Introduction
The Warm Homes Loan Scheme offers government-backed no- and low-interest finance, some of it interest-free, for heat pumps, batteries and solar panels.1 Its "factsheet" sets out what a household might expect to save:
“Installing a heat pump, battery and solar panels could help families save up to £550 a year on their energy bills, rising by a further £300 a year with a time-of-use tariff.”1 Added together, the two figures implies a ceiling of about £850 a year.
The Governments assertion is based on cautious assumptions however.3 The modelled household is in Yorkshire, where solar yield is lower than further south. The heat pump is assumed to run at a seasonal coefficient of performance (SCOP) of 2.8, which the annex calls a COP. That is well below current equipment: a Vaillant aroTHERM plus, for example, is published at a SCOP of 3.77, about 35% higher.5 The 4 kW of solar and 4 kWh battery are also modest beside many systems installed today. Each choice is defensible on its own. Together, they pull the estimate towards the lower end of what the technologies can achieve. This is demonstrated in the modelling results of this article.
The quoted figure matters because it is likely to become the benchmark against which households judge installation quotes. A quote well above £850 risks being dismissed as sales optimism, even where it is realistic for the house and the equipment.
This work proceeds in two stages. The first is to replicate the government’s own model from its published assumptions, drawn from the Warm Homes Plan and the Cost Optimal Domestic Electrification (CODE) study on which it rests.24 The second is to modernise their assumptions, adjusted for the performance of equipment on sale today. This article covers both stages: what was assumed, what was not published, how Solar Butter is configured to match, and how the results change with a modern heat pump, a larger battery and higher-wattage panels.
Methods and assumptions
Sources and order of precedence
Each assumption is drawn from the most specific source available. Where the technical annex states that it applied a value, that value is used, even where CODE reports a different one. This covers the SCOP of 2.8, the 2024 average prices, and the time-of-use tariff of 8 off-peak, 13 standard and 3 peak hours.3 Where the annex defers to CODE, and its footnote 5 directs readers to the full study, the value comes from Palmer and Terry.4 Where neither document gives a number, the government entry reads “Not published”. The results come from Solar Butter historic simulations of the 2016 household, and each simulation report is linked beside its table.
Weather basis
CODE uses a weather file for Finningley, near Sheffield, with an annual mean of 9.5 °C. It is a reference file and does not correspond to a calendar year.4 Neither the annex nor CODE gives a postcode or a weather year.34 The Solar Butter replication therefore uses postcode DN9 3RH, in Finningley, South Yorkshire, and calendar year 2016, the representative year that every Solar Butter proposal report simulates from 1 January to 31 December. The annex uses 2024 average prices but does not publish them,3 so the electricity and gas rates are Solar Butter assumptions.
What the documents publish
Table 1 lists every assumption the annex states, followed by the CODE values the annex incorporates through footnote 5.
| Parameter | Published value |
|---|---|
| Technology comparison | Heat pump and a gas boiler3 |
| Package | Heat pump, 4 kW of PV on east- and west-facing roofs, and a 4 kWh battery3 |
| Property characteristics | Cavity-wall insulation, 100 mm loft insulation, and double glazing3 |
| Heat-pump SCOP | 2.83 |
| Battery on a conventional tariff | Run for solar self-consumption3 |
| Gas standing charge | No standing charge paid3 |
| Prices | 2024 average prices3 |
| Time-of-use household | A household in Yorkshire. The annex chooses it because its weather is representative of the UK overall3 |
| Time-of-use hours | 8 off-peak, 13 standard, and 3 peak hours3 |
| Battery on the time-of-use tariff | Charged off-peak and kept off the peak3 |
| Weather file | Finningley, near Sheffield. Annual mean 9.5 °C. A reference file4 |
| Design outdoor temperature | −3 °C4 |
| Indoor temperatures | Living area 21 °C, other rooms 20 °C4 |
| Gas-boiler setback | 12 °C, so heating stays off overnight4 |
| Boiler efficiency | 85%4 |
| Heat-pump setback | 16 °C and 18 °C, modelled as options.4 The annex does not say which the £550 run used.3 |
| Heat-pump weather compensation | A 4 °C reduction in flow temperature from March to November. COP follows manufacturer curves that vary with outdoor temperature and flow temperature.4 The annex’s 2.8 does not say that this control was used.3 |
| Heat-pump radiator flow | 45 °C low-temperature and 65 °C high-temperature cases.4 The annex does not say which the £550 run used. It only quotes a COP of 2.8.3 |
| Baseline cavity-wall U-value | 0.65 W/m²K4 |
| Baseline loft U-value | 0.42 W/m²K4 |
| Baseline solid-floor U-value | 1.2 W/m²K, uninsulated4 |
| CODE detached cavity archetype (Sprawling-C) | 104 m², infiltration 0.64 air changes per hour, a system boiler and a 140-litre cylinder, heated morning and evening, with the evening period 17:30–22:30. One archetype in the range4 |
What remains unpublished
Several inputs needed to reproduce the figures accurately are absent from both documents. Most notably, neither gives annual electricity, gas, space-heating or hot-water demand in kilowatt-hours.34 Table 2 lists these gaps.
| Parameter | Published value |
|---|---|
| Annual space-heating demand | Not published |
| Annual hot-water demand | Not published |
| Annual gas consumption | Not published |
| Annual heat-pump electricity | Not published |
| Other annual electricity | Not published |
| Design heat loss | Not published |
| Heat-pump flow temperature | Not published. The case used for the £550 run is not published, and the annex only quotes a COP of 2.8.3 |
| Window U-value | Not published |
| Solar generation | Not published |
| Export tariff | Not published |
| Self-consumption share | Not published |
| Unit rates | Not published |
| Standing-charge amounts | Not published |
| Time-of-use prices | Not published |
| Occupancy as a number for Sprawling-C | Not published |
| Weather calendar year in the annex or CODE | Not published |
Reproducing Government Model in Solar Butter
Table 3 translates each published assumption into the Solar Butter input that represents it. Fabric, U-values and infiltration are represented by a design heat loss of 5000 W, estimated from U-values and properties around that period. Annual electricity and hot water are simulation outputs, so they are not listed. The variable-rate tariff is the annex’s time-of-use tariff. The results and the simulation reports call it the heat pump tariff.
| Parameter | Government assumption | Solar Butter replication |
|---|---|---|
| Weather | Yorkshire. CODE’s weather file is Finningley, near Sheffield. No postcode or calendar year is published.34 | Postcode DN9 3RH, calendar year 2016 |
| Design outdoor temperature | −3 °C4 | −3 °C |
| Indoor temperature | 21 °C in the living area, 20 °C in other rooms4 | 21 °C. The other-room setpoint is not a separate input |
| Design heat loss | Insulation and U-values in Table 1, plus infiltration of 0.64 air changes per hour34 | 5000 W, estimated from U-values and properties around that period |
| Floor area | 104 m², one CODE archetype in the range4 | 104 m² |
| Flow temperature | 45 °C and 65 °C cases. The annex does not say which the £550 run used.4 | 45 °C |
| SCOP | 2.83 | 2.8 |
| Heating schedule and setback | Gas boiler setback 12 °C, so heating stays off overnight. For the heat pump, CODE models 16 °C and 18 °C as setback options, and the annex does not say which the £550 run used. Heating is morning and evening, with the evening period 17:30–22:30.4 | No setback. The heat pump holds 21 °C continuously, the worst case for heat loss. The 12 °C boiler setback is not modelled |
| Hot water | 140-litre cylinder. Annual demand is not published.4 | Cylinder volume 140 litres. Daily draw 50 litres per occupant per day |
| Hot-water tank set temperature | Not published | 55 °C |
| Electric load | Not published | 3500 kWh/year |
| Occupancy | Not published | 2 occupants |
| Solar | 4 kW, east- and west-facing3 | 4 kW: ten 400 W panels, five east and five west. Generation is calculated from that array, DN9 3RH and 2016 |
| Battery | 4 kWh3 | 4 kWh |
| Battery control | Solar self-consumption on a conventional tariff. Charged off-peak and kept off the peak on the time-of-use tariff.3 | Auto-optimised setpoints, except the government flat-tariff run, which lists no setpoint mode |
| Inverter | Not published | 5 kW |
| Heat-pump capacity | Not published | 5,000 W rated |
| Fixed-rate tariff | 2024 prices. The battery is run for solar self-consumption. The gas standing charge is no longer paid.3 | Import £0.28/kWh. Export £0.12/kWh. Standing charge £0.60/day |
| Variable-rate tariff | 2024 prices. 8 off-peak, 13 standard and 3 peak hours. The battery is charged off-peak and kept off the peak.3 | Off-peak £0.15/kWh. Standard £0.28/kWh. Peak £0.45/kWh. Export £0.12/kWh. Standing charge £0.60/day |
| Gas boiler counterfactual | Gas boiler, 85% efficient, 65 °C flow34 | Calculated in Table 4. The bill is in Modelling Results |
Gas comparison
Each scenario is compared with the same house heated by a gas boiler. Table 4 sets out how the gas is calculated from the thermal output each simulation reports.
| Parameter | Assumption |
|---|---|
| Boiler efficiency | 85%4 |
| Space heating | 20% less than the reported 16,456 kWh of heat, then divided by 85%. The 20% is an assumption, discussed under Limitations |
| Hot water | The reported 2,185 kWh of heat, divided by 85%. No 20% reduction |
| Gas unit rate | 7.5 p/kWh |
| Gas standing charge | 31.66 p/day. Direct Debit average for England, Scotland and Wales, 1 October to 31 December 2024, including VAT.7 |
Each results table compares all-electric heat pump situations with gas and electricity together. The flat tariff and heat pump tariff totals are the electricity bills printed in the simulation reports, which include solar and the battery. Heat pump only, with no solar or battery, prices the 3,500 kWh household load and the heat pump electricity at £0.28/kWh and adds the £220 electricity standing charge. An all-electric heat pump no longer pays the gas standing charge, so it is £0 in the heat pump columns. The gas-and-electric total adds the gas energy, the gas standing charge, and the household electricity: 3,500 kWh at £0.28/kWh (£980) plus the £220 electricity standing charge, £1,200. Solar and the battery are not re-simulated for that household electricity. They remain inside the reported heat pump bills, and those bills are not reduced by removing the 3,500 kWh. Estimated savings vs gas are the gas-and-electric total minus each heat pump total.
Modelling Results
Government Modelling Scenario (SCOP 2.8)
Both electricity bills come from historic simulations of the same South Yorkshire household for 2016. Only the tariff changes. The 4 kW array generates 3,075 kWh. The gas energy is calculated from the reported thermal output, using the assumptions in Table 4.
Flat tariff.pdfHeat pump tariff.pdf
| Parameter | Flat tariff | Heat pump tariff | Heat pump only (no solar or battery) | Gas and electricity |
|---|---|---|---|---|
| Space heating | 5,225 kWh electricity | 5,225 kWh electricity | 5,225 kWh electricity | 15,488 kWh gas |
| Space heating thermal | 16,456 kWh | 16,456 kWh | 16,456 kWh | 13,165 kWh |
| Hot water | 1,000 kWh electricity | 1,000 kWh electricity | 1,000 kWh electricity | 2,571 kWh gas |
| Hot water thermal | 2,185 kWh | 2,185 kWh | 2,185 kWh | 2,185 kWh |
| Heat delivered per kWh of electricity | 3.15 space heating, 2.19 hot water | 3.15 space heating, 2.19 hot water | 3.15 space heating, 2.19 hot water | |
| Gas used | 0 kWh | 0 kWh | 0 kWh | 18,059 kWh |
| Solar generated | 3,075 kWh | 3,075 kWh | ||
| Grid import | 7,286 kWh | 7,517 kWh | ||
| Grid export | 595 kWh | 687 kWh | ||
| Average import price | £0.28/kWh | £0.22/kWh | ||
| Load met by solar and battery | 25.2% | 22.8% | ||
| Electricity bill | £2,188 | £1,786 | £2,943 | £1,200 |
| Gas energy | £0 | £0 | £0 | £1,354 |
| Gas standing charge | £0 | £0 | £0 | £116 |
| Total | £2,188 | £1,786 | £2,943 | £2,670 |
| Estimated savings vs gas | £482 | £884 | −£273 |
The gas energy is 18,059 kWh at 7.5 p/kWh (£1,354). The gas standing charge is 365 days at 31.66 p (£116), rounded to the nearest pound in the same way the reports round the electricity standing charge to £220. Together these are a gas bill of £1,470, and the gas-and-electric total is £2,670. Heat pump only is the 6,225 kWh of heat pump electricity at £0.28/kWh (£1,743), plus the £980 household load and the £220 electricity standing charge, £2,943. The average import price on the heat pump tariff is £0.22/kWh.
With no solar or battery, the heat pump costs an estimated £273 a year more than gas and electricity together. The estimated saving for a heat pump with no solar or battery is lower because the comparison assumes a SCOP of 2.8.
Modern Heat Pump Scenario (SCOP 3.77)
The run is the same South Yorkshire household for 2016. The heat pump uses the Vaillant aroTHERM plus SCOP of 3.77 at 45 °C.5 The reports still give 16,456 kWh of space-heating heat and 2,185 kWh of hot-water heat, so the gas column is the same as Table 5. Electricity falls to 3,881 kWh for space heating and 743 kWh for hot water.
Modern heat pump on flat tariff.pdfModern heat pump on heat pump tariff.pdf
| Parameter | Flat tariff | Heat pump tariff | Heat pump only (no solar or battery) | Gas and electricity |
|---|---|---|---|---|
| Space heating | 3,881 kWh electricity | 3,881 kWh electricity | 3,881 kWh electricity | 15,488 kWh gas |
| Space heating thermal | 16,456 kWh | 16,456 kWh | 16,456 kWh | 13,165 kWh |
| Hot water | 743 kWh electricity | 743 kWh electricity | 743 kWh electricity | 2,571 kWh gas |
| Hot water thermal | 2,185 kWh | 2,185 kWh | 2,185 kWh | 2,185 kWh |
| Heat delivered per kWh of electricity | 4.24 space heating, 2.94 hot water | 4.24 space heating, 2.94 hot water | 4.24 space heating, 2.94 hot water | |
| Gas used | 0 kWh | 0 kWh | 0 kWh | 18,059 kWh |
| Solar generated | 3,075 kWh | 3,075 kWh | ||
| Grid import | 5,706 kWh | 5,922 kWh | ||
| Grid export | 617 kWh | 707 kWh | ||
| Average import price | £0.28/kWh | £0.21/kWh | ||
| Load met by solar and battery | 29.8% | 27.2% | ||
| Electricity bill | £1,743 | £1,396 | £2,495 | £1,200 |
| Gas energy | £0 | £0 | £0 | £1,354 |
| Gas standing charge | £0 | £0 | £0 | £116 |
| Total | £1,743 | £1,396 | £2,495 | £2,670 |
| Estimated savings vs gas | £927 | £1,274 | £175 |
Heat pump only is the 4,624 kWh of heat pump electricity at £0.28/kWh (£1,295), plus the £980 household load and the £220 electricity standing charge, £2,495.
A more efficient heat pump uses less electricity during the peak-rate hours. Even so, the average import price on the heat pump tariff is £0.21/kWh. A larger battery could reduce that average by moving more import into the off-peak hours. That case is covered in the Modern Equipment Scenario.
Modern Equipment Scenario
The run is the same South Yorkshire household for 2016. The heat pump is the modern unit used in Table 6, so the heat output is unchanged and the gas column is the same. The battery is 12 kWh. The array is five 450 W panels east and five west, 4.5 kW. Solar generation is 3,459 kWh.
Modern heat pump, battery, solar on flat tariff.pdfModern heat pump, battery, solar on heat pump tariff.pdf
| Parameter | Flat tariff | Heat pump tariff | Gas and electricity |
|---|---|---|---|
| Space heating | 3,881 kWh electricity | 3,881 kWh electricity | 15,488 kWh gas |
| Space heating thermal | 16,456 kWh | 16,456 kWh | 13,165 kWh |
| Hot water | 743 kWh electricity | 743 kWh electricity | 2,571 kWh gas |
| Hot water thermal | 2,185 kWh | 2,185 kWh | 2,185 kWh |
| Heat delivered per kWh of electricity | 4.24 space heating, 2.94 hot water | 4.24 space heating, 2.94 hot water | |
| Gas used | 0 kWh | 0 kWh | 18,059 kWh |
| Solar generated | 3,459 kWh | 3,459 kWh | |
| Grid import | 5,004 kWh | 5,221 kWh | |
| Grid export | 275 kWh | 342 kWh | |
| Average import price | £0.28/kWh | £0.17/kWh | |
| Load met by solar and battery | 38.5% | 35.8% | |
| Electricity bill | £1,588 | £1,089 | £1,200 |
| Gas energy | £0 | £0 | £1,354 |
| Gas standing charge | £0 | £0 | £116 |
| Total | £1,588 | £1,089 | £2,670 |
| Estimated savings vs gas | £1,082 | £1,581 |
The inverter is the same 5 kW unit as in the other runs. The average import price on the heat pump tariff is £0.17/kWh, down from £0.21/kWh with the 4 kWh battery. Heat pump only has no solar or battery, so it is the same £2,495 as Table 6, with an estimated saving of £175. The savings are higher than the 4 kWh, 400 W scenario because the battery is 12 kWh and the panels are 450 W. The heat output is the same 2016 output.
Limitations
Several important missing parameters required for accurate replication were missing or could not be found from Government documents. These include tariff price data, household general electricity consumption. This will limit the accuracy of the comparison generally. However these figures could be estimated from other parameters given.
The setpoint behaviour of the gas boiler was modelling by the government to use a setback temperature of 12 DegC. Because gas boilers can quickly heat up a room, they are often run only when needed. Reducing gas consumption and heat loss. Solar butter does not yet model the gas boiler and the setpoint behaviour, therefore an assumption was made on this basis of 20% reduction in heat loss. This roughly corresponds to a fall in room temperature of on average of 2 DegC between heating periods.
Why does the solar butter model predict slightly lower savings, £482 vs £550 for the government for the default tariff case? We've assumed the heat pump holds 21 °C continuously with no setback, the worst case for heat loss. This means the house is kept constant at 21°C for the heat pump case. The government also did not publish the gas and electricity prices assumed, so these have had to be estimated based off recent price data.
Why does the model predict slightly better savings, compared to the government study for the heat pump tariff case? Solar butter auto-optimisation algorithm is fairly intelligent and uses the least cost algorithm. This means it will only charge the battery in low solar generation periods and would avoid charging during summer if the historic weather forecast predicts it will be a sunny day. The algorithm used by the government is not known and difficult to compare to. The government also did not publish the variable gas and electricity prices, so these have had to be estimated based off recent price data.
Every scenario uses a single weather year, 2016, at DN9 3RH. A colder or warmer year would change both the heat demand and the solar generation.
The 5000 W design heat loss is estimated from U-values and properties around that period, because the government documents do not publish one.
The gas unit rate of 7.5 p/kWh is an assumption. The gas standing charge is the Ofgem figure for late 2024.7
The electricity prices are also Solar Butter assumptions: £0.28/kWh import and £0.12/kWh export on the flat tariff; £0.15, £0.28 and £0.45/kWh off-peak, standard and peak on the heat pump tariff; and a £0.60/day standing charge on both. Prices are held flat for the whole year.
The reports give 16,456 kWh of space-heating heat for 5,225 kWh of electricity at a SCOP of 2.8, a ratio of 3.15, and for 3,881 kWh at a SCOP of 3.77, a ratio of 4.24. For hot water the ratios are 2.19 and 2.94. The simulation applies its own outdoor-temperature and flow-temperature curves, so the delivered ratio differs from the SCOP entered.
The savings are annual running costs only. They do not include the purchase or installation cost of the heat pump, panels or battery, or the cost of borrowing under the Warm Homes Loan Scheme.1
Discussion
The factsheet estimates a saving of up to £550 a year for a heat pump, battery and solar panels, and a further £300 a year with a time-of-use tariff.1 Table 9 reports each modelled saving against the gas boiler home’s total bill of £2,670. The flat-tariff savings correspond to the £550. The additional saving from the heat pump tariff corresponds to the £300.
| Government | Solar Butter | |
|---|---|---|
| Flat tariff | Up to £5501 | £482 |
| Heat pump tariff | About £8501 | £884 |
| Scenario | Changes | Total bill | Estimated savings vs gas |
|---|---|---|---|
| Gas boiler and electricity | Gas boiler in place of the heat pump | £2,670 | — |
| Government Modelling Scenario (SCOP 2.8), flat tariff | Baseline | £2,188 | £482 |
| Government Modelling Scenario (SCOP 2.8), heat pump tariff | Baseline | £1,786 | £884 |
| Government Modelling Scenario (SCOP 2.8), heat pump only | No solar or battery | £2,943 | −£273 |
| Modern Heat Pump Scenario (SCOP 3.77), flat tariff | Heat pump SCOP: 3.77 | £1,743 | £927 |
| Modern Heat Pump Scenario (SCOP 3.77), heat pump tariff | Heat pump SCOP: 3.77 | £1,396 | £1,274 |
| Modern Heat Pump Scenario (SCOP 3.77), heat pump only | Heat pump SCOP: 3.77. No solar or battery | £2,495 | £175 |
| Modern Equipment Scenario, flat tariff | Heat pump SCOP: 3.77. Battery: 12 kWh. Panels: 450 W (4.5 kW) | £1,588 | £1,082 |
| Modern Equipment Scenario, heat pump tariff | Heat pump SCOP: 3.77. Battery: 12 kWh. Panels: 450 W (4.5 kW) | £1,089 | £1,581 |
Replicating the government’s own assumptions gives an estimated saving of £482 a year on the flat tariff, slightly below the factsheet’s £550.1 Moving to the heat pump tariff the total savings vs gas boiler were £884, against the factsheet’s 850. With equipment on sale today, the savings are considerably higher. A heat pump with a SCOP of 3.77 raises the flat-tariff saving to £927, and adding a 12 kWh battery and 450 W panels raises it to £1,082, about twice the factsheet’s figure. On the heat pump tariff, the Modern Equipment Scenario saves an estimated £1,581 a year. Without solar or a battery, the heat pump costs £273 more than gas at a SCOP of 2.8 and saves £175 at 3.77, so most of the saving comes from solar, the battery and the heat pump tariff. These estimates rest on the assumptions set out under Limitations, in particular the 20% reduction applied to the gas boiler’s space heating.
Conclusion
The Government models were replicated in Solar Butter and the baseline results were well aligned.
The findings showed considerable more savings were possible given up to date equipment, including use of a modern higher efficiency heat pump, larger battery and higher performing solar panels available on the market. The modelled saving runs from −£273 to £1,581 a year, and that is not a ceiling, since other electricity tariffs, a larger battery, and a lower flow temperature with underfloor heating can increase it further. A Vaillant aroTHERM plus at a SCOP of 3.77 and a flow temperature of 45 °C,5 with a 12 kWh battery and 450 W panels on the heat pump tariff, saves an estimated £1,581 a year.
References
- Department for Energy Security and Net Zero. Warm Homes Loan Scheme: factsheet [Internet]. London: GOV.UK; 2026 [cited 2026 Nov 8]. Available from: https://www.gov.uk/government/news/warm-homes-loan-scheme-factsheet
- Department for Energy Security and Net Zero. Warm Homes Plan [Internet]. London: GOV.UK; 2026 [cited 2026 Nov 8]. Available from: https://www.gov.uk/government/publications/warm-homes-plan/warm-homes-plan-html
- Department for Energy Security and Net Zero. Warm Homes Plan: technical annex [Internet]. London: GOV.UK; 2026 [cited 2026 Nov 8]. Available from: https://www.gov.uk/government/publications/warm-homes-plan/warm-homes-plan-technical-annex
- Palmer J, Terry N. Cost-Optimal Domestic Electrification (CODE). BEIS Research Paper 2021/051 [Internet]. London: Department for Business, Energy and Industrial Strategy; 2021 [cited 2026 Nov 8]. Available from: https://www.gov.uk/government/publications/cost-optimal-domestic-electrification-code
- Vaillant Group UK. Installer's Quick Guide - aroTHERM plus [Internet]. 2024 [cited 2026 Nov 8]. Available from: https://professional.vaillant.co.uk/downloads/aproducts/renewables-1/arotherm-plus/arotherm-plus-installer-quick-guide-2848532.pdf
- Department for Energy Security and Net Zero. Warm Homes Fund: call for evidence [Internet]. London: GOV.UK; 2026 [cited 2026 Nov 8]. Available from: https://www.gov.uk/government/calls-for-evidence/warm-homes-fund-innovative-finance-for-investments-and-loans/warm-homes-fund-call-for-evidence-accessible-webpage
- Ofgem. Changes to energy price cap between 1 October to 31 December 2024 [Internet]. London: Ofgem; 2024 [cited 2026 Nov 8]. Available from: https://www.ofgem.gov.uk/news/changes-energy-price-cap-between-1-october-31-december-2024
