Oct 2012

Life Outside the City Limits

Collage of October Images
Solar Photovoltaic (PV) Economics in Nebraska- "Doing the Math"
By Alexi Brown, 2012 UNL Extension Energy Intern

Ensuring your solar PV systems is an economically sound choice will be one of the most important considerations when deciding on solar energy. You should view your solar PV system as an investment. This decision should be made after determining the feasibility of installing a solar system at a specific site.

Determing Costs and Payback Period

After talking to a solar array installer you will know the total cost of solar panels, mounting system, and installation. You should also check your electrical provider's cost per kilowatt-hour consumed. After you know all this information, it is best to determine the payback period for the solar system. A payback period is the length of time required to cover the cost of an investment. Here is an equation that can be used to help determine the payback period for your specific solar system.

Simple Payback Period = Cost of Project
(Annual produced kilowatt -hours) x (Grid price per kilowatt hour)

Image of Solar PanelsNet Present Value and Return on Investment
However, a simple payback period does not take into account the time value of money and does not measure profitability. Nor does it include the calculations for price inflation. For these reasons it is also important to compute the net present value and internal rate of return for your investment.

Net present value compares the difference between present cash outflows and present cash inflows essentially comparing the value of the dollar today and in the future. Internal rate of return is the rate of growth a project is supposed to generate. These can be calculated with Microsoft Excel or with online financial calculators. The mathematical equations are not shown in this document as a key factor in the equation is a changing given based on time and interest rates.

Such factors as the price of electricity per kilowatt-hour and its inflation rate will play a large role in the pay back period of a solar PV system. One key example of this is the system size with regard to net metering. When building a system, you are able to size it according to your electrical usage. Sizing refers to how large you build the system based on how many kilowatt-hours of electricity it can produce. This means that if you under-size your system you will be using all of the electricity it produces plus electricity from the grid to meet your electrical needs, transversely if your system is larger than the electrical load that you use you will be putting electricity back onto the grid. This is important to understand because the electricity you put back on the grid may be sold to the utility company only for a "wholesale price" while the amount of electricity you produce and use to offset your electrical bill is priced at its "retail value."

Along with financial equations, state and national economic incentives can play a large role in the feasibility of installing a solar system. Federal incentives available to all solar PV installations (and many other renewable systems) include a 30% tax credit the year of installation. In Nebraska, incentives such as net metering and low interest loans are available. Qualifying farms and rural businesses may also have grants available through USDA. To learn more specifics or gain knowledge on other states' incentive programs visit DSIRE, the Database of State Incentives for Renewables and Efficiency.

Example of the Economic Factors Presented Above

A 10 kW solar PV system is created for $4 per watt installed. The figures below show its estimated energy out put, simple payback period, internal rate of return, and net present value for the 30 years of projected life.


  • Price of Electricity: $.0931/kWh
  • Standard Net Metering applies
  • Electric load exceeds system size load (if load is greater than production, most or all of electricity produced by solar systems gets used or credited at full retail rate)
  • Electricity production is estimated at 15,000 kWh per year. (Use only solar estimates or materials from the panel manufacturer to calculate estimated production.) One simple method which works for many Midwest sites- Multiply solar array rating (kW) x 6 hours a day x 365 days a year x 70%. The 70% takes into account system efficiencies. For our example this would give 15,330 kWh per year.

Installation Cost: 10,000 W x $4/W = $40,000
Annual Offset Electrical Cost: $.0931/kWh x 15,000 kWh = $1,396

Simple Payback
$40,000/$1,396 = 28.6 years simple payback period
Internal Rate of Return: 0.2%
Net Present Value: -$24,482

Payback Including Incentives
USDA Renewable Energy for America Program - 25% grant (must be farm, ranch, or rural business to qualify)
Federal Tax Credit - 30%
$40,000 x 25% = $10,000 leaving $30,000
$30,000 x 30% = $9,000 leaving $21,000
$21,000 / $1,396 = 15 year simple payback

Payback Including Incentives and Inflation
Assuming a 4% annual increase in electricity costs yields a payback of just over 11 years
Internal Rate of Return: 9.0%
Net Present Value: -$1,951

Websites with financial calculators


Net Metering

It is becoming increasingly economical to produce your own solar electricity. Once a solar array is properly installed and wired, the electricity produced is free to the owner. Excess electricity may also be sold back to the grid (local power company) for profit or to offset electrical bills during other times.

Federal law ensures small renewable systems are allowed to connect to the grid. States and electrical utilities each have different policies on how the excess power is bought and sold. Net metering is a policy where the "net" electricity usage is used to calculate a bill at the end of the billing period. In the case of net metering electricity put on the grid goes to offset electricity used from the grid at other times during the same billing period.

For example your solar array produces electricity while you are not home (and thus not using power) the electricity flows to the grid. When you return you use electricity, your bill at the end of the month will represent the "net" amount referring to how much you used minus how much you produced.

In the case of Nebraska's Net Metering Law (LB 436 passed in 2009) the bill is totaled at the end of each month. If the renewable system produced more than was used the excess energy is purchased by the utility at wholesale rate (usually much lower than retail). Each Nebraska Utility sets their own rate for purchasing the excess.

Other states allow the excess to roll over each month only totaling at the end of each year. This annual system allows for balance between a solar systems high production in the summer and lower in winter. Allowing any net metering is a benefit to renewable energy systems, the annual type is of greater value to the system owner due to the seasonal differences in production and usage of electricity, and the ability to bank credits from a time of year where more energy is produces to times when more energy is used.

In Nebraska's system of monthly net metering it is of greater benefit to undersize a system with respect to the load. Undersized systems will generally have most or all of the energy they produce used or offsetting retail priced electricity.

Alexi is currently a Senior Environmental Economics Major at the University of Nebraska- Lincoln.




This month features caring for goats, soil testing, and chainsaw safety.

Sara Ellicott, University of Nebraska Extension Educator, explains how to trim your goats hooves.


Fall is a perfect time to collect soil samples.  Get the "dirt" on how to collect a soil sample from P. Allen Smith. Find the Nebraska soil testing lab nearest you.


Next, UNL Extension Educator John Fech takes a look at the results of a soil test and gives us tips about what you can do to correct the pH in your soil.


Review the main points of chainsaw safety with Jeff Culberston, UNL Landscaping.


 Next, Jeff Culbertson demonstrates cutting a small tree, so you can see chainsaw safety in action.

Ultraviolet Light for Water Disinfection
By Sharon Skipton, UNL Extension Water Quality Educator

Image of alternate faucet for drinking waterUltraviolet (UV) light has been used to disinfect water supplies for more than 75 years, but only recently have home UV systems and portable UV systems become available. UV devices for the home may either be point-of-use or point-of-entry. Small, portable UV devices are available for backpacking and other similar use.

UV systems expose water to the light from a special lamp. The light is at a specific wavelength capable of killing bacteria. There is a limit to the numbers of bacteria that can be treated with UV. An upper limit for UV disinfection is 1,000 total coliforms per 100 milliliters or 100 fecal coliforms per 100 milliliters. The percentage of organisms killed depends on the intensity of the UV light, the contact time the water has with the light, and the amount of suspended solid particles in the water.

Suspended solid particles in the water can shield organisms from the light. Therefore, the untreated water must be completely clear and free from any sediment or turbidity to allow all of the bacteria to be contacted by the light. In addition, inorganic minerals such as iron, manganese, calcium, and magnesium must be below certain specified levels for the UV unit to treat the water effectively. For this reason, UV devices often are combined with other technologies such as particle or sediment filters, carbon filters, ion exchange water softening units, or reverse osmosis systems to remove particles prior to UV disinfection. No disinfection occurs beyond the treatment unit to kill bacteria that survived or were introduced after UV treatment.

UV lights gradually lose effectiveness with use, so the lamp must be cleaned on a regular basis and should be replaced as recommended by the manufacturer. Regardless of the quality of the equipment purchased, it will not perform satisfactorily unless maintained in accordance with the manufacturer's recommendations for maintenance, cleaning, and replacement of parts.

Information was adapted from an eXtension drinking water article, which was adapted from Wagenet,L., K. Mancl, and M. Sailus. (1995). Home Water Treatment. Northeast Regional Agricultural Engineering Service, Cooperative Extension. NRAES-48. Ithaca, NY.



Emerald Ash Borer Found Closer to Nebraska
By Nicole Stoner, UNL Extension Horticulture Educator

Image of Emerald ash borer An invasive insect pest has moved closer than ever to Nebraska, Emerald Ash Borer. Emerald Ash Borer, EAB, has not been found in Nebraska, but it now has been confirmed that it was found around Kansas City on both the Missouri and Kansas side.

EAB was first found in the United States in 2002, killing ash trees in southeast Michigan. EAB was probably transported to the United States a few years before the confirmed presence on solid wood packing material, such as pallets. Currently, Emerald Ash Borer has been found throughout much of the northeast portion of the United States, but it has not been found in Nebraska. Prior to 2012 the closest locations of EAB were in Minnesota and one hitchhiker found in southeastern Missouri. After this past summer, officials of the United States Department of Agriculture have confirmed the presence of Emerald Ash Borer in the surrounding areas of Kansas City on both the Missouri and the Kansas sides of the state line.

Image of EAB tunnelsImage of ash tree suckersEmerald Ash Borer is a wood boring insect that is ½ inches long and is a metallic green color with a bronze color underneath the wings. The problem with Emerald Ash Borer is that it bores into perfectly healthy ash trees. Most borer insects will only feed on stressed or dying trees, that is what makes EAB so much worse than normal borers and it is why it is destroying so many trees.

Emerald Ash Borer feeds only on true ash trees, which means that mountain ash is not attacked because it is in a different family and is not a true ash tree. The signs of EAB infestation include suckering at the base of an ash tree, decline in the tree from the top of the canopy downward through the tree, 1/8 inch D-shaped exit holes along the trunk and branches, increased woodpecker damage, S-shaped Serpentine galleries underneath the bark of the tree. If you notice any of these symptoms in your ash tree, you should contact your local University of Nebraska-Lincoln Extension Educator.

There are insecticides labeled for control of Emerald Ash Borer, but unfortunately they haven't been able to contain it's spread. To prevent the insect's entry into our state, do not move firewood or ash wood products into Nebraska from quarantined states.  A USDA Federal quarantine is in place for all states with known infestations, which prohibits the movement of ash wood from the infested state to other areas of the United States.  Be sure to follow all of these laws if you are travelling.

For more information go to:
EAB Found in Kansas City
Nebraska Invasive Species Project
Emerald Ash Borer Info
USDA Stop The Beetle



Moles and Pocket Gophers
By Stephen Vantassel, Project Coordinator-Wildlife Damage Management

Cooler weather often brings increased burrowing activity of moles and pocket gophers. Here are a few tips to handle these animals if you wish to initiate control.

Image of Plains Pocket Gopher Image of Mole
  1. Be sure you have identified the suspect accurately!  Moles create round mounds as well as surface runs that collapse when you step on them. Pocket gophers create kidney- or fan-shaped mounds and do not create surface runs.
  2. Act in a timely manner. The damage of both animals can remain visible for weeks and sometimes years. Control works best when it is done in response to fresh damage.
  3. Select the right tools and use them properly.

Lots of people fail in the management of these species because they don't use the right equipment. Moles don't eat grain, so grain-based toxicants are not recommended. I suspect that the cause behind toxicant failure for pocket gophers lies in neglecting to position the bait in the main tunnel or accidentally burying the bait.

If you prefer trapping, understand that all the traps work. Trapping is most effective when setting more than 1 trap and when the trapper pays attention to the details. The benefit of trapping is that you have proof of control.

University of Nebraska-Lincoln Extension has NebGuides on moles and pocket gophers that will provide further details to make your control of these species successful.

Moles and Their Control
Controlling Pocket Gophers in Nebraska



Be Aware When Buying Forages for Livestock
By Steve Tonn, UNL Extension Agronomy Educator

Image of cattleLivestock owners are cautioned to be aware of the forages they are buying for their livestock this winter. The dry summer may have caused those forages to be high in nitrates which can cause problems for livestock especially ruminants. Ruminants such as cattle, sheep and goats are more susceptible to nitrate poisoning. Horses are relatively resistant to nitrate toxicity because they are hindgut fermenters and do not have a rumen.

Nitrates occur naturally in all forages. Plants vary in the amount of nitrate that accumulates in various tissues. Nitrates taken up from the soil by the plant roots normally are incorporated into plant tissue as amino acids, proteins and other nitrogenous compounds. But excessively high nitrate amounts likely are to occur in forages having been grown in stressful conditions. Drought is one of those conditions. Oat, millet, sorghum, sudan, sorghum sudan hays have a tendency to be higher in nitrates. Weeds, such as pigweed, kochia, puncture vine, and lambsquarter, also have a tendency to be high in nitrates. Brome and alfalfa generally do not contain high nitrate concentrations. However this year, there is a chance these forages may also contain higher levels of nitrates.

Symptoms of nitrate toxicity include colic, diarrhea, respiratory difficulty, weakness, muscle temors, abnormal gait, shaking, elevated heart rate, seizures, blue to brown discoloration of the gums, frequent urination, low tolerance to exercise, incoordination, and death. Abortion of a fetus is also possible. Blood in affected animals might be chocolate brown instead of deep red.

Before buying grass hay, ask the seller if they have tested the hay for nitrates. Or if you have already purchased hay or have baled hay that may be high in nitrates, then testing the forages for nitrates would be advised. The cost of testing for nitrates is inexpensive so get representative samples of the questionable feeds analyzed by a laboratory. Most commercial feed laboratories will analyze feed for nitrates. Contact your local UNL Extension Educator to obtain information regarding laboratories in your area that tests feeds for nitrates. The cost of the nitrate test would be $10-$20.

Using feeds that contain high nitrate concentrations is not without risk, but feeds high in nitrates can be fed successfully. Using proper management practices can help to reduce the chance of animal loss.

For more information on nitrates in livestock feeding, view the University of Nebraska-Lincoln Extension publication G1779 Nitrates in Livestock Feeding.



Cutleaf Teasel, Dipsacus laciniatus L.
By Brent Meyer, Lancaster County Weed Superintendent

Image of cutleaf teasel foliageAppearance
Teasels are monocarpic perennials (produce seed only once in a lifetime) that form basal rosettes for at least one year until enough resources are acquired to send up flower stalks. Cutleaf teasel can reach 6 to 8 ft. in height. The plant dies after flowering.

Foliage - Opposite leaves are joined at the base and form cups that surround the prickly stem.

Flowers - The small, white flowers densely cover oval flower heads and are present from July to September. Spiny bracts are located on the ends of flower stems.

Fruit - A single plant can produce up to 2,000 seeds and can remain viable in the soil for at least two years.

Image of cutleaf teasel seedheadsEcological Threat
Cutleaf teasel grows in open, sunny habitats preferring roadsides and other disturbed areas, although it can sometimes be found in high quality areas such as prairies, savannas, seeps, and meadows. Cutleaf teasel was introduced from Europe in the 1700's and spreads by producing abundant seeds. It has been found in Lancaster county and the surrounding areas and should be eradicated if found. Cutleaf teasel is a noxious weed in Missouri and Colorado and is on Nebraska's "watch list" for new invasive species.

Cutleaf vs. Common teasel
There are two species of teasel found in Nebraska. Common teasel Dipsacus fullonum L. has pale purple flowers while cutleaf teasel has white flowers. Common teasel is typically smaller and the leaves are smoother around the edges. Both varieties can spread rapidly and control is recommended.

Contact Information
We need everyone's help, so if you would like more information on cutleaf or common teasel, or would like to report an infestation contact the Lancaster County Weed Control Office. Email: weeds@lancaster.ne.gov or phone 402-441-7817.



Fall Care of Trees
By Sarah Browning, UNL Extension Horticulture Educator

Image of Sycamore in fallOur trees have been through one of the hottest and driest summers on record since the 1930s, and many have been damaged even through the effects may not be seen until next year. Even though temperatures are cooler, dry conditions have not improved much and woody plants require more time and water to fully rehydrate.

Soon they will have to endure Nebraska's equally difficult winter conditions. Summer's drought stressed trees will face dry, open periods with little snow cover, mid-winter warm spells followed by very cold conditions, and drying winds that are all typical of a Nebraska winter. Plants continue to lose water through their stems and leaves throughout winter. If trees are dry going into winter, and this winter's conditions are as dry as last years, then branch and twig dieback or leaf scorch will be likely.

You can prepare your trees for the coming winter by following a few simple steps. Small investments of your time and energy now can pay-off in a big way later on by yielding a healthy and structurally sound tree.

Here are some important things you can do to winterize your trees.

  • Monitor the amount of weekly precipitation we receive, whether rain or snow. Water whenever we do not receive an inch of precipitation per week throughout fall and winter when soils are not frozen. A deep soaking every two weeks is adequate for most trees in unirrigated landscapes with clay soil. Deeply water trees with a slowly running sprinkler left in place long enough to moisten the soil 18 to 24 inches deep. Apply the water slowly so it can soak in and not run off. Move the sprinkler to a new location until the entire area beneath, and a several feet outside the tree's drip line has been watered.
  • Stop fertilizing. Trees and shrubs need to hardened off before going into winter. Succulent, new growth triggered by late summer fertilization is much more susceptible to winter burn and leaf scorch.
  • Once trees have gone dormant, remove or correct structural faults that are clearly visible. Remove damaged, dead or dying twigs, branches, and bark. However, be conservative in the amount of branches you remove this fall. Plants may have gone dormant earlier than usual due heat and drought. If in doubt whether a branch is dead or dormant, wait until spring and watch for new growth. Also, remove suckers and watersprouts that have grown on the tree's trunk or branches.
  • Spread a 3-4 inch thick layer of coarse organic mulch, like wood chips in a 3 to 6 foot diameter area around the base of the trunk to blanket the soil. This helps conserve valuable moisture and minimizes harmful winter temperature fluctuations around the tree's roots.
  • Prevent sunscald on young, thin-barked trees by shading the south and west face of the tree's trunk with a white painted piece of wood, pounded into the ground in front of the tree. Or use a section of black drain tile, slit down the side, then fit around the tree's trunk.
  • Protect trees from rabbit and vole damage by wrapping the trunks with ¼ inch hardware cloth. The cylinders should extend higher than a rabbit's reach while standing on the expected snow depth, and stand 1 to 2 inches (2.5 to 5 cm) out from the tree trunk. Usually a height of 2-3 feet is sufficient. Bury the bottom edge of the cylinder 2-3 inches in the soil to prevent voles from going under it.
  • Consider applying an antidessicant or anti-transpirant. These products, when properly applied, form a protective layer on leaf and stem surfaces slowing the rate of winter water loss. This is particularly helpful on plants susceptible to winter desiccation, such as boxwood and arborvitae, or fall planted trees & shrubs. One such product is called Wilt-Pruf, a liquid pine oil polymer that forms a clear, flexible coating on plant leaves and stems, but does not interfere with normal plant respiration or photosynthesis. Use the winter application rate and spray plants thoroughly AFTER they have hardened off and become dormant, usually late November or early December. Read and follow all label directions carefully, particularly the re-application recommendations, to avoid plant damage and maintain the product's effectiveness throughout the winter.

Trees are important investments in your landscape and they do require a small amount of care. For the sake of your tree's quality of life and your own, take a few minutes to winterize your tree.



Making Family Meals Happen
By Lisa Franzen-Castle, UNL Extension Nutrition Specialist

Image of family eating watermelonOctober is National Eat Better, Eat Together Month and when families eat together, meals are likely to be more nutritious and kids who eat regularly with their families are less likely to snack on unhealthy foods and are more likely to eat fruits, vegetables, and whole grains.

Beyond health and nutrition, family meals provide a valuable opportunity for children and parents to reconnect. When adults, children and teenagers eat together children do better in school, have fewer behavioral problems, and communication improves.
When is the last time you sat down and ate a meal with your family? If you cannot remember, October is a great time to start having a meal with your family as often as you can. Check out the following tips to make family meals happen at your house.

Tips on How to Make Family Meals Happen:

  • Schedule Family Meals. To plan more family meals, look over the calendar and choose a time when everyone can be there. Figure out which obstacles are getting in the way of family meals and see if there are ways to work around them. Even if it is only once a week, making it a habit to have family meals once a week is a great start and you can work your way up to 2 to 3 times a week. Don't forget that breakfast and lunch are meals as well; there are no rules that say family meals should only happen in the evening.
  • Prepare Meals Ahead of Time. It is important to make a shopping list and make time to go to the grocery store so you have foods on hand to create meals. Try doing some prep work for meals on the weekend to get ready for the week ahead. On a night when you have extra time cook double and put one meal in the freezer so when you are short on time you have a backup plan. Remember that a meal at home does not have to be complicated or take a long time to make.
  • Involve Kids at Family Meals. Family meals can be fun and it is important to involve kids in them. Celebrate National Eat Better, Eat Together Month by having kids help at mealtime. Younger kids can put plates on the table, pour beverages, or fold napkins. Older kids can get ingredients, wash produce, mix, and stir. You could even have your teens be the cook and you as the parent could be their helper in the kitchen.

During mealtime, make your time at the table pleasant and enjoy being together as a family. Remember to keep your interactions positive at the table. Ask your kids about their days and tell them about yours. Give everyone a chance to talk.
Another topic to discuss is future family meals and favorite foods that could be included. If you cannot remember the last time you sat down for a family meal, take the time this October to start a family tradition of eating together and eating better.