Geothermal Map of the United States


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, 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.

California’s Clean Energy Future, Part 3


On Tuesday, January 25, I was in the audience at the SPUR Urban Center in San Francisco as Panama Bartholomy, CEC, and Emma Wendt, PG&E, gave presentation about California’s clean energy future.

The post below consists of Part 3 of my record of the presentation –  Emma Wendt’s presentation. All portions are included in chronological order.

An ellipsis (…) indicates that I was not able to capture the words or thoughts skipped. The presentation is transcribed as accurately as possible – punctuation choices are mine. I also added any photos or images.

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Emma Wendt

Most people don’t think of utilities as wanting to do something to address the clean energy future… You might know PG&E through your utility… We’re a really large but really green utility… We’ve won greenest utility in America for the last 2 years… We have a really green portfolio… We have a significant amount of solar interconnected into our system…

… …

What do we mean when we talk about a sustainable electric system?… … The first step in cleaning up the system is to supply green power… On the customer side, you can add rooftop solar and plug-in electric vehicles. But because you have peaks in demand, and an intermittent demand… you need some sort of storage system to make sure demand can always be met by supply… Also need a way for all of this to talk to each other.

On the renewable side, there are a number of ways you can interconnect renewables into our grid… There are a number of programs – California Solar Initiative, Self-Generation Incentive Program, net energy metering, feed-in tariffs, and the renewable auction mechanism, which are hot of the policy presses…

We have a renewables RFO, where we look  at the feasibility of projects … … and PG&E is looking at more options for owning renewables.

So why are we doing all this? … … We do have the renewable portfolio standard…

Another policy hot off the presses is the TREC decision – only allowed to buy out-of-state renewables for up to 25% of our renewables obligation… …

[Showing 2009 electric power mix.] This is what was actually delivered. We don’t yet have final 2010 numbers…

In the future, we have a ton of contracts for new renewable sources. A large part is solar – both solar thermal and solar PV… … You’ll only see a small amount coming from small hydro – basically the rivers that can be dammed are already dammed up… …

PV program hopes to speed up future PV installations… … if you are a developer of small-scale renewables projects, the RFO comes out next week… … On the utility side, we are planning to build more substations… … We want to build solar PV near our substations…

In reality, renewables projects in California don’t always get built. As of the end of 2009, half of our projects were cancelled or significantly delayed… … transmission is causing the most delays, but other barriers are significant – financing, developer inexperience… permitting, technology risks… site control, and the list goes on.. …

PG&E is involved in a statewide initiative called California’s Renewable Energy Transmission Initiative (RETI)… you can’t have clean generation without a way to get it to where the people are. This is a really big problem… …

PG&E customers lead in on-site solar generation… but the best resource is energy efficiency… … PG&E offers a wide range of customer energy efficiency programs… … we also have a program where we work on appliance standards… And we work with retailers… to give them the incentive, then they have control over what they put in front of their customers… …

A cool tool to help customers find out more about EE is also SmartMeters. You may have heard a number of things about SmartMeters… But there is the possibility of seeing what your load is like.

PG&E is also looking at options for plug-in electric vehicle integration… looking at meters for the charging of EVs, and having a separate pricing system… We have a number of partnerships with organizations working on electric vehicles.

… …

We hope that we’ll have a really involved community to help this all move forward.

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This presentation was followed by a question and answer session with the audience.

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Part 1 is posted here. Part 2 is posted here.

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Assorted Links

NRDC rates the USA’s cities on smart energy use and clean energy sources.

Contractors in Montana develop portable housing for $20 per square foot.

CalISO opens market to demand response.

The city of San Francisco launched a website listing products it considers eco-friendlySFapproved. org

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Patch-working the Grid


This Friday’s links highlight a few examples of global progress toward integrating cleaner energy into conventional energy grids.

Image credit: Wikimedia Commons

The New York Times reports on the impressive bump from 17% to nearly 45% renewable-source energy in Portugal’s grid over the past five years. However, the gain in cleaner energy has come at a hefty premium for consumers- take a look at how the Portuguese are balancing it all.

Visit Australia’s Clean Energy Council website and have a look at the interactive map of all clean energy plants over 100kW in operation.

Denmark’s official website cites 12 large scale solar operations in the country that add up to 20% of annual energy demand and offer flexibility within the national grid.

Lastly, read a discussion of progress toward integration of wind energy into European energy grids on the European Wind Energy Association’s website.

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