資料3

Electricity Network Tariffs
Manuel BARITAUDEGC Working Group
METI, Tokyo
11 November 2016
© OECD/IEA 2016

The Future: Utility Scale Renewables?

World’s largest PV Plant-Solar Star, California:
around 600 000 kW spread over 25 square kilometres© OECD/IEA 2016

Or Off-Grid Solutions?
Off-Grid Solutions© OECD/IEA 2016

Outline The changing role of networks
 Principles of network tariff design
 Locational signals
 Network tariff structure Regulation 2.0© OECD/IEA 2016

Outline The changing role of networks
 Principles of network tariff design
 Locational signals
 Network tariff structure Regulation 2.0© OECD/IEA 2016

Efficient Co-ordination Between Generation
and Network Needed at all Levels
Where to Invest?
Continental Markets

Locational Markets

Local, Distributed Markets

Market designs with a high geographical ‘resolution’ can provide incentives for
efficient and secure co-ordination of distributed power resources and across borders.

© OECD/IEA 2016

Network as the Backbone of Low-Carbon
Electricity Markets
New Transmission Investments between
Renewable Energy Zones and Load Centres in Texas

Renewables can be deployed in 2-3 years, much more rapidly than new transmission,
which takes at least 7 years … and this can create congestions.
© OECD/IEA 2016

European Interconnections are Promotedby the EU to Reinforce the Internal Market
EU Interconnection Levels in 2020 After the Completionof Current Projects of Common Interest

Interconnectors between countries already represent 11% of installed generation
capacity and Europe is currently introducing a target of 15% by 2030
© OECD/IEA 2016

Meeting Decarbonisation Targets Requires
a Strong and Reliable Transmission GridTrilemma of Transmission and Distribution Planning

Cross-regional interconnectors are often a cost-efficient alternative to investingin other resources in order to balance a system with high shares of VRE© OECD/IEA 2016

Changing role of networks

Reduced Energy Flows

But More Frequent Congestions

 Declining demand Large renewable capacity needed Distributed generation reduces Local acceptability problems

energy flows on the network
 Network investments remain keypriority
 Efficient resource planning© OECD/IEA 2016

delays transmission investments
 Non-transmission options (storage) Curtailment helps to integrate
higher shares of renewables

Outline The changing role of networks
 Principles of network tariff design
 Locational signals
 Network tariff structure Regulation 2.0© OECD/IEA 2016

Network Tariffs: High Level Principles
The overall objective of network tariffs is to ensure fair
access to, and to regulate, a natural monopoly Access to the Network on Equal Terms
 Cross-subsidies between different consumers (by voltage level) Avoid price squeeze of competitors and foreclosure of the market

 Unbundling of Generation Activities and Network Different type of unbundling (accounting, legal, ownership) Key issue is the allocation of common and overhead costs

 Cost-Reflective Tariffs Send the Right Long-Term Signals
 Congestion costs can be either mutualised or explicitly charged
 Long-run costs calculation methodology⇒ Network charges are a significant part of final electricity bills

and influence both the level and the structure of final electricity prices© OECD/IEA 2016

Network Tariffs Level
 Capital expenditures
 Operating expenditures
 System services costs
 Congestion costs, if not reflected in energy market prices
 Network losses, included or not© OECD/IEA 2016

Network Tariffs Differentiationand Structure
Key dimensions: Connection Charge (deep versus shallow connection costs)
 Differentiation by Voltage Level
 Generation and Load (G/L) Tariffs
 Geographical Differentiation
 Capacity and Energy Components
 Time Differentiation© OECD/IEA 2016

Outline The changing role of networks
 Principles of network tariff design
 Locational signals
 Network tariff structure Regulation 2.0© OECD/IEA 2016

Locational signals:
energy prices Vs network tariffs
Highly Meshed Networks

Radial Networks

 Energy flows different from Dominant physical flow of electricity-> Zonal energy prices provide
locational signals in Continental Europe-> Geographical differentiation of theG-tariff provide locational signals in the UKcommercial flows New transmission benefits arespread over many countries Fragmented regulation© OECD/IEA 2016

(North-South) Benefit of new transmission canbe allocated One regulator

Using G-tariff to provide locationalsignals for generators
 Generators can be charged a significant fraction of costs ‘Postage stamp’-like tariffs
 Postage stamps can be differentiated by network company
and/or zone Energy or capacity charge?

 Compensation between TSOs for transit energy flows
 Cost-reflective tariffs can be based on long-run

incremental costs (LRIC)© OECD/IEA 2016

Outline The changing role of networks
 Principles of network tariff design
 Locational signals
 Network tariff structure Regulation 2.0© OECD/IEA 2016

Capacity and Energy Componentsof Network Tariffs
 Existing network tariffs based mainly on energy Consumers used to be inelastic to electricity prices
 Different options (multipart-tariffs)

 Utility and network companies ask regulators to moveaway from electricity tariffs based on energy A capacity charge provides more stable revenues fornetwork operators

 Declining total electricity demand Increasing of distributed resources A capacity charge is more cost-reflective
 Investments driven by peak load

⇒ A clear trend of rebalancing from the energy to capacity charge is taking
place in countries with rapid deployment of rooftop solar PV© OECD/IEA 2016

Distributed Resources Can Be Financed
by Savings on Electricity Bills
Comparison of LCOE for PV and the Average Retail Price in Germany
400

TaxesUSD/MWh350
300

Policy surcharges +concession fee

250EEG

200
150
100
500

Fixed network charge
at 3%interestrate

at 7%
interestrate

Service charges
Energy procurement

LCOE
Rooftop solar PV

Average retail priceBehind the meter generation and storage can be installed rapidly
while a retail-price reform may take some time to implement.
© OECD/IEA 2016

A Slippery Slope Towards Self-Consumption

Regulation of retail and network prices have to adjust to a reduced
billing base and retail prices should give the right incentives toboth network users and distributed energy resources.
© OECD/IEA 2016

Network Tariff Structure Can Be
Improved to Better Reflect Costs
Network charges in Spain
100%
80%
60%

Consumption

40%

Contractedcapacity

20%
0%

Up to July From Feb.
2013
2014
Residential

Up to July From Feb.
2013
2014
SME and commercial

Up to July From Feb.
2013
2014
Industrial

Rebalancing from a volumetric charging basis towards a capacity
basis better reflects the cost structure of distribution networks.
© OECD/IEA 2016

Tariff Rebalancing to a kW Charge Raises
Many Implementation Issues
 Cost-reflective tariffs are difficult to calculate Many methodologies for the allocation of fixed and common costs

 Higher capacity charges increase smaller consumer bills
 Retroactive change affecting the economics of rooftop

solar PV In Nevada, the regulator decided the grandfather clause for tariffs
for solar PV already installed High-capacity charge creates incentives for peak-load

shaving and for installing storage behind the meter Tariff-rebalancing should not discourage the installationof behind-the-meter generation where it is efficient© OECD/IEA 2016

Network Tariffs Can Be a Barrierfor Demand Response and Storage Demand Response Issue: demand response requires high price difference between thepeak period and off-peak period Ongoing discussions about the need for network tariff options
specific for critical peak pricing (demand response), to the extent
this reflects network costs Electricity Storage
 Issue: Electricity storage plants are both loads and generators andhave to pay the G and L components of the tariffs, which increases
cost of storage
 Storage companies (such as pumped hydro) ask exemption from allor part of network tariffs© OECD/IEA 2016

Outline The changing role of networks
 Principles of network tariff design
 Locational signals
 Network tariff structure Regulation 2.0© OECD/IEA 2016

Ofgem’s RIIO Regulation
Constraints set up-front to ensure:

Revenue=Incentives

Networkcompanies
arefinanceable

Transparency
andpredictability+Outputs

Flexible for
new outputs

Deliver outputs efficiently over time with:
Up-front
efficiency rate

8-year control+
Innovation

Balance between
costs faced bycurrent andfuture consumers

Rewards/penalties

Technical and commercial innovation
Core pricecontrol incentives

Exploring competitivetendering

Innovation
stimulus package

Outputs set out in clear contract
Source: Ofgem

Output-oriented incentive scheme contributes to tap the potential of new
distributed resources to optimise network investments and minimise overall costs© OECD/IEA 2016

Distributed Market Platforms

Wholesale Markets
Transmission Level

Network
Distribution Market

DisCo

DisCo

Aggregated Active Generation

Aggregated Active Loads
Two-way information and physical flows
Option 2:
Simultaneous participation in distribution and wholesale markets

Option 1:
Participation as net load or net generation

A network regulation 2.0 is needed to establish a smart distribution network,
enabling market platform where distributed energy resources can participate© OECD/IEA 2016

Conclusions
 Networks remain the backbone of power systems. They

will not disappear, but their utilisation is changing.

 Network tariffs have to ensure undistorted competition.
 Cost-reflective tariffs send the right signals to themarket and should not be distorted to promote
specific technologies.

 Locational signals can come from energy prices or can bebased on G-tariffs in radial power systems.

 Tariff rebalancing from energy to capacity but raises

implementation issues.

 Integration of distributed resources calls for amodernisation of network regulation.

© OECD/IEA 2016

Thank you
http://www.iea.org/topics/electricity/publications/re-poweringmarkets/© OECD/IEA 2016

Efficient Deployment of Behind-the-Meter
Resources Requires Modernised Retail Tariffs
An Example of Hourly Profile of Household Load and Solar PV Generation

Real-time pricing reflects the variations in the cost of electricity generation,
providing consumers the right incentive to install storage and generation© OECD/IEA 2016