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Beware of the Power Parasites!

(Calulating power use)

Going back to this accounting of power use, lets have a think about those parasitic type loads that your house may have. The clock on the microwave, the T.V. on standby, look around and I'm sure you can find a few more. I know that my TV on standby draws 30 watts so I turn it off at the wall.

What would happen if it was left on for 24 hours??


24hours X 30watts = 720watt/hrs


For a house on the grid that is only a few cents worth of power but when you have to produce it yourself, it is a very different story. 720 watthrs is about the amount of power my chest freezer uses a day and I'd much rather it was consumed there than by a TV waiting to talk to the remote!

That's 24% of our 3000 watts and it's only one example. 4 more loads like that and nearly all the power in a 3kW/day system is used up! An analogy I have used else where on this site is that it is like having a leaky tap when you are on tank water


I have seen a calculation that suggests that over the life of the machine the clock on a microwave oven uses more than the microwave does cooking!

Inverters that don't go into standby mode are another potential power waster but we'll deal with this when we talk about the various devices that a power system is comprised of. See our system components page.

2012 Many modern firdges need continuous power for their thermostats so we are finding that search mode can not be used as often as it once was. Fortunately with solar being so much cheaper now, an extra panel to compensate is not the financial burdon it once was.

So, before you plan to go off grid take a while to think about how much power you are using and for how long.

Perhaps a simple log book may be the answer. Have a think about seasonal changes.

I have noticed with our system we tend to use more power in summer because the fridge and freezer work harder. Its pretty difficult to measure how much your refrigeration is using, so allow 500-1000 watthrs. As an example: Our fridge and chest freezer combined use about 1000 watthrs a day. One of the better upright fridge freezers we sell is rated at 460 watthrs/day.

So grab that notebook and pencil and see how close I came with my 3 kilowatthrs / day Guestimate.



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