04. Learn how net-zero home builders are building a better world

Tags: Geothermal, Solar

Published May 11, 2012

Blog: Net-zero home builders push the envelope

The idea that a home could produce as much energy as it consumes has been a reality for at least five years. Called net-zero homes, cutting edge homebuilders have pushed the envelope and created monuments to efficiency, air-tightness and insulation.

Now comes the slightly less sexy but just as important next step–take the best ideas from the net-zero concept homes and work them into everyday Canadian homes.

Les Wold is a part of this second wave of net-zero home builders. A baby-faced 38-year-old he’s a managing partner with Effect Homes, an Edmonton based homebuilder that currently builds about 10 houses a year.

In a rather serendipitous turn of events Les Wold responded to a community newsletter ad from Jeanette Bowman and Kevin Taft when they were looking for two other families to build net zero homes with.

Together they embarked on the Belgravia Green project to build three super energy efficient homes in the mature Edmonton neighbourhood of Belgravia.

Two attractive, modern infill homes now bookend a net-zero show home with a large solar array in the middle and all three feature different heating systems, which brings home the point that there many ways to get to net-zero.

The big net-zero heating test

While all three homes are airtight and super insulated with R40 foundations and triple pane windows all three homes have different heating systems. This gives Effect Homes the opportunity to see how different heating systems work for future net-zero projects.

All three heating systems have replaced the typical gas-fired furnace.  None of these three homes has a gas line connected to it.

House #1: Geothermal heating

Its heating comes from a geothermal heating system that uses a ground source heat pump.  It’s easiest to think of this kind of heating system like a reverse refrigerator.

 

  More…

Podcast: Solar panels are sexy but it is passive solar design which helps make a home net-zero

CKUA logoLes Wold, managing partner with Effect Homes, lays out just how a home can be designed to produce as much energy as it consumes. One of the key design elements is taking advantage of the free energy provided by the sun. By having a lot of south-facing glass and a thermally massive floor (in this case concrete) you can get 30 to 50 per cent of your home's heat for free.

 

Podcast: Simplicity the key to net-zero homes

CKUA logoLes Wold is part of the second wave of net-zero home builders who are bringing costs down. A net-zero home is one that produces as much energy as it consumes and it is becoming more and more accessible. Wold has learned some simple lessons from building one net-zero home and two net-zero ready homes next to each other in the neighborhood of Belgravia in Edmonton.

 

 

 
Quick Facts

BELGRAVIA GREEN ENERGY CALCULATIONS

The  net-zero showhome is modelled to consume 28.9 GJ of heating energy per year.  Here’s how much energy each heating system would use for heat energy only (warning this is a simplified calculation):

Gas furnace (96% efficient): 30.1 GJ
Electric baseboard: 8027 kWh
Air Source Heat Pump (C.O.P. 2): 4014 kWh
Geothermal Heat Pump (C.O.P. 3): 2676 kWh
 
At $3.50/GJ and $0.08/kWh:
Gas furnace: $105.35
Electric baseboard: $642.16
ASHP: $321.12
GSHP: $214.08
 
If you add the fixed charges for gas service ($40/month X 12 months=$480):
Gas furnace: $585.35
Electric baseboard: $642.16
ASHP: $321.12
GSHP: $214.08
 
Compare this to the Taft residence (53 GJ/14722 kWh):
Gas furnace (96% efficient): 55.2 GJ
Electric baseboard: 14722 kWh
Air Source Heat Pump (C.O.P. 2): 7361 kWh
Geothermal Heat Pump (C.O.P. 3): 4907 kWh
 
At $3.50/GJ and $0.08/kWh:
Gas furnace: $193.20
Electric baseboard: $1177.76
ASHP: $588.88
GSHP: $392.59
 
If you add the fixed charges for gas service ($40/month X 12 months=$480):
Gas furnace: $673.20
Electric baseboard: $1177.76
ASHP: $588.88
GSHP: $392.59
 
As you can see, the less energy required for heating, the more attractive the electrical heating options are.  That’s because the more gas that’s used, the less of a percentage of total cost the fixed charges become.
 
NOTE: The Taft house heating requirements include the above garage office.  That’s why the figure is significantly higher.  When comparing just the houses, which are similar sizes, the heating energy requirements are virtually identical.  I used the higher figure for the purpose of illustrating how the costs change with a different variable.

 
Resources

These resources relate to this episode. They may be helpful in many ways, but we list them only for your information. This is not an endorsement of any of these programs, services or organizations and we make no guarantees about the products or services these companies or organizations may offer.

Paper: Design and Optimization of Net Zero Energy Solar Homes

By Remi Charron. A report prepared for ASHRAE. Useful for wider design considerations. GO >

Tags: Energy Efficiency, Solar

Paper: Identifying Affordable Net-Zero-Energy Housing Solutions

A report prepared by Gary Proskiw for Sustainable Buildings and Communities (Housing Group) CanmetENERGY.

Net Zero Energy Houses (NZEH) represent the ultimate development of low energy housing technology. Defined as a house whose annual energy consumption is equal to, or is less than, the energy generated using on‐site renewable energy systems, NZE houses are usually net consumers of energy during the heating season and net producers of energy during the non‐heating season. To appreciate how this technology evolved, it is interesting to briefly review the history of low‐energy housing technology in Canada. GO >

Tags: Energy Efficiency, Solar

Presentation: The challenges of designing and building a net-zero energy home in a cold high-latitude climate

The companion presentation for the paper written by Mark Brostrom and Gordon Howell. GO >

Tags: Energy Efficiency, Solar

Paper: The challenges of building a net-zero home in a cold high-latitude climate

Written by Mark Brostrom and Gordon Howell this paper is a technical exploration of the challenges faced when building a home that produces as much energy as it consumes in a location that sees winter temperatures dip below -30 Celsius and the winter solstice means it only gets 7.5 hours of daylight.


GO >

Tags: Energy Efficiency, Renewable Energy

Official website of the Net Zero Energy Coalition

The Net-Zero Energy Home (NZEH) Coalition is a federally incorporated, multi-stakeholder not-for-profit organization. It is comprised of North American champions in advanced energy efficient residential construction and building products, the utility sector, research and development, and manufacturing and deployment of on-site renewable energy technologies. GO >

Tags: Renewable Energy

 
Extras

Slideshow of Effect Homes' three net-zero houses - Flickr Slide Show

Even Martha Stewart is getting into the net-zero home game - Green Building Advisor

BC Hydro looks at the lessons learned from a net-zero home build - BC Hydro

Conrad Nobert has catalogued and blogged building and living in his net-zero home. If you're considering this option as a homeowner I would recommend reading this blog all the way through - Green Edmonton

Builder Peter Amerongen of Habitat Studio and Workshop gives a presentation on what he's learned from building multiple net-zero homes;

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6

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