LEED Certification Where Energy Efficiency Collides with Human Health, An EHHI Report
Report Summary
LEED Standards Are Being Adopted into Many Laws
Green Building Council standards are being incorporated into federal, state and local laws through legislation, executive orders, resolutions, policies, loan-granting criteria and tax credits. As demonstrated in this report, LEED standards are clearly insufficient to protect human health, yet they are being adopted by many levels of government as law. Thus the Green Building Council, a trade association for the building industry, is effectively structuring the regulations. The number of jurisdictions adopting these standards as law is growing, which will make them difficult if not impossible to change, unless federal law and regulation supersede the “green” standards with health-protective regulations.
No Federal Definition or Regulation of Green Building Standards
There is no federal definition of “green building standards” analogous to federal “organic food standards” or drinking water standards. Given regulatory neglect, many trade organizations have worked to create their own certification programs, hoping to capture growing demand for environmentally friendly and heath-protective buildings.
Energy Efficiency Given Priority Over Health
The LEED credit system is heavily weighted to encourage energy-efficient building performance. Nearly four times as many credits are awarded as energy conservation technologies and designs (35 possible credits) as for protection of indoor environmental quality from hazardous chemicals (8 possible credits).
Green Building Council Board Has Little Expertise in Environmental Health
Directors of the LEED Program are predominantly engineers, architects, developers, real estate executives, chemical industry officials and building product manufacturers. One medical doctor representing Physicians for Social Responsibility was recently appointed to sit on the board, which has 25 directors.
False Impression of Healthy Buildings
The Green Building Council’s award of “platinum,” “gold”, and “silver” status conveys the false impression of a healthy and safe building environment, even when well-recognized hazardous chemicals exist in building products.
Time Spent Indoors
Americans today are spending more than 90 percent of their time indoors. The EPA spends the majority of its resources working to manage outdoor threats to environmental quality and human health.
Tighter Buildings Increase Human Exposure
Energy conservation efforts have made buildings tighter, often reducing air exchange between the indoors and outdoors. Since outdoor air is often cleaner than indoor air, the reduction of outdoor-indoor exchange tends to concentrate particles, gases and other chemicals that can lead to more intense human exposures than would be experienced in better-ventilated environments.
However, the LEED program has been effective in encouraging more efficient heating and ventilation techniques, such as solar panels, geothermal wells, window placement and building orientation.
Toxic Chemicals in Built Environments
Tens of thousands of different building materials and products are now sold in global markets. Many of these products contain chemicals recognized by the U.S. National Toxicology Program, the CDC, or the World Health Organization to be hazardous.
These products include pesticides, chemical components of plastics, flame retardants, metals, solvents, adhesives and stain-resistant applications.
Some are carcinogens, neurotoxins, hormone mimics, reproductive toxins, developmental toxins, or chemicals that either stimulate or suppress the immune system.
Chemicals in Buildings Are Often Found in Human Tissues
The CDC began testing human tissues to determine the presence of some chemical ingredients of building materials. Most individuals whose tissues were tested carried dozens of these chemicals in their hair, blood or urine. Children often carry higher concentrations than adults. Chemicals released by building materials to indoor environments may be inhaled, ingested or absorbed through the skin.
No Level of LEED Certification Assures Health Protection
It is possible for new construction to be certified at the “platinum” level with no credits awarded for air quality assurance in the category “indoor environmental quality.”
Fuel cell gets energy from water.
Tuesday, August 10th, 2010Aug 09, 2010
Dreizler, AM, and E Roduner. 2010. A fuel cell that runs on water and air. Energy and Environmental Science 3:761-764.
What did they do?
What did they find?
What does it mean?
Resources
More new science from EHN
Chemists in Germany have figured out a way to extract energy from just water and oxygen. The discovery uses existing fuel cell technology and minimal additional chemicals, providing a safer way to generate electricity for low-power applications.
Context
Concern about the impacts of petroleum as the world’s major energy source has driven research into alternative energy sources, such as solar radiation, wind and biomass.
One of the tools for converting these sustainable energy sources into usable forms of electricity is the fuel cell. Fuel cells are devices that use chemical reactions to change energy from one form to another.
Because of their efficiency and their ability to harvest energy from diverse sources, fuel cells show promise as one of the keys to sustainable power generation. Fuel cell technology has already matured to the point where it can be used in power plants to supply electricity to buildings, and portable fuel cells have been demonstrated in prototype cars as well as military vehicles. Smaller fuel cells can be used in place of batteries for electronic devices like radios or laptop computers.
A fuel cell has an anode and a cathode, just like the positive and negative terminals of a battery. Chemical reactions occur at the two electrodes.
Generally, conventional fuel cells get power from a carrier molecule – usually hydrogen – that is added to the device. The fuel cell harvests electrons from the carrier molecule, producing electrical current. When hydrogen is used in fuel cells, it combines with oxygen in air to make water as a byproduct, also releasing heat. Fuel cells generally do not require wind or sun and operate quietly.
Tens of thousands of scientific studies have focused on fuel cell technology in attempts to find the chemical fuels and components that produce the greatest energy efficiency. While many varieties of fuel cells have been demonstrated, one thing they have in common is that they depend on energy that was previously generated – in effect they are just tools for converting one form of energy into another. A fuel cell that consumes hydrogen generated from natural gas, for example, still depletes fossil resources. In other types of fuel cells, the carrier molecules are toxic, or the byproducts produced are harmful. Ideally a fuel cell would derive its energy from a renewable source and avoid unsafe chemicals in the process.
To move toward this goal, there is another way to drive the reactions inside a fuel cell. This not-so-common approach is to use entropy. Entropy is a measure of disorder, and nature favors increasing disorder: it is one of the fundamental laws of thermodynamics.
What did they do?
The authors purchased a commercially available fuel cell, the kind that would ordinarily be used to harvest power from methanol, an energy carrier chemical commonly used in fuel cells. They poured water into the anode side of the cell. The cathode side was exposed to a temperature-controlled stream of air.
In the study, the pH of the water was changed by adding sulfuric acid or sodium hydroxide, and the electrical current and voltage were measured with a multimeter. The pH was adjusted because it affects the rate at which electrons can be harvested by the cell.
What did they find?
The fuel cell was driven by evaporation of water from one end of the cell, “pulling” the chemical reactions forward. This form of entropy powered the cell.
Considering the chemical reactions involved, at one end of the cell, water breaks down to make oxygen, hydrogen ions, and electrons. At the other end of the cell, the oxygen, hydrogen ions and electrons recombine to make water. In other words, the chemical input (water) is the same as the output. The net enthalpy, or heat balance, is zero, because any heat released at one side of the cell would be balanced by an equal absorption of heat at the other side, so release of heat cannot be the driving force for the fuel cell.
However, this fuel cell used two different forms of water: liquid and vapor. Liquid water is fed into the cell and vapor escapes. Vapor is more disordered than liquid, so the entropy increases and the chemical reaction moves forward. The electrons are forced through a circuit in the process, to make electricity.
The researchers found that temperature and pH affected performance. The optimum temperature was 70 degrees celsius (about 160 degree farenheit) and the voltage was highest at pH 11 (about the same pH as household ammonia).
What does it mean?
This paper reports a unique approach in developing fuel cells. It takes advantage of the fact that a chemical reaction can be “downhill” or spontaneous even if no heat is released, as long as there is an increase in entropy.
The fuel cell design reported in this study uses this technique to drive the overall chemical reaction.
Remarkably, the fuel cell setup can be used to generate electricity from water and air, producing just water and oxygen as byproducts. This is extremely attractive compared to hydrogen, methanol or other common fuel cell chemicals that only carry energy that was generated elsewhere. For example, it is possible to derive hydrogen from solar or wind power, but in practice most hydrogen comes from natural gas or oil, and a fuel cell would only be capturing the energy from those non-renewable sources.
In addition, the use of water as the energy source avoids problems of flammability and toxicity. Many existing fuel cell technologies based on liquids have the drawbacks that the fuels, byproducts or sometimes both are very hazardous. For example, methanol fuel cells can produce formaldehyde, a cancer-causing chemical. The authors noted that high pH gave better results; in other words the use of a pH-raising additive like sodium hydroxide would be necessary to give optimum performance. This could be considered a drawback but it might be possible through further research to improve the reaction rate by other means.
Because evaporation of water is critical to the process, the researchers suggested that the technology would be most effective in dry, windy areas.
The main limitation of the water fuel cell is that it needs more space, and materials, to generate the same amount of power as a denser fuel cell. The researchers suggest that the water fuel cell is perhaps 100 times less dense than would be practical for most applications. The performance, though, is similar to fuel cells that produce electricity from microbial activity. The researchers suggest the cell would be adequate to power sensors or wireless transmitters.
Further research on these fuel cells might compare the amount of energy used to construct the fuel cell and its component parts, including membranes and metal catalysts, to the amount of energy that could be generated in the fuel cell’s expected lifetime.
Resources
Demirci, UB. 2010. How green are the chemicals used as liquid fuels in direct liquid-feed fuel cells? Environment International 35:626-631.
Fuel cell basics. Smithsonian Institute.
Fuel Cell Technology Program. U.S. Department of Energy.
Tollefson, J. 2010. Hydrogen vehicles: Fuel of the Future? Nature 464:1262-1264.
2 August High hopes in the search for clean-burning hydrogen. As General Motors gets ready to sell its new Chevrolet Volt plug-in car this year, and with Nissan right behind with its all-electric Leaf hatchback, there’s not a lot of talk about hydrogen fuel-cell cars. Toronto Star, Ontario.
28 July US seeks solar flair for fuels. The US Department of Energy has launched an ‘artificial photosynthesis’ initiative with the ambitious goal of developing, scaling up and ultimately commercializing technologies that directly convert sunlight into hydrogen and other fuels. Nature.
18 July The case of the poisoned fuel cell. Hydrogen fuel cells have their own Achilles’ heel: They are easily poisoned by carbon monoxide. Now, researchers report that they’ve created novel catalysts for fuel cell cars that strongly resist carbon monoxide contamination, potentially solving a problem that has vexed the industry for years. Science.
15 July UK firm B9 eyes hydrogen as gas plant alternative. Britain’s B9 Gas is exploring hydrogen fuel cells as an alternative cheap, low-carbon way to generate electricity instead of burning gas, the clean fossil-fuel company said on Wednesday. Reuters.
10 July UK hydrogen cars are coming – if you can fill up. Britain’s hydrogen fuel cell car fleet may hit top gear within five years, but only if there is enough investment in filling stations, the UK Hydrogen and Fuel Cells Association told Reuters on Friday. Reuters.
Hydrogen fuel cells
Tags: energy, GREEN CHEMISTRY, water
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