Tuesday, December 30, 2014

Robyn O'Brien at TEDxAustin 2011

She explains the problem of untested GMO proteins in the USA food supply and the side effects of Cancer and Allergies that have come from that.

Sunday, December 28, 2014

Wells Generator Wave Energy Converter


Saturday, December 6, 2014

Passive Radiator Cools by Sending Heat Straight to Outer Space


Illustration: Nicolle R. Fuller/Sayo-Art
In this illustration a panel coated with a multilayered material designed by Stanford engineers helps cool buildings without air conditioning. The material works in two ways. It reflects incoming sunlight [yellow] that would otherwise heat the panel. More importantly, it sends heat from inside the structure directly into space as infrared radiation of a particular wavelength [red]. The result is a cooler [blue] roof.
Conventional cooling is all about moving heat from a place where you don’t want it to a place that you care about slightly less. Your refrigerator, for example, cools itself by pumping heat into your house. Your house cools itself by pumping heat into the outdoors. It takes a significant amount of energy to keep this up—15 percent of the energy consumption of most buildings is spent just on air conditioning—meaning that the work put into transferring the heat generates even more heat. And then it’s not like the heat just vanishes when it gets outside: in urban areas, all of this waste heat builds up to increase local temperatures as part of the urban heat island effect.

In Nature this week, Stanford researchers describe a passive radiator system that can lower the temperature of anything that it’s placed on by up to five degrees Celsius by absorbing heat and sending it directly into outer space, and it even works in direct sunlight.

Radiative cooling is a way of passively moving heat from one place to another through thermal radiation, without the need for any additional energy (like electricity). If you have a hot thing, it will radiate its heat into whatever cooler thing is most convenient. In your house, this is probably the air outside, and in your car, it’s also the air outside, by way of the water in your radiator.
Since the general approach here is to use the atmosphere as the final heat sink, radiative cooling doesn’t work if you’re trying to end up at a temperature lower than the ambient temperature outside, which is why completely passive air conditioning isn’t a thing.

The clever thing about the passive radiative cooling system that Stanford came with is that it skips the atmosphere completely, and uses the entire Universe as a place to dump heat. The entire Universe, being mostly empty space, has an average temperature of just under three Kelvin, meaning that it’ll happily absorb just about as much heat as you can possibly throw at it, making it a heat sink that’s nearly, you know, universal.

To use outer space as a heat sink, you need to have access to outer space, which sounds like it’s probably a difficult thing to achieve. But fundamentally, it just means being able to transfer heat straight through Earth’s atmosphere. Stanford’s cooling system emits thermal radiation in a very specific infrared wavelength that the Earth’s atmosphere is completely transparent to, between 8 and 13 micrometers.

So, this is great, but the other part of the problem with radiative cooling is that we really need it to work during the day, when the sun is out and it’s hot. But if the sun is warming the radiator more than the radiator can cool itself, the system isn’t going to accomplish much. Stanford’s radiator also functions as a mirror that can reflect 97 percent of incident sunlight, enabling the radiator to cool itself (or something underneath it) by up to five degrees Celsius even during the heat of the day.  In a three-story commercial building with a 1600 square meter roof, using the radiative cooler would save an estimated 118,500 kWh annually, the engineers calculate.

The radiator itself is composed of seven layers of silicon dioxide and hafnium oxide on top of a thin layer of silver. The structure has been tuned to only radiate at the specific infrared wavelengths that can pass through the atmosphere. It’s just 1.8 microns thick in total, and the researchers say that it can be fabricated at production scales in existing facilities. Otherwise, the only remaining issue is to figure out how to conduct the heat from inside a building through to the exterior walls, to where the radiator could do its job.

These problems both seem surmountable, and even surmountable in the near future, as opposed to the “five to ten years” void that many technologies like this fall into. If this radiative cooler material can in fact be produced inexpensively and efficiently, it could have a significant impact on energy usage, especially in the developing world where off-grid cooling is often the only option in rural areas.

Friday, December 5, 2014

New Study Shows White Roofs are Three Times More Effective than Green Roofs at Fighting Climate Change

Green roofs offer a lot of environmental benefits – they provide additional insulation, reduce rainwater runoff, and can lower your electricity bill. However a new study suggests that roofs painted white might actually be more effective at fighting climate change. A study published in the Energy and Buildings Journal compared three types of roofs – green, black and white – and came to the conclusion that white roofs have great economic benefits, and they are also three times more effective than the other two at fighting climate change.

Researchers at the Lawrence Berkeley National Laboratory conducted an economic analysis of the costs and benefits of white, black and green roofs and found that white roofs are far superior in fighting climate change than the other two. While roofs painted black absorb heat and contribute to the urban heat island effect, white roofs reflect the sunlight back into the atmosphere and help cool down its lower parts. The study advises those concerned with global climate change to choose white roofs, adding to a host of other studies in the past decade that have allowed the “white roof movement” to gain momentum across the United States. However, things are not as simple as they seem.
A series of climate simulations carried out by Mark Z. Jacobson and Ten Hoeve of Stanford University showed some unexpected results. Despite their beneficial effects on the lower parts of the atmosphere, white roofs decrease the temperature difference half a mile above ground-a difference which drives cloud formation and less clouds means more sunlight reaching the Earth’s surface. This, among other issues like the impact on fossil fuel consumption and summer cooling vs. winter heating gains, is still subject of scientific debates. Meanwhile, it should also be noted that vegetated roofs offer built-in storm water management mechanisms in addition to some cooling benefits.
Although we are excited to find out how different roofing strategies may affect climate change, one should be aware of the fact that these investigations involve a wide spectrum of factors and potential consequences far too complex for a hotheaded (pun intended) thumbs-up verdict.
+ Energy and Buildings Journal
+ GATOR-GCMOM Environmental Model
Via Fast Co.Design, Huffington Post