The innovative approach to solar energy is our way of life. We are solar artists. Joseph Tan

Facade Solar PV System (Wall Mounted Solar Installation - BIPV/BAPV)

Challenges Of Constructing Wall Mounted Solar PV Systems On Building Facade

Solar photovoltaic systems are often installed on roofs to generate energy for buildings. However, the ability of solar systems to use renewable energy for neighbourhood services is currently limited by the space available on building roofs

Wall mounted solar photovoltaics (PV) on building facades or cladding (BIPV / BAPV) has the potential to overcome constraints imposed by limited roof space and various authoritative regulations. The installation area is distributed by the additional façade, which significantly increases the building’s power generation capacity to meet the building’s energy needs and provides protection from the weather. The application of photovoltaic technology on the vertical facade wall mounted of buildings is considered an integral part of building integrated photovoltaics. This will primarily reduce installations on the east and west facades, where there are fewer or no windows. Due to the diurnal cycle, this also reduces the overall power generation, as typically only one facade at a time will be widely exposed to sunlight.

Despite potential advantages in terms of aesthetic design, solar gain, and lighting, optimizing the performance of wall-mounted PV systems (Façade) in urban areas remains difficult. Two of the bigger challenges in designing and developing such systems are: 1) minimizing losses from shading from nearby structures, and 2) reducing reflected light that causes sun glare problems. Careful planning is critical to constructing a vertical solar PV system that can overcome such challenges and maximize the energy generated by the system, and cost-effectiveness analysis (CEA) is also one of the main considerations.

Background

Fossil fuels such as natural gas and coal are limited. Given Singapore’s geographic size and scarcity of natural resources, we receive relatively more sunlight compared to the rest of the world, so solar energy is the most readily available renewable energy source in Singapore. Solar photovoltaics (PV) enhance our energy security by enabling us to reduce our dependence on fossil fuels and ensuring we have alternative energy sources that lessen the environmental impact of energy consumption.

The Housing and Development Board (HDB) has been testing and implementing solar photovoltaics on HDB neighbourhoods since 2009. As solar PV potential and demand grew, HDB moved from a supply and install model earlier in 2009 to a solar leasing model in 2011, enabling sustainable, large-scale deployment of solar panels. The success of the solar leasing business model has spurred the government-wide SolarNova program to deploy solar panels on a large scale in public buildings.

Upcoming

So far, HDB’s efforts in solar PV installations have mainly focused on rooftop spaces. This is because the roof is an open space with relatively few structures or objects that may shade the panels, ensuring maximum exposure to sunlight throughout the day for maximum solar power generation. Additionally, roofs are generally out of public view, so issues such as glare and aesthetics are less of a concern.

While the focus of early solar PV deployments has been primarily on rooftops, vertical planes present an excellent opportunity to further expand the potential of solar PV. Especially considering the limited amount of roof space available (e.g., shading from adjacent blocks; roof design, e.g., pitched roofs where it is technically difficult to install solar PV; competing services, e.g., telecommunications, green roofs, etc., competing for roof space), will eventually be used up.

Given Singapore’s urbanized high-rise high-density environment, the façade area far exceeds the roof area. If these facade areas can be used for solar power generation, it will greatly increase Singapore’s solar photovoltaic potential. Therefore, HDB is further researching how to optimize vertical solar photovoltaic installations to utilize solar energy on the vertical facets of buildings.

These installations will allow HDB to assess the technical feasibility and performance of the system. The project thus provides an opportunity for HDB and the private sector to test and showcase new urban solutions for wall mounted Solar Photovoltaic Installation.

Wall mounted Solar PV System (BIPV/BAPV) Requirement

The proposed Wall mounted solar PV system should consist of 3 main components:

(i) Structural Support Mounting System

(ii) Solar photovoltaic panels

(iii) Safety, Regulatory and Authority Approvals

The proposed solar photovoltaic panels can be of rigid or flexible type, also farmed and farmless Types of solar PV panels may include, but are not limited to, monocrystalline and polycrystalline silicon and amorphous thin film types, and may include coloured and colourless solar PV panels.

Today, our photovoltaic manufacturers produce products with patterned designs that fit the sides of buildings. These panels are installed vertically on a townhouse located in a historic district to add greenery and elegance to the building’s facade

Notwithstanding the two parts detailed above, it is permissible to combine solar panels as an integrated solution in the installation structure itself (for example in the case of Building Integrated Photovoltaics (BIPV)). Other components required for the successful operation of the system, such as monitoring systems, inverters, wireways, wiring, etc., should be part of the vertical solar PV system.

The solar PV panels and inverters, where applicable, shall be third party tested and certified to relevant IEC standards, such as IEC 61215, and IEC 61727.

The proposed vertical solar PV system shall adhere to the Singapore Fire Code 2013, in particular, but not limited to Section 3.5.7 on vertical fire spread. The Qualified Person (QP) will be required to obtain the Singapore Civil Defence Force’s (SCDF) approval for the proposed vertical solar PV solution.

Technical Competency

General Standards

Some specific standards or classifications will be developed for solar photovoltaic panels installed in vertical façades or cladding. Solar photovoltaic panels should be third-party tested and certified to the relevant IEC standards, such as IEC 61215, IEC 61727, IEC 61730-2. Fire safety requirements also apply.

Preliminary requirement for adhere to regulations

  • Proposed Vertical Solar PV Systems shall comply with SCDF Fire Safety Clause 10.2.2 for Wall Mounted Solar PV Installations
  • Photovoltaic modules are tested and certified to meet the requirements of SCDF Acceptance Standard 39.2 for Regulated Fire Safety Products and Materials.
  • Qualified Persons (QP) are required to obtain approval from the Singapore Civil Defence Force (SCDF) for proposed Wall mounted solar PV solutions.

Photovoltaic components to be tested and certified for BAPV/BIPV Application

  • Solar Panels 
  • Junction Box
  • Solar cables
Energy Performance On Facade Photovoltaics
  • Module Charateristic
  • Climate-Oriented Design
  • Natural Daylighting ( Skylight)
  • Facade Envelope
  • Mountng Position
  • Shading
  • Optimising
  • Facade Thermal
  • Ventilation Air
  • Infiltrations

Vertical Solar Facade Photovoltaic

With the rapid changes in solar technology, solar panels are increasingly integrated into the overall design of building facades / cladding, what look like ordinary skyscrapers of the future may actually be energy-efficient zero-carbon buildings filled with glass solar panels. In addition, air conditioning and electricity costs are significantly reduced. Further evaluation analyses the potential of future ecological buildings, which can be upgraded to independent local photovoltaic power plants.

Vertical Solar BIPV or BAPV on Façade Application Type

  1. Curtain Wall / Cladding System (Warm Façade)
  2. Rain Screen Façade (Cold Façade)
  3. Innovative Envelope System
  4. Skylight / Solar Glazing System (Sunshade)
  5. Canopy / Car Park Shelter
  6. Balcony / Parapet Wall / Vertical Fencing
  7. Solar Window
  8. Acoustic Shielding
  9. Thermal Isolation

Other BIPV (Architectural) Application Type

  1. Architectural Design (Structure Art).
  2. Outdoor Open Plaza (Floor mount)
  3. Pedestrian Walkway (Floor) / Pavement
  4. Bus Stops
  5. Street Lighting
  6. Garden Landscape

Wall Mounted Solar Photovoltaic System (Facade / Cladding Application) – BIPV & BIPV

More and more high-rise buildings have been installed with Solar facades / cladding Photovoltaic System or Curtain Wall Photovoltaic System to generate free and clean energy and injected into the grid. As these BIPV modules that are installed onto the façade are not only a visible sign of environmental protection and sustainability, but also a key component for achieving nearly zero or surplus energy. One of the facades would be widely exposed to the sun at a time and interacts with the movement of the sun. Besides the BIPV generating solar power, the BIPV modules also acts as a thermal insulation, sound reduction and protection against the weather. With the ntegrating of the Photovoltaic into the Building envelope / cladding, this will improve the energy-efficiency with the building by reducing the air-condition and mechanical ventilation. This results in the reduce of GHG emissions.

 

BIPV & BAPV Design and Architectural Approach

1.     Transparent Solar Panel

2.     Colored BIPV

3.     Skylight

4.     Brise Soleil Orientable

5.     Louvers

6.     Roof tiles

7.     Ventilated Façade (Double skin)

8.     Retrofit

9.     Walkable Floor