Dynamic Glass

Project Drawdown defines dynamic glass or smart glass as glass that dynamically changes its opacity to reduce or increase the amount of light and heat that is allowed to pass through. This technology replaces high-performance static glass that’s already prevalent in commercial buildings in the Organisation for Economic Cooperation and Development (OECD).

Dynamic glass promises energy savings for both thermal and lighting systems in buildings and transportation, though we focus only on architectural applications. Applications include sunlight regulation in buildings and glare reduction on rearview mirrors. There are many technologies that allow this, including those that automatically change in response to light, heat, or an electrical current (that is, by human control). Dynamic glass can greatly reduce the inefficiency of building windows and other glazed surfaces and can also eliminate the need for shading, resulting in an increase in natural lighting in buildings. In this report, we examine the potential financial and climate impact of increased adoption of dynamic glass instead of high-performance static glass for commercial building applications.

Methodology

Total Addressable Market

The total addressable market (TAM) for dynamic glass was calculated using the Project Drawdown integrated buildings TAM model, which collectively calculates the TAMs of building floor area, roof area, space heating and cooling, and all other floor-area driven TAMs used in the building sector. The estimated areas are also subdivided by building type (residential and commercial), and by building climate zone[1]. This model used numerous sources. The total addressable market for commercial architectural glass was determined based on the estimated growth in commercial floor area from this model and the average commercial window-to-floor-area ratio from several sources. Recent sales data of dynamic glass from four market research sources was used to estimate the solution’s current adoption[2] in square meters of glass installed (2.48 million) and in square meters of commercial floor area adopted (42 million).

Adoption Scenarios

Impacts of increased adoption of dynamic glass from 2020 to 2050 were generated based on two growth scenarios, which were assessed in comparison to a Reference Scenario where the solution’s market share was fixed at the current levels.

For dynamic glass, scenarios were developed based on near-term projections and long-term targets from international organizations:

• Scenario 1: For near-term forecasts to 2022, historical and trend data estimated by Navigant Research (2012) were used and interpolated with a far future forecast guided by the World Green Buildings Council's target of 100 percent net zero buildings by 2050.[3] A more conservative number of 30 percent adoption in 2050 was chosen.

• Scenario 2: The same procedure was performed as in the Scenario 1, but 50 percent adoption in 2050 was used.

Emissions Model

Lighting, heating, and cooling energy data for commercial buildings were obtained from several sources and weighted by climate zone where possible. Energy efficiency of lighting, heating, and cooling were all found to be between 7 and 9 percent. Electricity and fuel consumption were included, and emissions factors were based on the Intergovernmental Panel on Climate Change (IPCC) data.

Financial Model

First costs of dynamic glass are around three times those of conventional glass based on over 20 sources, but a learning rate of 8 percent was applied for dynamic glass.[4] As the technology is still relatively new, and as some types of dynamic glass do use small amounts of electricity whereas others do not, operating costs of the glass itself were not included. Cooling, heating, and lighting costs however, were included for commercial areas with dynamic glass adoption and those with conventional glass adoption.

Integration

The dynamic glass solution was integrated with others in the Buildings Sector by first prioritizing all solutions according to the point of impact on building energy usage. This meant that building envelope solutions like insulation were first, building systems like building automation systems were second, and building applications like heat pumps were last.[5] The impact on building energy demand was calculated for highest-priority solutions, and the dynamic glass input value was reduced to represent the impact of higher building envelope solutions. The output from the dynamic glass model was used as the input in lower-priority solutions.

Results

Scenario 1 forecasts that just over 200 million square meters of dynamic glass could be installed by 2050, thereby avoiding 0.3 gigatons of carbon dioxide-equivalent greenhouse gas emissions compared to high performance static glass. The marginal capital cost compared to the Reference Scenario would be US$69 billion, which assumes that conventional glass is purchased in the Reference Scenario,[6] but this scenario saves US$99 billion in operating costs over glass lifetimes due to reduced energy consumption.

Scenario 2 of growth to 341 million square meters of glass shows 0.5 gigatons of emissions reduced and US$165 billion in lifetime savings at a cost of US$103 billion.

Discussion

It is clear that dynamic glass can help commercial buildings reduce their emissions and save operating expenses, though the costs would be significant. For buildings going through a retrofit anyway, it could be financially viable to have dynamic windows installed instead of static high-performance windows. For buildings that do not need any other retrofit, the business case for retrofitting high-performance windows with dynamic windows (as opposed to staying with existing high-performance windows) may be weak. Some aspects that may affect this result have not been examined, however, such as the regional nature of adoption due to dynamic glass’s high price and weather application. Realistically, architectural dynamic glass will be mainly adopted in wealthier regions with higher average temperatures, such as Australia and the southern and western areas of the US. Additionally, there are likely some residential applications that would increase the impact of dynamic glass.

The high up-front cost of dynamic glass has inhibited its growth. As new competitors enter the market (including for transportation applications of dynamic glass, which were not included in our model), the price of dynamic glass is expected to drop, and adoption is expected to accelerate. Growth could be further driven with government support and the development of programs that demonstrate the benefits of dynamic glass to consumers. It’s important to note, though, that for some areas and applications that still use plain glass (that is, non-high-performing), a large portion of the benefits of dynamic glass can be obtained with mature technologies that are considered high performance static that are mostly cheaper. This is examined in another model.