Last Friday the BBC science correspondent, Victoria Gill, reported on news that US scientists have developed a ‘super’ white paint that reflects more than 98% of sunlight and wondered whether white paint could help fight climate change?
Commercially available white paint currently reflects between 80 and 90% of sunlight and the scientists are quoted in the article as saying this is “a big deal, because every 1% of reflectance you get translates to 10 watts per meter squared less heat from the sun”.
The theory is that the buildings will then need less energy consuming cooling but although the paint may be new, the theory certainly isn’t as I have pointed to this before when I wrote about the effects of urban heat islands.
Of course it wouldn’t reverse the impact of climate change, but it could help delay it.
Ellina Webb Marketing Specialist
Nothing new
But is white paint the answer to combating not only urban heat islands but also helping us tackle climate change?
The benefits of white paint in terms of its ability reflect sunlight is nothing new, but using it as a means to reflect the sunlight and capture less heat in the city kinda is…
The concept was previously put forward by Hashem Akbari, a scientist whose idea was inspired by the white towns and cities of the Mediterranean and beyond, like Santorini and Casablanca who have been using white for centuries to keep their buildings cool.
So can this work in our modern metropolitan cities too?
Painting the World White
Akbari began his campaign in 2009 in a quest to unite all of the world’s largest cities to replace their dark materials used to cover roads and roofs with reflective white.
The science of the white paint as a form of geo-engineering reduces the way heat accumulates in built up areas, keeping buildings cooler in summer and if accepted by the masses, could potentially cool the earth enough to cancel out the global warming caused by 44bn tonnes of CO2 pollution.
Of course it wouldn’t reverse the impact of climate change, but it could help delay it.
Other benefits for buildings, building owners and occupiers is that air conditioning units wouldn’t need to work as hard, helping with efficiency levels and cost savings. Of course air conditioning would still be required in many commercial properties, but with smart choices like efficient air conditioning with heat recovery, the ability to turn to heating only in winter is ideal.
Cool rooftops
According to the latest reports though, painting urban rooftops white is seen as an easy climate combating solution, with New York already having coated more than 10 million sq ft of rooftops.
California is also reported to have updated building codes to reflect the benefits and promote these ‘cool’ roofs.
Whilst the full benefits are still being explored, it seems pretty clear that these white roofs can reduce energy demands and create lower ambient temperatures within the building.
Across a city, that is going to make quite a difference to energy consumption and, as the world moves to more renewable electricity production, this could have a dramatic effect on carbon reduction.
A lean meanie
For us at Mitsubishi Electric, this is another useful tool in Step One of our ‘Lean, Mean, Green’ philosophy.
By being ‘Lean’ and reducing the amount of energy you need to consume to keep your building as warm or cool as needed, you are reducing the amount of air conditioning and heating systems you need to fit to that building.
Being ‘Mean’ simply refers to the best use of whatever technology you use to heat or cool your building.
Using the best control systems to automate as much as possible and including the correct maintenance regimes so that your systems operate at maximum performance throughout their working life.
And being ‘Green’ – well the world is already on a path to ‘greeness’ with electricity production now provided by more and more renewable sources and less and less by burning fossil fuels.
As these renewable sources of electricity continue, they make the case for electric heating even stronger, whether that is from an air source heat pump, or an air conditioning system.
Ellina Webb is a Marketing Specialist at Mitsubishi Electric
