Costs

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

	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
OK, here is where things are not going particularly well. The tankless water heater didn't work out so it has been replaced (see the water heat page). Now we have a solar hot water tank in place but it is just working electrically for now. Hopefully in the future I can get the rooftop solar collectors hooked up to it. I may also be able to retrofit a desuperheater to the geothermal unit to heat water. I expect that the hot water saga is going to continue for years to come.

	Credits Energuide Rebate Credit 2,148 Edmonton CO2RE Rebate Credit 500 Total 2,648
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. So overall we spent about $65,500 with a rebate of about 4%. 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 about double our pre-heat pump usage at about 1,100 kWh per month.


	Although the usage of gas and electricity is easy to explain the cost of utilities includes significant service charges. In this graph I compared the years 2003 and 2007. Both of these years had about the same number of degree days (about 5,000 degree days per year). That means that seasonal usage should be about the same. What is immediately apparent is that the gas use charges go to just about nothing while the service charges are still about the same. In Edmonton we pay about $300 per year for the priviledge of having a gas line connected to our house. You can see that it makes little sense to pay gas service charges at our current usage rate. Now that we have eliminated the gas service to our house the gas use and gas service charges are gone from this graph. It's pretty obvious then that the geothermal reduces your overall bills to somewhere near 50%. On this graph the numbers go from $2300/year in 2003 to $1300/year in 2007 however the changes in the cost of gas and electricity are not factored in to this graph.

Costs and Comments