Calculating Module Wattage

[Mike90250]

The good "energy star" rated fridges in the USA, generally consume about 1Kwh daily. A freezer may be about 2/3 of that. So you are looking at needing about 2KWh daily harvest, and about 8KWh storage.

And you will need a pure sinewave inverter to power the fridges with. Starting surges can be quite high (5-10x running power) for fridges, so you will need an inverter large enough to power 1 fridge, and have enough capacity to start the other. Most of the high efficency fridges need power 24/7 so you need an inverter to power them all the time, Idle or Sleep mode not wanted for the inverter.

A non-energy star fridge, would consume about 2x the power for 1/2 the cost !!

[tag]

A non-energy star fridge, would consume about 2x the power for 1/2 the cost !!

Hi Mike,

I am not sure what you mean by this statement.....would you please spell it out for me. Thanks.

Tag

[Mike90250]

A non-energy star fridge, would consume about 2x the power for 1/2 the cost !!

Hi Mike,

I am not sure what you mean by this statement.....would you please spell it out for me. Thanks.

Tag

18CF fridge:

ES fridge= $900 1KWh daily usage
cheap fridge = $400 2KWh daily power usage (twice the PV, twice the batteries to replace, larger charge controller, larger inverter)

So conserving power, with a ES frodge, costs you the price of an additional solar panel, but you save a lot over the span of 10 years, with other gear you don't have to buy

http://www.energystar.gov/index.cfm?fuseaction=refrig.calculator

And don't cheap out and think a mini-fridge will save you anything, because for their small size, they waste as much power as a full size fridge does.

[Amy80a]

calculating module wattage

The output of photovoltaic systems varies with the intensity of sunshine and other conditions. The more sun, the more power the PV module will generate. Losses, compared to performance in optimal conditions, will occur due to non-ideal alignment of the module in tilt and/or azimuth, higher temperature, module power mismatch (since panels in a system are connected in series the lowest performing module defines performance of the string it belongs to), soiling and DC to AC conversion. Importantly, power, a module generates in real conditions, can exceed the nominal power, when the intensity of sunlight exceeds 1000W/m2 (which corresponds roughly to midday in summer in, for example, Germany) or when sun irradiation close to 1000W/m2 happens at lower temperatures.

Source : http://en.wikipedia.org/wiki/Watt-peak