The project undertaken by EDP has helped to maximise the efficiency of the photovoltaic panels by locating them on water. In summer, low temperatures near the surface increase their effectiveness by as much as 11%. By floating the panels on water, EDP incurred no real estate costs for the purchase of land.
Moreover, because the Alqueva dam was already producing hydroelectricity, there was an existing grid connection and therefore it was not necessary to construct new transmission and distribution lines. An additional benefit is the battery storage system that is one of the largest in the country. In times of low consumption, the design allows solar power to pump water from the reservoir to produce new hydroelectric power.

This shiny man-made island floating on a man-made lake is a ‘win win’ situation that has minimised the impact on the environment and boosted EDP’s desire to become a fully green company by 2030. A further license has been granted to float another solar park on the reservoir. EDP’s ambitions include the installation of solar panels on all public buildings by 2025; these plans comply with the objectives of the Portuguese Government to become Carbon Neutral by 2050.

A treat for visitors
Aside from the innovation of the solar park, the Alqueva reservoir is able to cater for tourists providing a plethora of activities for them to discover. Described as the largest artificial lake in Europe – 83 kms in length – the shoreline is as long as the coast of the Algarve. Fourteen species of fish breed in the lake and wildlife, particularly a variety of birds, are drawn to the area. Seven villages perch on the lakeside’s edge and there is holiday accommodation, camp sites and numerous boat trips including self-drive houseboats with sleeping facilities.

I chanced upon a half day trip across the tranquil waters. The guide explained that in parts the lake is 100 metres in depth and buoys mark the course of the River Guadiana which is the lake’s source. The dam gates closed in 2002 and by 2010 water from the river reached its maximum capacity.
Some 426 islands still stand above the level of the water. On one island a Billy goat has been stranded for 11 years. Like a character from a fairytale, he bleated when our pleasure boat passed by. Although goats can swim long distances, presumably he prefers life on his private island. According to our guide the food source on ‘goat island’ is reliable and replenished with the seasons. There is sufficient vegetation to support a hermit and of course there is no shortage of water for him to drink!

Another point of interest in the area is Aldeia da Luz. Nothing about this sleepy place appears to stray from the image of a typical rural Alentejo village. Bright whitewashed houses with terracotta roofs line the calçada streets but this village was the only physical obstacle standing in the way of creating the reservoir. Rather than it being destroyed, in 2002 it was dismantled and reconstructed stone by stone before the area was flooded. Although its location is new the village has not changed. A short distance away a small and modern museum catalogues events that have altered the character of the area.

Perhaps one of the most extraordinary occurred in 2011 when the reservoir and the surrounding countryside were designated as the First Starlight Destination in the World. The official Dark Sky Observatory is open to the public and located in the village of Cumeada. It is equipped with state-of-the-art telescopes for solar and astronomical observations allowing a unique visual experience beneath one of the least polluted skies in the world. In 2020 the Dark Sky Alqueva Reserve received two awards at the World Travel Awards; Europe’s Responsible Tourism Award and Europe’s Leading Tourism Development Project. Those awards compliment improved water supplies and renewable electricity. A fascinating and totally unspoiled area with a visitor centre that is open to the public explaining the technology that supports the Alqueva solar and hydropower plants.

Alqueva Visitor & Interpretation Centre
Open every day including Sundays and public holidays
T: 284 315 100 | W: edia.pt/en/

Museu da Luz
Open Tuesday to Sunday, 09:30–13:00 and 14:30–17:30
T: 266 569 257 | W: museudaluz.org.pt

Dark Sky Observatory
T: 913 103 540 | W: darkskyalqueva.com
Open Tuesday to Saturday, 14:30–21:00

Words: Carolyn Kain