Merge pull request #124 from StephanieWillis/update-rates-and-grant

Update rates and grant
StephanieWillis · Oct 28, 2023 · b4317b0 · b4317b0
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diff --git a/README.md b/README.md
@@ -94,11 +94,11 @@ In the step where we pickle the demand profile we normalize it so the profiles s
 
 ### Heating system efficiencies
 
-**Heat pumps** - using rounded values from 5 kW 
-[Vaillant arotherm SCOP data](https://www.vaillant.co.uk/downloads/aproducts/renewables-1/arotherm-plus/arotherm-plus-1/quick-guides/new-5/installers-quick-guide-arotherm-plus-1949445.pdf),
- with flow temperature of 55C. These efficiencies are above
+**Heat pumps** - using rounded values from 7 kW 
+[Vaillant arotherm SCOP data](https://www.vaillant.co.uk/downloads/aproducts/renewables-1/arotherm-plus/arotherm-plus-spec-sheet-1892564.pdf)
+with flow temperature of 55C. These efficiencies are above
 recorded averages (2.76 according to this [nesta analysis](https://www.nesta.org.uk/report/reduce-the-cost-of-heat-pumps/))
-but lower than reported values for high quality installs.
+but lower than reported values for [high quality installs](https://heatpumpmonitor.org/graph).
 
 **Gas boiler** - using 84%, as used in this 
 [Delta EE report](https://www.climatexchange.org.uk/media/1897/electrification_of_heat_and_impact_on_scottish_electricity_system_-_final_report1.pdf)). Using 80% for water heating due to lower
@@ -119,30 +119,28 @@ Electricity emissions factors are UK average from the start of 2022 to 2022-10-2
 ### Tariffs
 
 The default tariffs for gas and electricity are based on the average rate under the
-[Energy Price Guarantee](https://www.gov.uk/government/publications/energy-bills-support/energy-bills-support-factsheet-8-september-2022),
-which is active until April 2023.
-Without further government support, bills will increase after that date, at least in the short term. Some clues
-as where rates might go in [this Cornwall Insights analysis](https://www.cornwall-insight.com/predicted-fall-in-the-april-2023-price-cap-but-prices-remain-significantly-above-the-epg/)
-and [this nesta analysis](https://www.nesta.org.uk/report/how-the-energy-crisis-affects-the-case-for-heat-pumps/how-the-costs-of-heat-pumps-compare-to-gas-boilers-since-the-energy-crisis-1/#content)
+[October 2023 price cap](https://www.ofgem.gov.uk/energy-price-cap),
+which is active until the 30th of December 2023.
+The electricity export tariff is Octopus's [Outgoing Fixed](https://octopus.energy/smart/outgoing/).
 The oil tariff is a rough average based on [Boiler Juice](https://www.boilerjuice.com/heating-oil-prices/) 
-data since prices stabilised in April 2022.
+data for September and October 2023.
 
 
 ### Cost data
 Solar costs are from [BEIS data](https://www.data.gov.uk/dataset/738a7bdb-a533-443d-bd02-69a8dd7fe68d/solar-pv-cost-data)
 for 2021/22 installs accredited under MCS. 
 We used the upper confidence interval given prices have likely risen since 2021/2022
 
-Heat pump and gas boiler costs from Nesta's [How to reduce the cost of heat pupms report](
+Heat pump and gas boiler costs from Nesta's [How to reduce the cost of heat pumps report](
 https://media.nesta.org.uk/documents/How_to_reduce_the_cost_of_heat_pumps_v4_1.pdf)
 - Used tables 1 (for semi only) and 2 (for terrace, flat, detached) from
 - Corrected gas boiler cost for semi-detached by same amount as heat pump shifts to keep equivalent
 - Assumed oil and direct electric baseline costs are the same as gas boiler costs. This is probably a poor assumption in the direct electric case
 
 The Nesta prices were in £2021 so we inflated the figures by ratio of retail price index from [Oct 2021](
-https://www.crosslandsolicitors.com/site/hr-hub/October-2021-inflation-data-CPI-CPIH-RPI) to [Oct 2022](
-https://www.crosslandsolicitors.com/site/media/October-2022-inflation-data-CPI-CPIH-RPI). That amounts
-to a 14% cost increase.
+https://www.crosslandsolicitors.com/site/hr-hub/October-2021-inflation-data-CPI-CPIH-RPI) to [September 2023](
+https://www.crosslandsolicitors.com/site/media/hr-hub/September-2023-inflation-CPI-CPIH-RPI). That amounts
+to a 21% cost increase.
 
 Other relevant cost resources [here](
 https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/656866/BEIS_Update_of_Domestic_Cost_Assumptions_031017.pdf)

diff --git a/src/constants.py b/src/constants.py
@@ -11,12 +11,12 @@
 BASE_YEAR_HOURLY_INDEX = pd.date_range(start="2013-01-01", end="2014-01-01", freq="1H", inclusive="left")
 EMPTY_TIMESERIES = pd.Series(index=BASE_YEAR_HOURLY_INDEX, data=0)
 
-KWH_PER_LITRE_OF_OIL = 10.35  # https://www.thegreenage.co.uk/is-heating-oil-a-cheap-way-to-heat-my-home/
 ELEC_TCO2_PER_KWH = 186 / 10 ** 6
 ELECTRICITY = Fuel("electricity", tco2_per_kwh=ELEC_TCO2_PER_KWH)
 GAS_TCO2_PER_KWH = 202 / 10 ** 6
 GAS = Fuel(name="gas", tco2_per_kwh=GAS_TCO2_PER_KWH)
 OIL_TCO2_PER_KWH = 260 / 10 ** 6
+KWH_PER_LITRE_OF_OIL = 10.35  # https://www.thegreenage.co.uk/is-heating-oil-a-cheap-way-to-heat-my-home/
 OIL = Fuel(name="oil", units="litres", converter_consumption_units_to_kwh=KWH_PER_LITRE_OF_OIL,
            tco2_per_kwh=OIL_TCO2_PER_KWH)
 FUELS = [ELECTRICITY, GAS, OIL]
@@ -94,27 +94,27 @@ class HeatingConstants:
         normalized_hourly_heat_demand_profile=NORMALIZED_HOURLY_HEAT_DEMAND_DF[
             'Normalised_Resistance_heater_heat']),
     "Heat pump": HeatingConstants(
-        efficiency=3.0,
+        efficiency=3.4,
         fuel=ELECTRICITY,
         normalized_hourly_heat_demand_profile=NORMALIZED_HOURLY_HEAT_DEMAND_DF['Normalised_ASHP_heat']),
 }
 
-RPI_ratio_oct_21_to_oct_22 = 356.2/312.0
-HEAT_PUMP_COSTS = {"Terrace": 10000 * RPI_ratio_oct_21_to_oct_22,
-                   "Semi-detached": 11100 * RPI_ratio_oct_21_to_oct_22,
-                   "Flat": 9100 * RPI_ratio_oct_21_to_oct_22,
-                   "Detached": 13100 * RPI_ratio_oct_21_to_oct_22}
-GAS_BOILER_COSTS = {"Terrace": 1800 * 10000 / 11100 * RPI_ratio_oct_21_to_oct_22,
-                    "Semi-detached": 1800 * RPI_ratio_oct_21_to_oct_22,
-                    "Flat": 1500 * RPI_ratio_oct_21_to_oct_22,
-                    "Detached": 2200 * RPI_ratio_oct_21_to_oct_22}
+RPI_ratio_oct_21_to_sept_23 = 378.4/312.0
+HEAT_PUMP_COSTS = {"Terrace": 10000 * RPI_ratio_oct_21_to_sept_23,
+                   "Semi-detached": 11100 * RPI_ratio_oct_21_to_sept_23,
+                   "Flat": 9100 * RPI_ratio_oct_21_to_sept_23,
+                   "Detached": 13100 * RPI_ratio_oct_21_to_sept_23}
+GAS_BOILER_COSTS = {"Terrace": 1800 * 10000 / 11100 * RPI_ratio_oct_21_to_sept_23,
+                    "Semi-detached": 1800 * RPI_ratio_oct_21_to_sept_23,
+                    "Flat": 1500 * RPI_ratio_oct_21_to_sept_23,
+                    "Detached": 2200 * RPI_ratio_oct_21_to_sept_23}
 HEATING_SYSTEM_COSTS = {"Gas boiler": GAS_BOILER_COSTS,
                         "Heat pump": HEAT_PUMP_COSTS,
                         "Oil boiler": GAS_BOILER_COSTS,  # assume they are the same
                         "Direct electric": GAS_BOILER_COSTS
                         }
 HEATING_SYSTEM_GRANTS = {"Gas boiler": 0,
-                         "Heat pump": 5000,  # Boiler upgrade scheme,
+                         "Heat pump": 7500,  # Boiler upgrade scheme,
                          "Oil boiler": 0,
                          "Direct electric": 0
                          }
@@ -135,8 +135,8 @@ class TariffConstants:
 
 
 STANDARD_TARIFF = TariffConstants(
-    p_per_kwh_gas=10.3, p_per_kwh_elec_import=34.0, p_per_kwh_elec_export=15.0,
-    p_per_L_oil=95.0, p_per_day_gas=28.0, p_per_day_elec=46.0)
+    p_per_kwh_gas=7.0, p_per_kwh_elec_import=27.0, p_per_kwh_elec_export=15.0,
+    p_per_L_oil=79.0, p_per_day_gas=30.0, p_per_day_elec=53.0)
 
 
 @dataclass()

diff --git a/src/house_questions.py b/src/house_questions.py
@@ -327,10 +327,10 @@ def render_tariff_overwrite_options(house: House) -> House:
             tariffs["oil"].p_per_unit_import = st.session_state.p_per_unit_heating_fuel_import
 
     st.caption(
-        "Our default tariffs reflect the current [Energy Price Guarantee]("
-        "https://www.gov.uk/government/publications/energy-bills-support/energy-bills-support-factsheet-8-september-2022)"
-        " which is in place until April. "
-        "Rates will go up in April, but we don't yet know how this will be split between electricity and gas. \n  \n"
+        "Our default tariffs reflect the current [Ofgem price cap](https://www.ofgem.gov.uk/energy-price-cap). "
+        "Cheaper electricity rates are available. For example Ovo is offering a [15p/kWh heat pump tariff]("
+        "https://company.ovo.com/cheaper-than-a-gas-boiler-ovo-launches-best-in-market-heat-pump-offer/) where "
+        "you get this low rate just for the electricity your heat pump uses. \n  \n"
         "The electricity export rate of 15p/kWh is based on [Octopus Outgoing](https://octopus.energy/outgoing)"
     )
 

diff --git a/src/place_search/index.html b/src/place_search/index.html
@@ -13,7 +13,7 @@
     font-size: 16px;
 }
 </style>
-<input id="postcode"  placeholder="Enter your postcode to find your roof (then click on the matching address)"  class="stTextInput postcode-input"/>
+<input id="postcode"  placeholder="Enter your address to find your roof (click on the matching address)"  class="stTextInput postcode-input"/>
 <div id="output" value="" style="z-index: 99999"/>
 <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDE1h8LmQYFqt5_aHPd_7KKF-wpv14sJBA&libraries=places&callback=autoComplete&locationbias=ipBias"
         async defer></script>

diff --git a/src/savings_outputs.py b/src/savings_outputs.py
@@ -104,7 +104,7 @@ def render_heat_pump_overwrite_options(upgrade_heating: HeatingSystem) -> Heatin
     st.caption(
         "The efficiency of your heat pump depends on how well the system is designed and how low a flow "
         "temperature it can run at. A COP of 3.6 or better is possible with a [high quality, low flow temperature "
-        "install](https://heatpumpmonitor.org).  \n  \n"
+        "install](https://heatpumpmonitor.org/graph).  \n  \n"
         "A good installer is key to ensuring your heat pump runs efficiently. The [heat geek map"
         "](https://www.heatgeek.com/find-a-heat-geek/) is a great place to start your search."
     )

diff --git a/tests/test_house.py b/tests/test_house.py
@@ -132,21 +132,19 @@ def test_set_up_house_from_heating_name():
 
 
 def test_typical_home_hits_price_cap():
-    # price cap under Energy price guarantee is £2500 for house that uses 12,000kWh of gas and 2,900kWh of elec
+    # October 2023 price cap for house is 1834 for house that uses 11,500kWh of gas and 2,900kWh of elec
     gas_boiler = building_model.HeatingSystem.from_constants(
         name='Gas boiler',
         parameters=constants.DEFAULT_HEATING_CONSTANTS['Gas boiler'])
-    demand = 2900 * constants.NORMALIZED_HOURLY_BASE_DEMAND
+    demand = 2700 * constants.NORMALIZED_HOURLY_BASE_DEMAND
     envelope = building_model.BuildingEnvelope(house_type='typical',
-                                               annual_heating_demand=12000 * gas_boiler.efficiency,
+                                               annual_heating_demand=11500 * gas_boiler.efficiency,
                                                base_electricity_demand_profile_kwh=demand)
     gas_house = building_model.House.set_up_from_heating_name(envelope=envelope, heating_name='Gas boiler')
     assert gas_house.has_multiple_fuels is True
-    np.testing.assert_almost_equal(gas_house.annual_consumption_per_fuel_kwh['electricity'], 2900)
-    np.testing.assert_almost_equal(gas_house.annual_consumption_per_fuel_kwh['gas'], 12000)
-    np.testing.assert_almost_equal(gas_house.total_annual_bill, 2492.1)  # looks like it isn't exactly 2500 after all
+    np.testing.assert_almost_equal(gas_house.total_annual_bill, 1837, 0)  # prices we are using are rounded
     np.testing.assert_almost_equal(gas_house.total_annual_tco2,
-                                   (12000 * constants.GAS_TCO2_PER_KWH + 2900 * constants.ELEC_TCO2_PER_KWH))
+                                   (11500 * constants.GAS_TCO2_PER_KWH + 2700 * constants.ELEC_TCO2_PER_KWH))
 
 
 def test_upgrade_buildings():
@@ -190,6 +188,6 @@ def test_upgrade_buildings():
     assert solar_house.percent_self_use_of_solar > 0
     assert round(solar_house.percent_self_use_of_solar, 3) == 0.827  # so high because only 0.8kW of panels
     assert both_house.percent_self_use_of_solar > solar_house.percent_self_use_of_solar
-    assert round(both_house.percent_self_use_of_solar, 3) == 0.920
+    assert round(both_house.percent_self_use_of_solar, 3) == 0.914
 
     return hp_house, solar_house, both_house