(166b) Session Keynote - Hybrid Renewable Energy Systems: State of the Art of the Impact of Design and Control Strategy on Performance and Costs

The pushing development toward a greater and greater penetration of Renewable Energy Sources (RES), which are characterized by intermittent availability, is giving new challenges through the delocalization of power production, aiming at consuming energy wherever it is originally converted. The use of HRES (Hybrid Renewable Energy Systems), i.e. characterized by the presence of power subsystems generating from renewables (i.e. PV and wind turbine systems primarily), coupled to batteries for short term storage, and Electrolyzers/Fuel Cells to mange storage over the long term, may be interesting to improve the flexibility of the solutions.

Such systems however present some challenges, as the efficiency depends strongly on the control strategy implementation, which in turn may be based on simple rules (RBS=Rule Based Strategy), or on more sophisticated elaborations (e.g stochastic, or model predictive based [1]) taking into account the probable evolution of the system status due to future consumption pattern management (Demand Response) and weather forecasts. Also, the typical small size (in relative terms to usual power plant size) of the systems give rise to a major drive to downsize at the utmost the components and simplify the control strategies (for example minimizing the amount of hardware required to optimize the system behavior, such as inverters, measurements probe, etc) [2].

The solutions are usually evaluated in terms of efficiency and Total Cost of Ownership: it is clear that these parameters must be defined on an energy basis, over a timeframe of at least one year to make sure to take into account the seasonal variation of the weather. It is also very important to highlight that the relation between power production and consumption is very much dependant on the specific application: for example, performances of off-grid systems [3] may be very different from grid-connected [4]; the consumption of energy in electric vehicles [5] or the use of FC as CHP systems may give very different results in terms of cost effectiveness and global efficiency.

The cited aspects will be properly highlighted and commented in this presentation, which will provide the audience with a description of the state of the art of system design, as well as with details on control strategy and main trade-offs.

References

[1] Bruni G., Cordiner S., Mulone V., Rocco V., Spagnolo F,. En Conv Magag., 2015.

[2] Erdinc O., Uzunoglu M., Renew and Sust. Energy

[3] Bruni G., Cordiner S., Mulone V. et al., Int. J. Hydr. Energy, 2014.

[4] Dagdougui H., Minciardi R., Ouammi A., Robba M., Saciel R., En Conv Manag., 2012.

[5] Fazelpour F., Vafaeipour M., Rahbari O., Rosen M.A., En. Conv. Manag., 2014.