The project has saved 9,3 million CZK in average every year since 2008 in electricity, gas and water. The gas consumption has dropped by 50 %. The drinking water saving per year can be illustrated by 10 full Olympic swimming pools. The amount of electricity saved in 10 years is the yearly consumption of 3,250 households. The overall saving exceeds the investments by almost 18 million CZK. “We consider the project successful. Due to the fact that real saving outstripped the guaranteed one by almost 10 %, the investment returned earlier than in 10 years,” explains prof. MgA. Jan Burian, the director of the National Theatre. “The investment has been paid and we save energies of more than 9 million CZK every year.”
Many changes have taken place in the National Theatre buildings. The operations building and the New Stage have a sensitively located photovoltaic power plant on their roofs, which is part of roof waterproofing and can be seen only from above, thus it does not disrupt architecture of the surroundings. Warmth from the hydraulic heated oil in the stage technology is used to heat warm water. Oil was cooled down by drinking water in the flow before. Heat and cold is taken from the air conducted out of the stage and then returns back to air. There is a heat pump in the underground, which is able to heat or cool when it is connected to water in Vltava. Yet it can heat and cool at the same time. Heat from the insulated facades requiring cooling is used for heating the uninsulated parts of the buildings. CO2 sensors monitor the air inside and the air-conditioning system is set automatically. The special system regulates temperature in each room individually. All the data are evaluated in the dispatching centre and spots with the saving potential are being looked for. Bulbs and fluorescent lamps have been substituted by energy saving lights, some of them are controlled by motion and light sensors consuming up to 80 % less electric energy. The color of the light remained the same. A geocaching path around the National Theatre with information about the ND+ educational project National Tracking Game or Find a QR Code, which is part of the accompanying program, was installed last year.
In 2011 the National Theatre was part of the Best Energy research project focused on demonstrating the enhancement of energetic effectiveness of public buildings due to the application of advanced information and communication technologies. The National Theatre has become a European model project in the field of reducing the energy demands in historical objects.
A special SW application OPERETA was developed for the National Theatre in order to model operation for the upcoming 24 hours according to using stages and rehearsing rooms, weather forecasts and thermal characteristics of buildings. With the Opereta application, further saving between 4 – 7 % of the overall heat consumption has been attained. The time of air condition operation has been cut down to 45 %. Another benefit is making the job of the dispatching staff easier. Based on good results, the system has been implemented in Rudolfinum, the Estates Theatre and other objects, where ENESA provides similar services.
The costs for realization of all measures have been paid from future energy saving, which was guaranteed for the National Theatre in the contract and it is the basic principle of EPC (Energy Performance Contracting). Detailed information about the most well-known energy saving project with Energy Performance Contracting can be found at http://www.uspornedivadlo.cz/