Alternative energy systems, despite their promise for easing the nation’s dependence on imported oil, are still a solution searching for economic feasibility, says James Wooten, Extension associate, agricultural and biological engineering, at Mississippi State University.
“At this point, with current energy prices, farmers’ best use of money is not in producing power, but in finding ways to better conserve the power they use,” he said at the annual conference of Mississippi Women in Agriculture.
“In the future, who knows? Events in the Mideast or elsewhere could push energy prices up sharply — as we saw with $140 per barrel oil and $4 gas prices a while back — and make these alternatives more feasible.
“But right now, energy from most alternative systems is more expensive than using gasoline, diesel, or electricity to do the same jobs.”
A number of companies and businesses have begun adopting “green energy” systems and techniques, Wooten notes. “These generally cost more than the companies will realize in savings, but they garner a lot of PR value from it.”
One alternative energy system that may be economically practical, he says, is solar water heaters, but even that is a long-term proposition, needing 15 to 20 years for payback on investment.
There is a 30 percent federal tax break that is available until 2016 for purchases of energy-efficient appliances, insulation, doors/windows, and other improvements that could be cost-effective if those appliances or improvements are needed.
Of the alternative energy systems now available, Wooten says, costs are the major drawback. These include:
Photovoltaic (solar) cells: “These typically run $6,000 to $8,000 per kilowatt of energy for a self contained solar system, prohibitively expensive for most residential/farm uses. But, prices are dropping sharply, and some analysts are predicting they could decline 60 percent to 80 percent over the next three to five years, and that solar will eventually become competitive with natural gas.
“China has moved into this market in a big way, and prices may continue downward as production increases.”
While there are some small-scale solar installations for poultry houses, residences, and schools in Mississippi, Wooten says, “I wouldn’t be in any big hurry to get into this until prices come down more.”
Wind turbines: “These systems offer no potential in Mississippi. They require an average wind speed of 15 mph and in our state the average wind speed is less than 1 mph.”
Biodiesel: “These are made with fats and vegetable oils mixed with alcohol and a catalyst. Anybody can make biodiesel — there are all sorts of information kits available on the Internet — but only a few can make good biodiesel.”
And therein lies the rub, Wooten says. “It can have a cleaning effect on engines and result in clogging of oil and fuel filters in older engines. Bad Biodiesel can also be quite corrosive to aluminum engine parts.
“What do you gain if you save a few bucks by making your own biodiesel, but ruin a $20,000 diesel engine?”
Vegetable oils: While the original engine developed by Rudolph Diesel was designed to run on vegetable oil, these oils can cause serious problems of gumming up modern engines if even a small amount of water gets into the system, Wooten says. And they will eventually cause crankcase oil to solidify.
“Quite a bit of work is being done in Germany with vegetable oils, mostly canola,” Wooten says, “but at present, there isn’t much potential here.” Additionally, he notes, new vegetable oil is prohibitively expensive as a fuel.
Ethanol: Production of ethanol, chiefly from corn, skyrocketed during the period of $140 per barrel oil prices and federal mandates for blending ethanol with gasoline.
“Mixtures range anywhere from 5 percent to 85 percent,” Wooten says, “and price is generally the chief influence on how much is used.”
A gallon of ethanol has only about 85 percent of the energy content of gasoline, he notes, and gasoline mileage ratings for autos sold in the U.S. are based on gasoline only.
“In addition to reduced mileage, ethanol can be corrosive to copper and aluminum parts in some situations,” he says. “There have also been numerous reports of problems with ethanol/gasoline blends in two-cycle engines, such as chain saws and WeedEaters.”
Anaerobic digesters: Manures from livestock and poultry operations can be digested to produce methane gas, which can be used to run engines and generating systems.
Some poultry operations in Mississippi are using this method.
One problem, Wooten says, is that ammonia from some manure can corrode engine parts.
Net metering: This allows anyone generating excess electricity from a private system to feed it into a utility company grid and get paid for it.
Many states have net metering laws, Wooten says, but attempts have failed thus far to get legislation passed in Mississippi.
“Some utility companies have got onboard with this, but many oppose it because they say the cost of providing electricity to rural areas is not in the power itself, but in running the lines to those areas.
“At present, Mississippi has some of the cheapest electricity rates in the nation, so net metering isn’t such an attractive proposition economically.”
Biomass: This includes grasses such as switchgrass and giant Miscanthus, corn stover, wheat stubble, wood/forestry wastes, etc.
“Currently, there is little or no market for these,” Wooten says. “A number of companies are trying to get into the business, and if we see sharp increases in energy costs, this could be a big moneymaker for our landowners and tree farmers.”
Much of the U.S. paper industry has moved offshore, he notes, so a lot of pulpwood, wood chips, and forest understory vegetation could be used as feedstock for fuel production.
The cellulosic ethanol production process, converting cellulose from grasses or woody plants to sugar for fermentation for ethanol, is still prohibitively expensive, Wooten says. But again, should energy prices rise sharply, it could become economically feasible.
Handling of biomass also presents challenges, he notes, and researchers are looking at ways to compress materials on site, such as cubing and pelletizing, before moving them to processing plants.
Should farmers grow biomass grasses? “Not yet,” Wooten says. “There’s no commercial demand at this point. But if escalating energy prices make this a profitable industry, there could be huge demand. We see potential for a major biomass industry, fed by farmers.”
For production of switchgrass, giant Miscanthus, and other grasses, he says, “This most likely would be a contract arrangement, with a farmer providing the land and the contractor planting, overseeing, and harvesting the biomass.”
Mississippi State University’s Sustainable Energy Research Center is involved in a number of research efforts for alternative energy, Wooten notes.
“We’re heavily involved in a process that converts wood to bio-oil. This fast pyrolysis process applies heat to biomass, then cools it quickly. The result is a thick, black, nasty liquid that can be burned in furnaces for heat and power.
“The cost is probably around $1 per gallon and is cost competitive with oil at $70 per barrel. We’ve been trying to get a plant established in Mississippi.”
University researchers are also working with gasification systems that partially burn biomass to produce syngas that can be converted directly into gasoline or alcohol that can be refined into gasoline.
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