Building a green future for Australia means developing technology that is sustainable, functional and practical. For technology like solar PV, which is already consistently breaking records of integration on residential Australian rooftops, researchers are asking the question – why stop at rooftops? A new tool is being developed by researchers at RMIT to help make building integrated PV (BIPV) a practical and affordable solution.
Project lead for RMIT’s Solar Energy Application Group and head of the BIPV Alliance, Associate Professor Rebecca Yang, said building integrated PV (BIPV) products need to satisfy requirements as a PV product and also the building regulation product requirements.
This can include the solar heat gain coefficient performance to impact the thermal loads in the building, the fire safety rating, wind loads resistance and the value and static loads.
BIPV takes solar PV a step further; not only can the panels generate electricity, but they also function as a building product that can replace any elements on the building surface. BIPV is a customisable product, with different colours, transparencies and even flexibilities compared to conventional PV panels commonly used on rooftops.
This includes the roof tiles and roof sheets, but also includes vertical surfaces such as curtain walls, colliding products, windows, double-skin façades or shading devices.
With all these aspects to consider, the RMIT team have created the BIPV Enabler tool. Funded by RMIT and the Australian Renewable Energy Agency (ARENA), it is the first of its kind to be designed for Australian buildings with domestic data.
The challenge
In theory, building materials that simultaneously have the ability to generate energy sounds fantastic, but it comes with a few obstacles.
Firstly, because of the technology involved, the product itself is more expensive per square building metre compared to regular materials.
Secondly, the Australian market for BIPV products is smaller than overseas counterparts, making it more difficult for architects to have sufficient information to decide if BIPV is the right choice, let alone to select the right product for their designs.
Assoc Prof Yang said there was also a clear need to understand the products, its characteristics and try to design in a way that better matches with the energy demand profile in the building as well as consider the local physical environment in an urban context.
“On top of that, we always need to balance the capital investment and waste energy generation, so that causes a lot of difficulties for architects, property developers to make decisions regarding whether we should use the products or not.”
Overcoming barriers to architectural adoption
Assoc Prof Yang and the RMIT researchers have been compiling solutions to BIPV adoption, which has led to the development of the BIPV Enabler tool. The tool integrates product, regulation, technical, economic and construction data to create 3D models and detailed life cycle simulations tailored to each building’s planned location.
The tool provides the ability for users to create precise mock-up building models with accurate urban environments alongside specific filters for product comparison and design preferences.
“We have 200-plus products in our database and when we collect the product information, we also record not only their electrical properties as a PV product but also their characteristics related to building requirements.
“For example, their solar heat gain coefficient performance to impact the thermal loads in the building, their fire safety rating, their wind loads resistance, the value and static loads, et cetera. “We also collected information in relation to the conventional building material cost because that’s quite important when we consider BIPV benefits.
Once you use BIPV products, you’ll actually offset your cost for conventional alternative building materials, which we consider as well during our calculations.” “We also consider the local information, such as the energy price across different locations in Australia, of course, the weather condition in different locations across the country as well.”
Assoc Prof Yang said these features allow users to create their building model mock-ups with the urban environment quickly, and even include simulations for shading loss.
“After that, they can select products with their preferred criteria and then the tube will filter out the right products for them with different options, and then they can select one or multiple products and enable the calculation procedure, and tell them the result in terms of the economic and environmental benefits or the outcomes, let’s say economic and environmental outcomes fairly quickly.”
Assoc Prof Yang said BIPV Enabler also worked with computer-aided design programs and could be scaled and customised to incorporate other open-source datasets to suit changing needs.
Development process and industry workshops
From product design and development, to testing the tool within the industry, Ms Yang and the team received positive feedback across their multiple industry workshops. One feature that has been a major hit has been the design optimisation module. This feature allows users to select multiple products and input different design criteria for the selected buildings.
The module options include low capital investment, more energy generation or lower payback periods. The user can then compare and contrast the combination of products to find the perfect partnership of products for their wanted design. “We incorporate a lot of local information for the calculation that’s very unique, even globally.”
Supporting net zero
Solar PV already plays a major role in Australia’s renewable energy industry. For mid or high-rise building owners, they can also capitalise on the opportunities to generate electricity on site, rather than relying on power purchase agreements from remote areas.
Ms Yang explained that when electricity is bought offshore, there’s waste and loss on the transmission line, and this is avoided when energy can be generated on site. BIPV also creates energy generation benefits due to the ability for designs to involve vertical PV rather than relying on common, tilted PV which generates peak energy during midday.
“Another benefit is that if you consider the PV integration on vertical surfaces, with proper designs that are combined with rooftop PV, you can actually stabilise your energy supply during daytime.
With proper vertical PV designs, energy can be generated in the morning and evening, providing stable energy on site, while also reducing the impact to the grid and better satisfy the needs profile for the building – all with a product that triples as an aesthetic choice.
“We hope to see more buildings capable of generating solar electricity, while maintaining good design standards – a win for the planet and aesthetics.”
