Construction Outlook a Mixed BagThe outlook for the general economy is improving, but that doesn’t mean good news for construction yet, reports FMI’s Construction Outlook, a quarterly, construction-market forecast and supplement to the U.S. Markets Construction Overview that FMI has produced since 1985. Total construction in 2009 and 2010 will be down 14 percent and 5 percent, respectively.
- Residential construction will decline 25 percent in 2009,
and will recover in 2010.
- Nonresidential construction will decline 13 percent in 2009 and 16
percent in 2010.
- Nonbuilding construction will be the only positive contributor,
increasing 5 percent per year in 2009 and 2010.
- Project cancellations are five times the normal rate, and currently
are at 10 percent of backlog.
- Total residential construction will be $268.5 billion in 2009, down
from its 2006 high of $619.8 billion.
- 2009 will be the worst year for housing starts since records began
being kept in 1959.
- Power construction is expected to remain positive for the next 5 years, attaining new highs each year, and reaching $122.1 billion in 2013.
Marcellus Shale Drilling ProposedCaroline Mims, National Driller’s not-so-secret weapon, reports that regulators in New York are proposing to allow natural gas hydraulic fracturing to proceed – with some new restrictions – in the part of upstate New York that contains the multi-state Marcellus Shale underground rock formation.
The proposed new drilling rules for the oil and gas industry are contained in the New York State Department of Environmental Conservation’s Draft Supplemental Gen-eric Environmental Impact Statement (dSGEIS). The dSGEIS was released Sept. 30, and outlines draft rules covering the issuance of gas-well drilling permits for horizontal drilling and high-volume hydrofracturing in the Marcellus Shale and other low-permeability gas reservoirs.
Among the key themes of the state’s analysis has been hydrofracturing’s possible impact on aquifers tapped for drinking water. Energy companies are eager to tap the Marcellus Shale, one of the largest gas-containing rock formations in the United States.
The dSGEIS outlines safety measures, protection standards and mitigation strategies that operators would have to follow to obtain permits. For example, companies are required to disclose the chemicals they use in hydrofracturing fluids.
The report also requires the oil and gas industry to test private water wells within 1,000 feet of the drill site prior to drilling. The wells are to be tested to provide baseline information and to allow for ongoing monitoring, noting that if there are no wells within 1,000 feet, the survey area will extend to 2,000 feet.
Technical compliance proposals calls for operators to complete a new “Pre-Frac Checklist” and Certification Form” to ensure technical compliance with the permit, and to provide details about final wellbore construction and hydraulic fracturing operations.
All operators also would be required to prepare plans for mitigating greenhouse gas emissions, visual impacts and noise impacts before starting operations.
We've Got MailVFD Performance Challenged
A “green lie” is when companies, governments or individuals use false information, or are “economical with the truth,” to try and persuade the public into purchasing something they claim is good for the environment, when it really is not.
Countless articles preach that variable-frequency drives or VFDs will save energy and pay for themselves in just a few months or years. This is a green lie. Just because the amps go down when the RPM of a pump is decreased, does not mean energy is being saved. In fact, the opposite is true. A VFD causes more energy to be used per gallon when running at maximum RPM, and when the RPM is reduced.
A good example would be a 10-HP pump that can produce 100 gpm at 100 psi. This would be 10 gpm per horsepower without a VFD. At full speed and full flow, the energy used by a VFD itself, along with the VFD’s sub-standard voltage waveform, would cause an extra 5 percent in energy use. This means that the pump would only be producing 9.52 gpm per horsepower, compared to 10 gpm per horsepower for a pump without a VFD.
The Affinity Law states, “Horsepower is reduced by the cube of the speed.” Many people use this to try and show energy is being saved – by reducing the RPM. This is another green lie. The Affinity Law also states, “head is reduced by the square of the speed.” So reducing the speed of a pump by 50 percent would also reduce the head produced by 75 percent. At this speed, the pump would no longer be able to even lift water to the top of the well. Because the pump can no longer produce the head required, decreasing the horsepower to 12.5 percent is not possible.
A maximum reduction in speed of 15 percent would be a more-possible scenario. This would still be a reduction in head of 28 percent, but might be able to lift water to the top of the well and still produce the pressure required. Reducing the speed by 15 percent would reduce the horsepower by 39 percent. If the example pump could be slowed by 15 percent and still deliver the 100 psi required, it would be producing 10 gpm, and drawing 6.1 horsepower. This would only be 1.66 gpm per horsepower. That is 6 times or 600 percent more energy used per gallon when slowed with a VFD. Saving energy means reducing the energy cost per gallon of water pumped, not reducing the cost per hour to run the motor turning the pump. High flow or low, a VFD always causes more energy to be used per gallon produced.
It’ another “green lie” to say that a VFD can spare the motor damage from full voltage high torque start-ups. Surviving the voltage spikes, EDM currents, harmonics and resonance frequency vibration of a VFD can override the benefits of any soft start.
Countless before and after “studies” have been published, “proving” that VFDs save energy. However, reading the fine print on these “studies,” you can always find that a smaller pump was installed, dumping excess water was discontinued, or the pressure required was decreased. These are the real reasons for the documented energy savings. It’s another “green lie” to give the newly installed VFD any credit for energy savings, because VFDs always increase energy used per gallon. These “green lies” have been used so frequently, that even people who are smart enough to know better, still cling to the propaganda that VFDs can save energy.
We all want to do our part to save energy and make the world a better place. Look past the glossy ads and the tricky Web pages. Companies spend the most advertising dollars on products that are short lived, and make them the most money. Saving energy and money would be counter-productive to company profits. Falling for “green lies” about VFDs can actually harm the environment, while taking a “lot of green” out of your wallet.
Cycle Stop Valves Inc.
Rigs Were Misidentified
In the “Experienced Geothermal Drillers See Growth” article that appeared in the October issue ofNational Driller, you featured one of our good customers, Leuck’s Drilling Co. We would like to thank you for this and the mention of their owning several SIMCO drilling rigs. The 2800 and 5000 model rigs were correctly identified as SIMCO units. However, we would appreciate a correction to the spelling of the brand name for their two largest models. It should have read “two SIMCO 7000 units,” not “two SEMCO 7000 units.” Considering the fact that there is a SEMCO brand of pump hoists, this distinction is critical.
SIMCO Drilling Equipment
Drilled Shaft Foundations WebinarThe American Society of Civil Engineers will present a live interactive Web seminar titled, “Load and Resistance Factor Design for Geotechnical Engineering Features: Drilled Shaft Foundations.” The 90-minute Webinar takes place Monday, Feb. 8, at noon Eastern time.
This Webinar will include discussion on the terminology and construction of drilled shafts, identification of limit states and resistance factors, development and use of axial resistance charts, concept of mobilized resistance, group efficiency factors for evaluation of axial resistance of shafts in groups, p-multipliers for evaluation of lateral resistance of shafts in groups, redundancy, evaluation of settlement of shaft groups, use of construction point concept, uplift resistance, consideration of scour and seismic events, and typical structural detailing.
The registration cost is $299. For complete details, e-mail firstname.lastname@example.org.