Smart Windows Could Be the Next Big Thing in Renewable Heating
- Abigail Balkus - MSc. in Health and Social Psychology
- Jan 10
- 3 min read
Updated: Feb 12
World energy demand is continuing to soar as cities grow, technology advances and industries develop. Buildings make up about 30%-40% of the total – even more than industry or transport. This comes largely from heating, cooling and ventilation systems, with air conditioning especially energy-hungry.
Windows are a significant part of the problem. They allow heat to escape in winter and enter in summer, forcing temperature systems to consume more energy and drive up emissions. The challenge is to control this heat transfer without compromising on windows’ transparency and the amount of daylight they let in, both of which are essential for people’s wellbeing and productivity.
The answer is smart windows. Most of the current versions on the market are what is known as electrochromic (EC), meaning they work by applying electricity at the touch of a button to layers of particles or crystals inside the glass.
This causes a reversible molecular transformation which turns the window either opaque or dark, depending on the product. This blocks out the majority of infrared light, which is what makes rooms uncomfortably warm. This drastically reduces the need for air-conditioning in hot countries, keeping some 60% to 70% of heat outside at peak temperatures. They can also reduce heat loss from rooms by about 40% in colder weather.
For a few years, these windows have been selling fairly well both for commercial and residential properties. The total global market in 2023 is estimated to have been worth US$6.6 billion (£5.2 billion).
Yet they have several important limitations. Though the windows don’t use very much energy, they only operate with a power source. This can be challenging in locations that are remote or have unreliable electricity. And to the extent that renewable options from the grid aren’t available, users need to install an alternative like solar panels to make these windows carbon neutral.
With many varieties – though there are exceptions – you can only toggle between full restriction and full transparency. This means you’re losing the benefits from having windows when the weather is hot, and rooms will probably need artificially lit. And as previously mentioned, EC windows do a great job of keeping out heat in hot countries, but they’re a bit more limited in colder climes.
It’s difficult to predict an exact timeline, but maybe five or ten years from now, this kind of research should bring smart windows to market that will be just as useful in cold countries – as well as both in the daytime and at night. This is the key to the widespread rollout of a single type of window around the world.
It should make a significant difference not only to aircon requirements but also to the need for heating and radiators. My rough guess would be that by installing five smart windows in an apartment in a colder country, this might enable the owners to reduce the number of radiators from, say, five to two. And besides buildings, these technologies could also be used in aeroplanes and cars.
In the meantime, there’s every reason to assume that the market particularly for EC windows keeps growing. According to one projection, it should increase by nearly another US$4 billion or around 60% by 2028. With the right mix of research success and policy support, in both developed and developing countries, the next generation of smart windows should then be able to take this forward and make a big difference to the carbon emissions of buildings a decade or two into the future.
The full story is a doozy, but click here if you would like further information.
Today's Good News Report courtesy of https://cosmicnation.co/about/seb_tmg
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