Hello, Intro: My name is Joerg and I live in southern Alberta, Canada. I am following the geothermal idea for now 30 years and I am getting close to saying good-bye to NG, but as always the problems come when one has a vision (and a stubborn mind). We build a new home with about 4800 sqft in 2010 and I had envisioned geothermal with PV solar then already, but the best quote I got was CAD120,000 additional to our budget. You all will understand that this would buy lot of energy, particularly in Alberta, where we, literally, sit on the stuff. So, the idea was dropped in 2010, but our house and workshop is heated with in-floor water heat and radiators in the second floor. All heated with one 250,000 BTU NA boiler in our house and a 125,000 BTU in our shop, 60'x80', 18 eve. The house boiler kept up easy when we had -40°C, (-40°F) this past winter, but the shop boiler was running steady. Now, -40 is probably the coldest we have had in a long time, but nerveless, it showed us it can happen. I have 21.2kW PV production in my yard, more then I need and could run a heat pump theoretical free of energy costs (debatable, I know). Now to my thought and I know nothing about sizing the needed energy to meet my peak demand, but here is my thought in order of approach: Drill one 100m (330') deep well with core samples to check the formation we are dealing with and insert a Temperature probe with sensors every 10m (33') to be able to check the sub temp.s now and later. Once this is done, the structure and possible water movements are cataloged, I am planning to drill four wells around this first well in 3-4m (10-13') distance to the same depth (or adjusted depth if so told by the first test well) and insert one 1" closed loop in each hole. Second step: install evacuated solar panels to match the four wells to bring energy in to the boreholes in the summer and extract it when needed with a suitable heat pump. I know of one site that works like this, but can't get connected to the people that operate it, it is called 'DRake Landing' and can be seen here for awhile longer: https://dlsc.ca/dashboard.htm Now the setback: I received my first quote for the drilling and installing of the loops only, no hardware included: CAD117,000 plus three days room & board for the crew and meals. The total would probably run around CAD140,000 without connection the systems, switch gear and heat pump. Please give me your comments, hints, directions, links etc. Again, I am older, but never saw 'no' as an option. JoergK.
how much energy does your house need? Do you really need 250 KBTU to heat your 2010 house in -40C weather? If yes, 4 boreholes are not going to do much. What are your propane bills for the year? The wells should be further apart, at 10-13' distance they start to steal heat from each other. You also should use a larger diameter, and drill deeper. How deep to bed rock? The fact that you have radiators and in floor heat is not ideal, since the radiators are likely needing higher temperatures. At what temp do you operate them during peak hours (-40C)?
Hello docjenser, I heat with natural gas. My highest NA consumption was 499 GJ in 2019. My highest monthly was 95 GJ in Feb. 2018. My system in the house runs on 120°F and 132°F. Our house has a attached and heated garage with a apartment above for the chauffeur. The boiler was only running 50% when we had -40°, so I assume it could be 175KBTU demand. A heatpump should have no problem achieving this and it is the reason why we laid it out this way. For the hole spacing, remember, the plan is to bring energy down from April to October to heat the core and this will bring the 'battery' to 60-70°C, 140-160°F to be extracted from November to March. Again, the test hole and formation logging is the most important part of this to set the game plan. Also, the inserted sensor cable will provide the information on how much energy is stored. Bedrock? I don't think it is at any levels we will drill to, but will talk to some oil drillers. The boilers will stay in place until we have this all running properly and maybe converted to propane as standby, since I have them anyway.
So what does a year worth of NG cost you? IF my ruff estimate of GJ to therms and my gas comparisons is correct about $4800 a year? $140K will buy you a lot of NG, in terms of drilling cost that's before the equipment. Also your solar will the power company pay you for unused energy you put in during the summer? I'm wondering if you have a ROI on something like this, I know for me my NG bill is a whopping $88 last month, in Seattle WA.
