Geothermal district heating: basics to success

A district heating system using geothermal energy is a viable and economic option in many locations. A successful system, however, is dependent upon a variety of factors, and it is the purpose of this presentation to accent those items that are proving to have significant impact upon the successful operation of geothermal district heating systems. (These lessons can also apply to other sources of energy.) The six major basics to success that are discussed in this paper are economic viability, an adequate geothermal resource, simplicity of design, a closed loop system, a local champion, and good public relations

Tasleḍt tasnalɣant n tmeslayt n At Yeɛla n Uqemqum (Lesnam)

Tasleḍt tasnalɣant n tmeslayt n At Yeɛla n Uqemqum (Lesnam)Tutlayt d allal n teywalt1, d tamagit n yal agdud deg umaḍal. Tawuri-s ur teqqin ara kan ɣer teywalt, acku yal timetti, yal aɣref yettmeslay tutlayt-is, ayen i tt-yettağğan tẓeṭṭ assaɣ iğehden yid-s. Tutlayt n tmaziɣt, d tutlayt seg tutlayin n umaḍal, ttmeslayen-tt yimezdaɣ n Tefriqt ugafa am : Lezzayer, Tunes, Maṛuk, Libya d Maṣer, tella daɣen deg kra n tmura n unẓul am : Mali, Niğer, Muriṭanya akken i d-yenna ACHAB, (R) : « Tamaziɣt tettbin-d s wudem n waṭas n tmeslayin, ttwazuzrent ɣef yiwet n trakalt d tahrawant 2». Tutlayt tamaziɣt tebda-d s timawit (timucuha, inzan,…), imiren ulac tizrawin yettwaxedmen fell-as armi d tasuta tis 19 i bdan yimusnawen xeddmen tizrawin ɣef yiḍrisen n tsekla i d-gemren, am tmucuha d yiḍrisen n tmedyazt, daɣen tella-d temhazt s yisegzawalen i xedmen ɣef tmeslayin aladɣa taqbaylit. Seg wid yuran, ad d-nebder asegzawal amezwaru « Dictionnaire Kabyle- Français » n DU PARADIS Venture deg useggas n 1790, i d-yefkan anamek i wawalen n teqbaylit s tutlayt tafransist, syin iban-d usegzawal yettwassnen mliḥ : « Dictionnaire Kabyle-Français (Parler des Ait Menguellat, Algérie) » n DALLET Jean-Marie deg useggas n 1982, yexdem tazrawt i tmeslayt n taddart n At Mengellat i d-yezgan deg waɣir n Tizi-Wezzu. Llant daɣen tezrawin neɣ leqdicat i xedmen imusnawe

Hydrothermal commercialization baseline for state of Wyoming

Wyoming does have numerous hot springs; but there has been little development effort in geothermal energy, since the state's primary interests are in coal, gas and oil. The hot springs of Thermopolis are among the largest in the world. Recent data from the central portion of the state indicate the potential for electric power generation from geothermal energy. Oil and gas wells (about 70,000) have been drilled in the state and some have geothermal waters that can be utilized for direct applications. The Madison Aquifer extends into the northeastern quadrant of the state and offers considerable potential for geothermal energy. Leasing activity is very limited. Geothermal legislation is basically non-existent, but the State Engineer has the responsibility for protecting the thermal springs. This handbook provides a synopsis of various aspects of the geothermal program in Wyoming. The section on Basic State Data (Section 2) lists government personnel (both legislative and executive branches) who are most directly involved with geothermal development. Some basic demographic data are also included. The various hydrothermal resources and the pertinent geology are summarized in Section 3. Activities (ranging from leases to operational systems) that lead to commercialization are described in Section 4. Plans for various developments are summarized in Section 5, while government assistance to Wyoming projects is list4ed in Section 6. The section on energy use patterns (Section 7) summarizes existing energy use and identifies counties and industries likely to be impacted most by geothermal energy. The section on leasing and permitting policies (Section 8) deals with legal and institutional considerations and includes a time table of institutional procedures for a typical resource to show the interrelationships among various organizations involved in development and regulation of the resource

Direct applications of geothermal energy market penetration analyses and infrastructure requirements

EG and G Idaho is performing geothermal market penetration analyses, and investigating infrastructure requirements. This paper provides a brief summary of some of the analyses being conducted to serve as a guide in the preparation of comprehensive plans for the accelerated commercialization of geothermal energy

Geothermal direct use engineering and design guidebook avialable for an expanding market

The Geothermal direct use industry potential, growth trends, needs, and how they are being met, are addressed. The high potential for industry growth, coupled with a rapidly expanding use of geothermal energy for direct use, and concerns over the greenhouse effect is the setting in which a new engineering and design guidebook is being issued to support the growth of the geothermal direct use industry. Recent investigations about the current status of the industry and the identification of technical needs of current operating district heating systems provide the basis upon which this paper and the guidebook is presented. The guidebook, prepared under the auspices of the US Department of Energy, attempts to impart a comprehensive understanding of information important to the development of geothermal direct use projects. The text is aimed toward the engineer or technical person responsible for project design and development. The practical and technical nature of the guidebook answers questions most commonly asked in a wide range of topics including geology, exploration, well drilling, reservoir engineering, mechanical engineering, cost analysis, regulations, and environmental aspects. 6 refs., 2 figs., 4 tabs

Geothermal direct use engineering and design guidebook

The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of these resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse, aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental considerations. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very potential in the United States

The feasibility of applying geopressured-geothermal resources to direct uses

This study concludes that direct use technologies, especially desalinated water production, can contribute significantly to the value added process and the overall economic viability in developing a geopressured resource. Although agriculture and aquaculture applications are marginal projects when they are the only use of a geopressured well, the small margin of profitability can contribute to improving the overall economics of the direct use development. The added complexity from a technical and management aspect may add to the overall risk and unpredictability of the project. Six combination of direct uses received economic evaluation that resulted in 15% discounted payback periods ranging from 4 to over 10 years. Many other combinations are possible depending on the resource and market variables. Selection of appropriate technologies and sizes of applications will be established by the developer that engages in geopressured resource utilization. Currently, many areas of the country where geopressured resources are located also have surplus electrical capacity and generation, thus power utilities have been selling power for less than 2 cents per kWH, well below a reasonable breakeven value for geopressured produced electricity. However, when the energy demand of the integrated geopressured facility is large enough to install power generation equipment, operating expenses can be reduced by not paying the 10 to 12 cents per kWH utility rate. The study includes an analysis of a geothermal turbine unit installed with a desalination and an agriculture/aquaculture facility, taking advantage of the cascading energy values. Results suggest that this scenario becomes profitable only where the market price for electricity exceeds five cents per kWH

Association of mechanical bowel preparation with oral antibiotics and anastomotic leak following left sided colorectal resection:an international, multi-centre, prospective audit

Introduction: The optimal bowel preparation strategy to minimise the risk of anastomotic leak is yet to be determined. This study aimed to determine whether oral antibiotics combined with mechanical bowel preparation (MBP+Abx) was associated with a reduced risk of anastomotic leak when compared to mechanical bowel preparation alone (MBP) or no bowel preparation (NBP). Methods: A pre-planned analysis of the European Society of Coloproctology (ESCP) 2017 Left Sided Colorectal Resection audit was performed. Patients undergoing elective left sided colonic or rectal resection with primary anastomosis between 1 January 2017 and 15 March 2017 by any operative approach were included. The primary outcome measure was anastomotic leak. Results: Of 3676 patients across 343 centres in 47 countries, 618 (16.8%) received MBP+ABx, 1945 MBP (52.9%) and 1099 patients NBP (29.9%). Patients undergoing MBP+ABx had the lowest overall rate of anastomotic leak (6.1%, 9.2%, 8.7% respectively) in unadjusted analysis. After case-mix adjustment using a mixed-effects multivariable regression model, MBP+Abx was associated with a lower risk of anastomotic leak (OR 0.52, 0.30–0.92, P = 0.02) but MBP was not (OR 0.92, 0.63–1.36, P = 0.69) compared to NBP. Conclusion: This non-randomised study adds ‘real-world’, contemporaneous, and prospective evidence of the beneficial effects of combined mechanical bowel preparation and oral antibiotics in the prevention of anastomotic leak following left sided colorectal resection across diverse settings. We have also demonstrated limited uptake of this strategy in current international colorectal practice

Evaluating the incidence of pathological complete response in current international rectal cancer practice

The mainstay of management for locally advanced rectal cancer is chemoradiotherapy followed by surgical resection. Following chemoradiotherapy, a complete response may be detected clinically and radiologically (cCR) prior to surgery or pathologically after surgery (pCR). We aim to report the overall complete pathological response (pCR) rate and the reliability of detecting a cCR by conventional pre-operative imaging.A pre-planned analysis of the European Society of Coloproctology (ESCP) 2017 audit was performed. Patients treated by elective rectal resection were included. A pCR was defined as a ypT0 N0 EMVI negative primary tumour; a partial response represented any regression from baseline staging following chemoradiotherapy. The primary endpoint was the pCR rate. The secondary endpoint was agreement between post-treatment MRI restaging (yMRI) and final pathological staging.Of 2572 patients undergoing rectal cancer surgery in 277 participating centres across 44 countries, 673 (26.2%) underwent chemoradiotherapy and surgery. The pCR rate was 10.3% (67/649), with a partial response in 35.9% (233/649) patients. Comparison of AJCC stage determined by post-treatment yMRI with final pathology showed understaging in 13% (55/429) and overstaging in 34% (148/429). Agreement between yMRI and final pathology for T-stage, N-stage, or AJCC status were each graded as 'fair' only (n = 429, Kappa 0.25, 0.26 and 0.35 respectively).The reported pCR rate of 10% highlights the potential for non-operative management in selected cases. The limited strength of agreement between basic conventional post-chemoradiotherapy imaging assessment techniques and pathology suggest alternative markers of response should be considered, in the context of controlled clinical trials

Removal of the Materials Test Reactor overhead working reservoir

Salient features of the removal of an excessed contaminated facility, the Materials Test Reactor (MTR) overhead working reservoir (OWR) from the Test Reactor Area to the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory are described. The 125-ton OWR was an overhead 160,000- gallon-capacity tank approximately 193 feet high which supplied cooling water to the MTR. Radiation at ground level beneath the tank was 5 mR/hr and approximately 600 mR/hr at the exterior surface of the tank. Sources ranging from 3 R/hr to in excess of 500 R/hr exist within the tank. The tank interior is contaminated with uranium, plutonium, and miscellaneous fission products. The OWR was lowered to ground level with the use of explosive cutters. Dismantling, decontamination, and disposal were performed by Aerojet Nuclear Company maintenance forces. (auth