1K. Seymenliyski, S. Letskovska, P. Rahnev, The efficiency of tariff policy in the power system of Bulgaria, presented at the Conference Proceedings-Ten Years of the Establishment of a National Military Institute "Vasil Levski" [Online], Veliko Tamovo, Bulgaria, May 21-25, 2012, pp. 91-100, http://www.nvu.bg.
2K. Seymenliyski, S. Mollova, P. Rahnev, State of the tariff policy in power system in Bulgaria, presented at the Conference Proceedings- Ten Years of the Establishment of a National Military Institute "Vasil Levski" [Online], Veliko Tamovo, Bulgaria, May 21-25,2012, pp. 100-105.
3K. Seymenliyski, S. Letskovska, P. Rahnev, Technical Factors Influencing the Cost and the Price of Electricity, Annual Book, Burgas Free University, Bulgaria, 2011, pp. 74-78, http://www.nvu.bg.
4New Electricity Prices for Household Customers of EVN Bulgaria as of 1 August 2013, EVN Web site, Bulgaria, 2013, http://www.evn.bglMedii.
5Solar Radiation (Europe) in PVGIS, Joint Research Centre, Institute for Energy and Transport (lET) Web site, Feb. 2012, http://re.jrc.ec.europa.eulpvgis/.
7Investors, Solar Enterprise Ltd. Web site, Sofia, Bulgaria, 2013, http://solarenterprise. bg.
8Solar panels, photovoltaic, solar systems, controllers, Sofia, Bulgaria, 2013, http://elektronikabg.com.
9P. Rahnev, S. Letskovska, Solar panels-present and future, presented at the Conference Proceedings-"Challenges to Higher Education and Scientific Research in the Crisis" [Online], Burgas Free University, Bulgaria, 2010, http://www.bfu.bg.
