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Tag: green roof

How the World’s Whitest Paint Can Reduce Energy Use

Posted on by dishanth
How the World’s Whitest Paint Can Reduce Energy Use

Scientists have long understood the climate and energy efficiency benefits of reflective white paints. Now, engineers at Purdue University have created the world’s whitest paint that reflects more than 98% of sunlight, leaving all other paints appearing grey by comparison. As demand for sustainable solutions grows globally, this innovation promises greener buildings and cities by passively lowering carbon emissions and energy use.

The world’s whitest paint formulation was reportedly completed in early 2021. While initially produced for research applications at Purdue, press releases indicate Perdue intends to optimize and commercialize the product for widespread availability as early as late 2023. This rapid early adoption timeline speaks to the hunger for market-viable incremental gains in cooling efficiency as global temperatures continue rising.

With the formulas and methods published openly, it remains to be seen whether alternate whitest paint variants may emerge from other research teams or commercial producers, sparking a global race toward passive cooling innovation. Even moderate cooling boosts from white paint could incentivize entities like major cities to begin budgeting for wide-scale reflective surface projects within the decade.

Applying the world’s whitest paint to building rooftops and envelopes can reduce their surface temperatures by over 20°C compared to conventional options. By reflecting rather than absorbing heat, the broad deployment of the world’s whitest paint could mitigate the phenomenon of urban heat islands, where dense cityscapes absorb and radiate increased warmth. Modeling suggests summer city temperatures could decrease by over 2°C using this approach.

The development of a highly reflective and renewable calcium carbonate-based paint offers an innovative solution to excessive urban heating. As climate change brings more frequent and intense heat waves, the cooling potential of reflective white surfaces will grow increasingly impactful. Deploying this paint across a city’s building stock can lower indoor and outdoor temperatures while cutting air conditioning demands as well. Transitioning rooftops from heat-trapping dark colors to the whitest paint formula could become a climate resilience strategy for communities worldwide.

Looking beyond buildings, custom reflective paints and paving materials show similar potential for cooling everything from vehicles to sidewalks to transit shelters. An urban landscape covered with maximum heat reflection could compound cooling benefits compared to white rooftops alone. More research into expanding high-albedo surfaces across the built environment will further quantify the associated quality of life and emissions reductions. Simple shifts in surfaces and materials at scale could make future cities markedly more livable.

The world’s whitest paint keeps surfaces cool to the touch, even in the hottest environments. Compared to the air temperature at mid-afternoon, a surface painted with the world’s whitest paint can be several degrees cooler than regular white paint. At night, the difference is even more pronounced, up to 19 degrees.

The corresponding drop in air conditioning electricity demand is equally significant from an emissions reduction perspective. Studies by the US Environmental Protection Agency show cool roofs can reduce a building’s annual air conditioning requirements by 10-30%. The increased grid energy efficiency will provide critical flexibility for integrating renewable energy sources as part of essential decarbonization efforts across the power sector.

While the world’s whitest paint’s exceptional solar performance will justify further optimization before mass production, its imminent commercial arrival heralds a shift in leveraging incremental materials innovation. The compound benefits of collective small-scale action represent meaningful progress, offering pragmatic climate hope. If cool paint alone makes summers more bearable, our combined creative efforts focused first on the possibly more than the ideal may yet brighten prospects for sustainable living.

With vision and patience, Perdue’s ultra-white paint is but a glimpse of a future where green cities are dotted with communities that thrive in the hotter world they’ve warded off, one roof at a time.

 

 

 

 

Source  Happy Eco News

6 Types of Cool Roof Technology

Posted on by dishanth
6 Types of Cool Roof Technology

Cool Roof Technology: a Low-cost Way to Reduce Energy Consumption and Carbon Emissions

Want a huge decrease in carbon emissions, a reduction in summertime cooling costs and a more efficient home? Cool roof technology can do all that. Cool roof technology has the potential to eliminate billions of tons of carbon dioxide at a very low cost.

If you’ve ever spent time on a black asphalt roof or up in an attic during the heat of summer, you understand how much heat energy is added to a home during summer months. This is heat that many of us pay to remove by using air conditioners and other means.

But what if, just by a better design and choice of materials, we could have a far cooler house that uses far less electricity each month? That is what people in the Mediterranean and other hot climates have been doing for centuries. White paint and chimney-style ventilation that distributes cool air from lower areas of the house are low-tech examples of cool roof technology that works.

Modern cool roof technology is similar. Most are just like regular roofs but are designed to reflect sunlight and shed heat, to keep buildings cooler in the summer. According to a study by the National Renewable Energy Laboratory (NREL), cool roof technology could reduce energy consumption for cooling by up to 20%. The study also found that energy savings from cool roof technology could eliminate up to 1.4 billion tons of carbon dioxide emissions annually in the United States. The equivalent of taking 300 million cars off the road!

According to Lawrence Berkeley National Laboratory, if all North American cities with populations over 1 million people adopted cool roof technology, air conditioner use would fall by one-third.

The Human Cost of Heat

The savings aren’t just in terms of money and carbon emissions. Climate change has disproportionately increased temperatures in urban areas. An urban landscape largely covered in asphalt, concrete and black roofing materials is far hotter than one covered in greenery or reflective materials, a phenomenon known as the urban heat island effect.

The urban heat island effect is the phenomenon of cities being warmer than surrounding rural areas. This is because cities have more dark surfaces, such as black roofs, which absorb sunlight and heat up the air. The heated air then rises, creating a convection current that draws in cooler air from surrounding areas. This process can lead to increased temperatures in cities, which can have a number of negative consequences, such as increased energy consumption for cooling, decreased air quality, and increased heat-related illnesses and deaths.

Black roofs also radiate energy directly into the atmosphere. This energy is then absorbed by clouds and trapped by the greenhouse effect, further contributing to global warming.

Type Depends on Location Climate

There are a number of different types of cool roof technology available, including:

  • Reflective roofs: Reflective roofs are the most common type of cool roof. They are made of materials that reflect sunlight, such as white or light-colored tiles, metal roofs, or paints. Reflective roofs can reflect up to 90% of the sun’s heat, which can help to keep buildings cooler in the summer.
  • Evaporative roofs: Evaporative roofs are made of materials that allow water to evaporate, such as clay tiles or metal roofs with a water-absorbing coating. As the water evaporates, it cools the roof and the building below. Evaporative roofs can be effective in hot, dry climates.
  • Phase-change materials: Phase-change materials are materials that change their state from solid to liquid and vice versa. When these materials change phase, they absorb or release heat. Phase-change materials can be used in cool roofs to store heat during the day and release it at night. This can help to keep buildings cooler in the summer and warmer in the winter.
  • Cooling paints: Cooling paints are paints that are applied to roofs to make them more reflective and to help them cool down. Cooling paints are effective in hot, sunny climates and typically contain titanium dioxide, a highly reflective pigment.
  • Cooling granules: Cooling granules are small, reflective beads applied to roofing materials like shingles. The granules reflect sunlight and help to keep the roof cooler. Like cooling paints, cooling granules are most effective in hot, sunny climates.

 

Green Roofs are Cool Roofs

Another type of cool roof technology is the green roof. Green roofs are made of a waterproof membrane with a layer of soil and vegetation on top that helps to insulate the roof and reflect sunlight. Green roofs can reflect up to 70% of the sun’s heat, which can help to keep buildings cooler in the summer. In some cases, they can provide vegetable gardens or just a nice place to sit and enjoy the feeling of being surrounded by nature – while in the city.

Green roofs also have the effect of providing bird and pollinator habitat as well as reducing stormwater runoff. Because of the benefits, many cities are now mandating the installation of green roofs on new construction. New York, San Francisco, Chicago, Seattle and Portland all require green roofs on new construction on buildings with roof areas over a specific set size. That said, retrofitting an existing building is often cost prohibitive due to the structural requirements to support the additional weight.

Cool roof technology is a promising way to reduce greenhouse gas emissions and improve the energy efficiency of buildings. As the technology continues to develop, the potential for cool roofs to reduce carbon dioxide emissions will likely increase.

This is an easy way to make big gains in carbon reductions, saving homeowners and businesses money. Something we can all get behind.

 

 

 

 

Source Happy Eco News

Rare orchids to flood resilience: How can green roofs help to tackle the climate and nature crisis?

Posted on by dishanth
Rare orchids to flood resilience: How can green roofs help to tackle the climate and nature crisis?

Eleven stories high in the heart of the City of London, there is a hidden haven for wildlife. Around 159 species of plants are flourishing on the rooftop of Nomura, a Japanese bank. By day, orchids, daisies and wild herbs provide food to 17 species of bees. At night, the bright yellow flowers of mullein plants bloom in the moonlight, tempting London’s moths.

It is here that an orchid thought to be extinct in the UK was recently discovered growing among the roof’s solar panels. The small-flowered tongue orchid – so named because its flowers resemble protruding tongues – has only been found growing wild in the UK once before, in 1989.

It’s still a mystery how the orchids made it onto the roof, though ecologist Mark Patterson, who manages the bank’s 10-year-old rooftop garden, suspects that the flowers’ seeds hitched a ride on winds blowing over from the Sahara.

“Orchid seeds are as small as specks of dust,” he tells The Independent. “So my theory is they blew over before establishing themselves.” On the Friday morning when The Independent visited Nomura’s green roof, he was collecting leaves from the flowers to send to experts at Kew Gardens. “They’re going to analyse the DNA from the samples. That might be able to tell us what region the seeds originated from,” he explains.

 

A colony of small-flowered tongue orchids (centre and right) were discovered on a London rooftop after not being seen in the UK since 1989. SOURCE: Daisy Dunne

 

Nomura’s green roof is one of 700 spread across central London, with the capital boasting more such idylls than other parts of the country. According to the Greater London Authority, a “green roof” is a “a roof or deck where vegetation or habitat for wildlife is deliberately established”.

As well as providing a safe space for rare wildlife, building green roofs in cities can offer a host of other benefits, ranging from improving local air quality to helping build resilience against worsening extreme weather events, says Dr Michael Hardman, a senior lecturer in urban geography at the University of Salford.

“There’s clear evidence out there that green roofs can mitigate against things like the urban heat island effect and flood events,” he tells The Independent. “In terms of climate change, they are definitely an important tool.”

The “urban heat island effect” is a term for how cities are typically hotter than rural areas. Major UK cities, such as London, Manchester and Birmingham, can at times be up to 5C hotter than their surrounding rural areas, research shows. The effect is caused by a combination of densely packed buildings and roads, which trap in heat, as well as air pollution, industrial activity and high amounts of energy use by homeowners.

Research shows that the urban heat island effect is likely to intensify in UK cities as the planet continues to warm.

Green roofs can help to tackle urban heat by providing a local cooling service. This is largely because plants naturally absorb water through their roots and later release it into the air as moisture, which has a cooling effect on the surrounding area.

At Nomura’s rooftop garden, this cooling effect is largely enough to allow the bank to cut back on the use of air conditioning in the summer, Mr Patterson says. “If all the buildings in this area had green roofs, it would probably reduce the temperature on a hot day by a degree or two,” he adds.

 

Tortoiseshell butterflies are one of many insects found on Nomura’s green roof. SOURCE: Mark Patterson

 

The bank’s green roof also plays a role in reducing flood risk in the city. “Every inch of soil you have on a green roof absorbs five per cent more water, so that’s five per cent less water that’s running off into drains,” he says.

A study conducted in Newcastle in 2016 found that a “city-wide deployment of green roofs” could reduce travel disruption from flooding by around a quarter. The authors of the research say that green roofs, along with more traditional defences such as flood walls, must be part of plans to cope with more extreme downpours.

The need to prepare for worsening heatwaves and floods in the UK is greater than ever. Earlier this month, the UK’s independent climate advisory group, the Climate Change Committee, warned that the country is now less prepared for the climate crisis than it was five years ago as a result of government inaction in the face of rising risks.

Increasing the number of green spaces in cities will be key to helping the country’s urban populations cope with increasing heat and worse floods, according to their assessment.

Despite recognising the benefits of green roofs, the UK is currently behind other countries when it comes to building them, says Dr Hardman.

“We need to look to countries, like Denmark, which have both the financial incentives and the planning incentives,” he says. “In Denmark, if a building’s slope angle is under a certain amount, it’s actually mandatory to put a green roof on. We need to be more innovative with our policies.”

He added that, at present, not enough is being done to ensure that the social benefits of green roofs can be accessed by disadvantaged groups.

“All the green roofs in Manchester that I know of are very inaccessible, they are closed to the public and you need a health and safety person to take you up there,” he says. “To me that’s a huge barrier to green roofs. The social benefits just aren’t there at the moment, as they are for other types of green infrastructure like parks”.

 

Source Independent