During the last half of January, the MCNZH consumed a whopping 957 kWh and produced a measly 121 kWh.

Here’s were we are so far on the year (starting October 18, 2010):

Consumption

Electricity Consumption, MCNZH, Oct 18 2010 - Jan 31 2010

We've consumed 4943 out of an estimated 8000 kWh.

Production

Electricity Production, MCNZH, Oct 18 2010 - Jan 31 2010

We've produced 845 out of an estimated 8000 kWh.

And here is how much of the year we have left:

Blue is how much of year has passed (Oct 18, 2010 – Jan 31, 2011).

105 days have passed. The warmest and sunniest days are ahead!

During the past 31 days the house consumed 1810 kWh and produced only 152 kWh. OUCH!

Our total consumption to date (since October 18) is 3986 kWh, with total production at 724 kWh. Since our total annual consumption budget is 8000 kWh, we’ve burned through 50% of our electricity budget.

Sounds pretty bad right? The game isn’t over just yet. We’ve just come through three of the four darkest months of the year. By February 15, we will be getting as many sunshine hours as we do on October 27. Plus, last year we virtually stopped heating the house as of the second week of February (due to a sunny, mild month).

So we are still in the ballpark, but we will definitely need some luck for this to be a net zero energy year.

Some numbers and observations:  read more... »

Free heat bathes the Mill Creek NetZero Home’s east wall.

October 18 – Dec 15

• • Net Import: 1995 kWh
  • Net Export: 391 kWh
  • Total Production: 572 kWh
  • Total Consumption (imported + production – export): 2176 kWh

On the production side, we produced about 9.7 kWh/day when our annual expected daily average is 23 kWh/day.

I’m a bit concerned that we consumed such a boat load of electricity over the past two months. We used 37 kWh/day. Most of that is space heating energy. Our annual expected daily average use is 23 kWh/ day.

I still think we’re in the game. The months clustered around the winter solstice will understandably be when we consume the most and produce the least. Last year we pretty much stopped heating on February 12th, so even if we burn up a large deal of our energy budget by then, the good times will have arrived.

Whatever happens, there will be no denying the numbers.

Today’s readings (October 18 readings in parentheses):

• bi-directional power meter (total import and export of electricity for the house):
  • import: 6155 kWh (4160 kWh)
  • export: 3327 kWh (2936 kWh)
• inverters (cumulative production from each of two PV arrays):
  • fixed modules: 3881kWh (3683 kWh)
  • movable modules: 990 kWh (616 kWh)

From a presentation that I gave a couple of years ago, the above slide shows the assumptions that we made in claiming that the Mill Creek NetZero Home (MCNZH) will produce all of the energy that it needs on a net annual basis. We got the numbers by running HOT 2000 simulation runs, estimating hot water consumption (ignore the stuff about WATSUN – it proved to be inaccurate), making best guesses on appliance use based on Energuide numbers, and by consulting Edmonton solar electricity guru Gordon Howell about how much production we would get out of our PV modules.

There are three adults (one with his own stove and fridge downstairs) and two chillins living in the house.

After living in the home for 1.3 years, the space heating number looks low. On the other hand, the appliances number looks high.

I think we’ll be in the ball park, at the very least.