Press releases

Report: Flexibility Options In Electricity Systems

Published: 11/06/2014

Leonardo ENERGY and Ecofys identify flexibility gap in power systems with higher shares of variable renewable energy sources

Brussels/Berlin, 11 June 2014 – A new overview clarifies the flexibility needs for the transition to power systems with very high penetration levels of variable renewable energy sources (VRES). The report provides a comprehensive assessment of the complete spectrum of flexibility options and identifies key barriers for their deployment. The report “Flexibility Options in Electricity Systems” has been launched by Leonardo ENERGY, the Global Community for Sustainable Energy Professionals, and energy consultancy Ecofys. It shows that increasing flexibility is key for the reliable operation of future power systems.

According to the report, a “flexible” power system is able to maintain continuous service especially in the face of rapid and large swings in supply or demand. The introduction of VRES such as wind and solar energy increases the requirements for power system flexibility for two reasons: VRES increase the variability in energy supply, increasing the need for flexibility; and VRES displace part of the conventional generation capacity, tending to reduce flexible resources in the system.

The “flexibility gap” unveiled in the report will need to be covered by new flexibility options. Sixteen fact sheets describe the characteristics of the key flexibility options, based on five basic flexibility categories: supply, demand, energy storage, network, and system. The options covered include flexibility in fossil fuels, nuclear, biogas, CHP, demand management, electric vehicles, power to heat, hydro, flywheels, batteries, power to gas and others. The authors also consider market options to uncap flexibility, and network options to increase flexibility.

“With increasing levels of VRES penetration, the electricity systems will need more flexibility options,” says Hans De Keulenaer, Leonardo ENERGY Programme Manager – Electricity & Energy. “As expected, the main mature options are currently on the supply side, but increasingly, the demand side will need to play a bigger role. Currently, demand side management is limited to large-scale industrial installations. It needs to be extended to buildings and eventually households.”

“New flexibility options in demand and storage require control and communication infrastructure”, says Dr. Georgios Papaefthymiou, main author of the report at Ecofys. “A more sophisticated control of the variable renewable energy sources can also be a cost-effective opportunity for providing system flexibility.”

The authors also recognise that active power control of VRES needs to take technical, institutional, perceptual, and potentially political challenges into account.

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The report is available for download online at:

Leonardo ENERGY     
The Leonardo Energy initiative (LE) unites professionals from all over the world dedicated to electrical power and sustainable energy. It is managed by the European Copper Institute, in close cooperation with various other partners. LE was established from growing understanding that copper is essential in achieving sustainability. Its high electrical conductivity is a favourable attribute for the construction of renewable energy systems and the manufacturing of energy efficient motors, transformers, and cables. The principal aim of LE is to accelerate the transition to a sustainable energy economy. LE provides free education, training, and the comprehensive exchange of expertise. It is also active in various standardization committees and provides regulatory advice.   

Ecofys – Experts in Energy
Established in 1984 with the mission of achieving “sustainable energy for everyone”, Ecofys has become the leading expert in renewable energy, energy & carbon efficiency, energy systems & markets as well as energy & climate policy. The unique synergy between those areas of expertise is the key to its success. Ecofys creates smart, effective, practical and sustainable solutions for and with public and corporate clients all over the world. With offices in Belgium, the Netherlands, Germany, the United Kingdom, China and the US, Ecofys employs over 250 experts dedicated to solving energy and climate challenges.          

For more information, please contact:

Hans De Keulenaer
Leonardo ENERGY
Avenue de Tervueren 168, b-10
1150 Brussels, Belgium
Phone +32 2 777 70 70
Direct  +32 2 777 70 84
Fax     +32 2 777 70 79

Yvonne Kettmann,
Press Office Ecofys
Am Wassermann 36
50829 Cologne, Germany
Phone +49 (0)221 27070-110