The Northeast of Brazil, made up of 8 states, represents 18% of the total area of the country, and is responsible for 16% of the production and it has a population of 42,000,000 people (28%). Approximately half of this area, 760,000 km2, is semi-arid where 17,000,000 people live. The climate of this region is hot and dry having a mean annual temperature of 27 °C and 2500 h/year of insolation. The annual precipitation varies from 400 to 800 mm, contrasting with an evapotranspiration of 2500 mm/year, which determines a dry period of more than 7 months. The vegetation that covers the semi-arid region is a deciduous tropical forest, locally known as the caatinga, that develops over a complex mosaic of soils, Fig.1. High level of insolation, scarce hydric resources and rare rainfall, poorly destributed over time, cause long periods of drought. Thus, the relative shortage of superficial hydric resources, make evident the importance of subterranean waters. The exploration of these waters is found to be limited because of the nature of its soils (predominanthy crystalline), low discharge rate ( mean of 3000 l/h) and mainly for its

quality. The great majority of the wells present higher salinity indices than the maximum limit permitted for human consumption, that is of 1000 ppm of dissolved total solids and in many cases above 6000 ppm, the extreme water salinity level for animal consumption. Another aggravating factor that makes the solution to the problem of water supply difficult is the low index of rural electrification in the Northeast.

To face this kind of challenge, the Federal Government established the PRODEEM — Program of Energy Development for States and Municipalities through a presidential decree in December 1994, with the following objectives:

• Make viable the installation of energy microsystems for production and local use in isolated needy communities that are not served by electric network, that are destined to aid in attending basic social demands;

• Promote the utilization of decentralized energy sources in the supply of energy to the small producers, to nuclei of colonization and isolated populations;

• Compliment the conventional energy system offer with the use of decentralized renewable energy sources;

• Promote the utilization of human resources and development of technology and national industry, that are essential for implantation and operational continuity of the implanted systems.

Since the year 1996 the PRODEEM has bought and installed thousands of photovoltaic systems that are spread around the national territory. In the phases denominated I to V and a special one denominated Pumping, three kinds of autonomous photovoltaic systems were installed: photovoltaic systems for generation of electric energy (energetic), photovoltaic systems for

pumping water and for public illumination. The systems were only destined for application in communities, which means that they should benefit the communities as a whole, and not only some individuals in particular. The total of photovoltaic systems installed in this program was 8,956, corresponding to a total power of 5.2 MWe, and it can be considered as one of the largest rural eletrification programs that use photovoltaic solar energy in developing countries. Most of the photovoltaic systems were installed in the North Northeast regions, 1,471 and 4,577 systems respectively. In the target regions of this project AL, PE and PB 905 systems were installed, in accordance with the MME Eletric Energy Atlas (2008).

Fig. 2 shows the settlement of the landless people called Gualter, in the municipality of Caninde of Sao
Francisco in Alagoas, after the construction of the water supply system all supplied by photovoltaic solar
energy: the water supply system, the collective laundry and the drinking trough for animals. Fig. 3 shows
some other productive applications in community with photovoltaic solar energy: electrified fence and
school. The experience accumulated by the PRODEEM in the last ten years shows the enormous challenge
of management, planning, training and sociology of the implantation, on a large scale and in large territorial
extensions, of innovating technology and decentralized technology as of photovoltaic generation. The
traditional tools demonstrate their limitations and make the execution of such tasks very difficult.