PV-Assisted Heat Pump Prototype with Dual Condenser Reaches 7.59 Coefficient of Performance

Why It Matters

The design demonstrates a scalable route to combine heat‑pump heating with rooftop solar, cutting grid demand and operating costs for residential users. It signals a shift toward smarter, higher‑efficiency domestic heating solutions in the decarbonisation era.

Key Takeaways

• Dual condensers enable targeted heating, improving stratification
• PV self‑consumption jumps from 9.9% to 55.5%
• Peak COP reaches 7.59 under PV‑assisted operation
• Seasonal COP improves modestly with dual‑condenser design
• Minute‑level monitoring essential for accurate solar contribution

Pulse Analysis

The convergence of heat‑pump technology and rooftop photovoltaics is reshaping residential energy strategies across Europe. Traditional air‑to‑water heat pumps, while efficient, often operate independently of solar generation, leading to sub‑optimal self‑consumption and higher grid reliance. By aligning domestic hot‑water production with daylight hours, homeowners can capture a larger share of on‑site solar power, reducing electricity bills and carbon footprints. However, achieving this alignment requires sophisticated control and system design, as the thermal storage tank must be heated at the right time without compromising water temperature or service quality.

The research team at Miguel Hernández University introduced a dual‑condenser configuration that directly addresses these challenges. Adding a second condenser at the top of a 215‑liter tank creates a two‑zone heating system, allowing the upper layer to be warmed during peak solar output while the lower layer remains cooler for later use. Coupled with an Arduino‑based controller that switches condensers minute‑by‑minute, the prototype boosted solar self‑consumption from under 10 % to more than 55 % and delivered a peak coefficient of performance of 7.59 when powered by PV. Seasonal COP rose modestly to 3.71, demonstrating that efficiency gains extend beyond peak conditions.

These results have clear implications for the residential HVAC market. Manufacturers can retrofit existing split‑type heat pumps with an additional condenser and smart controls, offering a cost‑effective pathway to higher renewable integration without redesigning the entire system. Utilities and policymakers may also see value in encouraging minute‑resolution monitoring, as coarse hourly data can dramatically overstate solar contributions. As building codes tighten and consumers demand lower operating costs, dual‑condenser, PV‑assisted heat pumps could become a standard solution for energy‑efficient homes, accelerating the transition to net‑zero heating.