One of the most visible cases of opposition in the region is located in the community of San Dionisio del Mar. Here the Spanish Company Preneal planned to deploy 102 turbines through the Santa Teresa Coastal Bar and 30 additional turbines in Santa María del Mar. Together, they would comprise an ambitious project (latter known as Mareña Renovables) expected to reach an installed capacity of 396 MW. The project was granted in 2006 to provide electricity to large beverage companies (including Cuauhtémoc Montezuma brewery and Coca-Cola Femsa). Two Environmental Impact Assessment studies for both installations were completed in June 2009, indicating potential biodiversity loss and increasing social conflict in the area. However, the project received strong support of both the Mexican government and the Inter-American Development Bank, promoting it as a significant step to expand energy supply while reducing emissions of greenhouse gases. Opposition against the Mareña project was mainly lead by the San Dionisio community, where most of the windmills were to be deployed. San Dionisio‟s landowners filed a lawsuit to nullify land leasing contracts with Preneal, claiming several irregularities committed by the company during the process of contract signing. Lawyers claimed that such irregularities violated both the Mexican Constitution and the ILO Convention 169. These claims were highly supported by the Assembly in Defense of the Land and Territory of the Indigenous People in the Isthmus of Tehuantepec ("the Assembly"), a resistance network which was getting a stronger presence in the region. Mobilizations were also joined by other thirteen nearby communities that would be affected by the enclosure of the inner sea, disturbing fishing and local commerce.

The conflict expanded and became more complex when the land leasing contracts intensified previous agrarian conflicts in the region. This happened among the Santa María and San Mateo del Mar communities, where an old struggle to define their borders restarted with the agreement of building 30 windmills in a disputed area, including a zone traditionally used for indigenous and catholic celebrations. This led to further tensions between both communities, while San Mateo del Mar refused to accept the project. Except for Santa María del Mar (which accepted the contract with Preneal) local groups started a visible and organized opposition in 2011, when the Assembly demonstrated outside the Federal Electricity Commission office in Oaxaca. Further mobilizations included railway blockades, street protests and the occupation of the San Dionisio Municipality. All these actions created political pressure and hampered the entrance of machinery in the region, delaying the project’s construction. Given such conditions, Preneal decided to sell the project by 89,000,000 USD to a transnational consortium constituted by Fomento Económico Mexicano (FEMSA), the Macquarie Mexico Infrastructure Fund (MMIF) and the Macquarie Capital Society. However, this strategic shift came with an additional corruption scandal on the accusation that the new consortium gave 20,000,000 Mexican Pesos (1.33 Million USD) to the local Mayor in order get support for the project. Controversies and tensions lead to stronger local mobilizations and a wave of violence increased against the members of the Assembly who were struggling against this and other future wind power projects in the region. Cases of harassment and persecution, as well as illegal detentions were registered. An emblematic case happened in 2012 with the arrest of Bettina Cruz, a local female leader who is member of the Assembly as well as of the National Network of Women Human Rights Defenders in Mexico. According to the International Service for Human Rights, the process against her was based on unfounded and baseless accusations. Although she was eventually freed of charges, such accusations were seen as a clear message against social opposition. However, at the end of 2012, political pressure finally succeeded when a Federal Judge ordered the suspension of the project in San Dionisio, arguing the violation of communal property rights. Although the government and the consortium resisted this decision trying to re-locate the project, the Assembly recognized this process as a successful outcome for local communities. Key words: windmills, indigenous complaints, international capital

The project required to lease 1,643 ha of communal lands in San Dionisio del Mar and 2,000 ha in Santa María del Mar).

The initial contract for the territorial reserve offered 100 Mexican Pesos (around 6 USD) per hectare per year, indicating that total annual costs for land leasing would be of 364,300 Mexican Pesos (around 22,788 USD). In addition to land owners, communities also were offered with a collective payment of around 0.97-1.5% of profits to be invested in social development programs.

In 2011 Preneal decided to sell the project by 89,000,000 USD.