3.7 Scenario 2020
3.7.3 Results
Long-term perspectives for balancing fluctuating renewable energy sources 34 heat demand is added to the heat demand for the bivalent systems. These profiles are the input for calculating balancing through CHP, which is similar to balancing through DSM only with an opposite sign.
Long-term perspectives for balancing fluctuating renewable energy sources 35
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0 1000 2000 3000 4000 5000 6000 7000 8000
Time of the year [h]
Power [GW]
Figure 3-20: Scenario I: Balanced with contribution of Demand Side Management
Balancing by Demand Side Management fulfils the role as a balancing mechanism. There is only one peak left during the whole year. The peak left is shown together with the storage content in Figure 3-21.
-100,00 -50,00 0,00 50,00 100,00 150,00
4100 4120 4140 4160 4180 4200 4220 4240 4260 4280 4300
Time of the year [h]
Power [GW]
-2,00 0,00 2,00 4,00 6,00 8,00 10,00 12,00 14,00 16,00
Power [GW]
Figure 3-21: Scenario I: Balanced with contribution of Demand Side Management –II
The single peak, which can not be balanced, is during summer time. DSM is, like CHP-plant operation, linked with the heat demand. Therefore it is reasonable that this peak occurs in a time with low heat demand. The original peak reduced, but only hot water demand, is at that
Long-term perspectives for balancing fluctuating renewable energy sources 36 certain point not enough to gain a complete balancing. Normally the heat storage provides the needed flexibility to the electric heating system, but in this case the orange line in Figure 3-21 reaches the maximum, i.e. the storage has reached his total capacity at that time.
The same problem during summer time occurs when balancing with CHP-plants. Figure 3-22 shows the balanced profile with contribution of DSM and CHP.
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0 1000 2000 3000 4000 5000 6000 7000 8000
time of year [h]
power [GW]
Figure 3-22: Scenario I: Balanced with contribution of Demand Side Management and CHP The CHP-units fill some of the gaps and covers a high part of the demand, but the boundary conditions do not allow a total balancing. A detailed description of the behaviour of CHP-plants in a shorter period is shown in Figure 3-23.
Long-term perspectives for balancing fluctuating renewable energy sources 37
-100 -50 0 50 100 150
8000 8050 8100 8150 8200 8250 8300 8350 8400
time of year [h]
power [GW]
Figure 3-23: Scenario I: Balanced with contribution of Demand Side Management and CHP –II This figure shows that balancing through CHP is not as worse as it seems in Figure 3-22. The CHP-units often even out the fluctuations. At the times when an equilibrium can not be established the CHP are nevertheless operating. CHP-plants achieve 3.5000 operating hours, but the total capacity is not enough for balancing the profile in total. Since the CHP-capacity is 25 GW, it is not possible to balance gaps of around 50 GW.
Scenario II: high wind, high heat demand
In this scenario it is assumed that wind power is extended to a proportion of 50 % of the whole electricity production. The heat demand is kept at the high level of 200 kWh/m2a.
As already explained before base load is, reduced from 35 GW to 25 GW, because of the high wind proportion. Nevertheless peaks, as well as the gaps, are much greater than in the case of
“low wind”. The DSM for example has to be able to cut off peaks of 125 GW in this case.
Figure 3-24 shows the results for balancing through DSM.
Long-term perspectives for balancing fluctuating renewable energy sources 38
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0 1000 2000 3000 4000 5000 6000 7000 8000
Time of the year [h]
Power [GW]
Figure 3-24: Scenario II: Balanced with contribution of Demand Side Management
There are still only some peaks left and these peaks are again at times with low heat demands and a completely filled heat store.
Nevertheless once again it is impressive how the DSM is able to cut off such high peaks.
Especially at the end of the year there are two peaks with maxima of around 125 GW which are completely cut off.
Balancing with contribution of DSM and CHP is shown in Figure 3-25. Since the CHP-capacity is unchanged at 25 GW the principle results are similar to the first scenario.
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0 1000 2000 3000 4000 5000 6000 7000 8000
time of year [h]
power [GW]
Figure 3-25: Scenario II: Balanced with contribution of Demand Side Management and CHP
Long-term perspectives for balancing fluctuating renewable energy sources 39 The CHP-units have 3443 operating hours and take over a main share in balancing, but a total balancing can again not be reached. The explanation for this can again be found in the maximum CHP-capacity which is not enough to balance the gaps which are sometimes twice or triple as much.
Scenario III: low wind; low heat demand
This scenario assumes that wind power has a proportion of 25 % like in scenario I. The heat demand is drastically reduced in this scenario.
The results for balancing through DSM are shown in Figure 3-26.
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0 1000 2000 3000 4000 5000 6000 7000 8000
Time of the year [h]
Power [GW]
Figure 3-26: Scenario III: Balanced with contribution of Demand Side Management
The results for balancing through DSM are similar to the scenario I. The lower heat demand has nearly no effect to this balancing. This fact can be explained with the share of the electric heating system on the heat generation. In scenario I the electric heating system covers less than 3 % of the heat demand of bivalent and trivalent systems. The share of the heating-boiler is therefore around 97 % in the bivalent systems and 69 % in the trivalent systems. In scenario II with the low heat demand the proportion of electric heating system rises. It has a share of 8 %, while the share of fuel fired boilers decreases to 92 % in the bivalent systems and to 20 % in the trivalent systems. The share of fuel fired boilers is also affected by the share of CHP-plants.
Figure 3-27 shows the results for balancing through DSM and CHP.
Long-term perspectives for balancing fluctuating renewable energy sources 40
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0 1000 2000 3000 4000 5000 6000 7000 8000
time of year [h]
power [GW]
Figure 3-27: Scenario III: Balanced with contribution of Demand Side Management and CHP As already stated the share of CHP-units on heat generation is drastically increased.
Nevertheless a decreasing of the operating hours to 3062 hours takes place because of the lower heat demand. Balancing through DSM and CHP however still shows similar results to the previous scenarios.
Scenario IV: high wind, low heat demand
Scenario IV is the most optimistic. It is assumed that the wind power proportion is increasing up to 50 % and the heat demand is drastically reduced. This scenario is the ecological preferable one, but to achieve a complete balancing is the catchiest of all four scenarios. The high wind power production leads to high peaks and low gaps like in scenario II and the low heat demand results in a low flexibility. The results for balancing through DSM are shown in Figure 3-28.
Long-term perspectives for balancing fluctuating renewable energy sources 41
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0 1000 2000 3000 4000 5000 6000 7000 8000
Time of the year [h]
Power [GW]
Figure 3-28: Scenario IV: Balanced with contribution of Demand Side Management
Balancing through DSM is a bit worse than in scenario II. The high peaks, which have been cut off in that scenario, are only lowered in this scenario. The low heat demand is the explanation for this fact. The same is true for the results of balancing through DSM and CHP which are shown in Figure 3-29.
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0 1000 2000 3000 4000 5000 6000 7000 8000
time of year [h]
power [GW]
Figure 3-29: Scenario IV: Balanced with contribution of Demand Side Management and CHP The large gaps can not be filled with the assumed heat demand. The low heat demand and the high fluctuations are leading to only 2454 operating hours for the CHP-units.
Long-term perspectives for balancing fluctuating renewable energy sources 42