Impact Analysis - Electricity - Final Report

Abstract:

This project assessed the potential impact of selected, identified innovations on specific types of network (relating to heat, gas, electricity and hydrogen). Generic modelled networks will be developed utilising the 2050 Energy Infrastructure Cost Calculator model developed by a separate ETI project to understand the expected costs of certain types of network. The modelled networks will provide ‘business as usual data’ and a useful basis for further understanding of the impact of identified innovations in terms of overall cost and network performance.

This report considers electricity. Key points are:-

• Representative electricity transmission network model: Electricity networks modelled for 275kV and 400 kV network capacity
  • The increase in the costs is proportional to the increase in the network length for the same network capacity and installation date.
  • For the same installation date, NPV total per km is higher for the higher capacity network.
• Representative Electricity Distribution Model: Electricity network modelled in rural, semi-urban, urban and London context
  • The share of costs represented by each of the Assemblies changes slightly from 2020 to 2040, following the same trend in all contexts, except for London.
  • Residential connections represent one of the highest costs in all contexts.
  • The LV network makes a high contribution to total cost in the urban context while in London the LV substations make the highest contribution.
  • First costs per capita increase as the context changes from rural through to urban areas.
  • First costs per capita decrease slightly from urban to London contexts.
  • The NPVs per capita increase as the density increases.
  • One additional factor that influences costs in different contexts is their different lifecycle profiles.
• Generic upgrade costs at transmission scale: upgrading existing 275kV and 400kV lines to increase capacity by ~100%
  • For the same installation date, Capex NPV per km is higher for the installation of a higher voltage network.
  • Opex NPV per km is higher for higher voltages
• Rapid car charging: upgrading existing distribution networks to allow for connection of rapid car charging units
  • Costs for the upgrade of the distribution network are dominant in all variations and contexts.
  • For the same number of connection points at the same installation date the installation of rapid charge connections is more costly in the semi-urban context.
  • he first costs and NPV per connection fall as the number of connections increases, which indicates that it is more cost effective to install a group of charging points than isolated single charging points.
• Rapid car charging: impact of network reinforcement that could be required due to significant increase in electric vehicles in a residential context (semi-urban and urban)
• The analysis is based on the assumption that there is a 50% increase in peak load due to a significant increase in the use of EVs.
• The LV network represents the highest share of reinforcement costs in all contexts, with costs per capita being higher in urban areas than semi-urban areas.
• Storage v reinforcement: analysis to explore the costs of storage compared with conventional reinforcement in three different applications –increase in local demand; distributed energy exporting to grid; installation of rapid car charging units
  • The analysis suggests that considering current prices for electricity storage,l reinforcement is cheaper both in terms of Capex and Opex.
  • Car charging: local generation may improve the potential for storage if the existing OHL has limited potential to charge batteries during periods of low demand.
• Fault Current Limiter v Reinforcement
  • Conventional reinforcement is currently more cost effective than refurbishment of the substation with the installation of the FCL
• Power electronics: assessing the costs of using power electronics using STATCOMS for rural windfarms with utility scale battery storage
  • STATCOMs: the costs of the complementary utility scale battery dominate. 
  • The impact of the utility scale battery on the costs of the project increases at the later installation date
• Power electronics: assessing the costs of using power electronics using back-to-back HVDC connection for coupling DNO networks
  • The costs of the back-to-back converter dominate
• Cost comparison of up grading HVAC vs installing new HVDC at transmission level in rural areas–within an existing wayleave and in a new wayleave
  • One of the main differences between HVDC and HVAC is intransmission losses.
  • There is significant uncertainty with the planning consent process for installing new or refurbishing existing HVDC OHLs in the UK

Publication Year:

2016

Publisher:

ETI

DOI:

https://doi.org/10.5286/UKERC.EDC.000671

Author(s):

Gkogka, A. and Cooke, H.