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SmartSol2 - Smart Solar Hybrid Solutions for Sustainable European Buildings

Achieving the ambitious national goals in the Swedish building sector are impossible without smart, cost effective, scalable, and integrated solutions for heating, cooling and electricity. The combination of solar PV/thermal collectors and ground source heat pumps are a scalable sustainable energy alternative for not only Swedish Multi-family houses and micro-districts, but also other European residential districts.

The goal of this project is to advance the development of an integrated heating, cooling and electricity system solution for European buildings using solar PVT technology and ground source heat pumps. The project aims at investigating the methods and strategies to reduce both operational and capital cost of the system as well as increasing the system efficiency. A system pilot will be constructed and monitored with sustainable business models developed for diverse applications in domestic and export markets.

Funded by:

Mistra Innovation

Time period: 

January 2020 – December 2023

Project partners:

KTH Energy Technology

Solhybrid i Småland AB

Sonority Sustainable Energy AB

Bengt Dahlgren Stockholm Geo AB


A promising pathway to the electrification and decarbonization of buildings are solar heat pumps (SHP). There a numerous methods for combining the two technologies, however, one increasingly interesting approach is the integration of photovoltaic/thermal hybrid collectors (PVT) with ground source heat pumps (GSHP). The benefits from this approach are a;

  • dramatic reduction of the amount of land needed for boreholes in new systems,
  • recovery of degraded boreholes without the need for additional drilling,
  • high thermal production from PVT due to the low temperatures in a borehole circuit,
  • seasonal storage of solar heat from summer to winter,
  • greater electricity production from PV also due to the low temperatures, and
  • lower costs than traditional solar thermal designs.

Recent cost reductions have dramatically increased the solar PV market in Sweden, but PVT collectors have virtually no market share in comparison in part because the PVT+GSHP concept is at a very early stage of commercialization. This project is motivated by the potential for smart solar hybrid concepts to scale and decarbonize the building sector in Sweden and Europe. Its foundation stems primarily from two recently completed projects – the small Mistra Innovation project “Sunhybrid” (number MI15.18) led by Solhybrid i Småland and the Effsys Expand research project “Ground Source Heat Pumps for Swedish Multi-Family Houses: Innovative Co-Generation and Thermal Storage Strategies[A1] ” (number 40936-1) led by KTH.

Aim and Objectives

The overall objective of this project is to advance in the development of an integrated heating, cooling and electricity system solution for European buildings using solar PVT technology and ground source heat pumps. The project focuses on component, system, and business development and optimization.

At a component level, the goal is to further develop a PVT module specifically for heat pump integration that improves thermal efficiency while reducing production costs. At a system level, the goal is to validate and optimize the PVT heat pump concept in an expanded range of applications and markets. At a business level, the project aims at creating the necessary business models for deploying PVT collectors and PVT heat pump systems considering supply chains, component certification, systems integration and installer qualifications.


Upon completion, this project intends to:

  • Deliver a digitally optimized and physically prototyped PVT product ready for the market,
  • Identify techno-economically optimal solutions for the PVT integration in new and existing GSHP systems across building types and markets,
  • Quantify the techno-economic performance of PVT sourced heat pumps as an alternative to air source heat pumps across temperate regions and markets, and
  • Provide stakeholders in PVT heat pump systems with the necessary tools to move past pilots and prototypes to commercial scale and export.


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Project contact persons

Page responsible:Oxana Samoteeva
Belongs to: Energy Technology
Last changed: Jan 18, 2021
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