Selection of project site is the principal point in planning a wind project. The Pre-Analysis will progress through several stages:

• Initial Assessment.
• Site characterization.
• Wind resource.
• Detailed cash flow projection and financing.

It is important to identify critical requirements, ensuring that resources are not committed at unfeasible sites:

• Field visits.
• Analysis of critical information, environmental regulation, urban law, etc.
• Evaluation of affected land.
• Assessment of the possibilities for grid connection.

The result of the wind resource study in the pre-analysis stage will be the basis for the pre-micrositing calculation, using mesoscale data correlated with existing data makes possible to predefine the layout and, consequently, the installed power and energy generated.

Once the above mentioned tasks are performed, we issue a report assessing the suitability of the terrain for wind farm development. That report may also contain a recommendation of the wind farm boundaries, an estimation of total capacity the site could hold and suggested nodes for grid connection. Moreover, the report may also identify possible obstacles that could arise while promoting, such as environmental aspects related with protected species potentially affected, urban planning restrictions or potential social conflicts.

An outstanding layout of the wind campaign is fundamental in order to get a good knowledge of wind resource availability. The definite number of met masts, sensor configuration, type of mast and most appropriate location is determined after the calculation of the wind resource map and pre-analysis stage.

In order to have a bankable wind resource assessment, the campaign has to be designed according IEC61400 and taking into account the following basic requirements:

• Measurements heights.
• Proper location and configuration of met masts.
• Quality and calibration of wind measurement instruments.
• Data availability.
• Auditable wind data.

The data transmission and filtering process begin after the start-up of the met masts. The results of the data analysis are valuable information to detect and correct possible breakdowns, what conduct to achieve maximum data availability.

A preventive, corrective and predictive maintenance plan will be designed under the consideration of the following points:

• Data analysis algorithms.
• Anchor movement.
• Mast straightness.
• Guy wire tensions (register of all guy tensions).
• Guy wire integrity.
• Cable integrity.
• Enclosure condition.

Once the preliminary locations of the wind turbines have been determined, the next step is the development of a basic project to establish other elements of the wind farm:

• Wind turbine pre-selection.
• Access and inner roads, platforms.
• Electrical connection to the grid.

The scope of this previous project is to determine the technical and economical feasibility of these elements, which can have influence in the viability of the whole project. The content of this document will be also required by the public administration to obtain the permits and authorizations to install and operate the wind farm.

The main inputs in the economic-financial study are the development costs, plant factor or annual energy production, installations costs, operation and maintenance costs, insurance and price of electricity.

Uncertainty in the expected measured data and risk analysis are factors to be considered in the annual energy production, and in the definition of the acceptable limit of the IRR value that makes the project feasible.

Depending on the current regulation, all the necessary procedures to assure the specific rights for land use are defined in this stage: identification of land plots, cadastral boundaries, topographical survey/demarcation of land, if necessary, and negotiation of contracts with landowners. In certain cases this may require negotiating access rights and servitudes over other land parcels.

ECOIBERICA carries out the studies and documentation required to obtain the grid connection permits:

• Previous analysis.
• Grid impact assessment, using the software PSS/E from Siemens.
• Installation Study.
• Interconnection contract.

Some of the administrative permits and licenses required to install and operate a wind farm are:

• Contract registration at the Land Registry.
• Land use change to industrial practices.
• Rights of way for the electrical power evacuation line.
• Crossing permissions.
• Archaeological study.
• Approval document of the City Council.
• Approval document of Government Energy Authorities.
• Building permits for wind farm and access roads.

During the design of the wind farm and the Environmental Impact Assessment (EIA), multidisciplinary groups must be coordinated in order to optimize the project and adjust it to the technical, legal and environmental requirements:

• Health and safety assessment.
• Environmental Impact Assessment: landscape and visual impact, noise, shadow flickers, endangered species, Zones of Visual Influence, Ecological and Ornithological Impacts, Socio–Economic effects, global environmental benefits.
• Minimization of the environmental impacts generated by the wind farm.

In this the stage a fine micrositing calculation with specific simulation software will be carried out, testing different turbines and hub-heights.

In case of complex terrain, the construction of installation platforms and access roads have to be considered during the micrositing optimization.

The data at the site will be compared with long term mesoscale-data over the course of ten years or more. This will help determine whether the data represents a low, medium, or high wind speed year and allow adjustments to the long-term production estimates.

The time needed to conclude an acceptable final outcome measurement depends on the nature of the wind in the area, directionality, stability, seasonality and probability of event occurrence, such as hurricanes and extreme winds.

The engineering project will include the final detailed design of all the elements involved in the wind farm.

Mechanical and Electrical

Description of the Electrical Network, MV and HV network design, MV and HV calculations, short circuit calculations, voltage drop and energy losses, electrical equipment data sheet, bill of quantities, switchgear, substation.

Civil Works

Access Roads, MV cable network, structural design of wind turbines foundations, control building, substation, drainage, calculation reports, bill of quantities.

Control System

The engineering project shall include a section for all the elements related with communications and the control system of the wind farm.

The Power Purchase Agreements (PPA) define a long-term stream of revenue for the project through the sale of the electricity generated by the project, therefore are a critical part of planning a successful wind project. Securing a good PPA is often one of the main points of a wind project development.