C. Rodrigues, S. Viana, A. Joyce, H. Gonsalves, A. Silva

INETI, Department of Renewable Energies, Estrada do Pago do Lumiar, 1649-038 Lisboa, Portugal

Corresponding Author, carlos. rodrigues@ineti. pt

Abstract

The purpose of this paper is to present the results obtained in the first two years of operation of the grid-connected photovoltaic (PV) systems installed in the named “Solar XXI” building. One PV system, made with multicrystalline silicon modules, has a peak power of 12 kW and was installed on the fagade; another system made with amorphous silicon modules has a peak power of 6 kW and was installed in the surrounding park area near the building.

From 1st February 2006 until 31 July 2008, the measured daily average, of the building electrical energy consumption, was about 75 kWh and the two PV systems produced in average about 72 % of this energy. The averaged measured Performance Ratio of the systems was about 0.84 for the PV Fagade and about 0.76 for the PV in the Park.

Keywords: BIPV, Grid Connected PV systems, PV micro-generation

1. Introduction

The Portuguese commitment for electricity production from renewables, in the framework of the EU Directive 2001/77/EC, was that 39 % of all the electricity consumed in Portugal in 2010 should come from renewable energy sources. However in 2007 the Portuguese government decided a new objective of 45 % of renewable electricity in 2010.

Until the end of 2007, Portugal had an estimated installed PV capacity of about 17.4 MW, resulting from the start up of the new power plant at Serpa, with 11 MW, and of other plants of the order of 1 or 2 MW, witch gave rise to a jump in the installed PV capacity in the last year.

It is expected that in the next few years new jumps will appear due to power plants already announced mainly the one related to the big power plant of Moura with a final installed capacity of 46.41 MWp, which already started, and also the ones to be installed at several places in the South of Portugal and a 6 MWp power plant at the distribution market MARL near by Lisbon.

Recent legislation in Portugal related to energy production from renewable energy sources, namely Decree Laws 225/2007 and 363/2007, have provided the framework for the development of Building Integrated Photovoltaics (BIPV) in the electricity domestic market with a feed in tariff dependent of the integration of solar thermal solutions.

The PV market in Portugal is still dominated by the objective, which was stated for 2010, of 150 MW for PV conventional centrals plus 50 MW for BIPV (DL 225/2007). This market is almost completely filled and no new licences are being attributed for centrals or BIPV, putting a cap to the market growth.

The new law for micro-production (DL 363/2007) which started to be implemented this April, is supposed to contribute with about 10 MW of new PV capacity installed each year and until now it is well accepted by the consumers of electricity, stimulating the domestic production of electricity.

In this context the new “Solar XXI” building pretend to be, an example of low energy consumption for new buildings and simultaneously it is, an experimental facility of INETIs Renewable Energy Department.

The building and the surrounding car park, integrate two Photovoltaic grid connected systems: a 12 kWp system installed on the south vertical facade of the building with a heat recovering system in the back of the photovoltaic modules used to heat the offices of the south side of the building, and a 6 kWp system installed in the car park area as a shading device. The PV systems are part of a demonstration project, supported by the Portuguese PRIME Program. The building is an energy efficient building optimizing geographic orientation and natural lighting with integration of both passive and active solar thermal solutions, see also Gonsalves et al [ 2].

The purpose of this paper is to present the results obtained in the first two years of operation of the installed PV systems in terms of performance yields and contribution, of the energy produced, to the electrical energy needs of the building. We will present the results obtained for the two PV technologies used, amorphous silicon in the park and multicrystalline silicon on the facade, and the observed seasonal variations in performance, due mainly to temperature effects.