REPORT FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT, THE COUNCIL, THE EUROPEAN ECONOMIC AND SOCIAL COMMITTEE AND THE COMMITTEE OF THE REGIONS JRC technical report on "Assessment of the potential for energy efficiency in electricity generation, transmission and storage"
Date: 2023-01-09
Institutions: Directorate-General for Energy, European Commission
Subjects: Joint Research Centre, electrical energy, energy consumption, energy efficiency, energy grid, energy production, energy saving, energy storage, energy transport, energy use

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   EUROPEAN COMMISSION  Brussels, 9.1.2023  COM(2023) 1 final  REPORT FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT, THE COUNCIL, THE EUROPEAN ECONOMIC AND SOCIAL COMMITTEE AND THE COMMITTEE OF THE REGIONS JRC technical report on "Assessment of the potential for energy efficiency in electricity generation, transmission and storage" {SWD(2023) 1 final}  
 
 
REPORT FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT, THE 
COUNCIL, THE EUROPEAN ECONOMIC AND SOCIAL COMMITTEE AND THE 
COMMITTEE OF THE REGIONS 

JRC technical report on "Assessment of the potential for energy efficiency in electricity 
generation, transmission and storage" 

Summary of JRC technical report on “Assessment of the potential for energy efficiency 
in electricity generation, transmission and storage” 

The report presents, with a non-technical approach, the results of an assessment carried out to 
evaluate  the  potential  for  energy  efficiency  in  conversion,  transformation,  transmission  and 
storage of electric energy. 

The  report  follows  the  guideline  that  is  outlined  in  Article  24.13  to  the  Energy  Efficiency 
Directive 2012/27, as amended by the Directive 2018/2002; examining the three main pillars 
of  possible  energy  efficiency  development,  namely  conventional  fuels,  storage  and  High 
Voltage Direct Current (HVDC) transmission. Therefore, the document describes those three 
main  technological  solutions  focusing  on  energy  efficiency,  to  explore  possible  savings 
potentially  obtainable.  The  report  contains  a  review  of  current  efficiency  levels,  of  known 
margins  for  improvements,  and  a  rough  estimate  of  possible  primary  energy  savings  at 
European level; first it investigates the single technological solutions separately; then presents 
conclusions and ranking in the last Chapter. 

Chapter  2  presents  the  results  on  the  technology  adopted  and  efficiency  assessment  in 
thermal  power  plants,  with  particular  reference  to  conventional  fossil  fuels  (coal,  gas,  oil) 
power  stations,  complemented  by  selected  statistical  data  about  efficiencies,  consumptions, 
capacities,  etc.  The  report  describes  current  and  prospective  efficiency  levels  including 
estimates  of  potential  primary  energy  savings  under  some  assumptions  related  to  the 
decarbonisation policy currently adopted. 

The reason why efficiency in renewable electricity generation is not researched is essentially 
economic.  The  cost  structure  of  the  most  common  generation  facilities  is  strongly  lopsided 
towards investment costs (CapEx), while operation cost (OpEx) are limited to maintenance, as 
the  operators  do  not  have  to  pay  for  fuel  cost.  Consequently,  the  conversion  efficiency  of 
renewable  electricity  generation,  although  technically  interesting,  has  not  been  actively 
researched, and scientific literature is quite limited. Not very different considerations apply to 
the  nuclear  electricity  generation:  in  most  operating  nuclear  reactors  only  30-35%  of  the 
thermal  energy  produced  by  the  fission  is  converted  into  electricity,  while  the  remaining  is 
dissipated in the environment as waste heat. This share has only marginally improved in the 
last few decades. The cost structure of the nuclear electricity generation is quite similar, even 
if  not  identical  to  the  renewable  one;  the  bulk  of  the  costs  are  represented  by  the  CapEx 
(building and dismantling the plants), while the cost of fuel (usually enriched Uranium) only 
represents  a  small  share  of  the  total  generation  cost;  also  in  this  case  the  issue  is  poorly 
researched,  as  the  priority  is  improving  safety  and  reducing  downtime  for  refuelling  and 

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maintenance.  Some  projects  of  the  upcoming  ‘Generation  IV’  reactors  are  designed  for  an 
higher efficiency, but to date only prototypes exist.    

Chapter  3  describes  several  different  types  of  storage  available  for  electric  systems 
explaining the maturity of technologies, while providing more details for those technologies 
that  show  current  and  future  better  perspectives  (hydro  pumped  power  stations,  batteries, 
compressed  air,  flywheels).  Although  the  report  supplies  roundtrip  efficiency  assessments, 
one  should  also  consider  that  a  direct  comparison  in  terms  of  efficiency  among  storage 
alternatives  that  might  be  addressed  to  the  solution  of  very  different  technical  issues,  is 
difficult.  The  report  explains  for  example  that  one  cannot  use  (yet)  supercapacitors  to  deal 
with large amount of energy; each technical problem should be addressed by the proper class 
of  storage  systems;  within  that  class,  of  course,  the  most  efficient  technology  should  be 
adopted. The key message is that storage technologies are interesting not because they allow a 
direct saving of primary energy, but because they make it possible to integrate energy coming 
from Renewable Energy Sources (RES) into power systems, thus improving the efficiency of 
the system as a whole. 

Chapter  4,  dealing  with  HVDC  transmission  comes  to  similar  conclusions:  improving  the 
efficiency of transmission systems, which is already very high (about 98%) and approaching 
the  physical  limits  it  is  not  suitable.  HVDC  transmission  is  interesting  because  it  makes  it 
possible to transfer energy in conditions where HVAC systems would neither be technically 
nor  economically  affordable,  and  this  is  true  in  particular  for  subsea  cables  that  allow  the 
integration  of  wind  power  from  large  off-shore  wind  farms,  thus  resulting  in  an  indirect 
saving of primary energy. The chapter therefore describes the main characteristics of HVDC 
systems  and  presents  the  operating  conditions  leading  to  best  efficiency  and  highlights 
possible  future  uses  in  the  European  context.  In  fact,  the  real  efficiency  improvement  is 
indirect,  i.e.  improving  the  integration  of  renewable  energy  sources  and  minimizing 
curtailment; however these issues, as well as system integration, demand response and energy 
demand in general are outside the scope of the study. 

Chapter  5  reports  the  conclusions  of  the  assessment  carried  out  on  the  potentials  of  each 
technology for what  the energy efficiency is  concerned. Wherever possible, a quantification 
of realistic saving has been performed, under simplifying assumption, showing the potential 
for improvements in terms of primary energy saving. 

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