This week has been carried out one of the initial tests of the R&D project “Alternatives in the use and control of the potential of slurry ponds“, framed in the 2020 call for subsidies to support collaborative actions of agents of the agricultural sector of Aragon.
Recent Spanish legislation (Royal Decree 306/2020 of 11 February), in line with the objectives set by the European Union, establishes the obligation to incorporate commitments to reduce ammonia and other polluting gases in pig farms and the adoption of techniques for this purpose, such as covering slurry ponds.
In this context, the general objective of the project is to develop an innovative solution for covering slurry ponds to reduce the emission of environmentally harmful gases, such as ammonia, and to make it easier for farms and management centres to adapt and comply with the emission parameters set by national and European regulations. In addition, the aim is to use these ponds for the production of electricity from renewable sources, such as solar energy. This avoids having to allocate additional land areas by incorporating floating elements that incorporate photovoltaic panels. The electricity generated can be used to cover the farm’s consumption in self-consumption mode.
In order to achieve these objectives, the implementation of a demonstration pilot project to be placed in the slurry pond of a pig farm located in the municipality of Tauste (Zaragoza) is proposed. The prototype will consist of a floating photovoltaic system on the surface of the pond. The Isigenere solution will be used for this, consisting of HDPE plastic floating elements that function as a support for the photovoltaic panels, as well as other floating elements for the system’s perimeter corridors, with the aim of facilitating maintenance. The air spaces between the floats are to be filled with a plastic cover product. These are small hexagonal plastic elements which, when left on the liquid surface of the basin, are placed together in the form of a honeycomb and act as a floating cover, reducing ammonia emissions by up to 40%.
The objective of the test was to evaluate the buoyancy and the behaviour of the floating elements of the system in the middle of a pool of water, prior to the tests in the slurry pond.
During the test, two panel support floats, which would hold a photovoltaic module, and two perimeter corridor floats were mounted. The hexagons were poured into the water, which were repositioned between the free spaces between the floats and joined together, so that the sheet of water was almost completely covered.
As conclusions of the test, it was found that the buoyancy of the elements will allow the photovoltaic panels to be at a surface of the liquid film such that the risk of slurry splashing, due to the movement produced by the incorporation or churning of slurry in the pond, is minimised. In addition, it was found that the free space between floats is easily covered by the plastic elements, so that the objective of covering the pond as proposed by the project is easily achieved.
The assembly of the demonstration prototype on the slurry pond will take place during the last quarter of this year. This requires the prior design of the floating photovoltaic system, as well as the guidelines for its assembly, launching onto the pond, and incorporation of the hexagonal elements between the floats.