▸ We studied feasibility of a photovoltaic-thermoelectric hybrid by modelling. ▸ Such a hybrid may lead to increases total efficiency up to 23%. ▸ Annual yield increase of hybrid depends on location ...dependent average temperature. ▸ Future thermoelectric materials will allow for even bigger increase in efficiency.
Outdoor performance of photovoltaic (PV) modules suffers from elevated temperatures. Conversion efficiency losses of up to about 25% can result, depending on the type of integration of the modules in the roof. Cooling of modules would therefore enhance annual PV performance. Instead of module cooling we propose to use the thermal waste by attaching thermoelectric (TE) converters to the back of PV modules, to form a PV–TE hybrid module. Due to the temperature difference over the TE converter additional electricity can be generated. Employing present day thermoelectric materials with typical figure of merits (Z) of 0.004K−1 at 300K may lead to efficiency enhancements of up to 23% for roof integrated PV–TE modules, as is calculated by means of an idealized model. The annual energy yield would increase by 14.7–11%, for two annual irradiance and temperature profiles studied, i.e., for Malaga, Spain, and Utrecht, the Netherlands, respectively. As new TE materials are being developed, efficiency enhancements of up to 50% and annual energy yield increases of up to 24.9% may be achievable. The developed idealized model, however, is judged to overestimate the results by about 10% for practical PV–TE hybrids.
This paper aims to provide insights in the cost developments of offshore wind energy in Europe. This is done by analysing 46 operational offshore wind farms commissioned after 2000. An increase of ...the Capital Expenditures (CAPEX) is found that is linked to the distance to shore and depth of more recent wind farms and commodity prices. Analysis results indicate that these two factors are only responsible for about half of the observed CAPEX increase, suggesting other factors such as turbine market with limited competition also led to an increasing CAPEX. Using CAPEX, Annual Energy Production, Financings costs and Operational Expenditures, the development of average Levelized Cost of Electricity (LCoE) is shown to increase from 120€/MWh in 2000 towards 190€/MWh in 2014, which is a direct result of the CAPEX increase. The results indicate very different LCoE values among European countries, from currently about 100 Euro/MWh in Denmark and Sweden to 150-220 Euro/MWh in all other countries investigated suggesting an effect of national policy frameworks on the LCoE of offshore wind energy.
•New insights in cost developments of offshore wind energy in Europe.•Increase of CAPEX is linked to distance to shore and depth.•Increase of CAPEX partly due to limited competition in turbine market.•Levelized cost of electricity increases from 120€/MWh in 2000 towards 190€/MWh in 2014.
Spectral conversion of sunlight is a promising route to reduce spectral mismatch losses that are responsible for the major part of the efficiency losses in solar cells. Both upconversion and ...downconversion materials are presently explored. In an upconversion process, photons with an energy lower than the band gap of the solar cell are converted to higher energy photons. These higher photons are directed back to the solar cell and absorbed, thus increasing the efficiency. Different types of upconverter materials are investigated, based on luminescent ions or organic molecules. Proof of principle experiments with lanthanide ion based upconverters have indicated that the benefit of an upconversion layer is limited by the high light intensities needed to reach high upconversion quantum efficiencies. To address this limitation, upconverter materials may be combined with quantum dots or plasmonic particles to enhance the upconversion efficiency and improve the feasibility of applying upconverters in commercial solar cells.
Photon upconversion of sunlight for solar cells is reviewed and the possibilities to increase the efficiencies of the upconverter materials are discussed.
In a large number of energy models, the use of learning curves for estimating technological improvements has become popular. This is based on the assumption that technological development can be ...monitored by following cost development as a function of market size. However, recent data show that in some stages of photovoltaic technology (PV) production, the market price of PV modules stabilizes even though the cumulative capacity increases. This implies that no technological improvement takes place in these periods: the cost predicted by the learning curve in the PV study is lower than the market one. We propose that this bias results from ignoring the effects of input prices and scale effects, and that incorporating the input prices and scale effects into the learning curve theory is an important issue in making cost predictions more reliable. In this paper, a methodology is described to incorporate the scale and input-prices effect as the additional variables into the one factor learning curve, which leads to the definition of the multi-factor learning curve. This multi-factor learning curve is not only derived from economic theories, but also supported by an empirical study. The results clearly show that input prices and scale effects are to be included, and that, although market prices are stabilizing, learning is still taking place.
Building integrated photovoltaics (BIPV) is one of the most promising contributors to net-zero energy buildings, while also increasing the aesthetic value of the built environment. Nevertheless, it ...currently is predominantly operating in a niche market of ~ 1% of the global photovoltaics market. In this paper we provide a thorough Multi Criteria Decision Analysis of the BIPV ecosystem (markets, stakeholders, and policy and legislation) in various European countries, i.e. the Netherlands, France, Germany, Switzerland, and the United Kingdom. Environmental legislation and building requirements were found to be similar, as all countries have the European Energy Performance of Buildings Directive (EPBD) in common. It was found that implementation of the EPBD differs per country, evidenced by different support schemes in effect. Also, harmonisation of building codes hampers BIPV development. The analysis provides a basis for developing a BIPV ecosystem, which may differ per country. Also, clearly the BIPV sector crosses national boundaries, and should therefore be reviewed and developed from an international perspective.
The photovoltaic industry has been growing with astonishing rates over the past years. The supply of silicon to the wafer-based industry has recently become a problem. This paper presents a thorough ...analysis of the PV industry and quantifies the silicon shortage. It is expected that this leads to a decrease in production in 2006 rather than the usual increase. Due to a mismatch in expansion plans of silicon feedstock manufacturers and solar cell manufacturers, a large cell overcapacity will persist up to 2010. The thin-film PV market is expected to profit from the silicon shortage problem; its market share may substantially increase to about 25% in 2010.
A key issue in smart grid visions is the integration of the energy and mobility systems. Electric vehicles (EVs) can be charged with renewable photovoltaic (PV) solar power, and contribute to the ...integration of solar power in the electricity network via vehicle-to-grid systems. In such systems the role of consumers becomes crucial as they both generate and store energy. We investigate differences between PV and EV adopter groups and the implications of these differences for the transition to smart energy systems. We study how socio-demographic characteristics of the consumer base influence regional diffusion patterns. In turn, we build scenarios to explore the influence of diffusion patterns on the viability of regional EV-PV integration in terms of energy use and regional self-consumption. The results point out large differences in the spatial diffusion patterns between EV and PV. These differences have implications for the transition to smart sustainable grids; vehicle-to-grid systems may not be viable for certain regions.
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