Read more over at Berkeleyside.

(Photo credit: Anna LaRue)

During the holidays, I spent a couple weeks traveling in Cameroon. It is dry season there, and it is especially dry in the northern part of the country. The riverbeds are bone-dry sand.

Water is so precious that every single leaking water meter I saw had a bucket under it to catch the extra drops. The photo above was taken near a main road in the city of Ngaoundéré. While someone else is paying for the water, none of it is wasted.

Image Credit: Google Green Blog

According to the Google Green Blog, a recently completed project to update the Geothermal Map of North America by SMU Geothemal Laboratory (supported by Google.org), estimates that the technical potential of geothermal energy exceeds 2,980,295 megawatts. More details can be found on the blog here.

Google has also worked to develop this information as a layer in Google Earth. The file can be downloaded from a link towards the bottom of this page. The map shows Enhanced Geothermal Systems (EGS) Potential from depths from 3km to 6.5km and excludes protected lands such as National Parks.

An important note: I am not in any way endorsing EGS. Messing with the Earth at big scales makes me nervous, since we have so little information on the potential impact of our actions. I live in earthquake territory. Also, I read this alarming article in the New York Times a couple years ago. An excerpt:

All seemed to be going well — until Dec. 8, 2006, when the project [in Basel, Switzerland] set off an earthquake, shaking and damaging buildings and terrifying many…

As early as this week, though, an American start-up company, AltaRock Energy, will begin using nearly the same method to drill deep into ground laced with fault lines in an area two hours’ drive north of San Francisco.

…For geothermal energy to be used more widely, engineers need to find a way to draw on the heat at deeper levels percolating in the earth’s core.

Some geothermal advocates believe the method used in Basel, and to be tried in California, could be that breakthrough. But because large earthquakes tend to originate at great depths, breaking rock that far down carries more serious risk, seismologists say. Seismologists have long known that human activities can trigger quakes, but they say the science is not developed enough to say for certain what will or will not set off a major temblor.

It is well worth reading the entire article. And it is well worth remembering that just because it is called “clean” energy does not mean that there are no potential hazards associated with the energy production and use.

This is a lovely video of the San Francisco sky for a year. According to the YouTube description,

A camera installed on the roof of the Exploratorium museum in San Francisco captured an image of the sky every 10 seconds. From these images, I created a mosaic of time-lapse movies, each showing a single day. The days are arranged in chronological order. My intent was to reveal the patterns of light and weather over the course of a year.

More information on the project site: http://www.murphlab.com/ahots

It is also a very clear illustration of how day length changes symmetrically over the year. All of the days are synchronized, starting and ending at the same time. So you can see that some days are much shorter and longer than others, and that sunrise and sunset happen a little earlier or later than the previous one.  The exact times of sunrise and sunset depend on our latitude here in the Bay Area.

So… how does this connect back to resource efficient infrastructure?

Knowledge of the sun’s movement and its position in the sky at any given date and time are fundamental to energy efficient building design and the thermal and visual comfort of the building’s occupants.

THIS POST IS PART OF OUR FRIDAY VIDEO SERIES.

• Blue Roofs
• Photo – The Elevator
• More Tiny Houses!
• Home Energy Improvements
• New LEED Draft Open for Comment
• For The Truly Nerdy – An ASHRAE Download
• 3rd Round of AC Transit Cuts Averted – For Now
• PCL’s 8 Affordable Water Strategies
• Historic Vote by US Building Officials
• 10 American Cities Running Out Of Water?
• Prop. 26 and the Environment
• Regional Bike Sharing in the Bay Area
• Election Day 2010 – Go Vote!

Image from the report appendix

The Union of Concerned Scientists just released a new report on the effect of power plants on freshwater systems.  “One plant had to curtail nighttime operations because the drought had reduced the amount of cool water available to bring down the temperature of water discharged from the plant,” the report says. It quotes Kent Saathoff, a vice president of the Electric Reliability Council of Texas, who said last month, “If we don’t get any rain between now and next summer, there could be several thousand megawatts of generators that won’t have sufficient cooling water to operate next summer” (New York Times Green Blog).  You can read the entire report here.  Sewage overflow is the No. 1 source of pollution for New York’s waterways, says Leif Percifield, a graduate student at the School of Art, Media, and Technology at the Parsons New School of Design… Percifield’s dream is to place simple sensors at each of New York City’s 490 “combined sewer overflow” points. The sensors will be primed to send out text-message notifications every time the city’s drainage maxes out (Grist).  UC Berkeley has begun work in its quest to significantly taper its campuswide water use. The campus is aiming to cut its water usage by over 65 million gallons by 2020 (The Daily Californian).

Earth | Time Lapse View from Space, Fly Over | NASA, ISS from Michael König on Vimeo.

This video is striking for a number of reasons. Earth is so small. And yet you can see city lights all over the place, a sign of how much of an impact we have had on the planet. You can also see flickers of lightning through the clouds.

THIS POST IS PART OF OUR FRIDAY VIDEO SERIES.

photo attribution: CalderOliver at en.wikipedia

Zero Net Energy (ZNE) is a term that is increasingly heard throughout the architecture and building sector, but it is also a term that can mean different things to the different people who use it. This series of posts is an overview of the four common definitions of  ZNE, and a brief expansion on their respective implications in relation to policy structures and physical infrastructure. Part 1 of the post can be found here

The four common definitions of ZNE are: 1. Zero Net Site Energy, 2. Zero Net Source Energy, 3. Zero Net Energy Cost, and 4. Zero Net Energy Emissions. All four of  these calculations are as measured over a calendar year, or on an annual basis. The difference is in the metric (the “thing” being measured) and the boundary (what is included in the calculation). All four definitions can be applied to –and calculated at– a “community” or multiple-building scale as well. In all cases the “net” part refers to how energy is accounted for at the grid level; low energy buildings that are not grid tied would therefore not be under a zero net energy designation.

 Part 2: Zero Net Source Energy

what this is: A source zero net energy building  produces at least as much energy as it uses in a year when accounted for at the source.

what this means: “Source energy” refers to both the energy used by the building and the energy lost in the generation and delivery of the energy to the building. To illustrate the point, think of carrying a bucket of water with a small leak across a room; you then water a plant with it. The ZNE site definition would only be concerned with the water that was applied to the plant; the ZNE source definition would be concerned with both the water that was applied to the plant, and the water that leaked out onto the floor.

pros, cons & considerations:

• A ZNE source definition can be a benefit if one is striving to be extra conscientious about accounting for energy use and could have benefits depending benefits depending on the fuel mix of your building.

further reading:

P. Torcellini et al., Zero Energy Buildings: A Critical Look at the Definition, National Renewable Energy Lab, 2006.

This post is part of our definitions series on “eco-lingo” and technical terms