398, 2014. (Article)
HOMER (The Hybrid Optimization Model for Electric Renewables).
http://www.nrel/gov/HOMER. Available
from: [16] J.L. Bernal-Agustin, and R. Dufo-Lopez, Simulation and optimization of stand-alone hybrid renewable energy systems, Renew. Sust. Energ. Reviews, vol. 13, pp. 2111-2118, 2009. (Article)
G.J. Dalton, D.A. Lockington, and T.E. Baldock, Case study feasibility analysis of renewable energy supply options
accommodations, Renew. Energ, vol. 34, pp. 1134-1144, 2009. (Article) to medium-sized
tourist [18] M.J. Khan, and M.T. Iqbal, Pre-feasibility study of stand-alone hybrid energy systems for applications in Newfoundland, Renew. Energ, vol. 30, pp. 835-854, 2005. (Article)
M.H. Ashourian, S.M. Cherati, A.A. Mohd Zin, N.Niknam, A.S. Mokhtar, and M. Anwari, Optimal green energy management for island resorts in Malaysia, Renew. Energ, vol. 51, pp. 36-45, 2013. (Article)
G. Bekele, and G.Tadesse, Feasibility study of small Hydro/PV/Wind hybrid system for off-grid rural electrification in Ethiopia, Applied Energ, vol. 97, pp. 5- 15, 2012. (Article)
M.P. McHenry, A technical, economic, and greenhouse gas emission analysis of a homestead-scale grid- connected and stand-alone photovoltaic and diesel systems, against electricity network extension, Renew. Energ, vol. 38, pp. 126-135, 2012a. (Article)
M.P. McHenry, Are small-scale grid-connected photovoltaic systems a cost-effective policy for lowering electricity bills and reducing carbon emissions? A technical, economic, and carbon emission analysis, Energ. Policy, vol. 45, pp. 64-72, 2012b. (Article)
J.A. Duffie and W.A. Beckman, Solar engineering of thermal processes, 3rd ed., John Wiley & Sons, INC, 2006. (Book)
F.J. Manwell, G.J. McGouan, L.A. Rogers, Wind energy explained theory design and application, 2nd ed., John Wiley & Sons, LTD, 2009. (Book)
G.N. Prodromidis, and F.A.Coutelieris, A comparative feasibility study of stand-alone and grid connected RES- based systems in several Greek Islands, Renew. Energ, vol. 36, pp. 1957-1963, 2011. (Article)
R. Perez, Lead-Acid Battery State of Charge vs Voltage, Home Power, vol. 36, pp. 66-69, 1993. (Article)