RESUMO
Solar power generation in Sweden is far from required capacity to help with transition towards 100% renewables in the power sector by 2040. Decentralized PV system attracts attentions given the conflicts of future increasing demands and land scarcity in the urban areas. However, it is not easy to implement it due to challenges on local conditions and lack of references. This paper aims to propose an overview of the potential of small-scale grid-connected PV systems in a Swedish context and offer an example for urban PV system planning in Sweden or high latitude areas. A model considering weather, space, infrastructures and economics is developed and implemented with a real case in the Swedish context. The findings verify the technical and economic feasibility of urban decentralized rooftop PV systems in the Swedish context. It is found that this kind of system does have considerable power potential in the Swedish context without land requirements. This kind of PV system could be a promising option for future power generation which satisfies part of demands and reduces pressure on external grids. The full potential could be only achieved with improved infrastructures, and the profitability of the system relies heavily on market and political conditions. This study can be a refence for other high latitude areas.
RESUMO
Enhancing the operating temperature of concentrating solar power systems is a promising way to obtain higher system efficiency and thus enhance their competitiveness. One major barrier is the unavailability of suitable solar absorber materials for operation at higher temperatures. In this work, we report on a new high-temperature absorber material by combining Ti2AlC MAX phase material and iron-cobalt-chromite spinel coating/paint. This durable material solution exhibits excellent performance, passing the thermal stability test in an open-air environment at a temperature of 1250 °C for 400 h and at 1300 °C for 200 h. The results show that the black spinel coating can offer a stable high solar absorptivity in the range of 0.877-0.894 throughout the 600 h test under high temperatures. These solar absorptivity values are even 1.6-3.3% higher than that for the sintered SiC ceramic that is a widely used solar absorber material. Divergence of solar absorptivity during these relatively long testing periods is less than 1.1%, indicating remarkable stability of the absorber material. Furthermore, considering the simple application process of the coating/painting utilizing a brush followed by curing at relatively low temperatures (room temperature, 95 and 260 °C in sequence), this absorber material shows the potential for large-scale, high-temperature solar thermal applications.
