Evolutionary Optimisation of Semitransparent Building Integrated Photovoltaic Facades

The optimisation of semi-transparent building integrated photovoltaic facades can be challenging when attempting to find an overall balance performance between conflicting performance criteria. This paper presents a three-phase design optimisation method that maximises overall electricity savings generated by these types of facades by simulating the combined impact of electricity generation, cooling load, and daylight autonomy. Two demonstrations are performed, with the difference being that the second demonstration uses an enhanced model for calculating daylight savings that takes into account the use of blinds to counteract glare. For both demonstrations, the three-phase optimisation method significantly reduces optimisation run times. Comparing the design variants evolved by the two demonstrations, the use of the enhanced daylight savings model results in a total electricity savings that is more accurate but in terms of visual differentiation, the difference between the optimized design variants is relatively small

Investigating the climate impacts of urbanization and the potential for cool roofs to counter future climate change in Southern California

The climate warming effects of accelerated urbanization along with projected global climate change raise an urgent need for sustainable mitigation and adaptation strategies to cool urban climates. Our modeling results show that historical urbanization in the Los Angeles and San Diego metropolitan areas has increased daytime urban air temperature by 1.3 °C, in part due to a weakening of the onshore sea breeze circulation. We find that metropolis-wide adoption of cool roofs can meaningfully offset this daytime warming, reducing temperatures by 0.9 °C relative to a case without cool roofs. Residential cool roofs were responsible for 67% of the cooling. Nocturnal temperature increases of 3.1 °C from urbanization were larger than daytime warming, while nocturnal temperature reductions from cool roofs of 0.5 °C were weaker than corresponding daytime reductions. We further show that cool roof deployment could partially counter the local impacts of global climate change in the Los Angeles metropolitan area. Assuming a scenario in which there are dramatic decreases in greenhouse gas emissions in the 21st century (RCP2.6), mid- and end-of-century temperature increases from global change relative to current climate are similarly reduced by cool roofs from 1.4 °C to 0.6 °C. Assuming a scenario with continued emissions increases throughout the century (RCP8.5), mid-century warming is significantly reduced by cool roofs from 2.0 °C to 1.0 °C. The end-century warming, however, is significantly offset only in small localized areas containing mostly industrial/commercial buildings where cool roofs with the highest albedo are adopted. We conclude that metropolis-wide adoption of cool roofs can play an important role in mitigating the urban heat island effect, and offsetting near-term local warming from global climate change. Global-scale reductions in greenhouse gas emissions are the only way of avoiding long-term warming, however. We further suggest that both climate mitigation and adaptation can be pursued simultaneously using 'cool photovoltaics'

A strategic research agenda for photovoltaic solar energy technology : report of the EU PV technology platform

The EU PV Technology Platform [1] aims at joining forces on a European level to contribute to the further development of photovoltaic solar energy into a competitive technology that can be applied on a large scale and to the strengthening of the position of the European PV industry on the global market. The Platform mobilises a wide range of stakeholders from all European countries and mainly operates through its four Working Groups, addressing distinctly different fields of activity: 1. Policy and Instruments, 2. Market Deployment, 3. Science, Technology & Applications, and 4. Developing Countries. A key result of the Platform activities over the first two years of its existence is the Strategic Research Agenda (SRA), which was prepared by the Working Group on Science, Technology & Applications and published in June 2007. The SRA defines broadly supported overall development targets for PV technology and outlines research fields and topics to be addressed to reach these targets. In this context cost reduction of PV electricity generation is a crucial, although not the only, issue. This paper provides a brief summary of the SRA. The full document can be downloaded from the Platform website

A strategic research agenda for photovoltaic solar energy technology : report of the EU PV technology platform

The EU PV Technology Platform [1] aims at joining forces on a European level to contribute to the further development of photovoltaic solar energy into a competitive technology that can be applied on a large scale and to the strengthening of the position of the European PV industry on the global market. The Platform mobilises a wide range of stakeholders from all European countries and mainly operates through its four Working Groups, addressing distinctly different fields of activity: 1. Policy and Instruments, 2. Market Deployment, 3. Science, Technology & Applications, and 4. Developing Countries. A key result of the Platform activities over the first two years of its existence is the Strategic Research Agenda (SRA), which was prepared by the Working Group on Science, Technology & Applications and published in June 2007. The SRA defines broadly supported overall development targets for PV technology and outlines research fields and topics to be addressed to reach these targets. In this context cost reduction of PV electricity generation is a crucial, although not the only, issue. This paper provides a brief summary of the SRA. The full document can be downloaded from the Platform website

PV Quality and Economy

The strong growth of the PV sector is accompanied by high cost pressure, accelerated innovation cycles and dynamic deployment, clearly indicating that the quality of PV products and the holistic economy of PV electricity deserve special attention. PV is expected to deliver electricity at low LCOE, Energy Pay-Back Time (EPBT) and Product Environmental Footprint (PEF). This report defines quality as the ability of a product to meet demanding customer expectations while focusing on the impact of quality parameters on monetary, energy and environmental cost