1. 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

2. 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

3. The case of Orlova Housing Association

4. The case of Orlova Housing Association

5. 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

6. The energy model - scheme

7. 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.)

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

9. 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

10. Findings - impacts of the energy saving measurements

11. 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 % %

12. 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

13. Thank you
Contact info:
Frantisek Macholda
Dept. of Economy, Management and Humanities
Faculty of Electrical Engineering, Czech Technical University in Prague
EkoWATT CZ s.r.o.