PhD student Mikko Wahlroos Supervisor Prof. Sanna Syri. Department of Mechanical Engineering

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1 Department of Mechanical Engineering PhD student Mikko Wahlroos Supervisor Prof. Sanna Syri Smart low-carbon district heat systems supporting the energy system transition Following issues are considered in order to utilize District Heat (DH) networks efficiently in carbon-neutral future: 1. Energy efficiency Increased utilization of waste heat the case of cold climate data centers in Nordic countries 2. Cost effectiveness New mechanisms for DH pricing e.g. hourly pricing Two-way district heat network 3. Flexibility Demand side management of heat increasing customer interaction in the heat markets 4. Role of Combined Heat and Power (CHP) in DH systems Possibilities for both small- and large-scale biomass CHP

2 Potential for demand side management of district heating in Otaniemi campus and Espoo Case: TUAS-building pilot Mikko Wahlroos, Aalto Yliopisto Vihreä Foorumi: Älyteknologiasta ja avoimesta datasta vauhtia energiatehokkuuteen Kaukolämmön kysyntäjouston potentiaali Otaniemen kampuksella ja Espoossa Case: TUAS-talon kysyntäjousto pilotti, Helsinki Source: Aalto University,

3 Contents Introduction Demand side management of district heating DSM pilot in TUAS-office building Scaling TUAS-pilot to Otaniemi and Espoo 3

4 Aalto University Properties & Otaniemi Ecocampus 2030 Aalto University Properties Ltd are carrying out Ecocampus project to increase energy self-sufficiency and energy efficiency in their buildings in Aalto University s Otaniemi Campus. - Aalto University Properties owns most of the buildings in Otaniemi Campus area - Electricity consumption 37GWh and DH consumption in Otaniemi 45GWh in New projects related to energy efficiency and increasing the share of renewables in both electricity and heat production have been implemented and planned in the Otaniemi campus area. Ecocampus 2030-project is conducted in close co-operation with several research institutes, commercial enterprises and external consultants. 4

5 DH load (MW) Temperature ( C) District heating in Espoo District heating (DH) is produced according to production costs of different DH technologies and the production can be roughly separated into two categories: Base load production: in Nordic countries mainly combined heat and power (CHP), which are highly efficient. CHP profitability depends also on electricity prices Peak load production: typically heat-only boilers, which are expensive and mainly fired by fossil fuels (heavy fuel oil or natural gas (in Espoo)). Thus, peak load production is typically highly emission-intensive Nowadays DH is losing competitiveness against heat pumps DH producers need to find new measures to increase profitability e.g. through demand side management (DSM) by decreasing production costs In this study it is analyzed how much of the most expensive peak load DH production could be cut by using demand side management (DSM) in Otaniemi ,0 20,0 10,0 0,0-10,0-20,0 Source: Fortum 5

6 What is demand side management (DSM) in district heating? DSM can be conducted in many ways, e.g., through air ventilation, lowering the inflow water temperature or reducing DHW consumption. The most convenient method is to control inflow water temperature. DSM can be considered shifting time of actual consumption to a different time period to avoid the most expensive peak production. Distinctive difference between DSM and pure energy saving measures is necessary. In this study DSM is defined as follows: DSM is reduction in energy consumption at some point of time, without decreasing customer satisfaction. 6

7 TUAS-office building Pilot TUAS is newly built (2003) and owned by Aalto University Properties. Well-automated and insulated building. Heating system based on DH through radiator system and partly on controlling ventilation. Depth of DSM ( C) Length of DSM (h) Count of DSMs Average temperature decrease in H7 rooms ( C) Pilot was conducted to measure customer satisfaction during DSM measures between October 2014 and March Customers were not aware of timing of DSM measures. Indoor temperature was kept between ºC. Few times DSMs were abandoned in the pilot due to too high indoor temperature decrease. DSMs were conducted by controlling supply water temperature. Supply water temperature was decreased -5 ºC, -10 ºC, -15 ºC or -20 ºC. Time period for DSMs was 1 hour, 2 hour, 3 hour or 4 hour. Typical supply water temperature ºC, in wintertime up to 75 ºC. Timing of DSMs decided according to production costs. Fidelix algorithm, difference between hourly production costs 5 EUR per MWh. Daily maximum was 2 DSM measures. We analyzed data from the pilot to estimate impacts of DSM measures on energy consumption

8 Customer satisfaction in the Pilot Two different surveys were used to analyze the user satisfaction in the pilot, Happy-or-not survey and more in-depth survey for personnel working in the building. The initial results demonstrate that most of the users did not feel DSM measures to be distracting or they may not even have felt the temperature changes Satisfaction index Number of respondents DSM Time period No DSMs Outdoor temperature Range Average -5 C C +6 C -9 C - +8 C +0 C -5 C - +6 C +2 C -12 C - +5 C -1 C -15 C - +6 C -1 C -6 C - +3 C -17 C - +2 C +0 C - +5 C +0 C -6 C +3 C C C +2 C 8

9 Data analysis and results of the Pilot We used following real data to analyze the effects of DSM measures and calculate energy savings in the Pilot. DH load / energy consumption. Supply and return water temperature of DH. Indoor and outdoor temperature. Data on DSM measures (depth, length and timing). We estimated and calculated what would DH load have been if DSMs would have not been conducted. DSMs with same depth and length typically differ from each other (i.e. load reduction is not the same). Typically after DSM measures there is a spike in DH load which is accounted in the calculations. Our calculations showed that approximately 27 MWh of heat was saved during January-March 2015 in the Pilot, which was close to what Fortum had estimated. 9

10 Load (kw) Temperature ( C) Demand side management measures in January DH Load DSM Depth Outside temperature Indoor temperature (H7) :00:00: :00:00: :00:00: :00:00: :00:00:000 10

11 Scaling pilot to Otaniemi and Espoo We selected 23 buildings in Otaniemi owned by Aalto University Properties Ltd., with available data on DH consumption It was assumed that DSMs could be conducted in the same proportional scale in all of the buildings as in TUAS-pilot We are considering that the energy saved would be directly deducted from the production of heat boiler fired by natural gas in Otaniemi Simplistic aggregated DSM calculations in 23 buildings resulted in savings of 580MWh between January and March (~1,3% of DH consumption in Otaniemi) 11

12 Conclusions Demand side management pilot conducted in Otaniemi provided insight on the effects of DH DSM. DSM measures were moderate as the indoor temperatures were typically kept above 21 ºC, even though satisfaction was not affected. The results of the satisfaction analysis indicate that more thorough research on allowing indoor temperature decrease even further should be conducted. Results suggest that larger cuts could be ok. The case of aggregated DSM should be studied in detail and this requires improved data collection. Aalto University Properties Ltd owns many buildings in Otaniemi where DSM measures could be conducted. Based on the real data available on consumption etc. we have analyzed what would the energy saving potential be when DSMs are conducted simultaneously in multiple campus buildings in Otaniemi if the proportional savings would be the same as in TUAS-pilot. However, all of the buildings will not react the same way in reality. More data required on individual buildings 12

13 Thank you for your attention! 13

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