Skip to main content
To KTH's start page To KTH's start page

Solar PV in prosumer energy systems

A techno-economic analysis on sizing, integration, and risk

Time: Mon 2019-12-16 10.00

Location: F3, Lindstedtsvägen 26, Stockholm (English)

Subject area: Energy Technology Planning and Decision Analysis

Doctoral student: Nelson Sommerfeldt , Tillämpad termodynamik och kylteknik

Opponent: Research Director Michel Haller, Institute for Solar Technology SPF, University of Applied Sciences HSR

Supervisor: Hatef Madani Larijani, Tillämpad termodynamik och kylteknik; Björn Palm, Tillämpad termodynamik och kylteknik

Export to calendar


In the transition towards a sustainable energy system, building mounted solar photovoltaics (PV) have unique benefits; they require no additional land and the energy is generated directly at load centers. Within residential buildings, multi-family homes (MFH) are particularly interesting because of the economies of scale and their greater potential for emissions reductions.

This thesis identifies and describes value propositions for solar PV within Swedish multi-family houses via three branches of inquiry; system sizing optimization, quantification of investment risk, and the techno-economic potential of PV/thermal (PVT) collectors integrated with ground source heat pumps (GSHP). Underpinning these investigations is a comprehensive review of technical and economic models for solar PV, resulting in a catalogue of performance indicators and applied techniques.

From the sizing analysis, no objective, techno-economically optimal PV system size is found without including the prosumer’s personal motives. Prioritizing return on investment results in small systems, whereas systems sized for net-zero energy can be profitable in some buildings. There is also a strong economic incentive to adopt communal electricity metering to increase self-consumption, system size, and economic return. Monte Carlo analysis is used to quantify investment uncertainty, finding that well-designed systems have an 81% chance of earning a 3% real return on investment, and even without subsidies there is a calculated 100% chance of having a positive return. PVT integrated GSHP can reduce the land needed for boreholes by up to 87% with a lower lifecycle cost than district heating, thereby broadening the heat pump market and reducing barriers to heating electrification.

The quantitative results provide guidance for Swedish MFH owners while the methodology presents solar PV value in a more useful manner for prosumers to identify their personal motives in decision making. This approach is also useful for researchers, business leaders, and policy makers to understand the prosumer perspective and promote adoption of PV in the built environment.