ETIP Photovoltaics

Roadmap 3

Hybrid systems including demand flexibility (PV+ Wind + Hydro with embedded storage + batteries + green hydrogen/fuel cells or gas turbines etc.)

Rationale for Support

RES systems are by nature highly dependent on the var- iability of the source that drives them. This variability characterises the generated energy resulting in a variety of problems to the system and the operators. At low pen- etrations of RES the inherent variability is easily absorbed by the generation systems that rule the energy mix and take the operational roles for balancing continuously the system without any problems transferred to the end users. In the case of CSP systems with the inherent storage, the cost of the system hinders its wider use due to higher LCOE price from the prevailing energy mix of countries.

While low penetrations of RES easily absorb variability, as RES penetration grows the variability becomes more pro- nounced especially in weak links and island systems. To im- prove on the above eventualities, developers have surged the possibility of building hybrid systems aiming to address the following issues:

  • Improve on the variability by mitigating it with com- bination of the various sources hence cancelling each other to a great extent.
  • Adopt the generation profile of Hydro power plants with generation coming from PV systems and com- bine it other storage/generation systems (batteries, green hydrogen, solar fuels).
  • In specific locations (e.g. Northern Africa) combine the generation profile of CSP system with genera- tion coming from PV systems a hybrid profile that meets all the requirements of operators to be dis- patched. This system is much cheaper to generate and uses the controllable CSP energy to absorb any variability coming from PV systems.


Currently RES systems are lightly hybridised to gain the benefits of building on individual strengths. PV has been linked with systems with embedded storage to raise dis- patchability and lower the cost of the complete system building on the strengths of embedded storage and the low-cost availability of PV systems. Thus, systems are de- veloped combining PV with storage or PV with other RES to serve very specific projects. PV is mostly linked with storage to improve energy management in buildings thus gain- ing on specific terms of tariffs or with other RES to offer a lower cost energy to the system.

Targets, Type of Activity and TRL

The objective of this roadmap is to develop systems and solutions for which PV, as an integral contributor of inter- connected systems, can offer hybrid solutions that better meet needs of the integrated grid. The following targets are anticipated:

Hybrid inverter solutions including the smartness of the system infrastructure can offer maximum use of local resources for the collective benefit of the sys- tem and the connected users. This can be extended to include hybrid solutions with floating PV on res- ervoirs in combination with hydropower.
Hybrid systems meaning PV in combination with wind and other available RES, can offer higher ef- ficiencies. This calls for a careful system approach capitalizing on local resources with available ena- bling technologies such as storage, V2G EVs, smart grids, or demand flexibility to minimize system cost for the benefit of system and users. These solutions will include specific PV-related challenges for P2X for achieving higher all-round efficiencies (where X = heating, thermal energy, fuels, feedstocks etc).
The above solutions will operationally require the services / advantages that grid forming inverter technologies offer with the added functionalities and intelligence to respond effectively to the inter- connected system needs in line with adapted pol- icies.
For improved operational and financial benefits of these hybrid systems, aggregated portfolios will be required to efficiently provide the resource availa- bility through the prevailing market rules allowing optimal controllability of available resources with the supportive technologies like smart systems and solutions, batteries, EVs, demand flexibility etc to maximise overall system benefits and hence the achieved revenues for the benefit of all contribu- tors.

Planned activities for developing the required hybrid sys- tems and solutions based on PV as one of the primary sources of energy are the following:

  • Action 1: Technical development of hybrid RES solu- tions for providing competitive energy using PV as one of the primary sources of energy moving TRL from 6 to 8 by 2025
  • Action 2: Technical development of hybrid RES solutions in combination with external storage systems for providing competitive energy using PV as one of the primary sources of energy moving TRL from 6 to 8 by 2027.
  • Action 3: Technical development of hybrid RES solu- tions using the flexibility of load including external storage systems and EVs for providing competitive energy using PV as one of the primary sources of energy moving TRL from 6 to 8 by 2030.


Possible KPIs that can be utilised for capturing progress in the above identified R&I fields are:

KPITarget Value
Hybrid RES solutions to be developed for cap-
turing the benefits of low-cost PV systems by
absorbing the variability of the solar resource

By 2025: offering an LCOE price of the
combined system lower than the prevailing
wholesale price of countries and islands in
southern Europe.

Hybrid RES solutions to be developed using
the added benefits of storage systems offering
combined solutions with PV systems

By 2027: LCOE price of the combined system
lower than the prevailing wholesale price of
countries and islands in EU.

Hybrid solutions to be developed using in
addition the flexibility of load including storage
systems and EVs supported by the advance
features of smart inverters
By 2030: grid to offer complete systems
serving energy communities throughout the
EU at lower LCOE price from the country