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basics:passive_house_-_assuring_a_sustainable_energy_supply:passive_house_the_next_decade:determining_application-specific_per_factors [2015/03/27 18:02] – jbreitfeldbasics:passive_house_-_assuring_a_sustainable_energy_supply:passive_house_the_next_decade:determining_application-specific_per_factors [2024/04/18 22:29] (current) – jgrovesmith
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-====== Determining application-specific PER factors ======+====== Passive House – the next decade | Determining application-specific PER factors ====== 
 +//This article is a chapter of the paper “Passive House - the next decade” by Wolfgang Feist. Click here to the [[basics:passive_house_-_assuring_a_sustainable_energy_supply:passive_house_the_next_decade|beginning of the article on Passipedia]].//
  
 +\\
 The findings show that the supply structure that needs to be built and its efficiency depend greatly on energy-consuming applications' load curves; it turns out that short fluctuations of a few days are less important((Author's note: Unlike what is frequently argued today, short-term storage is not the decisive issue here, since financially feasible technology is already available (pumped storage plants, etc.); it must "only" be expanded, and enough sites need to be found. The problem is, in fact, political, but it should be taken seriously, considering the prevailing attitude. Seasonal storage, which has also turned out to be essential (such storage has no location problems, since there is already sufficient storage used for natural gas), significantly increases costs for the applications that need it (heating, e.g.) because of high losses; this problem can also be solved (with improved efficiency).)), since medium-term grid storage (pumped storage, etc.) can generally balance them out. The situation is different when an application's demand has significant seasonal fluctuations, such as when heating drops to zero for several months at a time. Energy generated from primary power sources (wind turbines, etc.) then has nowhere to go – unless this excess power is sent to the P2G system and turned into methane. The requirement for complete supply is: \\ The findings show that the supply structure that needs to be built and its efficiency depend greatly on energy-consuming applications' load curves; it turns out that short fluctuations of a few days are less important((Author's note: Unlike what is frequently argued today, short-term storage is not the decisive issue here, since financially feasible technology is already available (pumped storage plants, etc.); it must "only" be expanded, and enough sites need to be found. The problem is, in fact, political, but it should be taken seriously, considering the prevailing attitude. Seasonal storage, which has also turned out to be essential (such storage has no location problems, since there is already sufficient storage used for natural gas), significantly increases costs for the applications that need it (heating, e.g.) because of high losses; this problem can also be solved (with improved efficiency).)), since medium-term grid storage (pumped storage, etc.) can generally balance them out. The situation is different when an application's demand has significant seasonal fluctuations, such as when heating drops to zero for several months at a time. Energy generated from primary power sources (wind turbines, etc.) then has nowhere to go – unless this excess power is sent to the P2G system and turned into methane. The requirement for complete supply is: \\
  
-PE<sub>prim</sub> = E<sub>dir</sub> + E<sub>MS</sub> / η<sub>MS</sub> + E<sub>SS</sub> / η<sub>SS</sub> + E<sub>PL</sub> \\+<WRAP center 60%> 
 +$$PE_{prim} = E_{dir} + \dfrac{E_{MS}}{\eta_{MS}} + \dfrac{E_{SS}}{\eta_{SS}} + E_{PL} $$ 
 +</WRAP> 
 + \\
  
-whereby E<sub>dir</sub> is the electricity from renewable primary power generators that can be directly and immediately used by the building, E<sub>MS</sub> is electricity from short/mid-term storage, E<sub>SS</sub> is reconverted electricity from seasonal storage, E<sub>PL</sub> is power losses, and η<sub>MS</sub> and η<sub>SS</sub> are the respective overall seasonal efficiency rates. The PER factor can then be determined with \\+Whereby E<sub>dir</sub> is the electricity from renewable primary power generators that can be directly and immediately used by the building, E<sub>MS</sub> is electricity from short/mid-term storage, E<sub>SS</sub> is reconverted electricity from seasonal storage, E<sub>PL</sub> is power losses, and η<sub>MS</sub> and η<sub>SS</sub> are the respective overall seasonal efficiency rates. The PER factor can then be determined with \\
  
-PER = (E<sub>dir</sub> + E<sub>MS</sub> / η<sub>MS</sub> + E<sub>SS</sub> / η<sub>SS</sub> + E<sub>PL</sub> ) / (E<sub>dir</sub> + E<sub>MS</sub> + E<sub>SS</sub> )+<WRAP center 60%> 
 +$$PER = \dfrac{E_{dir} +\dfrac{E_{MS}}{\eta_{MS}} + \dfrac{E_{SS}}{\eta_{SS}} + E_{PL}}{E_{dir} + E_{MS} + E_{SS}} 
 +$$ 
 +</WRAP> 
 + 
 +\\
 The results show that while PER factors determined with this equation are relatively stable compared to, say, changes in the primary power mix or the technology mix, they also depend //greatly on the individual energy application// and its demand profile. \\ \\ The results show that while PER factors determined with this equation are relatively stable compared to, say, changes in the primary power mix or the technology mix, they also depend //greatly on the individual energy application// and its demand profile. \\ \\
  
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 Figure 6 shows how the PER factor for domestic power supply depends on the primary power mix used: with 90 percent wind, for example, it comes out to 1.75 kWh<sub>PER</sub>/kWh<sub>el</sub>; with 90 percent PV, 1.5 kWh<sub>PER</sub>/kWh<sub>el</sub>. An PER factor of 1.39 kWh<sub>PER</sub>/kWh<sub>el</sub> is achieved for the "ideal mix" (here) of 54 percent PV, 36 percent wind, and 10 percent hydropower. We suggest a somewhat conservative factor of PER<sub>DEel</sub> = 1.4 kWh<sub>PER</sub>/kWh<sub>DPel</sub> for the analysis. This PER factor is relatively low, so domestic power can easily be provided by renewable primary power generators; almost all buffering results from an improvement of grid simultaneities and from short-term grid storage capacities, which are in some need of expansion. Costs are still quite low for storage cycles of less than 106 hours. Seasonal storage capacity (with a little more than two cycles but low efficiency) accounts for only 11 percent of domestic electricity demand; the storage capacity required is low at less than 62 Nm³ (cubic meters at normal conditions), and the conversion infrastructure required can also be relatively small. The infrastructure could easily be entirely located at sites for regional combined-cycle plants used for reconversion; the methane network can serve as the connection to the underground methane storage (the current natural gas network can continue to be used here). \\ Figure 6 shows how the PER factor for domestic power supply depends on the primary power mix used: with 90 percent wind, for example, it comes out to 1.75 kWh<sub>PER</sub>/kWh<sub>el</sub>; with 90 percent PV, 1.5 kWh<sub>PER</sub>/kWh<sub>el</sub>. An PER factor of 1.39 kWh<sub>PER</sub>/kWh<sub>el</sub> is achieved for the "ideal mix" (here) of 54 percent PV, 36 percent wind, and 10 percent hydropower. We suggest a somewhat conservative factor of PER<sub>DEel</sub> = 1.4 kWh<sub>PER</sub>/kWh<sub>DPel</sub> for the analysis. This PER factor is relatively low, so domestic power can easily be provided by renewable primary power generators; almost all buffering results from an improvement of grid simultaneities and from short-term grid storage capacities, which are in some need of expansion. Costs are still quite low for storage cycles of less than 106 hours. Seasonal storage capacity (with a little more than two cycles but low efficiency) accounts for only 11 percent of domestic electricity demand; the storage capacity required is low at less than 62 Nm³ (cubic meters at normal conditions), and the conversion infrastructure required can also be relatively small. The infrastructure could easily be entirely located at sites for regional combined-cycle plants used for reconversion; the methane network can serve as the connection to the underground methane storage (the current natural gas network can continue to be used here). \\
 \\ \\
-|{{:picprivate:en_18pht_139_plenum_sanm_feist_wolfgang_fig_06.png?600}}|\\+|{{:picopen:en_18pht_139_plenum_sanm_feist_wolfgang_fig_06.png?600}}|\\
 |//**Figure 6: \\ Primary renewable energy (primary electricity) required \\ for total domestic power demand from PV, wind, and hydropower (high efficiency).**//|\\ |//**Figure 6: \\ Primary renewable energy (primary electricity) required \\ for total domestic power demand from PV, wind, and hydropower (high efficiency).**//|\\
 +
 \\ \\
 Figure 7 depicts the equivalent area for renewable generators that would be needed to cover total domestic electricity demand. A (very flat) optimum of only about 35 m² can be reached with a solar share of 35 to 75 percent. The actual area for PV (with a share of 55 percent) would come out to 19 m². Such a small area could almost always be located very close to the building in question, often directly on the roof. \\ Figure 7 depicts the equivalent area for renewable generators that would be needed to cover total domestic electricity demand. A (very flat) optimum of only about 35 m² can be reached with a solar share of 35 to 75 percent. The actual area for PV (with a share of 55 percent) would come out to 19 m². Such a small area could almost always be located very close to the building in question, often directly on the roof. \\
 \\ \\
-|{{:picprivate:en_18pht_139_plenum_sanm_feist_wolfgang_fig_07.png?600}}|\\+|{{:picopen:en_18pht_139_plenum_sanm_feist_wolfgang_fig_07.png?600}}|\\
 |//**Figure 7: \\ Size of the equivalent PV array (primary electricity) needed to cover total domestic power \\ demand with PV, wind, and hydropower (with buffer storage in the grid and \\ seasonal P2G methane storage) with high efficiency.**//|\\ |//**Figure 7: \\ Size of the equivalent PV array (primary electricity) needed to cover total domestic power \\ demand with PV, wind, and hydropower (with buffer storage in the grid and \\ seasonal P2G methane storage) with high efficiency.**//|\\
 \\ \\
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 Figure 8 shows the PER factors from the simulation relative to the share of PV in the production mix for hot water supply. A quite flat optimum can be seen with a PV share of 55 percent. Because of the locally available storage, this subsystem requires very little power from seasonal storage (only 10 Nm³ of methane). With a small safety margin, the PER<sub>DHW-hp</sub> factor result is 1.23 kWh<sub>PER</sub>/kWh<sub>el</sub>, suggesting that renewable power is well suited to supplying domestic hot water systems. An equivalent PV area of about 8 m² is enough to cover //all// domestic hot water demand including conversion losses. \\ Figure 8 shows the PER factors from the simulation relative to the share of PV in the production mix for hot water supply. A quite flat optimum can be seen with a PV share of 55 percent. Because of the locally available storage, this subsystem requires very little power from seasonal storage (only 10 Nm³ of methane). With a small safety margin, the PER<sub>DHW-hp</sub> factor result is 1.23 kWh<sub>PER</sub>/kWh<sub>el</sub>, suggesting that renewable power is well suited to supplying domestic hot water systems. An equivalent PV area of about 8 m² is enough to cover //all// domestic hot water demand including conversion losses. \\
 \\ \\
-|{{:picprivate:en_18pht_139_plenum_sanm_feist_wolfgang_fig_08.png?600}}|\\+|{{:picopen:en_18pht_139_plenum_sanm_feist_wolfgang_fig_08.png?600}}|\\
 |**//Figure 8: Renewable primary energy (primary electricity) needed to cover power demand \\ for hot water with solar, wind, and hydropower (grid buffer storage / seasonal P2G methane \\ storage); hot water heat pump with seasonal performance factor SPF of 2.5.//**|\\ |**//Figure 8: Renewable primary energy (primary electricity) needed to cover power demand \\ for hot water with solar, wind, and hydropower (grid buffer storage / seasonal P2G methane \\ storage); hot water heat pump with seasonal performance factor SPF of 2.5.//**|\\
 \\ \\
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 The picture is very different if the building is instead built as a Low Energy House with a heating demand of 56 kWh/(m²a). Electricity demand for running the heat pump then increases to 3,631 kWh, while the PER<sub>heat</sub> factor stays about the same and the equivalent renewable primary electricity generator area required jumps to 67 m² for heating alone. \\  The picture is very different if the building is instead built as a Low Energy House with a heating demand of 56 kWh/(m²a). Electricity demand for running the heat pump then increases to 3,631 kWh, while the PER<sub>heat</sub> factor stays about the same and the equivalent renewable primary electricity generator area required jumps to 67 m² for heating alone. \\ 
 \\ \\
-|{{:picprivate:en_18pht_139_plenum_sanm_feist_wolfgang_fig_09.png?600}}|\\+|{{:picopen:en_18pht_139_plenum_sanm_feist_wolfgang_fig_09.png?600}}|\\
 |**//Figure 9: \\ Renewable primary energy (primary electricity) needed for heating power demand \\ in a Passive House building, wind power and PV (grid buffer storage / seasonal P2G methane); \\ heat pump with an SPF of 2.53 (German test reference year 12).//**|\\ |**//Figure 9: \\ Renewable primary energy (primary electricity) needed for heating power demand \\ in a Passive House building, wind power and PV (grid buffer storage / seasonal P2G methane); \\ heat pump with an SPF of 2.53 (German test reference year 12).//**|\\
 \\ \\
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 ==== Following section ==== ==== Following section ====
  
-[[basics:passive_house_-_assuring_a_sustainable_energy_supply:passive_house_the_next_decade:Initial comparisons based on the analysis]] \\ \\+[[basics:passive_house_-_assuring_a_sustainable_energy_supply:passive_house_the_next_decade:initial_comparisons_based_on_the_analysis]] \\ \\ 
 + 
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 +\\  
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 +(read also in {{ :picprivate:determinacion_de_factores_per_para_aplicaciones_especificas.pdf |Spanish}}) {{:picopen:members_only.png?nolink&20|}}
basics/passive_house_-_assuring_a_sustainable_energy_supply/passive_house_the_next_decade/determining_application-specific_per_factors.1427475747.txt.gz · Last modified: 2015/03/27 18:02 by jbreitfeld