Mill Creek NetZero Home

Planting Grass (or, Just Say No To Sod)

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We decided to add a patch of grass to the Mill Creek NetZero Home’s yard. Although xeriscaping has become popular among Edmonton homeowners who don’t want to do any yard work (shouldn’t they really just buy condos?), there’s a problem with it: it can be ugly and uninviting. Too often, it involves yards full of itchy scratchy rocks:

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Anyone feel like sitting down and having a picnic?

Grass has its place, and it can have a minimal impact while at the same time providing an inviting space to sit and/or play soccer.

(Not) Watering

I have never watered an established piece of grass turf. Not watering is the key to grass being a benign, easy-to-care-for piece of a yard. When it’s dry in Edmonton, I just let the grass go brown. Of course, this is easier in my neighbourhood than in most. You see, we’re dirty hippies in Mill Creek. We elect communist politicians, and we care more about how much food you grow in your yard than how immaculate your monoculture front lawn is. That said, I would take the same stand anywhere. Grass is not a good enough reason to use up drinking water.

I have also never fertilized grass. If you really want a yard to be a lot of work, fertilize and water your grass often.

Planting Grass (Just Say No To Sod)

The two major ways in which we "greened" our little patch of grass was to plant it from seed, and to choose a drought-resistant variety.

Sod production uses a lot of chemicals and a lot of diesel fuel. It then uses more diesel to transport the pieces of sod to your yard.

Instead of phoning the sod guy, I picked up a bag of Scotts Pure Premium Heat & Drought Grass Seed Mix from Home Depot for $17. Containing "varieties of Chewing Fescue, Creeping Red Fescue, Kentucky Bluegrass and turf-type Perennial Ryegrass", it will look and feel better than regular grass on the rain-only diet that I intend to feed it.

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I seeded the grass in early spring following the instructions from one of the many grass seeding videos on Youtube. I did ignore the boilerplate advice to fertilize the soil before seeding. Grass will grow just fine without ever being fertilized. The city has great advice on grass' ongoing maintainenance.

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We're happy with how our grass turned out. The kids will finally have a place to play soccer, and the cheapskate in me is enthused that we only spent a few bucks to get it.

Landscaping - Sidewalks, etc.

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(Mill Creek NetZero House backyard)

Ron Berezan of Urban Farmer fame designed and constructed our yard. He thoughtfully helped us create a beautiful space with as little environmental impact as possible (I’ll discuss the permaculture aspects of the design in a future post).

We wanted a sitting place in the yard, as well as paths, sidewalks, and a large window well to let sunlight into the basement. We also wanted to minimize the use of concrete in the yard. Concrete has a huge carbon footprint, and is rarely reusable (it can be recycled, but only with a major downgrade in utility – it basically becomes gravel).

To achieve our goals, we used paving stones, reused sidewalk blocks, reused bricks, field stones and wood chip mulch.

Paving Stones and Reused Sidewalk Blocks

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(sidewalk blocks and red paving stone sidewalk, Mill Creek NetZero Home)

We used sidewalk blocks that I salvaged from the yard (before we built the house) in combination with red paving stone to create our outdoor patio and sidewalks. The humble sidewalk block has a lot of potential to save concrete in Edmonton. It is found piled up in back alleys across the city in virtually the same shape as when installed in the 60s and 70s.

We chose paving stones for the front sidewalks as well. Although they are very energy-intensive to produce, they are extremely durable, and they retain their value as a reusable product for many years. A properly-made paver can be pulled up and installed elsewhere 50 years after it was first installed, and still look and act as good as new.

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(paving stone sidewalks, Mill Creek NetZero Home front yard)

Actually, if we had known how well the sidewalk blocks would work, we would have used them in the front yard as well.

Field Stones

To build a retaining wall and a window well, we chose to use field stones.  read more... »

A Net Zero Energy Year : April 2011

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Energy use, MCNZH, April 2011. Negative numbers represent export of electricity.

Our Net Zero Energy Year finally turned around in April. We stopped heating the house pretty much as of March 31, and it’s been generally sunny ever since.

Here are the numbers for Oct 18, 2010 – April 30, 2011 (all units in kWh of electricity):

Consumption: 7643

Production: 2785

Net Consumption: –4858

We’re in the hole overall, but April was a net positive month. We exported 550 kWh to the grid!

A Net Zero Energy Year : February and March 2011

 

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The above picture would actually be one of grey skies and snow if it represented March and February of 2011, but I’m not one to dwell on bad weather.

Barring a solar miracle, the Mill Creek Net Zero Home (MCNZH) will not be net zero in its energy consumption for the period of Oct 18, 2010 – Oct 17, 2011. The fact is, it was a tough winter for a passive solar house, with cold temperatures in February, and a very overcast March.  In 2010, for example, we virtually stopped heating the house by the second week of February. This year, it was April before the heaters stopped kicking in.

The results so far bring us back to some of the questions I asked when we started this little experiment. Although I have no sunshine data for this year, I’m sure that it was below average for insolation (how sunny it was). Here are some numbers on how sunny Edmonton has historically been:

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(source)

The three-week period in March 2011 without a ray of sun makes me sure that we came well under these numbers this winter.

Here are the numbers for Oct 18, 2010 – March 31, 2011 (all units in kWh of electricity):

Consumption: 7333
Production: 1925

So we’re –5408 on a net basis for the year. Even though we’re just entering our prime solar production months, I don’t think we’ll cover the bet.

Here is a snapshot of the net power consumption for the months of February and March, 2011. Negative numbers represent exporting of power to the grid:

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Our net energy use was higher in March than in February due to the aforementioned overcast weather.

A couple of daily snapshots:

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March 28, 2011 was a terrible day for solar houses in Edmonton. The sun hadn’t shone for days, so the thermal mass in the house had lost its solar charge. The weather wasn’t that cold (low of –5, high of 0), but the heaters ran all day to keep the house heated.

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On the other hand, February 25, 2011 was the kind of day that our house was built for: brutally cold (a low of –26, high of –9) but sunny. Notice how the energy use is much lower after 6pm than it was in the middle of the night. That is the residual effect of the day’s sun keeping the heating load down.

These days our PV arrays are really cranking out the juice. It will be interesting to see how close we can come to overcoming our deficit.