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Waldsee BioHaus: First certified PassivHaus in North America

Waldsee BioHaus is the new Environmental Living Center in the German Language Village of Waldsee at Concordia Language Villages in Bemidji, Minnesota, U.S.A.

The building is modeled on Germany’s Passivhaus standard: a highly-efficient building design (beyond that of the U.S. LEED standard) which improves quality of life inside the building while using 85% less energy than comparable U.S. structures.

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Report from U of M Renewable Energy Workshop Oct. 12

I attended the Renewable Energy Workshop today sponsored by the U of MN Electrical Engineering Department. As expected, it was largely technology-focused, with some general discussions of the challenges facing renewable energy here and elsewhere. (And a good buffet style lunch). Here a few salient points of the talks I attended.

A Power Grid for the Hydrogen Economy - Thomas Overbye, U of Illinois

The speaker talked about his research into superconducting transmission lines. The idea behind the project is to supplement our existing grid with a network of underground high voltage DC transmission lines made with superconducting material. The benefit of using superconductors is that the current density can be much higher, so fewer transmission lines have to be built. Line losses would also be minimized.

Each line would consist of a superconducting core for carrying the electricity with an outer ring of liquid hydrogen, which would act both as a coolant and an energy storage mechanism. During times of low electricity demand, excess electricity from renewable sources would be used to create the hydrogen via electrolysis.

Though such a grid is technically feasible, cost is a major issue, though the speaker was quick to note that anything transmission related is expensive. He quoted a figure of roughly $2.5 million per mile to install these cables. Water scarcity may also be an issue in some places.

Lessons from Norway - an unlisted speaker, didn't get his name

(A grad student actually did this talk in place of his professor, who was scheduled to speak but couldn't make it.)

This talk mainly focused on the challenges facing Norway in meeting its future electrical demand and making use of its vast renewable energy potential (enough to supply twice that of its current annual consumption.) Currently, 99% of Norway's generation comes from low cost hydropower. However, similar to here, demand is outpacing supply. More supply will have to be brought on in coming years.

I was struck by how similar the challenges facing renewable energy are to here - public resistance (in the case of wind), cost (wind energy is still more significantly more expensive than hydropower), and political uncertainty (will subsidies continue?) Norway is also facing transmission limitations, just like here.Especially of note is that public resistance to wind energy projects has increased in recent years, for all the typical reasons - avian mishaps, other wildlife impacts, and aesthetics.

Planning for Renewable Energy at a MN Utility - Glen Skarbakka, Mgr of Resource Planning, Great River Energy

The speaker talked about the challenges of meeting GRE's rapidly growing load (about 100 MW/year) while incorporating renewables. GRE's load is mostly residential, meaning that demand goes way up in the summer, but varies a lot day to day, depending on weather. This makes it a challenge to use wind energy, which is not dispatchable in the traditional sense (though forecasting has gotten highly accurate.)

I was mostly impressed by GRE's goals to reduce its CO2 emissions to 2000 levels by 2020, as well as doubling its renewable objective of 10%. The speaker admitted that meeting the first will be extremely challenging, to say the least.

Wind Energy - Present Projects and Potential in Minnesota - John Dunlop, American Wind Energy Association

The speaker talked about how wind turbine technology has advanced over the last 20 years and how wind energy continues to grow rapidly in the US and elsewhere. He also provided a nice summary of the recent situation with the Dept of Defense blocking new wind farms due to concerns over radar. The report finally came out on Sept. 27, 143 days late. It didn't really say anything that could not have been written in one day - only that wind farms can interfere with radar. It didn't offer any mitigation measures to help current or future projects move forward. Sounded like a great use of taxpayer dollars.

Update on CapX 2020 - Terry Grove, GRE

The CapX project is an ongoing transmission planning project involving all major utiltiies in Minnesota, planning transmission needs through 2020. I already knew how long this process takes, but the uninitiatied would probably be shocked. Though, there are good reasons it takes this long. The Certificate of Need process for the first group of lines, mainly to improve reliability, alone will take through 2008. Then route permits have to be aquired, which will take through 2010. During this time, lots of meetings are held with city governments, landowners, and other agencies. The proposed Brookings -SE Minnesota line alone will require that 200,000 landowners be notified. This is just a massive undertaking.

From what I've heard, the last round of tranmission construction was an extremely drawn out and painful process. It will be even worse this time around, due to the industry restructuring that has occured since then. Now, independent power producers can bid in new projects to the MISO queue. Most of these projects fail to get off the ground, since banks won't supply the financing until a power purchase agreement is signed - a chicken and egg problem - meaning that planners don't know where new generation will actually be.

Results of Research Funded by NSF, Xcel Energy, and ONR - Ned Mohan, Electrical Engineering, U of MN

Ned gave an overview of renewable energy-related research in the EE department, then talked mainly about a matrix converter his research team developed. The converter can be used with any variable speed generator, including wind turbines and will boost power output by 1.5X of nameplate ratings. This would also eliminate the problem of bearing currents in typical motors, which eventually destroy the bearing and represent a major maintenance headache. Ned also talked about the benefits of using silicon carbide (SiC) in power electronics, which improves device performance by 10-100 times over plain silicon (Si). The cost of SiC continues to fall, making the use of this material more feasible.

Skepticism About Distributed Generation

When one has made a decision to kill a person, even if it will be very difficult to succeed by advancing straight ahead, it will not do to think about doing it in a long, roundabout way. One's heart may slacken, he may miss his chance, and by and large there will be no success. The Way of the Samurai is one of immediacy, and it is best to dash in headlong.

-Ghost Dog: The Way of the Samurai


So Al Gore’s speech at NYU on September 18 got me thinking about Distributed Generation. For those who haven’t read it yet, an archived webcast and the full text can be found here.
It was a terrific speech, by the way, and I could occupy a lot of space praising it, but that wouldn’t be very interesting. After all, you probably liked it too. But it was one issue that got me thinking, and which gave the impetus for this post. What I really want to talk about today is Distributed Generation, or DG. Gore gave voice to some ideas that are very widespread among left-leaning energy advocates, and many of those ideas deserve closer consideration.

I’m using this post to flesh out some of my critiques of the idea of Distributed Generation. Fundamentally, in reference to the quote above, I think DG advocates are setting out to solve the wrong problem. Our problem is not large-station electricity generation, our problem is climate change and energy security. Its my feeling that in dealing with climate change we are likely to deploy carbon-neutral energy technologies using the same large station (or refinery) production and distribution model that we use right now.

Wikipedia describes DG thus:

Distributed generation is a new trend in the generation of heat and electrical power. The Distributed Energy Resources (DER) concept permits "consumers" who are generating heat or electricity for their own needs (like in hydrogen stations and microgeneration) to send surplus electrical power back into the power grid - also known as net metering - or share excess heat via a distributed heating grid.

 Here’s what Gore says on the subject.

Today, our nation faces threats very different from those we countered during the Cold War. We worry today that terrorists might try to inflict great damage on America’s energy infrastructure by attacking a single vulnerable part of the oil distribution or electricity distribution network. So, taking a page from the early pioneers of ARPANET, we should develop a distributed electricity and liquid fuels distribution network that is less dependent on large coal-fired generating plants and vulnerable oil ports and refineries.

 So the main point of DG is that we rely more and more on homes and businesses producing their own electricity, and possibly selling electricity onto the grid and less and less on large station power generation (how we, by and large, do things now). Gore extends DG to include distributed (presumably somewhat larger scale) biofuels production as well. The main arguments are security (Gore’s argument), greater energy efficiency through the use of combined heat and power, and economic/self-reliance benefits (producing your own power, yeah!).

I think a lot of DG advocates miss some glaring problems.

DG and Economies of Scale

One problem with DG is that it would rely on small-scale power generation. This is actually put forward as one of the main BENEFITS of DG by many advocates. What these advocates miss is that the economics of energy production are absolutely dominated by economies of scale.

Let’s use wind as an example. A 1MW turbine produces cheaper electricity than a 200 KW turbine. And a large scale project produces cheaper electricity than a small scale project. The reasons for this are fairly intuitive. There are a lot of fixed costs that must be paid whether you’re building a large project or a small project – feasibility studies, wind measurement, planning, running around securing financing and power purchase agreements, paying to secure all of the cement manufacturing capacity in your county to pour the bases for the towers, etc. A larger project produces more kWhs, and the fixed costs can be divided over more kWhs, making the levelized cost of power cheaper.

But if you don’t believe me, you can use NREL’s online Wind Energy Finance Calculator.

To prove my point, I calculated the real levelized cost of energy for a 500 kW project (small), and for a 100 MW project (200 times bigger). I used all of the default assumptions, and only changed the size of the project.

Small (500 kW) real LCOE – 64 cents/kWh

Large (100 MW) real LCOE – 1.29 cents/kWh

So the electricity from the small-scale project is about 60 times more expensive, give or take. Its also about 6 times more expensive than retail grid electricity at about 7 cents/kWh. So in asking people to adopt small-scale distributed wind, we’re asking them to pay a LOT more for electricity than they would pay for grid electricity. Note also that, according to this calculator, a large scale project sells electricity that’s probably cheaper than even WHOLESALE electricity.

Economies of scale differ for various energy technologies, but are almost always a factor. The optimal size for pulverized coal plants, for example, is on the order of 1000 MW or larger. Gas turbines burning natural gas or fuel oil have low capital cost, and are therefore more economical at small scale. But because the levelized cost is more expensive then large station power, and they can be quickly ramped up and down, they are typically used only for peaking power.

Solar power is also cheaper at scale. Home or business scale photovoltaic panels produce electricity at around 20 cents/kWh (around 3 times higher than retail electricity). Only large-scale concentrating solar can produce electricity at anywhere near retail rates.

I could go on and on. The fact is that I can’t point to a DG technology that delivers electricity at a rate that is cheaper than, or even close to, the cost of grid power.

Economies of scale aren’t going away. If we have a limited amount of money to spend, as a society, on dealing with climate solutions, the cost of individual solutions must be a factor. Until we see the new cheap solar panels or fuel cells that we constantly hear are 6 months away (how’s that for a “Friedman”?) may not be able to afford the deployment of DG on a large scale.

Giving Up our Great Renewable Energy Resources

Another damning aspect of DG is that it may mean giving up most of our greatest renewable energy resources. Renewable energy resources like wind, solar, and biomass are not uniformly abundant around the nation. And, unfortunately, many of the best resources fall far from population centers. To stick with the wind example, taking advantage of the vast wind resource of the Great Plains likely means building large transmission lines connecting the wind resource with the potential users of that wind energy (or building large hydrogen pipelines, or building infrastructure for some other energy carrier).

This is true for biomass as well. In urban areas, where most energy is used and most people live, there are serious limits on the potential biomass supply. Take the Twin Cities as an example. There is a famous district heat project in St. Paul (District Energy) that has recently switched from coal to biomass as an energy source. Other projects are being planning, including Rock Ten and the south Minneapolis project formerly run by the Green Institute. Those projects are reportedly having great challenges in finding a sufficient supply of biomass because District Energy has secured much of the available supply of urban wood trimmings and the like. So we’re reaching the limited of the DG biomass potential in the Twin Cities, and supplying only a small fraction of the metro area’s biomass needs.

Utilizing the country’s biomass supply on a large scale probably means having projects in rural areas – with cheap land, fertile soil, and lots of biomass, and transporting products like cellulosic ethanol to demand centers. This will likely be wonderful for rural areas, but its not DG.

Solar energy may one day be an exception to this, but right now economics and the efficiency of panels stand in the way.


My point is not to argue that DG shouldn't be done. I think there are many niche applications for DG. In rural areas and small rural communities, for example, there will be applications for Distributed Generation from renewables, possible in combination with combined heat and power. I know some people who are very excited about their rooftop solar panels, and they don't really care that they're paying a lot for the electricity. I also think that there are credible scenarios under which DG could play a larger role in our energy system, provided there are some really fundamental technological innovations. I think that the vision of mass-produced, highly efficient, renewable DG technology, similar to Personal Computers, is pretty exciting to contemplate. But lets not fool ourselves. This kind of thing is a ways off, whereas there are a variety of large-scale carbon-neutral technologies that are commercial or near commercial and could be deployed over a relatively short time frame.

There are many energy advocates who feel that large station electricity generation is bad by its very nature. There are some who offer DG as an alternative, and even use the DG alternative as a rationale for fighting new transmission and new large energy projects. In the MN legislature last year there was infighting between those who wanted only community, small-scale wind development and those who wanted 20% renewable energy standard which would require a lot of large-scale projects.

All that said, I think that macro-scale analysis of power generation technologies, resources, and demands, will reveal that DG is likely to play a small role in the near term. DG can't be used as an excuse to fight large carbon neutral energy projects.

I welcome comments, and hope this starts some discussion.


Carbon-Free Processing

Computers are responsible for much electricity demand. Slashdot is reporting that one manufacturer is offering a greener chip. It requires very little energy to run and comes as part of a program that will offset the greenhouse emissions used to run the chip from a variety of programs.

Will this remain a niche market or are we going to start seeing all products come with options to reduce the carbon footprint of owning it? Would this be the energy equivalent of forcing fast food companies to dispose of the burger wrapper when you finish eating it?

Given the low cost of offsetting carbon emissions right now this could help at a low cost. However, it would not require us to rethink how we live our lives and how we could be more efficient.

Metro Transit Greens

Green Car Congress noted Pawlenty's announcement of 150 new hybrid buses and B10 next year.

Metro Transit is retiring some 300 buses. Half of the replacement buses will be hybrid and the rest are supposedly the cleanest diesel burning models available.

The time frame is over the next 5 years. The hybrid buses are 22% more efficient and have 50% less exhaust.

Helpful back-of-the-envelope fact:

Metro Transit consumes and supplies about 10 million gallons of diesel fuel each year.

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