Heat Pump, Solar PV &
Cold-Weather Battery Simulator
Solve the European winter heating dilemma. Cross-model seasonal heat pump electricity demand against solar PV irradiance deficits, simulate 2:00 AM – 5:00 AM smart-tariff battery arbitrage, and evaluate LiFePO4 battery cold-temperature throttling.
1Property BER Archetype & Heat Demand
2Heat Pump Hardware & Rooftop Solar PV
Industry-standard European air-to-water heat pump with Bluevolution inverter compressor.
3Battery Storage & Cold-Weather Preheating
4Tariff Arbitrage & Fuel Price Benchmark
System Performance Metrics
Annual Heating Fuel Benchmark
The Cold-Weather LiFePO4 Trap
In sub-5°C winter conditions, standard unheated lithium batteries must throttle charging to prevent internal lithium plating. When temperatures drop below 0°C, outdoor unheated batteries cannot accept 2:00 AM cheap night boost charging, forcing the heat pump onto expensive day peak grid power.
12-Month Seasonal Energy & Cost Breakdown
Observe the winter solar gap (Nov–Feb) and how night-boost battery arbitrage bridges the deficit.
| Month | Avg Temp | Effective COP | Thermal Demand | Solar Output | Direct Solar | Night Arbitrage | Grid Peak | Optimized Cost | Savings vs Oil |
|---|---|---|---|---|---|---|---|---|---|
| Jan | 5.2°C | 4.40 | 1890 kWh | 143 kWh | 43 kWh | 257 kWh | 130 kWh | €74 | +€182 |
| Feb | 5.5°C | 4.42 | 1680 kWh | 257 kWh | 77 kWh | 257 kWh | 46 kWh | €42 | +€185 |
| Mar | 7.2°C | 4.51 | 1470 kWh | 485 kWh | 291 kWh | 35 kWh | 0 kWh | €3 | +€196 |
| Apr | 9.3°C | 4.63 | 840 kWh | 656 kWh | 181 kWh | 0 kWh | 0 kWh | €0 | +€114 |
| May | 11.9°C | 4.77 | 420 kWh | 798 kWh | 88 kWh | 0 kWh | 0 kWh | €0 | +€57 |
| Jun | 14.5°C | 4.91 | 210 kWh | 826 kWh | 43 kWh | 0 kWh | 0 kWh | €0 | +€28 |
| Jul | 16.1°C | 5.00 | 105 kWh | 770 kWh | 21 kWh | 0 kWh | 0 kWh | €0 | +€14 |
| Aug | 15.9°C | 4.99 | 105 kWh | 684 kWh | 21 kWh | 0 kWh | 0 kWh | €0 | +€14 |
| Sep | 14°C | 4.88 | 315 kWh | 513 kWh | 65 kWh | 0 kWh | 0 kWh | €0 | +€43 |
| Oct | 11°C | 4.72 | 945 kWh | 314 kWh | 188 kWh | 12 kWh | 0 kWh | €1 | +€127 |
| Nov | 7.8°C | 4.54 | 1155 kWh | 143 kWh | 43 kWh | 211 kWh | 0 kWh | €20 | +€136 |
| Dec | 6°C | 4.45 | 1365 kWh | 114 kWh | 34 kWh | 257 kWh | 16 kWh | €30 | +€155 |
Empirical Cost Per Delivered kWh of Useful Heat
Frequently Asked Questions: Heat Pumps, Solar & Batteries
Can rooftop solar PV heat my house in winter with a heat pump?
Solar PV alone cannot adequately power a heat pump during Irish and Northern European winters. Over 60% of annual home heating demand occurs between November and February, when solar irradiance drops to less than 15% of summer levels. However, combining solar PV with a home battery on a smart night-boost tariff (e.g. 8.5c/kWh between 2:00 AM and 5:00 AM) allows homeowners to run their heat pump during the day at night-rate prices, slashing winter heating bills by over 70%.
Why do outdoor home batteries stop working or slow down in winter?
Standard unheated Lithium Iron Phosphate (LiFePO4) battery cells cannot safely accept rapid charging below 5°C and must shut down charging completely at or below 0°C to prevent permanent lithium plating and dendrite short circuits. Systems like Sigenergy SigenStor feature integrated thermal heating pads that automatically warm internal cells to 25°C, preserving 100% full-speed charge and discharge down to -20°C.
Is a heat pump running on smart night-boost electricity cheaper than kerosene heating oil?
Yes, significantly. Kerosene heating oil at €1.15/L costs approximately 13.5c per useful kWh of heat (accounting for 85% boiler efficiency). A modern heat pump operating with an SCOP of 3.8 and powered by 8.5c/kWh night-boost battery electricity delivers useful thermal heat for just 2.2c per kWh—delivering over an 83% running cost reduction compared to heating oil.
What SEAI grants are available in Ireland for heat pumps and solar?
In Ireland, the Sustainable Energy Authority of Ireland (SEAI) offers capital grants of up to €6,500 for air-to-water heat pump installations in homes built prior to 2021, alongside up to €2,100 for rooftop solar PV installations, providing up to €8,600 in total capital grant relief.