{"id":795,"date":"2008-06-01T14:14:55","date_gmt":"2008-06-01T14:14:55","guid":{"rendered":"https:\/\/informatech.energir.com\/?p=795"},"modified":"2021-04-15T15:33:56","modified_gmt":"2021-04-15T20:33:56","slug":"unveiling-the-results-of-the-geothermal-natural-gas-demonstration-project","status":"publish","type":"post","link":"https:\/\/informatech.energir.com\/?p=795&lang=en","title":{"rendered":"Unveiling the results of the geothermal natural gas demonstration project"},"content":{"rendered":"

It’s now an alternative. The new absorption heat pump technology is added to the options of customers who want to increase their buildings’ energy performance. The results of the demonstration project are available after more than one year of continuous measurement. This is a promising technology, because it is the only one that can provide heating temperatures higher than 45°C (115°F) by adapting it to a geothermal system. It is also the only technology that can operate as air source heat pump (ASHP) from outdoor temperatures as low as -29°C.<\/p>\n

The versatility of natural gas, which achieves 95% heating efficiency levels by condensing water vapour from its own combustion, is thus reaching new highs. Its efficiency now achieves levels ranging from 120% to 135%.<\/p>\n

A successful demonstration<\/p>\n

In spring 2005, Gaz Métro’s DATECH Group undertook a commercial demonstration of the performance and reliability of natural <\/span><\/span>gas ground source heat pump, a first in North America. The Montréal engineering firm CIMA+ integrated a natural gas geothermal option into its plans and specifications for renovation of one of the multiple buildings of the Benny Farm housing complex. Unlike the complex’s other buildings, the 24 units belonging to <\/span>Société d’habitation et de développement de Montréal<\/em> (SHDM) accepted this option. The costs of this implementation amounted to $140,000 for five vertical wells 168 metres deep and three Robur heat pumps with a single-pump capacity of 38 kW (130 MBh) for heating and 18 kW (5 tonnes) for air conditioning.<\/span><\/p>\n

The building’s original cast iron hot water system was kept for greater comfort and due to the fact that it can handle lower temperatures efficiently. Startup of the units was in March 2007, and after one year of mea-surement, the results meet the reliability and efficiency expectations.<\/p>\n

An excerpt of the efficiency results measured on a monthly basis by the Natural Gas Technologies Centre (NGTC) is also presented below. They corroborate the manufac-turer’s specifications (G.U.E. is similar to COP). Note that as in any geothermal project, efficiency varies according to the temperature of the well (evaporator) and the heating temperatures (condenser). The physical accuracy of the possibility of obtaining a temperature of 60°C (140°F) on the evaporator could have been verified.<\/p>\n

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Comparative application scenarios<\/p>\n

Two theoretical scenarios of the heating needs of these 24 housing units were simulated for comparison: a hot water-heated radiant floor system (low temperature) and a cast iron heat transfer system (medium temperature). For each scenario, three technologies were evaluated on the basis of a standard heating installation to define the energy cost of the different possibilities.<\/p>\n

Scenario 1<\/p>\n

Considering that geothermal electricity requires auxiliary backup (70%\/30% rule), we find that for the same new commercial building, geothermal natural gas would not necessitate auxiliary heating for use of the same ground sink, while the energy costs of heating would be totally comparable.<\/p>\n

Scenario 1: THEORETICAL COMPAriSON OF DIFFERENT OPTIONS RELATED
\nTO A PROJECT WITH HOT WATER-HEATED RADIANT FLOORS (evaporator input T° = 5°C; condenser output T° = 46°C (115 °F)<\/p>\n\n\n\n\n\n<\/colgroup>\n\n\n\n\n
Basic volume for a standard installation Building heated with conventional equipments (75% efficiency) – Reference volume 52,800 m3\/year or $28,456\/year (2000 Gj\/year) at 20% ECDear)<\/td>\n<\/tr>\n
Condensing boiler<\/td>\nGeothermal with electricity<\/td>\nGeothermal with natural gas<\/td>\n<\/tr>\n
\n
    \n
  • 100% gas heating<\/li>\n
  • With boiler at 94% efficiency<\/li>\n
  • Predicted volume of 42,130 m3<\/sup>\/year @ 54.6 ¢\/m3<\/sup><\/li>\n
  • = $23,003\/year<\/li>\n
  • (1596 Gj)<\/li>\n<\/ul>\n<\/td>\n
\n
    \n
  • Electrical GSHP (COP of 2.5)<\/li>\n
  • With auxiliary gas heating and ECD 94% eff.<\/li>\n
  • 120,050 kWh\/year for 90% heating of the envelope @ 7¢\/kWh 11,795 m3\/year @ 59¢\/m3<\/sup> (ECD + 10% heating of the envelope)<\/li>\n
  • = $15,363\/year<\/li>\n
  • (879 Gj)<\/li>\n<\/ul>\n<\/td>\n
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