Costs and Comments

thz.ca, Costs, Electrical, Geothermal, Water Heat, Insulation, Landscaping, Roof, Windows, Deck

   201020092008,   2007,   2006,   2005

So now I'd like to try and put some of this into perspective. First, the house we live in needed to be upgraded to start with. Most of the mechanical systems needed to be upgraded as they were reaching the end of their lives. The roof, the furnace and the hot water heater were all worn out and needed to go. I also wanted to move our elecrical underground so that we could expand our back deck. There were also a number of items that had just been built badly in the first place that I wanted to correct. It was time to upgrade.

The second part of the upgrade was to make our house better from an energy efficiency standpoint. Adding a geothermal heat pump in Alberta is not the panacea that many salespeople will tell you. By converting your heat to coal-fired electicity from gas you don't save that much CO2. But by getting everything moved over to electricity you do have the opportunity to start adding green electricity alternatives in the future. Currently we buy green electricity credits from Bullfrog Power. Hopefully in the future I will be able to add some photovoltaic capacity. That will be the next project!

Geothermal Costs         
Energuide Evaluation           150
Heat Loss Calculation           200
Geothermal unit with Drilling       16,700
Heat Recovery Ventilator           650
Duct Work and tie-ins         1,400
Total     $19,100

Ok let's start with the main item, the geothermal heat pump. In order to size the unit you need to do a heat loss calculation on your house. The trick for us was to estimate what the heat loss of the house would be after upgrading. We wanted the geothermal unit to be as small as possible so we figured in the heat losses after insulating, changing the roof, and draftstopping. That got us to a size of 48,000 BTU per hour as the size needed. We installed the geothermal unit based on that calculation and then had to complete the house upgrades to get to that heat loss level.


Grid Tied Solar         
Solar panels, inverters, and parts   7,350
Installation       4,300
Permits         337
Engineering         1,200
Special racking         400
Total     $13,587
The other major upgrade was the grid tied solar panels installed in the fall of 2010. In this case the major expense is for a contractor that supplies and installs the solar panels. I designed and installed the special racking that went on the dormers and had an engineer review the design for suitability. We received a major rebate on this system of $3 per installed watt. See the rebates below.

12V Solar         
Candian Tire 60 watt kit     325
Deep Cycle Battery           125
Aluminum frame       160
Conduit and wire           200
Solar controller and timer           150
LED Deck lights         300
Total     $1,260

The 12 volt solar system started with a sale on an RV battery charger at Canadian Tire. It evenutally ended up as a separate system with a timer to turn on the deck lights at night.


Electrical Upgrade         
Power Pole Post             75
Small Backhoe Rental           325
Breaker Panels         400
Check Meter         150
Cable for 100 amp Circuits         350
Contractor's Labour and Materials     3,000
My Materials     1,900
Total     $6,200
But the geothermal heat pump can't go in unless there is enough power to run it. The electrical upgrade took our house from 70 amp service to 200 amp service. I also put all the cables underground so that they would no longer be too close to the deck. Putting the cables underground makes for a tidier back yard and eliminates safety issues with overhead wires. While I was at it I added an underground conduit from the house to the garage that I hope to use for photovoltaic power in the future.

Roof Upgrade         
Engineer's Structural Review         100
Radiant Foil Barrier         100
Roofing Contractor       6,600
Siding Contractor       2,800
Eavestrough Contractor         600
Total     $10,200

I admit, we got a great deal on the roof for what we had done. Unfortunately the contractor that did this work for us has retired. He was absolutely the best contractor we had on our project and did excellent work. The foil radiant barrier I bought by special order through a local distributor once I searched out the manufacturer's product code on the internet. The engineer was also very inexpensive considering he visited the house and wrote a letter to the City saying that the structure would support the new roof.


Draftstopping and Insulation         
Cellulose Insulation Drill and Fill         850
Drywall Contractor     1,400
Paint Supplies       800
Peel and Stick Vapour Barrier       200
Insulated Steel Back Door       300
Misc Insulation and Supplies       500
14 new Double-Pane Windows   5,500
Total     $9,950
Our insulation contractor did a great job at a very reasonable price. The drywall contractor got about 90% done and then left. We finished up the drywall and then did all the painting. We got really good windows at a very good price. I did all the draftstopping.

Landscaping         
Large Tree Removal         550
Contractor for Front Yard     4,200
Plants Trees and Shrubs    1,100
Other Purchases       650
Cedar Mulch       300
2007 Back Deck, Sidewalks, and Sod   10,000
Total     $16,800

As far as the landscaping goes it ran about $6,800 for the front yard and about $10,000 for the back yard and deck. The front yard was absolutely necessary as the geothermal drilling left a big mess that needed to be cleaned up. The back yard was an upgrade of the old deck. The front yard was done in 2005 with the geothermal upgrade while the back yard went two years later in 2007.


Water Heat         
Tankless Unit       2,100

Solar Hot Water Tank     1,200
Last Electric Water Heater     220

Total     $3,520

OK, here is where things didn't go particularly well. The tankless water heater didn't work out so it was replaced (see the water heat page). Then we has a solar hot water tank that we just used electrically. It rusted through in less than 3 years so now we have a regular old electric water heater. Should have done that in the first place.


Credits         
Energuide Rebate       Credit 2,148
Edmonton CO2RE Rebate     Credit     500
Edmonton CO2RE Solar     Credit   4,620
Total   $7,268
But all is not negative. We had the Energuide for Homes evaluation done before and after our geothermal upgrade. The Energuide gives a small amount of credit to the geothermal upgrade but far more credit is given for insulation upgrades and draftstopping. It was the draftstopping that really got our Energuide numbers up. We went from a leaky drafty house to a house that is as draft free as a new house. Our original Energuide Evaluation gave our house a rating of 39 (which is really low). The final evaluation was a 79 (which is equivalent to a new home). Because our Energuide rating went up by 20 points the City of Edmonton CO2RE program kicked in $500 as well. Then the Solar Pilot Program paid $3 per watt to install solar panels. There were also some tax credits in 2009 for some other renos we did but I don't know the number specifically. So overall we spent about $81,000 with a rebate of about 9%. True, not everything we did was related to energy efficiency but one thing leads to another...

So how has the geothermal installation changed our utility bills? That's what I hope to show in the next graphs.

The first graph shows what has happened to our gas usage over the past years. We installed the geothermal heat pump and the Tankless Gas water heater in September of 2005. At that time our gas use stopped following the weather and settled in at about 3 Gj per month. In September of 2006 we got rid of the tankless gas water heater and went to an electrically heated tank. Then our gas usage dropped to 0.3 Gj per month which shows as 1 Gj every three months as the stove and dryer were our only gas appliances left. Those appliances are now changed and the gas service has been removed from the house. As of May 2008 our gas usage is zero.


The second graph shows what happened to our electical usage. Prior to 2005 we averaged about 500 kWh per month. After the geothermal heat pump was installed our electrical use follows the weather. Our average is now a little more than double our pre-heat pump usage at about 1,200 kWh per month.