08 Feb 09
Originally posted by FabianFnasVoltage, 100 million volts, amperage over 1000 amps, duration, about 100 milliseconds peak. Joule-wise, it amounts to about ten Giga joules I think.
Let's do some moth here. One thing we want to know is how much energy (kWh) there is in one bolt of lightening, right? Is it worth to harvest energy from bolts at all?
Okay, What we need to know before we do the mat is the following, and you have to help me to get these parameters...
How many Volts in one bolt?
How many Ampere in one bolt?
Myltipl ...[text shortened]...
To do this calculation we need Volts, Ampere, and duration of one bolt.
There I need help.
20 Feb 09
1 edit
Originally posted by FabianFnasA joule is a watt spread out over one second, a joule is a measure of energy. The watt-second is how quickly that one joule is expended. So there are processes with ultrafast lasers that use rather small amounts of actual joules but compress that joule to expend in say, 1 picosecond or faster, and achieve some result like drilling holes and such that would not happen with the same amount of energy expended in a longer period of time. The target gets slammed with what would be like the entire energy production of a country if that amount of expendature went on for a whole second. So that # of 10Gigajoules is an amount of power that would be 10 billion watts if expended in one second. or 1 billion watts spread out over 10 seconds, or 1 watt if it was divvied out over 10 billion seconds. It's like pouring water into a glass. The glass being the # of Joules. You can fill that glass in one picosecond but you stop when the glass is full, so you have used up one joule but it was compressed in time to one picosecond so for that instance of time, it can act like it was a thousand gigawatts.
Okay, 10 GJ. What's that in kWh?
Perhaps I'm surprised here...?
Getting back to your question then, 10 Gigajoules in Kw hrs, assume you mean how many Kw would that be spread out over one hour, so at one joule/second being one watt, just divide 10 E9 by 3600 (# of seconds in an hour) and you get 2.7777 million watts if spread out over an hour. So that would be 2,777 Kwhr.
20 Feb 09
5 edits
Originally posted by twhiteheadWell, a house averages about 2 Kw's going 24/7 so that is about 50 Kwhr/day so 100 times 180, about 18,000 Kwhr/yr per house so If you get 2,777 Kwhr per bolt, it could power a single house (assuming you can capture that much energy that quick) for about 2 months. So I would take 6 such bolts to power a single house for a year.
How many lightening bolts would it take to power 1 house for a year?
Now where is that boltcatcher🙂
Around my neck of the woods, our house gets close, that is to say, physically close, to maybe 3 bolts per year and if you could collect it, that would be about 6 months worth of power. But since by saying close, we would mean they come say within 100 feet of our yard, then if such an invention were to come about, that energy would have to be shared by people in some defined area. Around here, lightning comes mainly in September and by October there is no more. I don't think when all is said and done, there would be enough energy harvested to be worth it, at least in Pennsylvania, USA. I assume there are hot spots lightning-wise somewhere on the planet that could extract a lot more energy but I am not an atmosphere scientist, just an optical tech, so I don't know where those hot spots would be. Google would have it probably. Well Yahoo Answers says the southern states in the US, plus New Mexico and Wyoming get the most lightning. I used to live in Lincoln Nebraska (don't ask🙂 and the plains states get the weirdest lightning, more cloud to cloud sheet lightning than stuff that hits the ground, I guess if you made an attractor tall enough it could still suck out some of that energy, if you put two insulated towers a few hundred feet or half mile apart, just a guess. Two big asss kites with wires up in the air might do the trick too. Wouldn't want to be the one launching the thing though🙂
I think it's pretty much a pipe dream, you have to collect some multiple gigajoules that comes at you in one tenth of a second or so and somehow divert and store some 3,000 Kwhr safely and reliably.
I don't think we can collect ONE kwhr if it comes at you in one tenth of a second pulses much less thousands! Think about solar collectors, the ones that concentrate 200 times, now maximum in space with no pesky atmosphere to stop solar energy, which is about 1300 watts per square meter. So if you collected 200 square meters and stuffed it in a one square meter area, you would have ~270,000 watts per square meter. That would be like being about 10 million Km from the sun (sqr of 200=14.14 and change, 148 million Km / 14.14= about 10.5 million Km) That is WAY inside the orbit of Mercury. On Earth we get maybe half of that at best, and they can capture it with major cooling effort but that's with lots of cooling fluid which happens to make solar power more efficient if you can use that heat. There are plans afoot to put a spacecraft actually about that distance from the sun but they are making major efforts to SHIELD such a craft from that much power coming at it from the sun, and they think they can do it with a structure made out of something like the heat shield ceramic tiles that go on the Space Shuttle, but that is nothing like USING that power, that is SHUNTING it away so it doesn't fry the space probe. So we are a long way from getting even close to capturing and using a lighning bolt!