Abstract
This document reports the development of a technical and economical study related to the use of a renewable energy source - biomass for electricity and heat production. It is a hybrid and autonomous system with solar PV panels and environment friendly process aiming the reduction of energy demand, costs and emissions. This energy model is a new sustainable standard about efficiency consumption energy (electrical and thermal demands) of a small hotel building, with the biomass gasification cogeneration technology. This system is one relevant contribute to certify, the building agree to the new national legislation of building thermal behaviour.

Abstract
The Mike Basin - Water Quality modelling system was applied to the hydrographical basin of Sordo river located in the northeast of Portugal, in the region of Trasos-Montes and Alto Douro. This model allows the simulation of diffuse pollution caused by nitrate concentration in a small hydrographical basin (located in the demarcated region of the Port wine). The model allows the creation of a set of scenarios aiming at an effective planning of the basin under study. The available data for the drainages calculation were the monthly average effective rainfall between the years of 1960 and 2008. The Climate-change was predicted by the scenarios created in SIAM II and were simulated with the HadRM3 model. The limit quantities of nitrate present in the water should not contain over 25 mg/l; this is the maximum recommended value, and should not exceed 50 mg/l, this is the maximum allowable value by Portuguese law. We created simulation scenarios using the fertilizers produced by the bovine cattle and change of the agricultural uses or crops in this basin. For 2010 the fertilizers used were comprised between the recommended and the allowable maximum values. For 2071 the fertilizers were above the maximum allowable value. With these scenarios we found a 40% increase in nitrate levels due to climate change between the years 2010 and 2071.

Abstract
The main objective of this paper is to present a study on the wind energy potential that is being developed in the Region of Tras-os-Montes and Alto Douro. This study started in July 1996 and will continue until the end of 1998. In order to have an adequate characterisation of the wind energy potential in this region it is necessary to measure the wind speed and direction in several places. At this moment the data are being collected at nine places. Due to lack of space, only four places will be addressed in this article. The Region of Douro and Alto Tras-os-Montes has an area of 12,235 km(2). It is located in the Northeast part of Portugal and represents 57.7% of the North Region. Other projects refer to this region as having great potential in the field of renewable energies [1,2]. From the analysis of the collected data, it seems that wind energy in Marao and Alvao mountains is one of the most interesting renewable energies [3,4].