Determine heat demand
Heat demand defines the approximate electricity demand of the heat pump.
Guide
Understand solar + heat pump: how well do they really fit?
PV and heat pump only work well together when generation and heat demand overlap in time. The most important inputs are PV yield, heat demand, efficiency, battery and seasonal load profile; the critical limits are winter gap, weather, flow temperature, tariff model and peak loads.
Quick answer
How well do solar and heat pumps fit?
Judge summer surplus and winter demand separately. A strong PV yield in July does not automatically cover heat demand in January.
Example
Example: Match solar generation with heat demand
Start by clarifying how well PV and heat pump fit together across the year. Then the comparison clarifies the effect of PV yield, heat demand, efficiency, battery and seasonal profile and the boundary set by winter gap, flow temperature, tariff model and peak loads, load profile.
Decision focushow well PV and heat pump fit together across the year
Main leverPV yield, heat demand, efficiency, battery and seasonal profile
Separate checkwinter gap, flow temperature, tariff model and peak loads, load profile
Next stepjudge summer surplus and winter demand separately
How to read the resultDecision focus: how well PV and heat pump fit together across the year. Separate check: winter gap, flow temperature, tariff model and peak loads, load profile.
Read the result together with PV yield, heat demand, efficiency, battery and seasonal profile. Winter gap, flow temperature, tariff model and peak loads, load profile limit how directly you can act on it.
Decision view
Match solar generation with heat demand
The overview separates result, lever and boundary: how well PV and heat pump fit together across the year; PV yield, heat demand, efficiency, battery and seasonal profile; winter gap, flow temperature, tariff model and peak loads, load profile. This turns the graphic for Understand solar + heat pump into decision support rather than decoration.
What the visual shows
The values explain the most important parts of the visual.
Resulthow well PV and heat pump fit together across the year
Main leverPV yield, heat demand, efficiency, battery and seasonal profile
Separate checkwinter gap, flow temperature, tariff model and peak loads, load profile
The practical benefit becomes clear only when PV yield, heat demand, efficiency, battery and seasonal profile are realistic and winter gap, flow temperature, tariff model and peak loads, load profile are checked separately.
Winter gap, flow temperature, tariff model and peak loads, load profile can change the real-world result and should be reviewed separately before binding decisions.
How it is calculated · Mathematical background
How it is calculated
The starting point is PV yield, heat demand, efficiency, battery and seasonal profile. The transfer limit comes from winter gap, flow temperature, tariff model and peak loads, load profile.
Use the efficiency factor
The annual performance factor converts heat demand into electricity demand.
Compare PV generation
Summer surplus and winter heat demand often do not match.
Estimate direct use
Only simultaneously usable PV power reduces heat-pump grid import.
Derive grid share
The remaining demand still comes from the grid.
Review scenario
Robust results require realistic winter, battery and load assumptions.
The statement helps when how well PV and heat pump fit together across the year. Before binding steps, winter gap, flow temperature, tariff model and peak loads, load profile remain separate.
Detailed calculation explanation
Heat-pump electricity demand depends on heat demand and the annual performance factor. Simplified: heat-pump electricity = heat demand ÷ annual performance factor. PV value only arises for the share used at the same time or sensibly stored. Annual totals alone are not enough; seasonal timing matters.
If-then rules
If-then rules for the decision
When usage or prices can change
PV yield, heat demand, efficiency, battery and seasonal profile set the main driver. The statement is robust when less favourable assumptions still work.
When choosing technology or tariffs
winter gap, flow temperature, tariff model and peak loads, load profile also decide whether the calculation can become a binding next step.
When planning the next step
The next action should read the calculated value, main lever and model boundary together.
Step by step
How to interpret this topic
Read demand and generation
The central value needs a clear question: how well PV and heat pump fit together across the year. winter gap, flow temperature, tariff model and peak loads, load profile stay beside the number for interpretation.
Find the strongest energy lever
The main driver is PV yield, heat demand, efficiency, battery and seasonal profile. Small changes here can matter more than additional details.
Keep model limits realistic
Beside the result sit winter gap, flow temperature, tariff model and peak loads, load profile. This is where calculation ends and judgement begins.
Plan the next energy step
The calculation becomes practical when how well PV and heat pump fit together across the year leads to a concrete action with enough margin.
Checklist
Quick decision check
- Define the starting question: how well PV and heat pump fit together across the year.
- Vary the main lever within the same scenario: PV yield, heat demand, efficiency, battery and seasonal profile.
- Keep the boundary separate: winter gap, flow temperature, tariff model and peak loads, load profile.
- Compare base case and cautious case only with the same reference value: how well PV and heat pump fit together across the year.
- Turn the result into action only when PV yield, heat demand, efficiency, battery and seasonal profile and winter gap, flow temperature, tariff model and peak loads, load profile remain plausible together.
Common mistakes
Common decision mistakes
solar + heat pump: reading the result without context
The value helps only when its purpose is clear. Otherwise details hide the boundary from winter gap, flow temperature, tariff model and peak loads, load profile.
solar + heat pump: setting the main lever too optimistically
PV yield, heat demand, efficiency, battery and seasonal profile should not be set as wish values. Otherwise the normal case gets confused with the best case.
solar + heat pump: overlooking the model boundary
A binding step needs both the result and a clear view of winter gap, flow temperature, tariff model and peak loads, load profile.
FAQ
Frequently asked questions
Can PV run a heat pump completely?
If PV yield, heat demand, efficiency, battery and seasonal profile are uncertain, the decision should not depend on the most favourable scenario.
Why is the seasonal mismatch important?
The best comparison value is the one that turns an acceptable result into a risky one.
What is the next decision after calculating?
The result is useful for orientation. Binding steps also need a view of winter gap, flow temperature, tariff model and peak loads, load profile.