Eulalia Jadraque Gago

Solar Radiation Fundamentals and PV System Components

Solar PV technology has emerged as one of the most matured and fast evolving renewable energy technologies and it is expected that it will play a major role in the future global electricity generation mix. Keeping the rapid development of the PV technology into consideration, this chapter systematically documents the evolution of solar PV material as well as the PV applications and PV markets. It also provides insight into the trend in batteries and inverters used for solar PV applications. Furthermore, a comparative analysis of different PV technologies and its development is summarized. The rest of the chapter aims at providing a comprehensive analysis of solar radiation measurement and modelling techniques to assess the availability of solar radiation at different locations. The chapter presents comprehensive information for solar energy engineers, architects and other practitioners.

Inter-relationship between mean-daily irradiation and temperature, and decomposition models for hourly irradiation and temperature

Terrestrial temperature records have existed for centuries. These records are available for very many locations. Temperature is indeed the most widely measured meteorological parameter. In contrast, solar radiation being a parameter of secondary importance and also in view of the excessive measurement cost and the associated due care, it is recorded very infrequently. This article presents evaluation of a new type of model for mean-daily and hourly solar radiation based on temperature. The proposed model is of a very simple constitution and does not require any secondary meteorological parameters as required by other group of models that are available in literature. Furthermore, hourly temperature models are also presented that only require mean-daily temperature data. A comparison was undertaken regarding the performance of the presently proposed and previous models. It was found that the present models are able to provide reliable irradiation and hourly temperature estimates with a good accuracy. Copyright The Author 2010. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com, Oxford University Press.

Installation of roof-top solar PV modules and their impact on building cooling load

It has been shown by many researchers that over a long term there has been a slow but steady rise of ambient temperature within the Indian sub-continent. Due to an increased economic prosperity there has been an accompanied increase in the urban heat island effect. Furthermore, urbanisation of large cities in India has also led to higher population densities. The above factors had the combined effect of a significant increase of cooling load of buildings. The high density of dwellings and other building construction has resulted in shading of walls. However, the flat roof spaces are exposed to an uninterrupted solar radiation regime and this in turn leads to generation of high sol-air temperatures which cause higher cooling loads. Presently, it has been argued that roof spaces are one of the major contributors to building cooling load. In this article, the reasons behind the phenomenal rise in the installation of air-conditioners in India are reviewed. The dual role of roof-top PV systems in electricity generation and reduction of building cooling load due to the shading they provide is then investigated. For this purpose, the CIBSE method to obtain sol-air temperature with solar radiation and outdoor ambient temperature has been used. Sol-air temperature for five key Indian locations (Delhi, Bhopal, Ahmedabad, Bhubaneswar and Chennai), based on the recently presented data by the NREL-India Meteorological Department consortium, were then obtained. A computer simulation routine was presently developed for solving the classical transient heat conduction problem with hourly sol-air temperature data and roof construction details provided to the routine. This program was executed to obtain the cooling load profile for each of the five Indian locations for the respective design day. Practical application : The present work reviews the reasons behind the phenomenal rise in the installation of air-conditioners in India. The dual role of roof-top PV systems in electricity generation and reduction of building cooling load due to the shading they provide has been investigated. The computer simulation demonstrated that the energy required for roof-induced cooling load decreased between 73% and 90% after installation of the PV system. The method used in this work has the advantage that it enables the user to obtain cooling load estimates using a general transient heat conduction approach. Moreover, all software was developed within MS-Excel environment, this is also an additional advantage as the cost associated with purchase and training of proprietary building energy software can be prohibitive for many consultants who are based in developing countries.

Monthly averaged-hourly solar diffuse radiation model for the UK

Monthly-averaged daily global irradiation data are now easily available from NASA website. Using established models it is then possible to decompose the daily to averaged-hourly global irradiation. The missing link so far has been hourly averaged diffuse irradiation. In this article data was pooled from 10 UK locations to obtain a regression model to complete the above missing link. It was presently shown that the averaged-data regressions are distinctly different from previously available hour-by-hour regressions. Practical application : The present work has explored a correlation between averaged-hourly diffuse and global irradiation using the diffuse ratio–clearness index envelope. Results show that a strong regression relationship is thus obtainable. The present work has therefore the potential for other similar research that may be followed up in a likewise manner.

Electric vehicles: Case study for Spain

Abstract This chapter gives a brief overview of the current position the electric vehicle has in the automobile market and how it plays a role in sustainable transport and sustainable living. These negative impacts of road traffic have been some of the main preoccupations in recent policies on sustainable transport. Electric vehicles are gaining greater global interest as a viable component in the search for alternatives to sustainable mobility. Electric vehicles could reduce the consumption of fossil fuels, greenhouse gas emissions, and other contaminants. This chapter gives an overview of the current situation of energy use and environmental loading in Spain and the automobile population and its contribution to CO2 emissions and impact on air quality. In Spain, the actions taken so far have not been sufficient to reverse the dynamic of greenhouse gas emissions, to limit the generation of external costs, or to encourage collaboration with the wellbeing of its citizens in the field of transport, in line with the international compromises reached in Horizon 2020.