The evolution of AS „Augstsprieguma tikls” from the beginnings until present.
The history of the company has started before the world wars. The company worked successfully during the Soviet Union times and has worked fruitful since the beginning of the independent Republic of Latvia.

The most significant events for the Company:

Year 2013, October 30. Joint study by Baltic country TSO’s and GothiaPower consulting company from Sweden on the interconnection of the Baltic power systems with Continental Europe power system and energy market integration has been completed.

Year 2013, September 25. 330 kV cable line RigaCHP1–Imanta has been commissioned, closing the 330 kV ring around Riga city and providing improved security of supply.

Year 2013, July 3. Latvian trading area has been opened within Baltic energy market. With this date NordPoolSpot day-ahead energy market ELSPOT has started operation in Latvia.
August 30. Latvian TSO AS “Augstsprieguma tikls” acquires 2% of the shares of NordPoolSpot.
December 10. NordPoolSpot intra-day energy market ELBAS has been opened in Latvia.

Year 2013, January 30. Public Utilities Commission in Latvia has issued decision on certification of the power transmission system operator by which AS “Augstsprieguma tikls” (AST) is approved as independent transmission system operator on the conditions that transmission system assets are maintained by AST and transmission system development, network construction, refurbishment and reconstruction be also provided by AST. These conditions are to be fulfilled not later than 24 months after the decision making.

Year 2012, December 1. Construction of Kurzeme Ring 2 stage, transmission line Grobina–Venstpils, has been started.
December 19. Reconstruction of the open-air switchyard at the 330 kV substation Imanta has started. Connection port for the cable line RigaCHP1–Imanta is constructed.
December 20. 110 kV cable line Milgravis–Bolderaja has been commissioned.
December 21. Reconstruction of the switchyard at the 330 kV substation RigaCHP1 has started. New gas insulated 330 kV switchyard and connection port for the cable line RigaCHP1–Imanta is constructed.

Year 2012, April 30. Contract between Baltic TSO’s and Gothia Power consulting company from Sweden has been signed to perform a study on the feasibility of the interconnection of the Baltic power systems with Continental Europe power system and energy market integration. Study will be co-financed by EU.

Year 2012, January 2. Ministry of Finance of Latvia after share purchase agreement signed on 30-th of December, year 2011 becomes sole shareholder of AST. AST is no more included in the “Latvenergo” concern.

Year 2011, January 12. Cabinet of Ministers of Latvia signs the order to create independent transmission system operator, Parliament accordingly passes necessary amendments to the Electricity Market Law.
April 1. New stock company “Latvijas elektriskie tikli”, fully belonging to AS “Latvenergo” has been established. AS “Augstsprieguma tikls” (AST) is independent system operator, but AS “Latvijas elektriskie tikli” (LET) is the owner of the assets of transmission system. AST in cooperation with LET determined competence and responsibility areas of the future operations.
November 23. Public Service Regulatory Authority of Latvia issues rules on the certification of the transmission system operator, and rules on the transmission system development plan, defining the most important requirements for AST as independent TSO for the next 10 years.

Year 2009. Reconstruction of 330 kV sub-station Valmiera is completed. After closing of Ignalina NPP at the end of 2009 Valmiera becomes important power transit substation within the Baltic transmission network, therefore it was crucial to complete its refurbishing before closure of Ignalina NPP and resulting changes in power flow patterns in the Baltic transmission networks.
June 17. President Ministers of Baltic States and President of European Commission sign „Baltic Energy Market Interconnection Plan” (BEMIP) outlining interconnection of Baltic power systems with European power systems and opening of common energy market based on Scandinavian energy market principles. Document is outlining also the development of Baltic transmission networks and receiving co-financing from European Commission.
July 1. ETSO is replaced by ENTSO-E as the association of European TSO’s. AS “Augstsprieguma tīkls” becomes full member of the ENTSO-E. ENTSO-E includes 41 transmission system operators from 34 EU countries.

Year 2008. Reconstruction of 110 kV substations Riga CHP2 and Aizkraukle has been completed.

Year 2007, January.  AS “Augstsprieguma tikls” becomes full member of the European Transmission System Operator Association (ETSO).

New 330 kV sub-station at the Riga CHP2 has been commissioned.

Year 2006, March 30. Agreement on creation of Baltic TSO cooperation organization BALTSO has been signed in Riga by AS “Augstsprieguma tikls”, OU “Pohivork” and AS “Lietuvos Energija”. Agreement on dismissal of DC Baltija at the end of 2006 has been signed also.
December 1. After dismissal of Dispatch Centre DC Baltija AS “Augstsprieguma tikls” takes over functions of DC Baltija, creating two new divisions under System Control Department – Block Coordination Dispatch Department and Block System Security Department.
December 28. Agreement on parallel operation of power systems in Estonia, Latvia and Lithuania has been signed by AS “Augstsprieguma tikls”, OU “Pohivork” and AS “Lietuvos Energija”.

Year 2005, September 1. Latvenergo branch "Augstsprieguma tikls" (High voltage network -lat.) has been transformed into AS “Augstsprieguma tikls” (stock company) and is licensed by Public Service Regulatory Authority to perform electric energy transport on the whole territory of Latvia.
September 28. AS “Augstsprieguma tikls” becomes associate member of the European Transmission System Operator Association (ETSO).
December 6. AS “Augstsprieguma tikls” becomes 33.33% shareholder of DC Baltija instead of Latvenergo. OU “Pohivork” becomes 33.33% shareholder of DC Baltija instead of State Company “Eesti Energia” of Estonia, while stock company Lietuvos Energija remains 33.33% shareholder of DC Baltija from the Lithuanian side.

Year 2004. 330 kV switching point Liksna has been reconstructed.

Year 2002. Open air switchgear reconstruction at the 330 kV substation Riga HPP has been completed. SF6 circuit breakers have been installed on each connection point improving safety of the connection scheme. Construction of secure power supply scheme for Ventspils city is completed by commissioning of two new 110 kV substations Venta and Ventamonjaks, thus closing the 110 kV supply ring around Ventspils city.

Year 2001. Construction of new 110 kV substations Hanza and Bastejkalns in Riga city has been completed along with 110 kV cable line Grizinkalns – Hanza – Bastejkalns. Shunt reactors for reactive power compensation and voltage control has been installed at the Rezekne substation. Reconstruction of the 110 kV sub-station Riga CHP1 has been completed.
February 7. Parallel Operation agreement between power systems of BRELL (Belarus, Russia, Estonia, Latvia and Lithuania) has been signed along with agreements on operative control of the transmission networks and network development.

Year 2000. Reconstruction works at the 330 kV substation Riga CHP1 and 110 kV substations Plavinas and Aizkraukle has been finished.

Year 1999. Has been reconstructed 110kV substations Dzintari, Grizinkalns and Bauska.  New 110kV cable lines Grizinkalns – Hanza in Riga and Ventspils – Venta in Ventspils has been constructed.

„Augstsprieguma tikls” AS approves the concept of 330 kV and 110 kV transmission network and substation development and reconstruction plan.

Year 1998. The memorandum ofunderstanding between 17 energy systems of Baltic Sea region has been signed in Stockholm, what could consider for the first step on the Baltic energy ring establishment. This BALTREL Project provides the close cross-border cooperation on the energy production, transmission, distribution and trade. Also Project provides Baltic power systems connection to the BALTREL network, realizing future transmission network integration and energy production efficiency increasing.

For technical losses reducing in 110-330kV transmission network in Latvia and for transmission network security increasing, voltage level guaranteeing, is decided about reactive power compensation shunt reactors installation in the Latvian transmission network important nodes.

The first shunt reactors are installed in the substations Grobina and Valmiera.

Year 1997. Substation Salaspils 330kV switchyard reconstruction has been finished.

Year 1994. AS Latvenergo, Lietuvos Energija AB and OÜ Esti Energia signed the Agreement on the Parallel Operation of the Power Systems of Lithuania, Latvia and Estonia.

17 Energy companies from 11 Baltic Sea countries start to develop new alliance Baltic Ring Electricity cooperation (BALTREL) establishment.

Year 1992, January 7. Government representatives from Estonia (A.Hamburg), Latvia (A.Millers) and Lithuania (L.Ašmantas) have concluded the Treaty on Parallel Operation of Baltic Power Systems anddecided to establish DC Baltija Control Centre in Riga on the base of former Control Centre of the NW IPS of UPS.
March 9. To supervise and control the power systems of Estonia, Latvia and Lithuania, the DC Baltija Control Centre was established in Riga using the assets and human resources of the former Control Centre of the NW IPS of UPS.

Year 1991. Baltic countries have got independence from Soviet Union and Baltic power systems have discontinued subordination from USSR energy institutions.

Year 1989. The construction works of 750 kV electric transmission line has been stopped. Three sections of built 750 kV line and construction site of 750 kV sub-station Eleja are still de-energised and intact in Jelgava region.

Year 1987. The construction of 750 kV electric transmission line Ignalina – Latvia and substation Latvia have been started.

Year 1986. New building of AS Augstsprieguma tīkls in Riga, 86 Darzciema street is commissioned.

Years 1970 – 1994. New substations have being constructed and put into operation. Refurbishing of old 110 kV power lines and replacement of old wood pylons with steel reinforced concrete pylons is going on. Second transformer installation takes place on many 110 kV substations.

Year 1964. The Belorussian power system has been connected to the parallel operation to the Unified Power System of the North-Western region.

Year 1961. Latvian power system has been connected to the Lithuanian power system to work in parallel with the transit interconnection of 330kV from Salaspils via Jelgava to Siauliai.

Year 1961, January. In Riga the Control Centre of Unified Power System of the North-Western region of the Soviet Union (NW IPS of UPS)started to operate. It connected the power systems of Lithuania, Latvia and Estonia, and the power systems of six administrative regions of Russia: Karelia, Leningrad, Kaliningrad and others.

Year 1960 – 1969. All high voltage lines updated to 110 kV voltage and developed standards and tolerances of 330 kV lines for adoption.

Year 1960. The first 330kV overhead transmission line between Estonia and Latvia is constructed, which established parallel operation for the Estonian and Latvian power system. It became a precursor for further common Baltic power system operation.

Year 1959. Augstsprieguma tikls operated 765 km 110/88 kV lines and 16 substations with 32 transformers with a total capacity of 324.6 MVA.

Year 1956. Re-organization in Augstsprieguma tikls. Out of the four areas were set up two special regions that deal with all the 110 kV line maintenance and repair works of the republic of Latvia. In practice two departments have beingorganised: Line Department and Substation Department.

Year 1950. Central energy region was renamed to Augstsprieguma tikls, who is the owner of 88 kV power lines with total length of 408 km and 9 substations.

Years 1950 – 1959. In Latvia were years of an active grid construction. New substations and transmission lines are built. Start of development of the communications cable network for LATVENERGO needs.

Year 1946. Central energy combine is renamed to Central energy region.

Years 1944 – 1950. Latvian electricity grid renovations are actively started together with construction of new substations and power lines. Within a short time the level of power grid development of a year 1943 is reached. Network and substation equipment is adjusted to 110 kV voltage and high frequency communication system is established.

Year 1944. The German Army destroyed most of the Latvian power plants and substations. It is decided to create a high-voltage network business, but as the high-voltage lines and substations are destroyed instead Central energy combine is being created.

Years 1940 – 1943. Electricity networks continued to Vidzeme, Jelgava and Sloka direction. Some lines and substations construction went to Liepaja direction. After Soviet Union troops entered in Latvia and subsequent change of government in the whole republic of Latvia, whole electricity power system in July 1940 was transferred to the Latvian PSR People's Commissariat of Local Industrial Energy Trust's  responsibility, but in March next year created a local industrial company's High Commissioner for Energy management LATENERGO, its authority by transferring all Latvian existing electricity companies - from the current energy combines  and power plants.

Year 1939. In order to produce electricity of Kegums hydro power plant and supply it to customers in Riga and whole Latvian regions, in parallel with construction of Kegums power plant new substations in Kegums, Janciems, Viskali, Jelgava and in City Park in Riga were started to be built. Construction of the 88 kV power lines from Kegums to Riga (double circuit line), from Riga to Jelgava and from Kegums to Ieriki was started as well. Construcion of new 20 kV power lines from Jelgava to Bauska and from Ieriki to Valmiera took place as well. In the autumn of 1939 the company Siemens installed four 98 kV cables in Daugava river bed in order to deliver generated power of Kegums hydro power plant from the substation Janciems to supplying customers on the left bank of Daugava river.
October 15. The first hydro power unit in Kegums power plant was started with a capacity of 17,500 kW, power lines from Kegums to Riga were built and technologically advanced at the time the Park substation in Riga was comissioned. For first time at 23:36 the consumers in Riga received the power from Kegums hydro power plant. This day is regarded as beginning of history of „Augstsprieguma tikls” AS. Major Latvian newspaper headlines heralded: „Today Kegums light begins to flow to Riga!”
December 22. The President of the Republic of Latvia Karlis Ulmanis signed the law on the National Electricity Company "Kegums" establishment. This date is a birthday of unified electrical system and common Latvian energy family.