ESTONIAN ACADEMY
PUBLISHERS
eesti teaduste
akadeemia kirjastus
PUBLISHED
SINCE 1984
 
Oil Shale cover
Oil Shale
ISSN 1736-7492 (Electronic)
ISSN 0208-189X (Print)
Impact Factor (2022): 1.9
ENERGY PRODUCTION AND CONSUMPTION CHARTS IN ENERGY SYSTEM; pp. 309–318
PDF | doi: 10.3176/oil.2009.3S.12

Authors
J. LEPA, A. ANNUK, E. KOKIN, V. PÕDER, K. JÜRJENSON
Abstract

The main task of the energy system is to supply the consumers with high-quality electric and heat energy. As possibilities for accumulation of the energy and especially electrical energy in Estonia are very limited, one of the main energy parameters is its uninterrupted supply. The needs of consumers are charac­terized by the demand curve – the variation of load for a given time period (day, month, year). It is necessary to stress the difference between load and demand curves for the producer and consumer. Up to the recent time the producer load curve consisted of the individual consumers’ demand curves sum plus losses in the distribution elements (in electric net­works). Nowadays when by economical and ecological reasons the renew­able energy sources are more intensively used, the part of the energy pro­ducers using wind and solar energy is constantly rising, and they are increasingly influencing the work of the whole energy system. That complicates significantly the work of the high-powered electric energy generators (with large inertia) at power stations as, in addition to the load variations depending on demand, they have to compensate extremely stochastic production of wind turbines. In this paper the problem is discussed on the basis of load and demand curves of the Energy system of Estonia and Pakri wind farm. It is shown that these curves are not suitable for mutual compensation and that may disturb the stability of the energy system at the wind park maximum power. The result is that the Energy system dispatcher is forced to limit the production of the wind park.

References

  1. Statistical database: Economy − Energy − Energy consumption and production. http://pub.stat.ee/px-web.2001/I_Databas/Economy/07Energy/02Energy_consumption_
and_production/01Annual_statistics/01Annual_statistics.asp [24.01.2009].

  2. Tammeoja, T., Reinsalu, E. Forecast of Estonian oil shale usage for power genera­tion // Oil Shale. 2008. Vol. 25, No. 2S. P. 115–124.

  3. Estonian Encyclopaedia. Vol. 5. Tallinn, Estonia: Valgus, 1990. P. 740 [in Estonian].

  4. Kokin, E., Peets, T., Jürjenson, K., Lepa, J. The shape factor of demand curve // Agri­cultural Machinery, Buildings and Energy. Transactions No. 204. Tartu: Estonian Agri­cultural University, 1999. P. 90–94 [in Estonian].

  5. Nordex_N80- N90 Product Sheet. http://www.nordex-online.com/fileadmin­/MEDIA/Produktinfos/EN/Nordex_N80-N90_GB.pdf [24.01.2009].

  6. Raesaar, P. Resource and utilization of Estonian hydropower // Oil Shale. 2005. Vol. 22, No. 2S. P. 233–241.

  7. Liik, O., Oidram, R., Keel, M., Ojangu, J., Landsberg, M., Dorovatovski, N. Co-operation of Estonia’s oil shale based power system with wind turbines // Oil Shale. 2005. Vol. 22, No. 2S. P. 127–142.

  8. Meldorf, M., Täht, T., Kilter, J. Stochasticity of the electrical network load // Oil Shale. 2007. Vol. 24, No. 2S. P. 225–236.

  9. Valdma, M., Keel, M., Tammoja, H., Kilk, K. Reliability of electrical power generation in power systems with thermal and wind power plants // Oil Shale. 2007. Vol. 24, No. 2S. P. 197–208.

10. Lehtla, T., Järvik, J. Estonian possiblity – real time electricity tariff // Eesti Päevaleht. 24.03.2008 [in Estonian].

11. Tänavsuu, T. Smart meter is gaining share // Eesti Ekspress. 20.03 2008 [in Estonian].

Back to Issue