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Scientists at the University of Malaya have designed a roof that can help address an environmental conflict: increasing demands for energy to increase living comfort versus a need to scale back fossil fuel use to address climate change. The conflict has driven interest in more efficient renewable energy sources, especially in emerging economies.
The roof's most visible feature is a V-shaped structure set atop a peaked roof, which guides wind into a series of turbines situated below it to generate energy as they turn. The structure also increases airflow within the building by means of vents built into the peaked roof to enhance natural ventilation. In addition, a rainwater harvester is connected to an automated cooling and cleaning system that washes solar cells embedded in the sloped roof to keep them efficient. Transparent skylights brighten the main rooms inside the building during the daytime, reducing the need for artificial lighting.
The team says that adding the roof to an existing building creates minimal visual impact and can be used in urban and rural settings.
In Malaysia, the average person uses about 4,200 kilowatt hours (kWh) of energy per year. The researchers say their roof could support about six people by generating more than 21,200 kWh of energy a year while saving another 1,840 kWh because of its skylights. Also, the venting system could move about 217 million cubic metres of air and reduce carbon dioxide emissions by 17,768 kilos, while the rainwater harvester could collect close to 525 cubic metres of water.
Do they have homeowner's associations in Malaysia?
(Score: 1) by khallow on Monday April 10 2017, @07:36AM (5 children)
A building without this roof would still have a roof, and a conventional roof does entail costs for labour and materials--shingles, tiles or the like. This roof would take the place of those.
I wouldn't expect this roof to be worthless after ten years, as you seem to have done. PV panels are commonly assumed to last for around 25 years and buildings can last longer than that. For example, in the United States it was found that the median age of housing was 36 years.
This roof has moving pieces. The PV part might be ok for 25 years, but the wind power part won't be.
(Score: 3, Informative) by butthurt on Monday April 10 2017, @09:38AM (4 children)
In 2012 the UK Department of Energy and Climate Change stated:
Britain’s oldest commercial turbines at Delabole in Cornwall have only recently been replaced after 20 years of operation, and the technology has come on in leaps and bounds since that project started generating in 1991.
-- http://www.ewea.org/blog/2012/12/study-on-turbine-lifespan-just-more-anti-wind-propaganda/ [ewea.org]
In a new study, researchers from Imperial College Business School carried out a comprehensive nationwide analysis of the UK fleet of wind turbines, using local wind speed data from NASA. They showed that the turbines will last their full life of about 25 years before they need to be upgraded.
The team found that the UK's earliest turbines, built in the 1990s, are still producing three-quarters of their original output after 19 years of operation, nearly twice the amount previously claimed, and will operate effectively up to 25 years. [...]
[...]
[...] more recent turbines are performing even better than the earliest models, suggesting they could have a longer lifespan.
--
http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_20-2-2014-9-18-49 [imperial.ac.uk]
Engineering consultants estimated that a wind project in Kansas "would have a service life of 30 years or more."
http://www.burnsmcd.com/projects/wind-farm-life-expectancy-evaluation [burnsmcd.com]
A wind turbine mounted on a building would differ from those and might wear more quickly. However, failure of the turbine wouldn't make the roof worthless, as the roof would still be providing water, shelter and electricity--just a bit less electricity, and none at night. If the design were to become popular, it's likely someone would manufacture replacement turbines.
When electricity is generated from fossil, biomass, nuclear, geothermal, tidal or hydro power it's normally done with moving parts.
MHD generators have not been employed for large scale mass energy conversion because other techniques with comparable efficiency have a lower lifecycle investment cost.
-- https://en.wikipedia.org/wiki/MHD_generator [wikipedia.org]
(Score: 1) by khallow on Monday April 10 2017, @11:17AM (3 children)
A wind turbine mounted on a building would differ from those and might wear more quickly. However, failure of the turbine wouldn't make the roof worthless, as the roof would still be providing water, shelter and electricity--just a bit less electricity, and none at night. If the design were to become popular, it's likely someone would manufacture replacement turbines.
In other words, a small, lower quality wind turbine mounted on a building would have exactly the differences, particularly maintenance issues, that would break your comparison.
And you're erroneously valuing the whole based on a few components. This is a Rube Goldberg contraption with a number of problems introduced by those wind turbines, such as maintenance and the unsightly inverted "V" structure which wouldn't be present in a roof which didn't have those turbines. I don't believe the roof compares well to either a normal roof or a roof with solar cells. In other words, the wind turbines don't add value.
(Score: 2) by butthurt on Monday April 10 2017, @05:24PM (2 children)
> [...] small, lower quality wind turbine [...]
Are you saying that it must be of poor quality, perhaps because it is small?
> [...] you're erroneously valuing the whole based on a few components. [...] the wind turbines don't add value.
I said that, should the turbines fail, the roof would still have value: it would still provide water, electricity, shelter, and ventilation. It would still be useful. I don't see how that is erroneous.
How much value the turbines add is certainly questionable:
A small wind turbine can be installed on a roof. Installation issues then include the strength of the roof, vibration, and the turbulence caused by the roof ledge. Small-scale rooftop turbines suffer from turbulence and rarely generate significant amounts of power, especially in towns and cities.
-- https://en.wikipedia.org/wiki/Small_wind_turbine#Installation [wikipedia.org]
In the illustrations, they are close to what I assume are the air vents. That would seem to have a possibility for noise from the turbines to readily enter the building.
> [...] maintenance [...]
A conventional roof requires maintenance too. This roof is self-cleaning.
> [...] unsightly inverted "V" structure [...]
Clearly you mean the "V"-shaped structure. Some people find the aesthetics of free-standing wind turbines, PV panels, or central power plants displeasing. I don't spend much time looking at roofs. For myself, I wouldn't mind ruining that experience to have a bit more electricity.
Speaking of an inverted "V", the way the PV panels are arranged isn't optimal for collecting solar energy. A single plane would be better than two surfaces facing in different directions. The article doesn't say that both surfaces are to have PV cells. I have a hunch that with a single, large plane, the extra electricity harvested from the Sun could obviate the turbines. It would be better suited to the use of cheaper, less efficient cells.
(Score: 1) by khallow on Monday April 10 2017, @09:42PM
Are you saying that it must be of poor quality, perhaps because it is small?
Yes. If you have a large wind turbine, that generates a lot of electricity which buys a fair amount of maintenance (expected costs are a few percent of the revenue generated). Meanwhile, these wind turbines simply won't have the revenue stream to justify the maintenance. And any maintenance will be very specialized since one is working at the top of a roof.
I said that, should the turbines fail, the roof would still have value: it would still provide water, electricity, shelter, and ventilation. It would still be useful. I don't see how that is erroneous.
So would a roof without the wind turbines. The wind turbines don't make these other features more valuable. In fact, the "V" structure indicates to me that they'll probably make the solar cells less valuable through obstruction of light.
That's the problem in general with adding more features. Just saying that the other features are still functional even if this one breaks, ignores that they would still be functioning and might even function better without the questionable feature.
(Score: 1) by khallow on Monday April 10 2017, @09:47PM