Energy saving measures in buildings and their influence to small district heating systems Frantisek Macholda Dept. of Economy, Management and Humanities Faculty of Electrical Engineering Czech Technical University in Prague

Overview The case of Orlova - the bad boys increasing a heat price! Economy of a district heating in a nutshell The energy model of a housing estate Findings Conclusions

The case of Orlova Housing Association

The case of Orlova Housing Association

Economy of a district heating in a nutshell Fix costs (maintenance, … and the network heat losses) Variable costs (fuel, ….) Total costs Unit costs High consumption = 100 units 50 100 150 150 / 100 = 1,5 Low consumption = 10 units 10 60 60 / 10 = 6,0 Heat losses of the network are independent on the amount of the heat transferred

The energy model - scheme

The energy model - possibilities Real weather data, calculation step - one day District heating network: medium temperature, OTC regulation pipelines diameters and insulations sections lengths Buildings (for each): energy standard (from original to passive) local energy sources for heating and/or DHW (solar systems, heat pumps, CHPP, local gas boilers, etc.)

Findings - a single building heat consumption Pre-reconstruction Passive reconstruction Passive reconstruction + solar

Findings - impacts of the energy saving measurements The whole building stock point of view: The heat sales drops with number of reconstructed buildings The heat losses of ditribution network remains unchanged Every piece of the heat produced must be paid by final customers The wasted heat costs must be dissolved into decreasing amount of heat sold => the heat price increases with number of retrofitted buildings

Findings - impacts of the energy saving measurements

Conclusions All the heat produced must be paid by end consumers Reconstruction of low % of buildings = no problem Massive % of reconstructions = significant impact! Heat price impact 10% penetration 50% penetration 100% penetration Passive retrofit + 3 % + 21 % + 76 % Passive + solar DHW + 25 % + 113 % Passive + heat pump DHW + 4 % + 37 % + 420 % Passive + heat pump heating + DHW + 5 % + 42 % + 1295 %

Conclusions The described effects are not occurring very often but should be taken into account in cases of: large building stocks retrofits government subsidy programs local heat distributors business planning

Thank you Contact info: Frantisek Macholda Dept. of Economy, Management and Humanities Faculty of Electrical Engineering, Czech Technical University in Prague machofra@fel.cvut.cz EkoWATT CZ s.r.o. frantisek.macholda@ekowatt.cz www.ekowatt.cz