La Garrotxa in a mountainous district in Catalunya, characterized by a large number of masies (country dwellings) scattered among its valleys and mountains. 65 rural houses have been electrified with 51 kWp of PV, at a cost lower than extending the grid.

With the beginning of industrial activity, the arrival of basic services in larger towns and villages caused by many people to migrate from their isolated dwellings and hamlets to the more developed valleys. Nevertheless, there still remained a relatively large population living in masies, without services such as electricity or telephones. This prompted the district authority, the Consell Comarcaal of La Garrotxa, to launch a number of programmes aimed at providing the inhabitants of these residences with basic services.

A 1991 survey found some 220 masies without electricity, and assessed the cost of electrifying them by the two available alternatives: stand-alone PV of extension of the public grid. It was concluded that in over 90% of the cases, PV was the cheapest option. The following year, an electrification project was initiated. In 1993 work began, and most of the installations were commissioned in 1994. A total of 65 sites have now been electrified, with a total PV capacity of 51 kWp. A typical installation includes 800 Wp of PV modules; batteries (400 Ah at 48 V); and a power conditioner. The equipment includes a maximum power point tracking generator, a sinusoidal inverter of 1 to 4 kW at 230 V, 50 Hz, and a data logger to monitor the main energy parameters.

The average cost of each installation was USD 18000 (2,5 million pesetas) of which 25% was paid directly by the user in the form of a deposit, which can be recovered if the equipment is transferred to another site, due, for example, to the arrival of the grid, or if the user moves from the masia. The balance was financed through grants from the European Union, regional and national governments.

The programme is managed by the Users' Association SEBA, which carries out preventive maintenance and repair work, as well as training users. SEBA has also been instrumental in selecting low-consumption appliances and equipment.

Monitoring is ongoing, and actual operating experience from the project is still limited, but preliminary data suggests that systems are performing well. User satisfaction rating is high and the investment is considered a long-term alternative solution to grid extension. The PV systems installed to date have displaced 160 km of grid extensions.

It is difficult to quantify the benefits in terms of prevention of damage to the fragile mountain environment, but quantifiable cost savings, resulting from not extending the grid amount to approximately USD 2,7 million. The experience gained through this project is being used by IEA  PVPS Task 3 on stand-alone PV systems.

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