Wednesday, June 11, 2008

OutBack Power Systems' New FLEXware PV Combiner Box Delivers Improved Design, Faster Installation

OutBack Power Systems, Inc., a manufacturer of reliable and durable power electronics products for renewable energy applications worldwide, introduced today FLEXware™ Advanced Photovoltaic (PV) Combiner Box, the most recent addition to its standard-setting PV solutions product suite. Developed in response to installer demand for reduced implementation time and assistance in complying with new codes, the new FLEXware PV Combiner Box makes wiring during solar panel installations easier and faster.

"We have built on the foundation of our industry leading PSPV with this latest innovation in balance-of-system components from OutBack Power Systems," said Mark Thomas, CEO/President of OutBack Power Systems. "Our FLEXware PV delivers a marked level of refinement in combiner design which reduces array installation time while maintaining the necessary functionality that installers need in this type of product."

OutBack Power's FLEXware PV Combiner Box refines combiner design for installers of North American off-grid, grid-tie, residential, commercial, and utility PV installations. It is expected to cut installation time with optimized wire routing, which minimizes right angle bends of heavy gauge wire, a uniquely angled negative terminal bus bar design, and an increased number of knockout locations that ensure larger output conductors don't block access to smaller wiring terminals.

The FLEXware PV Combiner Box is ideal for either small or large systems, utilizing the FLEXware PV 8 model, which can hold up to eight 150 VDC rated breakers or up to six 600 VDC rated fuse holders, or the larger FLEXware PV 12 model, which can hold up to twelve 150 VDC rated breakers or up to eight 600 VDC rated fuse holders with either one combined or two separate output circuits. The new FLEXware PV accommodates dual 2/0 AWG output wiring, and includes a removable, tinted flame retardant polycarbonate dead front panel to meet NEC 2008 code compliance for installation, preventing accidental contact with live terminals and components.

The FLEXware PV Combiner Box is built to make expanding PV installations simple with the ability to combine multiple strings of solar panels into one array. And, like all OutBack Power products, the FLEXware PV Combiner Box is encased in a durable, rainproof, UL 3R, powder coated aluminum enclosure to survive in even the most extreme outdoor environments, whether mounted on a wall, pole or even directly on a sloped roof.

Available today, the FLEXware PV Combiner Box can be purchased through our alternative energy distribution channel.

About OutBack Power Systems

OutBack Power Systems manufactures innovative power conversion solutions that leverage solar, wind and hydro resources to provide reliable electric power for the renewable energy, mobile and backup power markets. OutBack Power's engineers have decades of power conversion electronics design and equipment installation experience and share a passion for leading the industry into a new era of performance, ease of use, durability, and standardization. OutBack Power is a privately held corporation located in Arlington, WA USA with a European sales office in Barcelona, Spain. For more information, please visit

Thursday, March 6, 2008

How Will the U.S. Produce 36 Billion Gallons of Biofuel by 2022?

from Worldwatch Institute - Independent research for an environmentally sustainable and socially just society. by Raya Widenoja

The new U.S. Renewable Fuels Standard (RFS), signed into law last month as part of the revised Energy Bill, sets high goals for the U.S. biofuels industry. It calls for the production of 36 billion gallons of biofuels—mainly ethanol and biodiesel—annually by 2022, with 21 billion gallons coming from so-called “advanced biofuels,” which can be produced using a variety of new feedstocks and technologies. Of this, roughly 16 billion gallons is expected to be from “cellulosic biofuels,” derived from plant sources such as trees and grasses.

But are these biofuels targets realistic, and can they be met without serious impacts on the nation’s farmlands, forests, waterways, and rural communities? The answer is complicated, but fortunately the RFS bill contains a few key caveats that can be used to “stop the buildup” if things go wrong.
An Ambitious Mandate

First, for biofuels to qualify for the RFS, they have to meet certain greenhouse gas emissions requirements. Ethanol derived from corn has to achieve at least a 20 percent reduction in lifecycle emissions compared to gasoline, and biodiesel and advanced biofuels have to reduce their emissions by 50 percent compared to the petroleum fuel they would replace. Cellulosic biofuels have to achieve at least 60 percent lower emissions.

Second, the emission reductions have to be based on lifecycle studies—that is, calculations of all the emissions that result from making the fuel, from the field to the tank. Perhaps most importantly, the bill specifies that emissions from changes in land use must be considered—a factor that was not included in most early studies of the climate impact of U.S. biofuels. Land-use changes can have a profound influence on the net climate impact of a biofuel, particularly if the feedstock for the fuel was grown on newly converted land that had been storing large amounts of carbon in its vegetation and undisturbed soils.

Third, the RFS bill states that an administrator should “re-evaluate” conditions annually and adjust the fuel mandate and emissions requirements if the impacts on the land or the economy from increased production end up being higher than the benefits.
Room for Improvement

Although the sustainability requirements in the new RFS are far from perfect, these three caveats at least provide openings to demand more improvements. And there are many improvements that can be made to ensure that biofuels reach their potential for sustainable production.

For example, the latest data on cellulosic ethanol made from switchgrass grown on marginal lands shows that the fuel will achieve emissions reductions of about 94 percent compared to gasoline. So why is the RFS content with only a 60 percent reduction? Why doesn’t it provide producers with an incentive to aim for the 94 percent reductions that the technology promises? Fortunately, as concerned citizens, we do have a lever for demanding higher standards and other improvements, since the new biofuels mandate and emissions requirements must be reviewed regularly.

The next obvious question about the sustainability of the new RFS is why the law allows corn ethanol to keep qualifying up until 2022, with its measly emissions reduction of just 20 percent compared to gasoline? Considering the mounting evidence of the inefficiency of producing ethanol from corn, and of the negative impacts of producing more and more corn, the most obvious answer is that Midwestern politicians want to appease the corn lobby rather than help the United States create a clean and renewable energy supply.
Meeting Long-term Goals

Which brings us back to my original question: How realistic is it that the United States can produce 36 billion gallons of biofuel annually by 2022? The answer depends in large part on the technologies and feedstock used, among other factors. For the sake of simplicity, and because the long-term goal is to use mainly cellulosic technologies, let’s consider whether the country will be able to produce 36 billion gallons using cellulosic biofuel technologies. That gives a better idea of the long-term value of the RFS, and of whether even the proposed 16 billion gallons of cellulosic ethanol is realistic. To further simplify the response, I will use estimates that apply to cellulosic ethanol derived from switchgrass.

Although cellulosic biofuels are still under development, the first commercial projects are expected to start producing in 2009, and researchers know both the theoretical yields and the current actual yields of cellulosic ethanol from switchgrass. Using biochemical methods (hydrolysis and fermentation), each dry ton of switchgrass can in theory yield 111 gallons of ethanol. Using thermochemical processes (gasification, pyrolysis, and deploymerization), the theoretical maximum is 198 gallons. In practice, researchers today estimate getting 100 gallons per dry ton of switchgrass, roughly double the 50 gallons a ton produced in pilot projects just a few years ago.

According to a 2005 government study of the total available biomass in the United States—known as the “billion ton study”—roughly 1.3 billion tons of cellulosic biomass could be harvested sustainably nationwide each year by mid-century. If this 1.3 billion tons were converted to fuel at 50 to 100 gallons a ton, the United States would produce between 65 billion and 130 billion gallons of cellulosic ethanol.

However, the billion-ton study uses aggressive assumptions about crop productivity and the use of residues from agriculture and forestry, which makes it quite likely that its estimate of available biomass for sustainable harvest is too optimistic. Figuring out how much of this billion tons could actually be harvested economically without increasing environmental problems will likely take many more years of research.

Another way to answer the question is to estimate how many acres of switchgrass it would take to hit the 36 billion gallon goal with cellulosic ethanol. Most of the switchgrass grown intentionally in the United States today is in the Conservation Reserve Program (CRP), which encompasses about 34 million acres, a tiny fraction of the country’s total agricultural land. If the average switchgrass yield is 3 tons per acre (as one study suggests, assuming that marginal land is used and that some biomass is left on the fields), and the ethanol is converted at 100 gallons a ton, then 120 million acres will be needed to produce 36 billion gallons of fuel. This is a large amount of land, though, for comparison, it represents only 15 percent of the total U.S. land currently used for grazing livestock.

But if the average feedstock yield is 10 tons an acre, rather than just 3, which could be realistic using a different grass variety or better-managed switchgrass, then only 36 million acres would be needed to meet the RFS. This is still more area than is currently enrolled in the CRP, but it represents only about 5 percent of the land used today for grazing, or 8 percent of the current cropland.
New Battles to Fight

So where does this leave the biofuel critic, or optimist? In no man’s land, as usual. Using 120 million acres for biofuel production is probably not sustainable and would impinge on food and environmental needs. Using 36 million acres sounds better, but if the feedstock is not grown with conservation in mind (i.e., if it degrades rather than enhances the land), then 36 million is far too much as well.

Necessity is the mother of invention, so the best way to make “sustainable biofuels” a reality is to give the inventors (the biofuel producers) precise standards they have to live up to—and to let them decide how to meet the standards. Only then, after all the standards are met, will we be able to accurately calculate the true volume of sustainably produced fuel. Creating clear frameworks to guide biomass “farmers” and biofuel producers will ultimately be more useful than attempting to make global estimates of how much land will be needed to meet our bioenergy goals.

Regulations to keep biofuels from causing more harm than good could include requirements to protect intact ecosystems and restore degraded lands, as well as limitations on chemical inputs like pesticides and inorganic fertilizers. Even just rewarding biofuel producers on the basis of their fuels’ lifecycle GHG emissions would go a long way toward reaching sustainability goals, if these measurements are done well and fairly.

That said, the next sustainability battle in the United States should not be about endorsing the benefits of one fuel over another, but about giving real incentives to the transport sector as a whole to lower its carbon footprint. If automakers had real sustainability incentives, they might direct more energy to developing plug-in hybrids and to using renewable electricity (derived from biomass) to power vehicle batteries. This approach to bioenergy—rather than the production of liquid biofuels—may ultimately be more useful for the transport sector, since more energy per unit of biomass can be captured in biomass electricity systems than in even advanced biofuels used in combustion engines.

However, liquid biofuels certainly have a part to play in bioenergy as well, even if plug-in hybrids become a reality this decade. Now that we have this ambitious RFS, which acknowledges the need to produce biofuels with a small carbon footprint and without causing social or environmental injustices, the next sustainability battles over the fuels should be about getting the law to look beyond the current minimum emissions reduction requirement of 60 percent for cellulosic fuels. Another useful battle will be about phasing out corn ethanol, unless it can meet emission reductions as great as the advanced biofuels. Since corn ethanol has been proven time and again to be the least efficient and least climate-friendly biofuel available, it seems unlikely that this turnaround will occur.

Raya Widenoja, a research associate at the Worldwatch Institute, is the lead author of the joint Worldwatch/Sierra Club report Destination Iowa: Getting to a Sustainable Biofuels Future.

Growing Sustainable Biofuels

Patrick Mazza

Biofuels received a fresh surge of bad publicity with recent publication of two studies in Science that looked at the greenhouse gas releases caused by land use changes connected to biofuels production.

The studies make complex and nuanced statements that were predictably mangled by the press, with headlines easily interpreted as a general condemnation of biofuels. Typical was the New York Times, “Biofuels Deemed a Greenhouse Threat,” The studies were creating new uncertainties even among biofuels supporters and tipping others toward a skeptical position. At very least the studies add to substantial public perception problems facing biofuels.

So it is crucial to line out exactly what the studies say, what they do not say, and what the critics are saying about the studies.


The two studies appeared in the Feb. 7, 2008 of Sciencexpress. The first is by Timothy Searchinger et al, “Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change.” Here is what it says:
• Prior studies “have failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels.”
• The study models an increase in U.S. corn ethanol of 56 billion liters above projected 2016 production levels. This would divert 12.8 million hectares of U.S. corn production to ethanol, bringing 10.8 million hectares of new cropland into cultivation, primarily in Brazil, China, India and the U.S.
• The study assumes that land converted to farming will release 25 percent of its soil carbon, an average of 351 metric tones per hectare.
• Employing a standard GREET model lifecycle analysis which assigns a 20 percent greenhouse gas reduction to corn ethanol compared to gasoline before indirect land use changes, researchers calculated that it would take 167 years to pay back soil carbon losses. Based on this researchers calculate that corn-ethanol would emit double the greenhouse gases of gasoline over the first 30 years after 2016.
• Cellulosic ethanol has far lower net emissions of greenhouse gases. But if switchgrass feedstock crops replace corn, the displacement effect would still require a 52-year carbon payback period.
• The study assumes average corn yields will stay the same. Researchers constructed a more positive scenario in which corn yields increase 20 percent, soil carbon emissions are only half of their estimates, and corn ethanol before land use changes reduces emissions 40 percent compared to gasoline. That scenario would reduce carbon payback time to 34 years.

It is important to specify that the Searchinger study does not say that current corn ethanol production increases greenhouse gases (GHGs). Its findings reflect land use changes tied to an increase in U.S. corn ethanol production approximately six times that of today.


The second study, “Land Clearing and Biofuel Carbon Debt,” by Joseph Fargione et al examines direct impacts of land clearing for biofuels crops. In other words, this is not about displacing food production, but about opening entirely new lands for biofuels feedstock growing. It gives carbon payback times for the following land conversions:
• Southeast Asian tropical rainforest to palm biodiesel – 86 years.
• Southeast Asian peatland rainforest to palm biodiesel – 423 years.
• Brazilian tropical rainforest to soy biodiesel – 319 years.
• Brazilian wooded Cerrado to sugarcane ethanol – 17 years.
• Brazilian grassland Cerrado to soy biodiesel – 37 years.
• US Midwest grassland to corn ethanol – 93 years.
• US Midwest conservation reserve lands to corn ethanol – 48 years.
• US Midwest conservation reserves to cellulosic ethanol – 1 year.
• US marginal croplands to cellulosic ethanol – no carbon payback time.


Key U.S. biofuels lifecycle researchers weighed in with a series of critiques of Searchinger et al. Michael Wang of Argonne National Laboratory, developer of the GREET model, and Zia Haq of the US Department of Energy Biomass Program, gave these responses:
• Searchinger et al “correctly stated that the GREET model includes GHG emissions from direct land use changes associated with corn ethanol production.”
• Argonne and other organizations are already updating their models to reflect indirect land use conversions.
• The corn ethanol growth figures used by Searchinger correlate to 30 billion gallons a year of production by 2015. However, the new federal renewable fuel standard caps corn ethanol production at 15 billion annual gallons. The Searchinger study “examined a corn production case that is not relevant to U.S. corn ethanol production in the next seven years.”
• It is incorrect to assume no growth in corn yields. Yields have increased 800 percent over the past 100 years, and 1.6 percent annually since 1980. They could well gain two percent annually through 2020 and beyond.
• Searchinger does recognize that corn ethanol production also yields produces Distillers Grain and Solubles (DGS) animal feed byproducts but underestimates its protein value. Thus the study lowballs the contribution of coproducts by at least 23 percent, which drives up their estimates of farmland needed to replace feed corn.
• “There has also been no indication that U.S. corn ethanol production has so far caused indirect land use changes in other countries because U.S. corn exports have been maintained at around two billion bushels a year and because U.S. DGS exports have steadily increased in the past 10 years… It remains to be seen whether and how much direct and indirect land use changes will occur as a result of U.S. corn ethanol production.”
• Wang and Haq cite a 2005 Oak Ridge National Laboratory on cellulosic potentials. “With no conversion for cropland in the United States, the study concludes that more than one billion tons of biomass resources are available each year from forest growth an byproducts, crop residues and perennial energy crops on marginal land. In fact, in the same issue of Sciencexpress as the Searchinger at al study is published, Fargione et al show beneficial GHG results for cellulosic ethanol.”

Another critique comes from David Morris of the Institute for Local Self-Reliance:
• “The vast majority of corn that will be grown in 2008 will be on land that has been in corn production for many years, perhaps for generations.”
• Future corn ethanol plants will achieve 2-4 times greater GHG emissions reductions than the GREET model estimates by converting to renewable energy, while future gasoline from unconventional sources such as tar sands will produce 30-70 percent more GHGs.
• No-till cultivation of corn adds 0.4-0.6 tons of soil carbon annually, which “would offset at least part of the carbon losses from bringing new land into production.”
• Of 14 million new acres of U.S. corn cultivation in 2008, 60 percent came from soybeans, 97 percent of which goes into animal feed. Because of the DGS coproduct, only a fraction of an acre of soybeans are needed to replace an acre of corn.
• Even with 14 million acres of increased U.S. corn production in 2008, “the likely overall conclusion is that as of early 2008, ethanol production continues to reduce greenhouse gases.”
• Most land conversion is due to urban and suburban development, are 2.2 million acres per year.


Searchinger et al is a scenario of future ethanol growth rather than an assessment of biofuels use today. The researchers base their scenarios on an assumption virtually all observers believe is unlikely, 30 billion gallons per year of corn ethanol – 15 billion annual gallons is generally regarded as the peak, and that is why it is embodied in the federal fuels standard. The Searchinger study does seem to tend toward more pessimistic conclusions about ethanol efficiency and farm productivity, and is built on modeling assumptions about land use conversion for biofuels rather than observed real world experience. Nonetheless, both Searchinger and Fargione send a strong signal that we must take into account of the whole system by which a new economic sector is created – bioenergy. That has to account for indirect as well as direct land use impacts.

This understanding is already being developed. In fact, while the new studies came as a shock to many, they were no surprise to people who have been working in the sustainable biofuels arena. As a result of advocacy by Natural Resources Defense Council and other green groups, the new federal Renewable Fuels Standard contains greenhouse gas criteria. Corn ethanol must yield a 20 percent reduction. Cellulosic ethanol must reduce emissions 60 percent and other advanced biofuels 50 percent. The latter two represent 21 billion of the annual 36 billion gallon by 2022 standard. The lifecycle studies that measure emissions are mandated by law to include both direct and indirect land use impacts. The Environmental Protection Agency is now conducting those studies, which will be used in rulemaking to adopt the standard. (EPA can reduce goals 10 percent, for instance, corn ethanol to a net 10 percent GHG reduction.)


Contrary to the tone of much of the media coverage, neither of the studies counts out the potential environmental value of biofuels. Fargione’s results for cellulosic ethanol points to highly sustainable biofuels production pathways, though other considerations such as wildlife and water use must be taken into account.

“Degraded and abandoned agricultural lands could be used to grow native perennials for biofuel production which could spare the destruction of native ecosystems and reduce GHG emissions,” they write. “Diverse mixtures of native grasslands perennials growing on degraded soils, particularly mixtures containing both warm season grasses and legumes, have yield advantages over monocultures, provide GHG advantages from high rates of carbon storage in degraded soils, and offer wildlife benefits.”

One of the coauthors, David Tilman of the University of Minnesota, was lead author on a previous Science study (“Carbon-Negative Biofuels from Low-Input High-Diversity Grassland Biomass,” Dec. 8, 2006) which documented the environmental and productivity advantages of diverse perennials. They found that the gain in soil carbon as grasses sink deep roots more than makes up for all greenhouse gas releases in the full bioenergy lifecycle.

Fargione et al found other sustainable feedstock options: “Monocultures of perennial grass and woody species monocultures also offer GHG advantages over food-based crops, especially if sufficiently productive on degraded soils, as can slash and thinnings from sustainable forestry, animal and municipal wastes, and corn stover.”

The Searchinger study also points to sustainable options: “This study highlights the value of biofuels from waste products because they can avoid land use change and its emissions. To avoid land use change altogether, biofuels must use carbon that would reenter the atmosphere without doing useful work that needs to be replaced, for example, municipal waste, crop wastes and fall grass harvests from reserve lands. Algae grown in the desert or feedstock produced on lands that generate little carbon today might also keep land us change emissions low, but the ability to produce biofuels feedstocks abundantly on unproductive lands remains questionable.”

That last point does raise a prospective dilemma – Marginal farmland is marginal typically because it sustains lower productivity, and whether such lands can produce enough biomass per acre to be economically feasible is indeed questionable. But if farmers are financially rewarded for growing soil carbon as well as bioenergy feedstocks, biomass production could be lower. This combined growing of bioenergy and biocarbon might well be what it takes to provide incentives for both.

Today U.S. biofuel production centers on the Midwest, where well above 90 percent of all U.S. biofuels feedstocks are grown in corn fields. The Searchinger study focuses on the impacts of corn ethanol. It would be ironic if the new studies were taken as a signal to shut down biofuels development, since biofuels feedstocks in other U.S. regions will primarily come from sustainable feedstocks identified in the Searchinger and Fargione studies – waste streams, cellulose crops and algaes. For areas that have limited corn production capacity, such as the Northwest, these represent the prime biofuels opportunities. If anything, the new studies indicate a need for accelerated development of these new feedstocks and production technologies to take advantage of them.

Part 2 of “Common Sense on Biofuels” will cover the larger contexts of oil, food, carbon and politics that are shaping biofuels growth.

This is part of a series of articles on Growing Sustainable Biofuels by Climate Solutions Research Director Patrick Mazza, . Send comments to

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(Posted by WorldChanging Team in Energy at 3:53 PM)