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Study evaluates clean energy technologies and declares winners

And the winner is wind! According to a study done by Mark Z. Jacobsen, a professor of civil and environmental engineering at Stanford, wind the cleanest of the "clean energy" technologies. Other winners, in order, are concentrated solar (the use of mirrors to heat a fluid), geothermal, tidal, solar photovoltaics (rooftop solar panels), wave, and hydroelectric. The losers include biofuels, nuclear, and "clean coal," which Jacobsen says are not nearly as clean as currently touted.

Not a huge surprise, but he used an apparently new method:

Jacobson has conducted the first quantitative, scientific evaluation of the proposed, major, energy-related solutions by assessing not only their potential for delivering energy for electricity and vehicles, but also their impacts on global warming, human health, energy security, water supply, space requirements, wildlife, water pollution, reliability and sustainability.

For more information, see:

Review of solutions to global warming, air pollution, and energy security
Wind, Water, and Sun Beat Biofuels, Nuclear, and Coal for Clean Energy
Stanford University Professor - Mark Z Jacobsen

Food Prices

The March/April 2008 issue of Foreign Policy discusses high wheat prices in its FP Quiz. I found the following interesting:

Although the price of gold rose 35 percent and the price of oil skyrocketed 57 percent in 2007, the price of wheat grew a staggering 80 percent during the same period. According to the International Grains Council, a ton of American hard red winter wheat -- the common standard for the price of wheat -- sold for $203 in early January before leaping to $365 by the end of December, thanks to rising demand in developing countries and heavy droughts.

No talk of biofuels? I guess they should talk to Shell Oil. I just wanted to note this because rising food prices involve many factors despite the one sided coverage that likes to insist they are heavily dependent on corn prices.

I would guess another factor is the high price of oil, which drives up transportation costs. And as extreme weather events from global climate change increase in intensity and frequency, food prices will continue to rise regardless of biofuels policy.

This suggests to me that we may want to encourage some sort of change in policy if we are worried about people not being able to afford food. But I'm guessing the concerns for food prices are driven largely by cynical anti-biofuels interests who will go back to ignoring the plight or the poor immediately after their anti-biofuels polices were enacted.

DoC Reports

Rock-Tenn Coverpage

The Minnesota Department of Commerce has two interesting reports on its site in the "What's New" section. One study looks at plug-in hybrid vehicles (PHEVs) and the other is a Green Institute report on the potential of biomass fuels to supply the Rock-Tenn plant with energy.

The "Air Emissions Impacts of Plug-In Hybrid Vehicles in Minnesota's Passenger Fleet" report resulted from legislation calling on the Minnesota Pollution Control Agency (MPCA) "to evaluate the emissions impacts of incorporating PHEVs into the vehicle fleet."

This study models the environmental impacts, specifically criteria pollutant and greenhouse gas emissions, associated with converting portions of all light-duty vehicles operated in Minnesota to PHEVs. We also evaluate the emission consequences of converting the fleet of light-duty vehicles owned or leased by the State of Minnesota to PHEVs. Light-duty vehicles include compact cars, sedans, and station wagons. Emissions are evaluated for 2020. To understand how PHEVs would affect emissions in 2020, a base-case non-PHEV scenario relying on conventional vehicles operating with standard internal combustion engines (ICE) was developed. As an additional alternative to conventional ICE vehicles, a scenario involving pure hybrid electric vehicles (HEVs) was considered.

They examined four future electricity generation scenarios - 100% coal (eek, a bleak future), 80% coal / 20% wind, 60% coal / 40% wind, 100% wind (I'm not sure this is plausible, even in the most blustery days of an autumn with Winney the Pooh).

They also considered different PHEV adoption rates as the cars become available - but if you want to know more about that you'll have to go to the trouble of reading the Executive Summary.

To summarize, generally the use of PHEVs in place of conventional gasoline-driven ICE vehicles will reduce air emissions. The sole exception appears to be SO2 emissions, which rise due to the high sulfur content of coal combusted to generate electricity. The effectiveness of PHEVs depends on the all-electric range capability; a PHEV with a 60 mile range has greater impacts on emissions than a PHEV with a 20 mile range. In comparison to hybrid electric vehicles, PHEVs emit less NOx, VOCs, CO, and particulate matter, but more CO2 and SO2. This results from the high sulfur and carbon content of coal per MMBtu. Depending upon our choices for electricity generation in 2020, it is possible that the impacts on carbon dioxide and sulfur dioxide could change.

No real shock that PHEVs will emit more carbon dioxide than convention hybrids in this region given our reliance on coal. The take home message should be that we need to incentivize low carbon options - from increased miles-per-gallon efficiency to mass transit.

The report on the Rock-Tenn plant is particularly interesting to me - we have discussed it previously and I have a neighbor who works there. The report is "Renewing Rock-Tenn: A Biomass Fuels Assessment for Rock-Tenn's St. Paul Recycled Paper Mill."

The Rock-Tenn St. Paul mill is the largest paper recycling plant in the Upper Midwest, recycling 1,000 tons of paper per day and employing approximately 500 people. It is also one of the largest energy users in the Twin Cities. Since the mid-1980s, Rock-Tenn has received its process steam via pipeline from the Xcel Energy High Bridge coal-fired power plant near downtown St. Paul. The High Bridge plant is closing by the end of 2007, to be replaced by an adjacent natural gas-fired power plant currently under construction. Thus this source of steam will no longer be available, and Rock-Tenn must find another energy source.

I poked through the executive summary and it offers some insight into the modern world of biofuels - what is available, what is reliably available, what will be reliably available for 20 years, and the like.

The solution appears to be a microcosm of the world-wide energy challenge posed by climate change ... they may need an amalgamation of several solutions rather than one (struggling NOT to write "silver bullet") all-encompassing solution.

There are sufficient quantities of biomass fuel sources within 75 to 100 miles of Rock-Tenn to provide all of Rock-Tenn’s energy needs. However, considering current and projected future demand for these sources, no single source of biomass considered in this study could supply all of Rock-Tenn’s long-term fuel needs. The one possible exception is agricultural sources, which could be sufficient if a long-term fuel contract were signed with an entity (or entities) with the necessary capabilities and assets to securely back up a 20-year contract.

The Twin Cities Daily Planet recently covered the Rock-Tenn plant with the background behind the study and where the process goes next.

Decision-making rests with several players. Obviously, Rock-Tenn will decide what kind of fuel to use and whether to keep the plant open. The St. Paul Port Authority, Ramsey County, Washington County and the City of St. Paul are among the public entities whose decisions factor in the process, including decisions on financing and public subsidies. District Energy currently has an agreement with Rock-Tenn to build an energy plant on Rock-Tenn's campus, and can decide either to continue or to end this agreement.

Once the various parties have reached a decision, a proposal would need to be made to the Minnesota Pollution Control Agency (MPCA) with an Environmental Assessment Worksheet. After the MPCA evaluates this worksheet, it will decide whether a full-scale (time-consuming and expensive) Environmental Impact Statement is necessary.

Community input into the process could happen at community meetings to be scheduled in May, and through a citizen advisory committee still under formation.

Bush acts on energy efficiency and renewable energy

The Energy Efficiency and Renewable Energy (EERE) office of the US Department of Energy is reporting today that President Bush signed Executive Order 13423 calling for increased energy efficiency in Federal Government operations and increased usage of energy from renewable sources.

Following are summaries of the directives in the order:

  • Agencies must reduce their energy intensity 3% per year or by 30% by 2015 relative to their 2003 baseline.
  • That at least half of mandated renewable energy use come from newer facilities. Agencies are also encouraged to work to have renewable energy sources constructed on agency property.
  • Agencies must reduce their water usage intensity by 2% annually or by 16% by 2015 relative to their 2003 baseline.
  • Requires increased sustainability in goods purchased and used by agencies. This includes requiring paper have at least 20% recycled content, use of bio-based products, and energy efficiency products.
  • Agencies to improve waste management including increasing recycling, reducing use and disposal of toxic materials, and improved waste handling.
  • Ensure that new buildings comply with the Guiding Principles for Federal Leadership in High Performance and Sustainable Buildings. 15% of all Federal buildings are to meet these guidelines by 2015.
  • The fleets reduce petroleum product usage by 2% annually and increase portion of fuel used that is non-petroleum-based (yes, it says non-petroleum instead of renewable) by 10% per year.
  • Increased use of Energy Star products.

Many of the provisions listed above are mandated by the Energy Policy Act of 2005.

CERTs conference summary

The MN CERTs conference was held on Tuesday and Wednesday this week...


MN CERTs Local Energy / Local Opportunities

Article Photo

On January 17, 2007 the Minnesota Clean Energy Resource Teams (CERTs) held their annual conference, Local Energy/Local Opportunities, in St. Cloud. CERTs is a program that is funded by several state agencies, private foundations and the University of Minnesota. Here is a brief description of the program from the CERTs web site:

“The Clean Energy Resource Team project is your opportunity to play a role in shaping energy conservation and renewable energy implementation for your region of Minnesota. A growing number of Minnesotans envision an energy future built on using energy wisely and generating energy from local renewable resources like wind, solar, biomass, and even hydrogen from renewable sources. By relying more on community-scale renewable energy resources and energy conservation, communities can help prevent pollution and create local economic development opportunities.”



Saying nice things

Though many of us have already heard about this, I thought I would throw up a post anyway, just in case. Yesterday Gov. Pawlenty announced a target for the state of 25 percent renewable electricity by 2025. It basically ups the ante from our current renewable energy objective of 10% by 2015 and adds some teeth in the form of financial penalties for utilities that fail to the requirement. I'm still not clear on how this differs from the renewable energy standard that has come up recently. Business interests support Pawlenty's version - in fact a Minnesota Chamber of Commerce representative is quoted as saying that it is the "best of both worlds" - it avoids possible rate increases of a "mandate" while growing the renewable energy industry in the state. That leads me to believe that either utilities would be prohibited from passing on the penalties to ratepayers or that the penalties are rather mild.

Anyone have any more information?

Regardless, I think this could be a major step forward. I hope that there will be incentives for utilities to go beyond the 25 percent, and that lawmakers won't be prohibited from increasing the percentage in the future.


Farming our Fuel

It has been a busy week this week. I wanted to give a brief update from some things I attended. First, is the Farming our Fuel conference hosted by Minnesota Environmental Initiative (MEI) on the Gustavus Adolphus College campus in St. Peter, MN.

The day long conference (full title is Farming Our Fuel: Growing a Sustainable Ethanol Industry) sought to address the questions: How green is ethanol? What can be changed to maximize environmental benefits AND local economic benefits? What about cellulosic feedstocks? What is the long term role of biofuelsin the State's energy future?

The speakers represented a diverse collection of acedemics, govenment agency reps, environmentalists, and those from the ethanol industry. Conspicuously missing were those representing farming interests. The closest would be a representative from the MN Department of Agriculture and a speaker from the Renewable Fuels Association.

I'll try to give a general gist of what was covered in each session. The only pen I brought died early so perhaps others who were there can leave comments to fill in details. Overall, I think there was a good level of reality and straight talk about the current situation with ethanol and what can/needs to happen in the future.

 The welcoming address and MC duties were handled by Peder Larson. He is an MEI board member and principle in the environmental law practice Peder Larson & Associates, PLC. He was previously Commissioner of the Minnesota Pollution Control Agency (MPCA).

The first session was on the current state of the industry. Bill Lee from the Renewable Fuels Association (RFA) lead off a good recap of the long history of the ethanol industry, the risks experienced by the industry, the role of Minnesota nationally, and the future role of ethanol. The histoy for ethanol as a transportation fuel dates back to the Model T...the first flex fuel vehicle mass produced in the US. The next phase brought failed attemptys to build an economically sustainable ethanol industry after the oil shocks of the 70's. Then there was the era of the "Minnesota Model" based upon small scale, farmer owned ethanol production from the mid-90's to the present. Minnesota's important national role in renewable energy was acknowledged. This ranges from the relatively high availability of E85 and the goal for biofuels to account for at least 20% of transportation fuels in the state (not an E20 mandate as was incorrectly stated several times during the conference) to C-BED and the growth of wind generation to the required used of biodiesel in all diesel sold in the state. The future for the industry involves consolidation, new technology, many more policy efforts and 60 billion gallons of production by 2013. In the first acknowledgement of the limitations of the current production model Lee clearly stated that ethanol production is not now sustainable and it must move toward that. It must move to a low carbon input model involving the use of biomass energy sources in place of fossil fuels (natural gas or coal) and changes in corn agronomy. Myrna Halbach closed out the first session with an over view of the role of the MPCA in regulation of the ethanol industry.

The next session focused on the environmental impacts of ethanol production. Todd Portas from NRG, Janette Brimmer from Minnesota Center for Environmental Advocacy (MCEA), Laurel Reeves from Minnesota Department of Natural Resources (DNR), and Mark Lindquist from The Minnesota Project. This session continued the talk by Habach digging into the regulatory environment around ethanol production and the variations being explored. Most discussed were those using coal to produce process energy and co-location of ethanol plants with electricity generation plants. The latter offers the option for a CHP configuration to provide process energy to the ethanol plant. It also faces a severe regulatory hurdle due to the cumulative impacts assesment complicated by the current emissions of coal plants; particularly those grandfathered under the Clean Air Act. Another favorite topic was water use for ethanol production. This has been of interest due to water availability problems for some of Minnesota's current and planned ethanol plants. Halbach presented a graph in her presentation of the water used per gallon of ethanol at all of the current plants in MN. There is considerable variability in the water used ranging from 3.6 gal/gal to 6.1 gal/gal for plants using corn feedstock. This was explained to be due to technical differences but also due to the quality of groundwater available. Poor quality water heavily laden with minerals requires a higher usage rate and results in additional difficulties in handling. The primary release of water from an ethanol plant is through evaporative losses of non-contact water in the cooling towers. Technology is readily available to stem or eliminate those losses but comes at much higher cost.

Following lunch, the keynote speaker was Maurice Hladik from Iogen Corporation. He talked about a possible future of ethanol production by fermentation of cellulosic feedstocks. Iogen, from Ottawa, Canada, is one of the world leaders in the rush to build the first commercial scale cellulosic ethanol plant. They currently have a site selected in Idaho using ag wastes from wheat and barley production.

The first session after lunch was on the paths toward sustainability of biofuels production. Vernon Eidman, U of M Department of Applied Economics, Cecil Massie, senior process engineer at Sebesta Blomberg, and Jim Kleinschmidt from Institute for Agriculture and Trade Policy were panelists. Dr. Eidman talked about the economics driving ethanol production now and the future. He talked about the strong tie between ethanol price and the price of gasoline. Linking this to the per bushel cost of corn, at a $60/barrel price for crude oil, expansion of ethanol production should increase until corn costs about $4/bushel. He also talked about the cost savings experienced by scaling up from 50 to 100 million gallons per year. It's about 3.5 cents per gallon (David Morris later argues that this gain experienced by the producer is small compared to the loss experienced by farmers and local communities).  Another area of economics covered is the cost savings of using coal for process energy instead of natural gas or biomass. It's understandable why firms are looking at it. I didn't catch all of Cecil Massie's talk but it was one of the few that talked much about the gasification approach to biofuel production instead of the fermentation (sugar platform) approach. I think this will be a very interesting battle down the road between the two technologies. Each have advantages, disadvantages, and their strong supporters and advocates. I hope that our policies do not pick one over the other and let them have a level playing field. Finally, Jim Kleinschmidt talked about the next generation of biofuel feedstocks...i.e. cellulosics. They are a much wider diversity and geographic area of supply. The major types of supplies are crop residues, perennial crops, and forest wastes.

The last session was on the future. The panelists were Gene Hugoson, Commissioner fo the Minnesota Department of Agriculture, Michael Noble from Fresh Energy, and David Morris from Institute for Local Self Reliance (ILSR). I missed much of this section catching up with some folks in the hallway but did catch some disagreement over the scale of production plants and the need to maintain a local based, small scale model previously referred to as the Minnesota Model.

Fossil Free Ethanol?


Renewable Energy Access is reporting that the first closed-loop ethanol plant using manure and methane to distill the ethanol will begin operations next month.  So it's not exactly fossil free since the electricity for the plant and the agricultural inputs for the corn are fossil-based, but it's getting there, i.e. no natural gas for distillation.  They plan to build 15 more plants like it.

An ethanol plant in Luverne reported earlier in the year that it is aiming to be the first cellulistic plant in the US, not by traditional fermentation and distillation methods, but by gasifying corn stover, skipping the whole issue with breaking down cellulose into usable sugars.

Iron Range Biomass Plant

Various news outlets are reporting that the Iron Range Biomass Energy Project is nearing completion and will begin test burns in November:

"Making Biomass a Reality" Mesabi Daily News, 10.30.06

"Bring on Biomass" Hibbing Daily Tribune, 10.31.06

"Iron Range biomass projects unveiled" StarTribune, 10.31.06

The $82 million project with the cities of Virginia and Hibbing has a 20 yr contract with Xcel Energy for 35 megawatts, to fulfill in part, the Biomass Mandate from the Prairie Island Nuclear Power Plant compromise from 1994. Notably, 25% of the fuel must come from closed-loop biomass, aka tree farms specifically grown for this project. The project will also provide district heating for the two cities. Word on the street is that the electricity contract is in excess of 10 cents/kWh.


NYTimes Energy Challenge


Roughly every two weeks, the NY Times has released a new article on various energy topics in what they are dubbing "The Energy Challenge."

Recent Topics:

  • Global Warming
  • Ethanol
  • Nuclear
  • Coal
  • Solar 

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.


Switchgrass Question

My father-in-law (Phillip Rutter) gets credit for this one, but I thought this would be a good forum:

Switchgrass is a perennial prairie grass that has great biofuel potential. However, to be harvested with least harm to the plant, it must dry out. But acres and acres of dry prairie grass = huge fire risk, whether from lightning, idiocy, or arson. Anyone know of any ways to deal with this? Apparently my father-in-law has posed the question to a variety of people-in-the-know and received no satisfying response.

Bioenergy crops on Industrial Brownfields

In the hopes of being able to address two problems at once, researchers have been investigating growing bioenergy crops in brown-fields; areas that are not usable for other purposes without considerable cleanup.  “Right now, brownfields don’t grow anything,” Thelen said. “This may seem like a drop in the bucket, but we’re looking at the possibilities of taking land that isn’t productive and using it to both learn and produce.” They are also investigating whether or not the plants will contribute to remediation of the pollution by taking up contaminants from the soil. While the plants are not going to be eaten I think it is still going to be important to investigate whether or not the contaminants taken up from the soil impact the use of the biomass. The processes used for conversion of biomass to ethanol involve a number of yeasts and enzymes that could be adversely affected by many different compounds. If the biomass is to be burned the concern would be the level of contaminants in the emissions. We certainly don’t want to just be trading soil and groundwater contamination for air contamination.  

Willow for Ethanol

IT Conversations has a podcast about non corn ethanol sources (also not sugar cane). 15 minute interview with Stephen Hall, Chief Executive of Genesis R&D.

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