Listed dimensions are intended as minimum values:

• maneuvering area (distance ≥ 1.000 mm): Figure 3 attached below in the Attachments section.
• M: distance margin for as-built error dimensions.
• a: Internal width ≥5.550 mm.
• b: Internal depth ≥ 2.300 mm.
• Internal useful height ≥ 2.300 mm.

About the material to consider:

The existing prefabricated substation is made of reinforced concrete. The material of the new one shall meet the requirements of circular by design additional requirements (see Solution Requirements below).

The material to be used in the manufacture will have to withstand a compressive stress resistance equal to or greater than 250 kg/m². External materials shall be resistant to temperature variations and ultraviolet rays.

Structure coverage

• Shall be able to withstand overloads of 480 kg/m² when its installation is planned for an elevation below or equal to 1.000 m.
• Must be properly fixed to the structure and ensure an average heat transfer coefficient of less than 3.1 W/°C m².
• The roof must also be protected by a proper waterproofing layer.
• It must proper hanging points for transportation and installation.

Walls

• Shall be capable of withstanding the vertical forces of their own weight, plus that of the roof and roof overloads, simultaneously with a horizontal stress of 100 kg/m².
• At least two through-wall in plastic material must be fixed, with a minimum internal diameter of 150 mm, embedded in the wall during the construction phase, to allow the passage of temporary electrical cables.

Floor

• Shall be able to withstand vertical overloads of 400 kg/m², except in the transformer movement and location area, where the resistance shall be adequate to the loads transmitted by the transformer. The weight to consider is 4.000 kg.
• For MV Switchgear a proper shaft opening adequately sized to ensure:
  • Adequate support of the MV switchgear on a firm floor
  • That the rear of the MV switchgear should maintain a minimum distance to the rear wall of 20 mm.
  • That the length of the opening is greater than the maximum expected total width of the MV switchgear to allow a certain tolerance in it installation (for example 650 mm x 2.800 mm).

Must be provided.

• For the LV switchboard:
  • Adequate support of the LV switchboard on a firm floor:
    • Aperture of suitable dimensions for LV switchboards (considering the dimensions on Table 1) for the access to the foundation basin of LV cables.
    • The base panel shall have a minimum thickness of 5 mm and enough mechanical rigidity to allow anchoring of the LV switchboard.
    • The fixing system between the base panel and LV switchboard shall be suitable so that the assembly can withstand the test of voltage applied at industrial frequency of 10 kV (rms value) for 1 minute and lightning impulse type 1,2/50 μs at 20kV peak.
  • The sides of the LV switchboard maintain a minimum distance to the adjacent wall of 20 mm.

Must be provided.

Note: In case of LV Switchboard with adjustable support, the substation must be able to fix it to the structure. 

Note: for both MV switchgear and LV switchboard, the opening for fixing the panels shall include a cover(s) covering 50% of the length of the opening. These covers shall withstand the same vertical overload. In addition, the covers shall be made in more than one piece so that they can be removed individually and none of them individually weighs more than 20 kg.

• For the transformer:
  • Minimum aperture of dimensions 300 mm x 150 mm for MV/LV transformer for the access to the foundation tank of MV cables.

Must be provided.

• For the Rack cabinet 19" with 40U:
  • Aperture of dimensions 500 mm x 500 mm (with provision for rack fixing), for the rack (example: DG2061 Ed.9) with access to the foundation basin of LV cables.

Must be provided.

Basement

Prefabricated, made in a single block, with a minimum depth of 500 mm and covering the whole area of the room. A mechanical connection must be provided between the box and the basement, with a coupling system that prevents the box from moving horizontally.

The lower part of the enclosure shall be equipped with holes for the passage of medium voltage cables, low voltage cables, as well as for the earth and protection circuit cables.

All the openings shall be provided with a plug that will ensure the same IP and IK protection ratings as those previously required.

The basement must be equipped with:

• 10 holes with a diameter of 200 mm for the passage of MV cables;
• 8 holes with a diameter of 200 mm for the passage of LV cables;
• 4 holes with a diameter of 200 mm for the passage of cables of other services.

These holes will be positioned at a distance from the bottom of the tank such as to allow the containment of any oil leaking from the transformer, fixed in a minimum volume corresponding to 650 liters.

Structures finishes

• Any joints between the structures and the entire perimeter of the box at the point of support with the base must be sealed for a perfect watertight fit.
• The external walls must be treated with wall coating additives that guarantee perfect anchorage on the structure, resistance to atmospheric agents even in industrial and marine environments, inalterability of the color to sunlight and stability to temperature changes (-20°C + 60°C).

Additional project request

The design loads to be considered in the calculation of the structures constituting the cabin are:

• Seismic action: structural checks will be carried out according to the requirements of the current Standards for Construction (relating to materials proposed for the challenge), in seismic zone, in the most conservative conditions for the country in which the prefabricated substation will be installed. (As example, the requirements for Italy are showed on the point 4.3.1-part C of the standard: DG2061 Ed. 9).
• Stresses due to lifting and transport of the box complete with equipment (excluding the transformer), for mobile and permanent loads on the floor of the substation.

Type test

A prototype will be subjected to the following tests, according to IEC standards except for specific description:

• Visual examination: Verification of the previously described components and systems; correct arrangement for the cable passages necessary for the connections of the elements inside the cabin.
• Dimensional check: Verification of the availability of space necessary to allow the components inside the substation enabling safe maneuvering and working spaces; verification of proper accessibility to install each component.
• Functional tests: As indicated in IEC 62271-202, section 6.10.2 (where applicable).
• Ventilation check: The verification of adequate ventilation shall be performed by means of the heating test indicated in point 6.5 of IEC 62271-202 for enclosure class 10K. Consider the maximum power of the transformers (1.000kVA) for the test.
• Verification of the characteristics of the material used based on tests carried out at an accredited laboratory
• Electric test
  • Equipotentiality: Electrical continuity shall be verified by suitable means between any of the metallic points connected to the internal reinforcement of the floor, walls, and roof.
  • Resistance test: Both electrodes shall be applied to the internal reinforcement and to the external elements. The test shall be considered to have been passed if the value of the electrical resistance in all cases considered is equal to or greater than 10.000 Ω.
  • Dielectric tests: Prototype shall be subjected to the industrial frequency withstand voltage and impulse withstand voltage tests as specified in IEC 61439-1 respectively, except where different parameters were specified in the preceding paragraphs.
• Verification of the prefabricated substation behavior during the lifting phase: The complete substation with all equipment, with the only exception of the transformer.
• Tests to verify mechanical resistance: For the verification of the mechanical effects on the enclosure, walls, and roof, proceed as indicated in IEC 62271-202, section 6.101. In addition:

A uniformly distributed vertical load of 800 kg/m² shall be applied on the floor, except in the areas of movement and location of the transformers, where the resistance shall be adapted to the load of a 1.000 kVA transformer. The test shall be considered to have been passed if the material used has not damage in any of the compressed areas and in the reinforcement bars the breaking stress has not been reached.

• Degree of protection check: The test shall be carried out in accordance with IEC 60529. The IP33 degree of protection shall be verified.
• Check for possible loss of oil containment: After filling with water, the basement, or the transformer tank if it has been expressly designed for this purpose, the test will be considered successful if no water leaks out after 12 hours from the filling.
• Waterproofing of the roof
• Resistance to temperature variations and ultraviolet rays
• Verification of paint surface treatments

THE CHALLENGE

Enel Global Infrastructure & Networks is looking for a new design concept for a prefabricated secondary substation, which must possess innovative features in design, materials, and construction, incorporating the principles of sustainability. In this sense, the new design should enhance natural integration in the human context (aesthetic and harmonic criteria) ensuring safety also for third parties, and it should deploy a circular by design approach.

The development of the new prefabricated secondary substation will have to meet the following needs:

1. Comply with the technical and safety requirements currently contemplated by Enel for a prefabricated secondary substation, to prevent safety risk for both workers and third parties
2. Have suitable dimensions for the installation of all components
3. Respond to a better integration within the city or rural context where it is installed (possibly with the possibility of foreseeing more variations of its version based on the location), ensuring aesthetic and visual landscape integration
4. Incorporate into its design the main principles of circular economy and sustainability and enhance the corporate image of Enel and its vision through design. The solution must provide for the possibility of conveying messages aimed at customers or the various stakeholders of the Company.

Submissions must address the following Solution Requirements.

• Height ≥ 2.300 mm; Width ≥ 5.500 mm; Depth ≥ 2.300 mm
• Provide IP 33 protection degree towards the outside according to IEC 60529 and IK 10 according to IEC 62262 (including doors and the grilles of the ventilation system).
• Accessible openings shall have the following minimum dimensions: Width x Height = 1.250 x 2.100 mm.
• The material to be used in the manufacture will have to withstand a compressive stress resistance equal to or greater than 250 kg/m².
• External materials shall be resistant to temperature variations and ultraviolet rays.
• Structure coverage shall be able to withstand overloads of 480 kg/m² when its installation is planned for an elevation below or equal to 1.000 m.
• Walls shall be capable of withstanding the vertical forces of their own weight, plus that of the roof and roof overloads, simultaneously with a horizontal stress of 100 kg/m².
• Floor shall be able to withstand vertical overloads of 400 kg/m², except in the transformer movement and location area, where the resistance shall be adequate to the loads transmitted by the transformer. The weight to consider is 4.000 kg.
• Basement is prefabricated, made in a single block, with a minimum depth of 500 mm and covering the whole area of the room. The lower part of the enclosure shall be equipped with holes for the passage of medium voltage cables, low voltage cables, as well as for the earth and protection circuit cables.
• Any joints between the structures and the entire perimeter of the box at the point of support with the base must be sealed for a perfect watertight fit.
• Adhere to all safety and technical requirements as pertains to Enel.
• Promote a positive visual impact of these infrastructures that improves their insertion in the territorial realities, favoring their reception in a closer dialogue with the nature of the places where they are located.
• To be the expression of a project research (design) able to provide the prefabricated substations with new quality and innovation.
• To be the symbol of a new vision of energy that the Company promotes and communicates: more participatory, bidirectional, sustainable, and enhances a closer relationship between the Company and customers. Provide for the possibility of conveying messages addressed to customers or to the various stakeholders of the Company.
• Is economically feasible and viable.
• Integrate the circular perspective into the design with the aim of ensuring asset longevity, encouraging modularity and therefore component replacement and maintenance, as well as recycling/reuse of cabin materials at end of life. Key drivers of a circular by design approach include:
  • Product Structure/Architecture: reduce the number of components relative to the main functionality required and adopt a design that facilitates the removal of hazardous materials.
  • Components: use durable components and avoid hazardous materials
  • Materials: select as much as possible recyclable/recycled and energy-efficient materials and minimize the variability of materials used. When analyzing materials, the assessment should be made considering IEC62474, REACH (European Union regulation for Registration, Evaluation, Authorization and Restriction of Chemicals) and RoHS (Restriction of Hazardous Substances, Directive 2002/95/EC). The incorporation in the design of recycled materials would be preferable. In particular, the use of most sustainable alternatives to traditional reinforced concrete would be the best option (including clinker replacement materials, recycled concrete, bioconcrete)
  • Design for dismantling: the component must be designed to facilitate disassembly and recovery of all materials at the end of its life.

PROJECT DELIVERABLES

The submitted proposal should include the following:

1. A detailed description of the proposed solution addressing specific Solution Requirements
2. Well-substantiated rationale and pertinent data to support why architectural design is sustainable and highlighting any innovative features
3. Schematics that illustrate important aspects of the design (e.g. electrical, mechanical, visual, functional)
4. A bibliography of relevant literature (e.g. journal articles, patents, trade materials) that support the proposed solution
5. An assessment of initial installation and continued maintenance costs
6. Estimate of cost level for different volumes, prototyping timeline, and go-to-market strategy

The proposal should not include any personal identifying information (name, username, company, address, phone, email, personal website, resume, etc.) or any information the Solvers may consider as their Intellectual Property they do not want to sharing.