RWE is testing two new technologies at an onshore wind farm in Spain. These technologies are intended to reduce the impact on the environment during the construction phase of the plant on the one hand and greenhouse gas emissions during subsequent operation on the other.
RWE has now made the investment decision for the Orkoien pilot project near Pamplona, Spain, where a 5.7MW turbine is being built to gather experience with the two technologies. Construction works are underway and commissioning is planned for summer 2023.
In the first method, special plastic mats are used in the construction phase. For temporary work areas such as access roads and storage areas, they minimise the construction-related impact on the soil. Normally, these areas are excavated and gravelled. Now, only the surface is smoothed with the excavator. Then the access and storage areas are temporarily covered with the plastic overlays. Following the work, the vegetation can regenerate completely. The mats, which are partly made of recycled material, can be reused in other projects.
A reduction in greenhouse gas emissions is made possible by the second technology. In the medium-voltage switchgear at the base of the turbine tower, the use of an insulating agent in the circuit breaker is necessary to interrupt the electrical currents by cooling and extinguishing the arc that occurs when a circuit is opened. Until now, the gas SF6 (sulphur hexafluoride), which is colourless, odourless, neither toxic nor flammable and harmless to humans and animals, has been used for this purpose. However, SF6 is a greenhouse gas that impacts the climate. Therefore, it may only be used under strict conditions. With the use of “SF6-free switchgear”, RWE is now testing an alternative that reduces greenhouse gas emissions to almost zero. This new, environmentally friendly technology relies 85 percent on dry air and 15 percent on C5 fluoroketones as an insulating agent. In addition to being environmentally friendly, the technology has the same technical reliability as SF6.
