A short payback period is key to rapid adoption, and technologies including double-pane low-e coated windows and daylighting glazing can have a payback period of two years or less, according to Balancing Energy Efficiency, Occupant Comfort, and Aesthetics in Architectural Glass. It says dynamic glazings not far behind.
Lux Research reports energy-efficient windows can save up to $135/m2 a year.
Lux Research analysts assessed technology developers based on their technical value and maturity, sorting them into four categories: faded incumbents, current winners, future winners and long shots.
The report says daylighting glazings a short-term winner. They offer the shortest payback among the emerging technologies — two years at the current installed cost of $200/m — making near-term winners of companies such as LightLouver, PhotoSolar and Skyshade. Lux Research also forecasts greater integration of daylighitng systems with solar tracker, daylighting sensors and backup LEDs.
While dynamic glazings will take more time, the report says these technologies will win in the medium- to long-term. A handful of dynamic glazing developers — including future winner Ravenbrick and current winner Pleotint — are scaling up but their value remains lower due to high cost, leading to longer payback times.
The report names building integrated photovoltaic (BIPV) glazings a long-term winner. BIPV combines energy generation and energy efficiency but has a long paybacks of 14 to 15 years. Lux Research says leading innovators include future winner Bisem, which makes curtain walls capable of integrating electrochromic glass, CIGS cells and daylighting louvers. It also says the best opportunities in BIPV glazings may be like those offered by Pythagoras Solar: crystalline silicon cells incorporated at close to right angle to the façade surface.
In December 2012, JE Berkowitz retrofitted the windows at the Kevon Office Center in Pennsauken, NJ, converting single-pane windows into energy-saving, triple-glazed insulated glass units. Arthur Berkowitz, president of JE Berkowitz, said simulations using energy-modeling software showed that the Renovate by Berkowitz (RbB) window retrofitting system could enable the office center to lower its annual energy costs by up to 26 percent.