A fully electric heat pump consumes electricity. The exact amount of power a heat pump uses depends on several factors, such as the heat pump's capacity, the building's insulation, and the system's efficiency. The heat pump requires electricity to deliver heat, and it does this exceptionally well: it generates far more heat than the energy it consumes during the process. This performance is called efficiency. In this blog, we explain the relationship between a heat pump's electricity consumption and its efficiency.
Energy consumption of a heat pump
The true power of a heat pump lies in its high energy efficiency relative to the electricity consumed during the process. In a running heat pump system, the refrigerant absorbs heat from the outdoor air and evaporates into a gas. The compressor then compresses this gaseous refrigerant, causing its temperature to rise drastically. Next, the condenser transfers this heat to the heating system of the commercial property. After this heat transfer, the expansion valve cools the refrigerant down further, returning it to a liquid state so the cycle can begin anew.
In a well-insulated space, a heat pump performs even more effectively, as less electricity is required to maintain a constant indoor temperature.
The efficiency of a heat pump
Efficiency is expressed using the Coefficient of Performance (COP) and the Seasonal Coefficient of Performance (SCOP). These metrics indicate how much heat energy the heat pump delivers relative to the amount of electrical energy it consumes, serving as an accurate benchmark for the system's performance.
COP value (Coefficient of Performance)
The COP indicates how much heat you receive per unit of electricity the heat pump consumes. A COP of 4 means that the heat pump produces 4 units of heat for every single unit of electricity it uses. Keep in mind that the COP fluctuates depending on the outdoor temperature and the specific type of heat pump.
SCOP value (Seasonal Coefficient of Performance)
The SCOP represents the average efficiency across an entire heating season, factoring in seasonal fluctuations in outdoor temperatures. An SCOP of 3.5 means that, averaged over the year, the heat pump delivers 3.5 times more heat than it consumes in electricity. This calculation also accounts for part-load hours and standby hours.
On average, an air-to-water heat pump achieves an SCOP between 3 and 4. A ground-to-water heat pump typically achieves an SCOP between 4 and 5. Ground-source systems deliver higher efficiency because the ground temperature is highly stable and consistently stays above 0 degrees.
Summary
In short, an SCOP of 4 translates to an efficiency rate of 400%, since you receive four times more heat than the energy required to produce it. In practice, operational efficiency generally ranges between 300% and 500%, depending on environmental conditions and the type of heat pump. These values may vary based on a colder or warmer average outdoor season.
Savings compared to a gas-fired central heating boiler
The efficiency of a heat pump is an essential metric for understanding its energy yield. As noted above, the average SCOP of an air-to-water heat pump is between 3 and 4. In contrast, the efficiency of an average central heating boiler sits around 0.9, making boiler efficiency significantly lower than that of a heat pump. A heat pump is therefore much more effective at generating heat. Does this mean we can conclude that a heat pump will save you 3 to 4 times more money compared to a gas boiler? No, that conclusion cannot be made directly. A central heating boiler consumes gas, whereas a heat pump consumes electricity. A quick calculation example helps clarify the actual financial returns.
1. Efficiency and cost calculation for a central heating boiler
Assuming a current gas price of around €1.10 per cubic meter, a central heating boiler utilizing 1 cubic meter (m3) of gas (at 90% efficiency) delivers approximately 9 kWh of energy. The cost for this is €1.10. While a central heating boiler also uses a small amount of electricity, we will leave that out of this basic calculation.
2. Efficiency and cost calculation for a heat pump
At a current electricity rate of around €0.30 per kWh, a heat pump with an SCOP of 3 (300% efficiency) will deliver 3 kWh of heat energy for €0.30. Therefore, generating 9 kWh of heat energy with this heat pump costs €0.90
Conclusion
A direct comparison regarding monetary savings depends on various shifting factors: the price of gas, the price of electricity, and the SCOP value of the heat pump. In our calculation example, using a heat pump saves €0.20 for every 9 kWh of heat generated
In addition to reducing your energy bills, purchasing a fully electric heat pump means you completely eliminate gas consumption. From an ecological perspective, this is a massive advantage that instantly boosts the sustainability profile of your commercial building.
Want to know more about heat pump electricity consumption?
Would you like to learn more about the consumption rates or operational costs of a heat pump? Read our dedicated blog post on heat pump costs. Alternatively, feel free to contact us directly. We are happy to answer your questions and help you gain insight into your specific situation.
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