Home again

We spent a fabulous week in Florida, working on Tai Chi (we aren't skilled enough for it to be all play). We met the instructor in the Atlanta airport on the way there - she recognized our T-shirts - she came down from Toronto. But now we're back. Here are some tracks we made coming home Tuesday morning (2 AM):















Note that the bottom of the car was acting as something of a snow plow.

Here's Rob doing some brushing:
















Can you see the two orange flags? Any guess as to what they mark?















That's right - beyond them is the drop-off. If you step out there, you'll sink to your knees and beyond.

Here's Rob adding some finishing touches to the shoveling:














Ester Dome from the top of our driveway:

Just a tiny bit of sun at sunrise this morning. It won't be long until it stays below that ridge on the right all day long:












I know this blog is pretty quiet. I've been posting more often over here.

Pink mountain

View on the drive home (new camera!):

Bunny Sitting

Some fun bunny sitting for a neighbor.  Just try to switch their water bottles out...

Bunny & Waterbowl...

GVEA Rates @ 96W: Do the math

Fairbanks, Alaska GVEA Rates as of 09/01/2011:

Each meter: $17.50/month
Utility charge: $0.08791/kWh/month
Fuel charge: $0.10924/kWh/month
Regulatory: $0.000492/kWh/month

What is the cost if you left a 96W light bulb on all the time?

First, calculate the kWh for the month, lets say 30 days on average.

30 days X 24 hours = 720 hours/month

720 hours X 96 Watts = 69120 Watt hours (Wh)

1000 W in 1 kW ==> 69.120 kWh of power used per month

Now multiply 69.12 kWh against the rates to get the cost of running 96W all day for a 30 day month:

For simplicity, we add all the rates up: $0.20207/kWh

69.12 kWh X $0.20207/kWh = $13.97 per month in power & regulatory fees.

With the meter charge, your nearly 100W light bulb is costing you $31.47 per month (or $377.64 per year).  That is some expensive light bulb!  No wonder they give out light bulbs for free at the annual meeting.

What things do you leave on all day?

What is left to save?

Here is an example. The power we are trying to save is the amps along the green line. During the day the system is consuming an average 4 amps. The higher spikes is the oil heater making hot water. If the system was turned off during idle periods, we could be conserving amp hours to stretch into our third day.

Additional note:

4 amps? This isn't 4 amps at 120V but 24V. Our phantom load is 96W or less than 1 amp at 120V (roughly 0.8 amps at 120V). So, at idle times we have a 100W light bulb on all the time. If we shut the house down, the inverter will consume much less.

Fall/Winter 2011 Project: More Power System Automation

We are still looking for ways to save energy and money on running the house, primarily during the winter. We are looking at a design that will potentially expand the same battery bank to last for 3 days instead of 2 days. Many of the parts have already been purchased. The one piece I could not find in Fairbanks is a torque wrench that can reasonably show me a torque of 3 1/2 newton meters. The standard torque wrenches from a auto supply store are factors much higher than that.

Why 3 1/2 newton meters (approximately 2+ foot pounds)? That is what is suggested by the inverter manufacturer when tightening the lug nuts for the connection. Higher pressure and you risk breaking the lugs (and voiding the warranty).