Tag Archives: energy

A profile of Freiburg, Germany

A good short profile of the city of Freiburg, Germany, and their many sustainability initiatives. Freiburg is a little more than double Boulder’s size — both in population and area, so it has a similar average population density. It’s also a university town with a strong tech sector locally. The whole city was re-built post WWII, but they chose to build it along the same lines as the old city, with a dense core, and well defined boundaries. Today about half of daily trips are done by foot or on bike, with another 20% on public transit. They have a local energy efficiency finance program, on top of the national one administered by KfW, and higher building efficiency standards than Germany as a whole. Half their electricity comes from combined heat and power facilities that also provide district heating and hot water. It seems like they’d be a good model city to compare Boulder to, and learn from.

Enhanced Geothermal Systems promise dispatchable zero carbon power

Icelandic Geothermal Power Plant by Scott Ableman at Flickr

Geothermal energy is the Earth’s own internal heat. It’s a huge potential resource, but so far it’s seen only very limited use. Traditional geothermal power can only work where there are naturally existing hydrothermal systems that bring the heat of the interior to the surface. A new technique called enhanced (or engineered) geothermal systems (EGS) may make geothermal power much more widely available. If it can be scaled up commercially, EGS will enable us to create hydrothermal systems anywhere there’s hot rock not too deeply buried — which includes a large swath of Colorado. This is potentially significant in the context of creating a zero-carbon electrical system because like hydroelectricity, and unlike wind and solar, geothermal power can be dispatchable: you can turn it on and off at will. This makes it a great complement to intermittent renewable power, as it can be used to fill in the gaps then the wind’s not blowing or the sun’s not shining.  It remains to be seen whether it’s technically feasible, and if so at what price, and on what timeline, but it’s certainly worth investigating.

Continue reading Enhanced Geothermal Systems promise dispatchable zero carbon power

Passive Passion a short film about Germany’s Passivhaus Building Energy Efficiency Standard

A beautifully finished Passivhaus building in Dresden, Germany.  With all the PV on the roof, this is almost certainly a net positive energy building.
A beautifully finished Passivhaus building in Dresden, Germany. With all the PV and solar-thermal on the roof, this is almost certainly a net positive energy building.

Passive Passion is a good 20 minute long film introduction to the German Passivhaus energy efficiency standard, which reduces building energy use by 80-95% (depending on what existing code you compare it to).  It looks at the roots of the design standard in Germany, and gives a few examples from the tens of thousands of Passivhaus certified buildings in Europe, including single family homes, row houses, apartment buildings, public low income housing, and office buildings.  They talk about what makes the standard work: airtight building envelopes, super insulation, no thermal bridging, heat recovering ventilation.  The film also looks at a few builders and designers in the US trying to popularize the cost effective implementation of these methods. It’s clearly possible.  The examples are out there today.  We just have to decide to do it!  If we’re going to get to carbon zero, someday our buildings will all have to function something like this.

The film can be viewed online thanks to the enlightened self interest of Four Seven Five, a high performance building components supplier in New York.

ALEC attacking renewable energy standards nationwide

The American Legislative Exchange Council (ALEC) is at it again, trying to roll back state renewable energy standards nationwide.  The argument behind their model bill, entitled the Electricity Freedom Act, is that renewable energy is simply too expensive.  The Skeptical Science blog offers a good short debunking of this claim, based on the cost of electricity in states with aggressive renewable energy goals, and how those costs have changed over the last decade.  And this is before any social cost of carbon or other more traditional pollutants is incorporated into the price of fossil fuel based electricity.

US States with renewable portfolio standards or binding goals.

Their summary:

  • States with a larger proportion of renewable electricity generation do not have detectably higher electric rates.
  • Deploying renewable energy sources has not caused electricity prices to increase in those states any faster than in states which continue to rely on fossil fuels.
  • Although renewable sources receive larger direct government subsidies per unit of electricity generation, fossil fuels receive larger net subsidies, and have received far higher total historical subsidies.
  • When including indirect subsidies such as the social cost of carbon via climate change, fossil fuels are far more heavily subsidized than renewable energy.
  • Therefore, transitioning to renewable energy sources, including with renewable electricity standards, has not caused significant electricity rate increases, and overall will likely save money as compared to continuing to rely on fossil fuels, particularly expensive coal.

But really, go read the entire post for more detail.