PV Gap

Lisa Said:

Help! Please compare the power capacity of these 2 rechargable batteries and tell me which has higher capacity?

We Answered:

first is listed at 20000 mAH (74W/h) (both numbers are listed)
The second number is presumably 74 watt-hour, as W/h is meaningless.

second is listed at 133 watts one one line, and at 133 Watt/Hours on a different line, which are obvious mistakes, it should presumably be 133 watt-hour.

Just on the numbers, 133 is larger than 74.

But I would not trust the second one, given the two basic mistakes in their ad.

For the first one, it also has arithmetic problems. 20000 mA-hour translates to 20 amp-hour. Multiply by the voltage output of 22 volts to get 440 watt-hours, which is much different from 74 watt-hours.


So, bottom line, neither of the specs make sense, they are riddled with internal errors, so I don't know which is best, which to believe.

But in general, you can take the amp-hour rating and multiply it by the voltage to get watt-hour (amp x volts = watts).

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Gail Said:

Nuclear power plants vs solar power?

We Answered:

Even if nuclear power was more (and I suspect..but don't know, that it is) Nuclear comes with waste problems. Also there is no industry around that is 100% accident free...an accident with nuclear can have devastating consequences. My vote: Solar with energy effecient products and reduction in usage.

Frank Said:

How much does the national grid by electricity for?

We Answered:

You will be paid 3p per kWh for the electricity you sell, and the ridiculous government feed in tariff (look it up!) will pay you 41.3p.

Link here to what companies pay:
http://rwecom-online-report-2009.product…

Companies typically pay under 4p to the power producer, although there was a big price spike in '08 to 10-12p a kWh for a few weeks.

Rhonda Said:

Solar Powered Torch Circuit?

We Answered:

yup, that looks like what you want. I'd buy 2, they are cheap enough, and you'll have spares.

Don't forget the batteries in your parts list. A solar torch isn't useful unless it can provide light when the sun is out, ie, it's dark. So it needs batteries to store the energy from the sun for later use.

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