2. Elering AS
Elering is managing Estonian electricity and gas transmission systems with purpose to ensure high-quality energy supply to Estonian consumers at every moment.
Starting from 02 January 2015 Elering AS (electricity TSO) is majority shareholder of Estonian gas TSO Elering Gaas AS
Efforts towards full ownership underway
Target to finalize merger of electricity and gas TSO-s by 2016

3. Estonian Gas Market – Recent Developments
Key figures 2014
Network length
885km
Transmission volume
538 mcm
Peak day
4,5 mcm
Forecasted demand for 2015 (ca 500 mcm) ca 50% from year 2006 (1008 mcm).
Over 60% of gas is consumed in Tallinn area
Elering operates pipelines with MOP38 and MOP55 bar; non-odorized gas
Interconnections with Russia (2) and Latvia (1)
In 2014 nearly 100% of import was by Eesti Gaas - in share of gas import from Lithuania ca 24%
Metering stations (#) 2
Regulation stations (#) 37

4. Over 60% of gas is consumed in Tallinn area

5. Gas Demand Annual Monthly profiles
Further decline in demand is expected due to fuel swich in district heating

6. Grid development
Estonia-Finland interconnection (Balticconnector)
Estonia – Latvia interconnection enhancement (bidirectional flow) – 2019
Projects are intended to develop regional Baltic-Finnish gas market
An integrated market with a larger market area and higher gas demand enables additional opportunities for new market-based supply sources (incl renewable gases)
Considering the huge potential of renewable gas (biomethane etc.) in Finland and other Baltic countries the new interconnections have a considerable role in developing a renewable gas sector in the region.
The vision is to support development of a renewable gas hub in the Baltic-Nordic area to contribute to climate goals by enhancing gaseous renewable fuel uses

7. Developing regional gas market
After acquisition of gas transmission network by Elering in the beginning of 2015 the Baltic gas market coordination group worked out short-term measures brought out below. Complete Baltic-Finnish gas market action plan will be composed beginning of 2016.
Harmonization of gas Network & Storage Access Rules in the entire gas market of the region
Accounting of cross-border gas flows offsetting the differences in energy value
Harmonization of gas quality requirements
Harmonization of the gas supply licencing framework (retail and wholesale) in the region
Roadmap for harmonized implementation of requirements of European Network Codes in Baltic States and Finland;
Financing of EU Projects of Common Interest (PCI)
Harmonization of measurement of gas flows for technical and commercial purposes in energy units (kWh at gross calorific value)
Launching a common virtual trading hub and a gas exchange in the region
Establishment of common gas Data Hub platform
Data exchange
Common approach to the definition of protected customers

8. Gas networks in Estonia
Gas distribution grids covering only limited area close to transmission pipelines (green circles)
Most of territory is not covered by distribution networks
Low demand – most of potential sites of production can’t be connected to distribution grids
Network configuration does not meet needs of distributed production/consumption, especially CNG stations

9. Gas Quality Standards
Quality standard of gas injected into Estonian transmission grid (MOP38; MOP55)
Quality requirements harmonazed with Baltic TSO-s
Follows EN (Draft when Baltic standard was adopted);
Common requirements for gas transported between Baltic gas systems

10. Corrosion – the main issue with renewable gases in transmission grid
The corrosion due to substances like H2S, O2, H2O, etc
Increasing oxygen content from 0.2 to 1% doubles the carbonic acid corrosion rate bar)
The hazardous corrosion rate sensitive to pressure
Oxygen limits for low (<75 mbar) pressure not limited and for intermediate pressure (75 mbar to 2 bar) up to % mol
Oxygen limits for transmission over 0,2 % mol, generally considered as substantially increasing risk of damage
Pipeline inspection have revealed considerable corrosion damage due to H2S, O2, H2O, whereupon the oxygen content was limited to 2 vppm
It is likely that a complex interaction between oxide, carbonate and sulphide corrosion products will occur that could either lead to localised attack (and consequently higher corrosion rates)
Further research would be required to determine the effect of higher oxygen partial pressures which would be generated in gas transmission and distribution pipelines
Elering is planning a reserch project in cooperation with Tallinn University of Technology to introduce justified requirements for renewable gases content, taking into account the aim to promote development of renewable gases

11. Gas quality standard, Estonian TSO
ERG-TS 9:2015
1 - Oxygen level of biomethane injected into transmission grid (38 or 55 bar) is ≤ 0,5 (% mol), presuming blending and co-mingling with natural gas in certain injection point. At the same time in all exit points gas blend must fulfil oxygen level ≤ 0,02 (% mol).
Gas infrastructure - Quality of gas - Group H
EN 16726

12. Conclusions
Elering as TSO promotes diversification of supply sources of gas, especially local (regional) production of renewable gaseous fuels
Transport sector could be a driver of increased demand and also local renewable gas production
Connection of new renewable gas production and CNG stations to grid is limited due to poor geographical coverage of todays network – need to review the topology
Content of hazardous substances in renewable gases imposes certain risk to gas pipelines - target to find balance between risks and costs
Based on the huge potential of renewable gas (biomethane etc.) in Finland and other Baltic countries, vision is to support development of a renewable gas hub in the area to contribute to climate goals by enhancing gaseous renewable fuels use.

13. Thank you! Mart.Landsberg@elering.ee