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--- planning:refurbishment_with_passive_house_components:economic_analysis_for_the_retrofit_of_a_detached_single_family_house_to_the_enerphit_standard [2016/05/02 16:39] – kdreimane
+++ planning:refurbishment_with_passive_house_components:economic_analysis_for_the_retrofit_of_a_detached_single_family_house_to_the_enerphit_standard [2019/02/28 09:41] (current) – cblagojevic
@@ Line 30: / Line 30: @@
 Fixed costs are known for each measure, for example wall insulation: scaffolding, exterior acrylic render, and displacement of drainpipes sums up to €36/m².
 [{{ :picopen:t._annual_costs_with_co2_tax.png?450|Figure 3: Total annual cost including CO2 tax with prices of electricity and CO2 in France (FR) and Germany (DE).}}]
-The Comparison worksheet in PHPP 9 enables us to compare two project variants, including maintenance costs like filter replacement. We’ll assume the following financial hypothesis:
+The Comparison worksheet in PHPP 9 enables us to compare two project variants, including maintenance costs like filter replacement.
-\\ -real interest rate 2%,
-\\ -financial assessment period = 30 years,
+We’ll assume the following financial hypothesis:
-\\ -no Residual Value,
-\\ -heating and hot water price = €0.15/kWh
+  * real interest rate 2%,
+  * financial assessment period = 30 years,
+  * no Residual Value,
+  * heating and hot water price = €0.15/kWh
 The comparison between EnerPHit and low-energy variants, for Step 1 (walls, windows, ventilation, stove) gives a slightly lower total annual cost than the low-energy variant (see Figure 2) at €6500/a. The actualised payback period of the EnerPHit variant is 28 years. The saved kWh price is €0.14/kWh.
 CO2 tax can be added to the operational cost. The price of CO2 is fixed according to a French law issued in 2015 [3]: stepwise increases from €22/tCO2 for 2016-2019 to €100/tCO2 after 2030. The declared CO2 content of the electricity mix is 88gCO2/kWh in France [4], against 532gCO2/kWh according to GEMIS [PHPP9]. Heating and hot water are fully electric. Figure 3 indicates that a CO2 tax is not a strong enough lever to shift towards efficiency if the energy source has a low carbon intensity (CO2 tax is only 3% of the total cost for existing French prices and CO2 electricity content). On the other hand, EnerPHit grants a “CO2 bonus” of 3% on the total investment with German carbon intensity and prices.
 [{{ :picopen:t_annual_cost_dbl_vs_trpl.png?500|Figure 4: Total annual cost compared: double glazing and triple glazing on a similar window type (left), supply only vs heat recovery ventilation (right)}}]
 The Comparison worksheet allows us to assess the economic efficiency of a single component. Application of this feature on a window type (casement windows, inward opening – 12m² gross area, 30 year investment period, 30 year product lifetime) gives a similar annual cost for triple glazing than double glazing (Figure 4). The actualised payback period for choosing triple glazing is 20 years, the saved kWh price is €0.10/kWh. Similar analysis on mechanical ventilation with heat recovery versus supply only gives a clear advantage to mechanical ventilation with heat recovery (saved kWh price = €0.08/kWh).
 The following factors can explain moderate total costs:
-\\ -Reusing supply air ducts reduced the investment by €1830 (35m supply ducts at €36/ml: €1670, and 5 inlets €30/u = €150).
-\\ -No specific treatment of existing render (good strength) prior to exterior insulation (€30/m² wall avoided for scraping and refill of existing render)
+  * Reusing supply air ducts reduced the investment by €1830 (35m supply ducts at €36/ml: €1670, and 5 inlets €30/u = €150).
-\\ -Good airtightness of concrete walls, which spared specific airtightness treatment on regular wall surfaces.
+  * No specific treatment of existing render (good strength) prior to exterior insulation (€30/m² wall avoided for scraping and refill of existing render)
+  * Good airtightness of concrete walls, which spared specific airtightness treatment on regular wall surfaces.
 A few measures could be further optimized:
-\\ -The position of the ventilation unit and layout of extract ducts
-\\ -The Lambda value of wall insulation, avoid dowels to fix insulation
+  * The position of the ventilation unit and layout of extract ducts
+  * The Lambda value of wall insulation, avoid dowels to fix insulation
 [{{ :picopen:total_present_value.png?300|Figure 5: Detailed total present value of retrofit variants, modelled with phEco.}}]
 **4. Detailed cost analysis with phEco**
@@ Line 55: / Line 70: @@
 **5. Sensitivity analysis: is the economic performance robust?**
 \\ The energy efficiency market is subject to high price variability. We can use the phEco model to find out if investing in EnerPHit is robust, given uncertainty on energy tariffs and component prices (wall insulation, windows and ventilation). Investment robustness is defined here as the probability of a total cost lower than the low-energy alternative (€560/m²TFA present value). A sensitivity analysis is carried out with the Crystal Ball Excel Plug-In.
 \\ Realistic price distributions are set up and the following parameters are fixed constant:
-\\ -Financial evaluation period = 30 years
-\\ -Average residual value of components after financial evaluation period = 10 years.
+  * Financial evaluation period = 30 years
-\\ -Thermal performance of components
+  * Average residual value of components after financial evaluation period = 10 years.
+  * Thermal performance of components
 Sensitivity assumptions:
-\\ -Log-Normal laws used for prices with observed stable minima: heat price (electric), wall insulation.
-\\ -Normal laws used for high added value components, for which prices have a higher reduction potential due to industrial scaling: windows and shutters, ventilation with heat recovery.
+  * Log-Normal laws used for prices with observed stable minima: heat price (electric), wall insulation.
-\\ -Ventilation: standard deviation is chosen equal to the investment reduction reached by reusing the existing supply distribution system = €6/m²TFA.
+  * Normal laws used for high added value components, for which prices have a higher reduction potential due to industrial scaling: windows and shutters, ventilation with heat recovery.
+  * Ventilation: standard deviation is chosen equal to the investment reduction reached by reusing the existing supply distribution system = €6/m²TFA.
 [{{ :picopen:total_cost_enerphit_step_1.png?400|Figure 6: Cumulated probability of total cost for EnerPHit Step 1 (cost analysis by phEco, uncertainty propagation by Crystal Ball). Reference cost for low-energy variant in red (560 €/m²)}}]
 [{{ :picopen:sensitivity_analysis.png?300|Figure 7: Sensitivity analysis for EnerPHit step 1 total cost, contribution to variance}}]
@@ Line 76: / Line 99: @@
 Two decision variables are investigated:
-\\ -	Lambda insulation for walls (0.022 to 0.038 W/m.K), linear cost dependency (+8% cost for lowest lambda). Thermal bridge coefficients are kept constant.
-\\ -	Ventilation heat recovery (79% to 95%), linear cost dependency (+20% cost for highest efficiency).
+  * Lambda insulation for walls (0.022 to 0.038 W/m.K), linear cost dependency (+8% cost for lowest lambda). Thermal bridge coefficients are kept constant.
+  * Ventilation heat recovery (79% to 95%), linear cost dependency (+20% cost for highest efficiency).
 A stochastic simulation to find minimum total cost while respecting constraint on heating demand (<25 kWh/m².a) gives the following results: