Case Study (143 Kb PDF)

Summary

A big pilot solar thermal installation was constructed and brought into operation in April 2002 in the elderly people home "St. Vassilij Veliki" in the town of Plovdiv, Bulgaria. The installation is situated on the flat roof of the building. It comprises 66 solar collectors, each of them with area 2 m2, with total area of 132 m2. The investment for the installation was provided within the framework of a 5-year Program of the Greek Government for Assistance to the Neighboring Countries. The aim is, by means of solar energy for heating the domestic hot water (DHW), to reduce the large expenses for energy bills and particularly for diesel oil. The results prove that the combined solar thermal installation with boilers on liquid fuels for DHW for a social house is a profitable socio-economic solution. This solution is economically attractive for the society. Besides, this action could be applied in all social houses, since the production of DHW is done on the base of local boilers on liquid fuel.

Results

The solar thermal installation was finished and brought into operation in April 2002. During the past 3-year period the operation of the system was monitored in the period April-October and the following conclusions were reached:

• The average annual use of diesel oil for heating purposes (heating and DHW) in the house is 160 tons. Thanks to the solar installation, the consumption of diesel oil is reduced in average by 20 tons. At the current price of diesel oil 1.65 lv/litre, the annual savings amount to 33 000 lv. (EUR 16 870).
• The price of the solar thermal installation comes up to EUR 64 500 or the simple pay-back is 3.8 years. This period could be reduced if the installation is adjusted for all-year operation.
• The annual energy saved is 232 640 kWh.