PV without Batteries?

If you want to run one item at about lunch (such as an electric frying pan) for about an hour with a full sunny day (and plan on only using the pv on full sunny days) would you need batteries? Any links to info or to books about using pv to run one item like an electric frying pan would be appreciated.

sgotr wrote:

If you want to run one item at about lunch (such as an electric frying pan) for about an hour with a full sunny day (and plan on only using the pv on full sunny days) would you need batteries? Any links to info or to books about using pv to run one item like an electric frying pan would be appreciated.

I'm sure others here are more qualified to answer your question. (so I won't try other than to say that it's certainly possible)
And maybe this comment wil be irrelevant to your situation, (for illustration only, not real numbers, ignores charging efficiency etc) but consider that 1000 watts of PV is a lot more expensive than 1000 watts of battery. ie, a 12V battery that supplies 80 amps is putting out ~1000 watts and will cost around $100. I don't know what PV goes for these days but I'll guess 1000 watts of PV would cost several thousand dollars. Say yor PV is $1000 for 1000 watts. you could use it for an hour and let it sit idle the rest of the time. or you could buy 100 watts of PV for $100 and let it charge an 80 amp hour, 12 volt, $100 battery for 10 hours and have spent $200 instead of $1000

sgotr wrote:

If you want to run one item at about lunch (such as an electric frying pan) for about an hour with a full sunny day (and plan on only using the pv on full sunny days) would you need batteries? Any links to info or to books about using pv to run one item like an electric frying pan would be appreciated.

A frying pan is a horrible example. You can build yourself a parabolic reflector roughly one square meter and it'll provide more than enough heat to fry anything you want. http://www.solarcooking.org/plans.htm
As the other fellow said, you can use solar PV to run something without batteries but you'll spend more. People are agreeable to this if they are powering small devices like calculators, transistor radios, boom boxes or other such things that don't need much power. Even with these, the addition of a battery helps.
Anthony

sgotr wrote:

If you want to run one item at about lunch (such as an electric frying pan) for about an hour with a full sunny day (and plan on only using the pv on full sunny days) would you need batteries? Any links to info or to books about using pv to run one item like an electric frying pan would be appreciated.

Lets say your electric frying pan needs 1500 watts. with a battery, your pv array would need to be 1500 watts minimum at a cost of about $9000. With batteries, it could be 600 watts ($3600) and 4 batteries for a cost of $200. Hooking up an inverter directly to a pv array without a battery isn't recommended either, due to high panel voltages.
-- Steve Spence Dir., Green Trust, http://www.green-trust.org Contributing Editor, http://www.off-grid.net http://www.rebelwolf.com/essn.html

A frying pan is a horrible example. You can build yourself a parabolic reflector roughly one square meter and it'll provide more than enough heat to fry anything you want. http://www.solarcooking.org/plans.htm

Will boil water and oil?
Olushola

On Tue, 14 Mar 2006 10:10:32 -0500, Steve Spence wrote:

sgotr wrote: If you want to run one item at about lunch (such as an electric frying pan) for about an hour with a full sunny day (and plan on only using the pv on full sunny days) would you need batteries? Any links to info or to books about using pv to run one item like an electric frying pan would be appreciated.
Lets say your electric frying pan needs 1500 watts. with a battery, your pv array would need to be 1500 watts minimum at a cost of about $9000. With batteries, it could be 600 watts ($3600) and 4 batteries for a cost of $200. Hooking up an inverter directly to a pv array without a battery isn't recommended either, due to high panel voltages.

A large majority of PV installations that are NOT fully off-grid have no batteries - just a grid-yie inverter - and they have no power when the grid goes down. Kinda silly in my opinion, but most common practice. *** Free account sponsored by SecureIX.com *** *** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com ***

olushola wrote:

A frying pan is a horrible example. You can build yourself a parabolic reflector roughly one square meter and it'll provide more than enough heat to fry anything you want. http://www.solarcooking.org/plans.htm
Will boil water and oil?

Sure. If you want it to boil water faster then you just build it bigger. I built one 4 feet on a side (square) that would ignite paper and wood within seconds when waved through the focal area. Did a pretty good job cooking anything that would fry in a pan.
It's not difficult to build such a device. A little cardboard, a little glue, some foil or 'space blanket' mylar, a little time. It's the kind of arts and crafts that they could be teaching small children right along with coloring inside the lines and learning how to print their own name.
Anthony

Anthony Matonak wrote:

olushola wrote: A frying pan is a horrible example. You can build yourself a parabolic reflector roughly one square meter and it'll provide more than enough heat to fry anything you want. http://www.solarcooking.org/plans.htm
Will boil water and oil?
Sure. If you want it to boil water faster then you just build it bigger. I built one 4 feet on a side (square) that would ignite paper and wood within seconds when waved through the focal area. Did a pretty good job cooking anything that would fry in a pan.
It's not difficult to build such a device. A little cardboard, a little glue, some foil or 'space blanket' mylar, a little time. It's the kind of arts and crafts that they could be teaching small children right along with coloring inside the lines and learning how to print their own name.
Anthony

One thing I really don't like about this type of solution is the extreme amount of light seen at the focus point. Welders wear goggles to protect their vision. It seems only common sense to shield the eyes from direct viewing of the focus area, something that kids are unlikely to do without supervision.

"sgotr" wrote in message

If you want to run one item at about lunch (such as an electric frying pan) for about an hour with a full sunny day (and plan on only using the pv on full sunny days) would you need batteries? Any links to info or to books about using pv to run one item like an electric frying pan would be appreciated.

What an incredible example of gross inefficiency. If you've got the money to burn, why not? But the cost of such a system would probably buy several lifetimes worth of bottled gas to do that same task.
I have another concept for you. I call it the "diesel-powered pencil sharpener."

"JoeSP" wrote:

I have another concept for you. I call it the "diesel-powered pencil sharpener."

LOL! I remember as a kid the first time I saw an electric pencil sharpener. I had a similar reaction.

In article , hchickpeaREMOVEME@hotmail.com says...

"JoeSP" wrote:
I have another concept for you. I call it the "diesel-powered pencil sharpener."
LOL! I remember as a kid the first time I saw an electric pencil sharpener. I had a similar reaction.
A couple years ago, when my 10 and 12 year old nephews saw my hand-

crank Boston brand pencil sharpener (the kind that used to be in almost every classroom in the US), they went nuts. Wow, no power cord, no batteries! How does it work? They sharpened the heck out of every pencil they could find.
steve

Thanks - the pv panel would need to produce 1,000 watts to run a 1,000 watt electrical product therefore the battery setup would lower the need on the pv panel wattage from the 1,000 watts.