Porous Paving

Why use porous pavement instead of regular concrete or asphalt?
- allows more land area to absorb water
- reduces runoff into storm drains by creating a larger reservoir for storm water
- this reduces the risk of flooding or overflowing of drainage networks
- reduces the cost of maintaining storm water infrastructure such as drains and retention ponds

By paving with this new type of aggregate, the adverse effects of blocking off so much land which would naturally filter water and create a groundwater reservoir would be alleviated. Instead of increasing runoff when it rains, the pavement will help draw down water into the ground, which will recharge groundwater reserves in the form of aquifers. Toxins which would normally be found in the runoff and added directly to streams will be eliminated by natural filtration through the ground. This will ensure a more reliable supply of water for future generations who live in the area. The health of the ecosystems around the area will also increase, including the vegetation bordering any roads which will receive a more gradual supply of water from the broader infiltration area. Since groundwater serves as the fresh water supply for most areas around the globe, this is a very important feature for our future habitation of many areas of the world.

The porous pavement also has the benefit of maintaining cooler temperatures in the paving areas and in surrounding streams where water normally heated after pooling on the pavement would drain to. It has the potential to reduce the "urban heat island effect" and the increased heath of surrounding plants can also reduce the heat normally radiating from paved areas. Since some of these systems include planted turf as the top layer, and help surrounding vegetation grow, it could be considered that the pavement helps reduce our carbon footprint by absorbing CO2.

There are a few requirements for the area however. The soil type must be able to drain at least a certain amount of water or it will still pool up and possibly harm the structure of the porous pavement. A few different types of porous pavements and what they consist of can be found here. Because the system has multiple layers, it must be deeper and more carefully engineered than any average road. There is also some maintenance requirements, which are not present for normal paving, that differ depending on the type of paving used. We can all do our part in reducing the damage done by normal paving by using simple methods of porous paving in our own driveways. This may be as simple as using crushed stone or seashells which do not hinder water percolation as normal asphalt driveways do.

A little solar powered wind

Today I was walking through a small earth day festival in my town and noticed an interesting looking fan. This fan, as it turns out, is installed into the attic of houses and pushed air out of the attic. What's so cool or even environmentally relevant about this? This fan is capable of reducing your electric bill in the summer, and it's solar powered! Since I just attended a lecture on solar power panels this past week I thought it was an interesting, smaller, and more cost efficient alternative to large panels which generate electricity but are costly to install.

The benefit to these fans is that they circulate air within the attic with the combined help of either a soffit or a gable vent, diagrams of which can be seen at the bottom of this page. The idea is that the vents allow air from the outside to enter, and the solar powered fan pulls the air that heats up in the attic out of the house. The fan is capable of moving air at a rate of 800 to 1200 cfm (cubic feet per minute). This prevents the air in your attic from reaching extremely high temperatures that are caused by the attic's stagnant air collecting heat from the sun heating the hot roof and keeping it insulated in there. This stagnant air collects and begins to radiate heat into the rest of the home. It also prevents the hot air in the rest of the home from rising up and radiate into the attic, and from there out of the house.

By circulating the air and keeping the attic and the house cooler, it reduces the need for energy on the airconditioning unit. Since this is one of the major energy consumers in the home during the summer, it will make a but impact on reducing cost. This reductiong is only possible because of the solar panel that comes attached to the fan. The unit is therefore not connected to the rest of the wiring of the house. The benefit of the fan being solar powered is that it operates during the highest concentrations of sun light. Since the highest need for cooling occurs when the sun is at its height, this system works out amazingly because it works it's hardest when it is needed the most.

One downfall is that it does cost slightly more than electrical systems according to one site, but if you consider the savings and that it doesn't have to have the extra connection to the electrical system, then it works out in the end to be more economical. The system to be very simple to install compared to other solar powered or electrical systems. There is also the advantage that this can be installed into any type of home with an attic. At the festival one woman was interested in installing one into her Victorian home. This therefore seems like a great way to retrofit a home to be more environmentally friendly and sustainable with minimal additions so that the character of the home is maintained.

Passive Solar and Light In Earth-Sheltered Housing

I've been reading a lot lately about this earth-sheltered housing phenomenon, but some people still remain skeptical about the potential "basement-like" feeling of living partially underground. This is understandable, considering most of the homes are enclosed on 3 sides. If you are lucky enough to own land on a south facing slope, however, or if you have an area where you are able to pick the direction of your home, then you can utilize passive solar energy and avoid that "basement" feeling

If the house is built to properly maximize its solar potential, then it will have an elongated layout, with all bedrooms and living areas to the front of the home where the windows are located, and all of the bathrooms, storage areas, and utility rooms toward the rear of the home because no windows are necessary. In south facing homes this allows the maximum amount of light to penetrate the home, even in the middle of winter. This light also has the benefit of warming the home in the winter, with the assistance of an absorber and a thermal mass to hold the heat inside the home. In the summer this is controlled by an overhanging roof, as discussed previously.

Back to the original topic; lighting. These homes can actually have more light than a conventional home without any lighting fixtures. Many of these houses are constructed with domed or cathedral ceilings and light colored paint. This allows the light that enters the room to bounce off all of the curved and angled surfaces, scattering the light and illuminating the would-be dark space. The homes may also be built with skylights which allow sunlight access to the rear regions of the home. A fairly large example of this can be seem here.

Earth-sheltered homes therefore utilize solar energy in two major ways which cut down on energy consumption. They use passive solar energy to heat the home in the winter. This is accomplished through direct gain through the windows, and through indirect gain from the earth around the home. The summer sun warms up the earth around the home and slowly releases it into the home as the winter wears on. The light from the sun is also used to light the house which prevents the need for lighting in the rooms with windows during the day.

We need to begin to use more of these qualities from the earth and sun which are all renewable sources of energy, or at least reduce our need for it. It may be able to cut down on our impact on the world enough to save it from being irreversibly damaged.

Solutions for Space and Rural Area Housing

So a little more on these underground homes. Gideon Golany has researched different types of homes using earth-sheltered technology around the world. Many of his study areas have been focused in rural regions with little to no advanced technology available for constructing energy efficient homes. Some of these regions are also greatly lacking in construction materials, such as some arid regions in Tunisia, and some are just generally lacking in space due to over crowding, such as China. A list and preview of some of his books and papers can be found here.

Golany traveled to many of these areas to study the efficiency of maintaining temperatures for comfort and how they can save space in overcrowded regions. Many of these building techniques have been taken from ancient housing designs from each region. These can teach us a lot about how to use passive practices to maintain a comfortable environment inside our homes. This could reduce our impact on the environment.

Golany's studies in China tested the efficiency of two typed of homes. In the rural regions he tested, he found that completely underground dwellings radiating from a central courtyard were less efficient than dwellings located in the cliff face. This is because the air in the courtyard dwellings becomes stagnant. It heats up to uncomfortable temperatures in the summer and becomes cold because of a lack of sun penetrating the courtyard in the winter. This problem with stagnant air does not exist in the cliff side dwellings because air circulates much more readily past the front face of a dwelling.

This is important for more technologically advanced earth-sheltered homes as well. Ventilation is very important for these houses, because they are only exposed on one side. For the more natural houses it is an important factor in maintaining a comfortable temperature and preventing a stagnant feel inside the home. Various ventilation systems can maintain a comfortable atmosphere within advanced earth-sheltered dwellings and normal air conditioning systems may also be used to maintain the small comfort window down to an exact cue. These systems, as discussed earlier, may be much smaller, and therefore less expensive than those meant for conventional homes.

Mole Men in Our Future?

Have you ever considered living underground? Well, not completely underground necessarily, but in an earth-sheltered home? I've been dreaming about the day when I could live in one of these unique houses of my very own. But before that happens, is it really worth it?

There are a number of benefits to owning an earth-sheltered home, such as reduced heating bills, environmentally friendly living, and no great loss of yard space! One company, Earth Sheltered Technology, Inc., offers a list of benefits to owning an earth-sheltered home, as well as some designs and frequently asked questions.

The main selling point of the houses for me is their efficiency of heat use. The company claims that their houses are up to 80% more efficient than standard home. This of course means that many of their homes are less efficient than this, since that is the maximum efficiency. Because of this efficiency, however, you would need a system that was only about 1/4th the power of a normal heating system. You could also then combine this with newer, energy efficient technology, such as geothermal, passive solar, and efficient light bulbs such as LED (expensive but the most efficient for now).

If you were to build the house with the windows facing south and with an over hanging roof, it will be warmed in the winter when the sun is lower in the sky and be more shaded in the summer when the sun is higher. All these little things have the potential to greatly reduce energy bills and make an earth-sheltered home even more sustainable.

Follow up

Here is Speaker Pelosi thanking Power Shifters for their lobbying efforts and accomplishments.

Power Shift

Over the past weekend I attended a conference, along with 10,000 other young people, called Power Shift. This was a great experience for me and I would like to encourage anyone interested in environmental and sustainability issues to go next year. There were a number of panels and workshops presented by leading researchers, entrepreneurs, and leaders in many fields concerning sustainable power and how to achieve it.

This was a great experience that allowed me to learn a little bit more about different methods of combating the energy crisis. Many of the forums focused on our dependence on oil or on new energy sources, such as wind, geothermal, and solar. One of the forums I attended looked at making buildings more energy efficient. This one was especially informative and covered everything from what types of insulation work best in new buildings to how to go through old buildings and find ways to improve their energy efficiency with minor upgrades.

One work in progress that one of the panelists mentioned was a water heater, for any sort of building, that would use the heat normally lost from the hot water holding tank to reheat the water in loop. This would greatly reduce loss of energy from the hot water and recycle it for more efficient water heating. The panelist mentioned that it has the potential to take the water heating bill for a normal family home from about $75 down to about $16 a month.

Other more simple updates can be made to your home or the places you work, such as using more energy efficient light bulbs and eliminating "decorative" lighting fixture. Replacing old windows with new, more insulating ones is also becoming a popular investment. These methods are especially important for old buildings that cannot handle major renovations, but that have e tendency to drain power and have high energy bills.

Consider going though your home or office and looking for minor upgrades that will help us all in the long run.