12 Volt Residential Systems
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Following that logic would 240VAC be better than 120VAC, Oz runs on 240 and I have always wondered why, other than we probably followed the UK standards. I obviously know practically nothing about electricity, we installed solar and I only then found out the house we bought has 3 phase power and therefore I needed to know what the hell it is. Now I'm looking for and efficient 3 phase battery solution.
Never underestimate the power of human stupidity RAH
USA did not follow UK standards! UK standard is 240volt for standard domestic supply and 440volt of 3 phase.
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You can get a reasonable lumpy DC supply from three phase with a suitable capacitor and that gives you the ability to run arc welders, lighting stantions (out door concert lights) all sort of big boy toys that you probably not want or need in your life, however a lumpy dc with near 100 amps means you could charge Tesla's with ease. Nice to have but you will pay over the odds to get kit that uses it safely keep with the safer more manageable 240v instead of 415v, you could use one phase for charging the battery pack, the other two for running the house. :)
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Following that logic would 240VAC be better than 120VAC, Oz runs on 240 and I have always wondered why, other than we probably followed the UK standards. I obviously know practically nothing about electricity, we installed solar and I only then found out the house we bought has 3 phase power and therefore I needed to know what the hell it is. Now I'm looking for and efficient 3 phase battery solution.
Never underestimate the power of human stupidity RAH
Wkipedia knows it: Three-phase - Wikipedia[^] Here in Germany power is always supplied as 3-phase for building connections. But private households usually do not have equipment that requires it. The only common devices that have 3-phase connections are cookers. But they just split it into three 240 V lines internally (e.g. one for the stove and the others for two plates each) and can be usually also connected to one or more 240 V lines. Similar is done in the distribution boxes: Splitting into three 240 V lines for supporting the different connections. There is also no "3-phase battery solution". There are DC batteries loaded by the panels and a switch supply generating the required AC. You might ask an electrician if it is really necessary to use a 3-phase switch or if the output of a 240 V switch can be attached to some or one of the 240 V lines from the distribution box (assuming that the solar power is not able to power the whole house).
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Wkipedia knows it: Three-phase - Wikipedia[^] Here in Germany power is always supplied as 3-phase for building connections. But private households usually do not have equipment that requires it. The only common devices that have 3-phase connections are cookers. But they just split it into three 240 V lines internally (e.g. one for the stove and the others for two plates each) and can be usually also connected to one or more 240 V lines. Similar is done in the distribution boxes: Splitting into three 240 V lines for supporting the different connections. There is also no "3-phase battery solution". There are DC batteries loaded by the panels and a switch supply generating the required AC. You might ask an electrician if it is really necessary to use a 3-phase switch or if the output of a 240 V switch can be attached to some or one of the 240 V lines from the distribution box (assuming that the solar power is not able to power the whole house).
We pump the same amount into the grid during the day as we use after the sun stops, paying 50c kwh getting 6c kwh. If I could use that 50% I could almost eliminate the power bill.
Never underestimate the power of human stupidity RAH
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Charging your home and your Tesla on solar? Only if your roof is big enough. :suss:
... such stuff as dreams are made on
I have seen some Aircraft Hangers suitable, however the heating bill in the UK would be a down side...
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USA did not follow UK standards! UK standard is 240volt for standard domestic supply and 440volt of 3 phase.
Well 240 is the old now you can get anywhere from 227 to 250 out your wall socket thanks to the fact the EU use 230 (with no earth!) and the 'easyest' way was to relax the standards. Not really an issues as most devices like washing machines will take 220-250 to make life easier for the manufacturer and most things that don't use motors have a switch mode power supply...(just to make life awkward for RF engineers...) :rolleyes:
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We pump the same amount into the grid during the day as we use after the sun stops, paying 50c kwh getting 6c kwh. If I could use that 50% I could almost eliminate the power bill.
Never underestimate the power of human stupidity RAH
You could buy a threephase UPS and modify it. But they're fucking expensive.
Wrong is evil and must be defeated. - Jeff Ello
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We pump the same amount into the grid during the day as we use after the sun stops, paying 50c kwh getting 6c kwh. If I could use that 50% I could almost eliminate the power bill.
Never underestimate the power of human stupidity RAH
Sounds good. Then you already have a switch supply and just need some batteries inbetween (and calculate the time until it gets a good return).
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Wkipedia knows it: Three-phase - Wikipedia[^] Here in Germany power is always supplied as 3-phase for building connections. But private households usually do not have equipment that requires it. The only common devices that have 3-phase connections are cookers. But they just split it into three 240 V lines internally (e.g. one for the stove and the others for two plates each) and can be usually also connected to one or more 240 V lines. Similar is done in the distribution boxes: Splitting into three 240 V lines for supporting the different connections. There is also no "3-phase battery solution". There are DC batteries loaded by the panels and a switch supply generating the required AC. You might ask an electrician if it is really necessary to use a 3-phase switch or if the output of a 240 V switch can be attached to some or one of the 240 V lines from the distribution box (assuming that the solar power is not able to power the whole house).
I think that it is standard in most European countries with the exception of UK.
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USA did not follow UK standards! UK standard is 240volt for standard domestic supply and 440volt of 3 phase.
Mycroft specifically mentioned Australia, not Merka. Reread his post.
Michael Martin Australia "I controlled my laughter and simple said "No,I am very busy,so I can't write any code for you". The moment they heard this all the smiling face turned into a sad looking face and one of them farted. So I had to leave the place as soon as possible." - Mr.Prakash One Fine Saturday. 24/04/2004
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Following that logic would 240VAC be better than 120VAC, Oz runs on 240 and I have always wondered why, other than we probably followed the UK standards. I obviously know practically nothing about electricity, we installed solar and I only then found out the house we bought has 3 phase power and therefore I needed to know what the hell it is. Now I'm looking for and efficient 3 phase battery solution.
Never underestimate the power of human stupidity RAH
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Now I'm looking for and efficient 3 phase battery solution.
In case you are NOT joking... (The above is the sort of joke EE guys might crack!): There is no such thing as "phases" in battery power. With 3-phase AC, (in the most common layout, you have 4 wires coming into your house. One is neutral, the 3 others carry a voltage varying along a 50 Hz (Europe) or 60 Hz (US) sine curve, relative to the neutral line. The 3 are "out of step" with each other, by one third of the entire 50/60 Hz sine curve, i.e. the voltage on the second wire reaches it peak 1/150 (US: 1/180) sec after the peak of the first wire, the third wire peak comes 2/150 (US: 2/180) sec after the first one - and after 3/150 (US: 3/180) sec, the first wire is at its next peak. Battery voltage is flat, it doesn't come in sine curves. It has no peak recurring every 1/50 (US: 1/60) second. If you need that, you may use the battery power to drive a DC motor that pulls a generator (i.e. a dynamo), which may provide either a single sine-curve voltage, or three that is out of step, like your old 3-phase power supply. Today, the motor and dynamo is frequently replaced with electronics that do the same thing without moving parts, and with lower losses; it is often termed an "inverter". Practically all your electric appliances do NOT use 3phase power: They hook up to the neutral wire and one of the 3, ignoring the remaining two. So they see only a single sine curve voltage, a single phase. Your power company is very happy if you hook up your dishwasher between wire 1 and neutral, your washing machine between wire 2 and neutral, and your electric heater between line 3 and neutral, in particular if you run them at the same time. If you put them all on the same wire, leaving the other two un-utilized, it might contribute to imbalance of the power supply system. (It is less of a problem if your 1000-houshold neighbourhood hooks up to the same supply transformer, but it is nevertheless a good practice. The decision which wire to use is done when your fuse box is installed: The circuit feeding your dishwasher hooks up to power wire 1, the circuit to you laundry room hooks to power wire 2 etc. So you don't have to worry about this in your daily life, but if you build a new house, the electrician doing the hookup should be informed about your major power surges, so that those circuits are distributed over the 3 power lines. There ARE appliances that hook up to all three power wires (plus neut
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I was looking at some Solar Energy stuff. The question in my mind: Can these systems truly power the common residence today ? I'm thinking, it's easily conceivable that the normal home today can be running these appliances all at once; particularly in the late afternoon and evening... * Washer * Dryer * Stove * Oven * Microwave * Water Heater * HVAC (in all its variations) * Computers * TVs * Vacuum Cleaner(s) * Refrigerators and Freezers ...and I'm sure my list is incomplete. I'm wondering (and asking those who have electrically minded brains which are superior to my own) is the extant 120 Volt grid a factor in all this ? I just bought a bunch of LED replacement lightbulbs last month. My guess is that, bang for the buck, the point of max economy today is about 80 or 90 Lumens Per Watt. (I welcome correction on that figure; it's based on my observation of a local grocery store's shelves.) Now then, if we can get 85 Lumens per watt from these new fangled bulbs, and if we can get a solar system that delivers lower voltage (e.g. 12 volts; whatever) yet higher current (big "ifs",,, I know) then do I have a workable science turned business model ?
I am putting together such a system at the moment but only the outdoor lighting will be off pure DC - the rest will be through DC/AC inverter. If you are doing a separate circuit this is reasonably easy. If you want to feed the solar into your existing mains power you need a grid tie inverter (so your phase matches the AC phase of the power company) and probably a professional electrician at that stage.
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Wkipedia knows it: Three-phase - Wikipedia[^] Here in Germany power is always supplied as 3-phase for building connections. But private households usually do not have equipment that requires it. The only common devices that have 3-phase connections are cookers. But they just split it into three 240 V lines internally (e.g. one for the stove and the others for two plates each) and can be usually also connected to one or more 240 V lines. Similar is done in the distribution boxes: Splitting into three 240 V lines for supporting the different connections. There is also no "3-phase battery solution". There are DC batteries loaded by the panels and a switch supply generating the required AC. You might ask an electrician if it is really necessary to use a 3-phase switch or if the output of a 240 V switch can be attached to some or one of the 240 V lines from the distribution box (assuming that the solar power is not able to power the whole house).
Jochen Arndt wrote:
But private households usually do not have equipment that requires it. The only common devices that have 3-phase connections are cookers.
Anything that contains large electrical motors may be wired for 3-phase. For domestic use, that may go for centralized air condition systems, as well as for heat pump systems for ground collectors. (Yes, the two are essentially the same thing in different wrapping!) If you go green and get yourself an electrical car, fast chargers usually require a 3phase power supply. Traditional hot water heaters has here in Norway been tanks of typically 2-300 liters of water preheated to 80-95 C, with a heat loss of typically 100W, or 1000 kWh per year. If house is poorly insulated, the loss may useful as house heating, maybe 6-9 months of the year here in Norway. With modern, well insulated houses, it is a waste, and some people replace the tank with an electrical on-the-fly heater (like gas heaters common in some other countries). These typically draws 25-30 kW while the water is running. At those levels, we use 3 phase power as well. In "the old days", say, 30+ years ago, 3-phase was not common in households, although it might be available in the cable in the street. I didn't have 3phase to my house, but having it installed 25-30 years ago was straightforward. Today I need it for the heat pump (ground heat) and the sauna heater. Since I am on an IT grid, I can't get a 3phase car charger (unless I buy an expensive, huge transformer for IT-to-TN network), but on the other hand: I just bought myself a new car that is NOT electric.
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Following that logic would 240VAC be better than 120VAC, Oz runs on 240 and I have always wondered why, other than we probably followed the UK standards. I obviously know practically nothing about electricity, we installed solar and I only then found out the house we bought has 3 phase power and therefore I needed to know what the hell it is. Now I'm looking for and efficient 3 phase battery solution.
Never underestimate the power of human stupidity RAH
Mycroft Holmes wrote:
Following that logic would 240VAC be better than 120VAC, Oz runs on 240 and I have always wondered why, other than we probably followed the UK standards.
No idea on your specific history, but 100+ years ago when electrification was beginning 120 vs 240 was a cointoss on costs. 240 needed thinner copper wires than 120; but needed double the insulation thickness. 240 wins hands down on wiring cost today because plastic is cheap and copper expensive; but at the time the cost of the thicker insulation completely negated the savings on thinner wire.
Did you ever see history portrayed as an old man with a wise brow and pulseless heart, weighing all things in the balance of reason? Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful? --Zachris Topelius Training a telescope on one’s own belly button will only reveal lint. You like that? You go right on staring at it. I prefer looking at galaxies. -- Sarah Hoyt
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Charging your home and your Tesla on solar? Only if your roof is big enough. :suss:
... such stuff as dreams are made on
In direct sunlight and no obstacles, the inflowing solar radiation may go up to roughly 900 Watt per square meter. That is at mid-day, sunlight taking the shortest way through the atmosphere; in the morning or late afternoon the radiation slopes through maybe 2-4 times as much air, and is significantly weakened. Photoelectric solar panels usually are 18-21% efficient, so don't expect more than 175 Watt/m2 even at midday. So it takes 6 m2 of panels to collect 1 kW (if you like: 1 kWh per hour :-)) That is if the panel points directly to the sun. It doesn't. If the angle between the panel's orientation and the sun is v, the energy collected is cos(v). If your panel is laying flat on your roof, and the sun is 60 degrees over the horizon, the theoretical influx is 150 W/m2. When the sun sinks to 30 degrees, influx drops to 85 W - but that is for the geometrical aspect only; the atmospheric loss comes in addition. When the angle increses, there is a third loss: At a microscopic level, the active element is not at the very surface, but lies in a "dip" or "valley", with "mountain sides" that may fully or partially shade it, reducing yield even furhter than cos(v) indicates. Yet another loss, caused by the way the cells are hooked up in a panel, in long chains: If a shadow falls on parts of a chain, e.g. from a tree branch, or a dry leaf landing on the panel: Even if only a few percent of the cells in the chain are shadowed, this will to a large degree choke the entire chain. Then you have the large "shadows": The clouds. How many hours of sun do you have during a year? That varies a lot from country to country, and from coast to inland, from lowlands to highlands. Photoelectric cells definitely do best in sunlight; they do have a yield even in cloudy weather with diffused light, but far less. So, the bottom line: In Sahara, California etc. where you have no need for heating, and you can have your batteries recharged every single day by at least eight hours of bright sunshine, you might cover your entire roof with solar panels, and you can probably go completely off-grid. Here up by the polar circle, you would have to cover your entire garden with panels, and fill up your basement with Li-Ion batteries to get through the winter. (That is after you have found that gold mine for paying the investment...). Solar is fine for low-effect uses, like light, alarm systems, communication, as well as for emegeny use. If you want to go completely off-grid, think of alternate solutions, like thermal he
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Well 240 is the old now you can get anywhere from 227 to 250 out your wall socket thanks to the fact the EU use 230 (with no earth!) and the 'easyest' way was to relax the standards. Not really an issues as most devices like washing machines will take 220-250 to make life easier for the manufacturer and most things that don't use motors have a switch mode power supply...(just to make life awkward for RF engineers...) :rolleyes:
glennPattonWork wrote:
230 (with no earth!) and the 'easyest' way was to relax the standards.
No Nanny State Safety Standards for you guys in the EU !
"The difference between genius and stupidity is that genius has its limits." - Albert Einstein
"If you are searching for perfection in others, then you seek disappointment. If you are seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010
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glennPattonWork wrote:
230 (with no earth!) and the 'easyest' way was to relax the standards.
No Nanny State Safety Standards for you guys in the EU !
"The difference between genius and stupidity is that genius has its limits." - Albert Einstein
"If you are searching for perfection in others, then you seek disappointment. If you are seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010
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No Nanny State Safety Standards for you guys in the EU !
My dear chap, former EU (!? :wtf: )
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I was looking at some Solar Energy stuff. The question in my mind: Can these systems truly power the common residence today ? I'm thinking, it's easily conceivable that the normal home today can be running these appliances all at once; particularly in the late afternoon and evening... * Washer * Dryer * Stove * Oven * Microwave * Water Heater * HVAC (in all its variations) * Computers * TVs * Vacuum Cleaner(s) * Refrigerators and Freezers ...and I'm sure my list is incomplete. I'm wondering (and asking those who have electrically minded brains which are superior to my own) is the extant 120 Volt grid a factor in all this ? I just bought a bunch of LED replacement lightbulbs last month. My guess is that, bang for the buck, the point of max economy today is about 80 or 90 Lumens Per Watt. (I welcome correction on that figure; it's based on my observation of a local grocery store's shelves.) Now then, if we can get 85 Lumens per watt from these new fangled bulbs, and if we can get a solar system that delivers lower voltage (e.g. 12 volts; whatever) yet higher current (big "ifs",,, I know) then do I have a workable science turned business model ?
I am currently setting up my own 12VDC net, but as you might infer from my other posts here: Only for low-effect use: Light, communication, alarm. I am not at all worried about the power bill, that's not why, but the bill from the electrician. Here in Norway you can't legally do much more than replacing burned-out light bulbs without calling an electrician. I want to handle things myself, setting up alternate switches, adding lights etc. And I want to keep communication and light and alarms operative even during power outages. Do not ignore cable length concerns! I put a battery bank in my loft, next to the central chimney, with a start of cables straigth to above the ceiling light, or wall lamp, charging socket etc. in the floor below. It cost a few extra meters of cabling, but the voltage loss is reduced both due to shorter distance and lower current - the current is spread over a number of wires. Also, that allows me to use smaller, lower-amp, fuses for each of the connections, giving better protection. And if I blow the fuse of one lamp, there are still light in the others. I plan another battery bank in the basement - it saves 5-6 meters of cabling (two floor heights), both for light, small fans and networking equipment. Getting straight to the point of light might take some drilling through concrete walls. The batteries will be charged from four panels that might in theory deliver a peak effect of about 900 W. That is highly theoretical! Two panels will be roof mounted, at 23 degrees angle from the horizontal plane, direction south-west (ideal a few hours after noon in April and August). Two panels will be wall mounted, vertically, directly towards SW and SE, respectively. I will have to see how much power I get in practice: If needed, I can easily mount two more on the roof. I hope to keep the batteries charged by sun alone from late February or March through September. From early October to mid February, the aun is so weak that it won't give much, and from December (or earlier) the roof panels may be covered by snow. So during the winter months, the necessary power to keep the batteries fully charged will be taken from the power grid. (I want to keep them fully charged especially during winter - that is the season for power outages!) For heating I use thermal collectors and a heat pump for ground heat. The thermal collectors keep the yield at a usable level far longer into late fall, and earlier in spring, than the photocells, and are more than four times as efficient. I do NOT plan on usi
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Now I'm looking for and efficient 3 phase battery solution.
In case you are NOT joking... (The above is the sort of joke EE guys might crack!): There is no such thing as "phases" in battery power. With 3-phase AC, (in the most common layout, you have 4 wires coming into your house. One is neutral, the 3 others carry a voltage varying along a 50 Hz (Europe) or 60 Hz (US) sine curve, relative to the neutral line. The 3 are "out of step" with each other, by one third of the entire 50/60 Hz sine curve, i.e. the voltage on the second wire reaches it peak 1/150 (US: 1/180) sec after the peak of the first wire, the third wire peak comes 2/150 (US: 2/180) sec after the first one - and after 3/150 (US: 3/180) sec, the first wire is at its next peak. Battery voltage is flat, it doesn't come in sine curves. It has no peak recurring every 1/50 (US: 1/60) second. If you need that, you may use the battery power to drive a DC motor that pulls a generator (i.e. a dynamo), which may provide either a single sine-curve voltage, or three that is out of step, like your old 3-phase power supply. Today, the motor and dynamo is frequently replaced with electronics that do the same thing without moving parts, and with lower losses; it is often termed an "inverter". Practically all your electric appliances do NOT use 3phase power: They hook up to the neutral wire and one of the 3, ignoring the remaining two. So they see only a single sine curve voltage, a single phase. Your power company is very happy if you hook up your dishwasher between wire 1 and neutral, your washing machine between wire 2 and neutral, and your electric heater between line 3 and neutral, in particular if you run them at the same time. If you put them all on the same wire, leaving the other two un-utilized, it might contribute to imbalance of the power supply system. (It is less of a problem if your 1000-houshold neighbourhood hooks up to the same supply transformer, but it is nevertheless a good practice. The decision which wire to use is done when your fuse box is installed: The circuit feeding your dishwasher hooks up to power wire 1, the circuit to you laundry room hooks to power wire 2 etc. So you don't have to worry about this in your daily life, but if you build a new house, the electrician doing the hookup should be informed about your major power surges, so that those circuits are distributed over the 3 power lines. There ARE appliances that hook up to all three power wires (plus neut
It is tough when you have to scroll up to vote :-O You have expanded my limited knowledge rather dramatically, thank you. The guy who built the house over engineered everything, not just the power. As he was an inventor (and now lives off patents) I can understand why. It will be worth getting an electrician to investigate the wiring and see if I can identify the circuit most important to the house. The goal is to reduce the power bill to the minimum rather than survive an emergency. I have been to Norway in the winter and I live in Cairns which is about as different as you can get. So sunshine volume is not a problem. An 8kw solar drives the house including a substantial A/C and pool pump during the day with 50% left over, I want that 50%.
Never underestimate the power of human stupidity RAH
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I was looking at some Solar Energy stuff. The question in my mind: Can these systems truly power the common residence today ? I'm thinking, it's easily conceivable that the normal home today can be running these appliances all at once; particularly in the late afternoon and evening... * Washer * Dryer * Stove * Oven * Microwave * Water Heater * HVAC (in all its variations) * Computers * TVs * Vacuum Cleaner(s) * Refrigerators and Freezers ...and I'm sure my list is incomplete. I'm wondering (and asking those who have electrically minded brains which are superior to my own) is the extant 120 Volt grid a factor in all this ? I just bought a bunch of LED replacement lightbulbs last month. My guess is that, bang for the buck, the point of max economy today is about 80 or 90 Lumens Per Watt. (I welcome correction on that figure; it's based on my observation of a local grocery store's shelves.) Now then, if we can get 85 Lumens per watt from these new fangled bulbs, and if we can get a solar system that delivers lower voltage (e.g. 12 volts; whatever) yet higher current (big "ifs",,, I know) then do I have a workable science turned business model ?
C-P-User-3 wrote:
Can these systems truly power the common residence today ?
Depends on what you mean. Often solar installs exist in two ways. 1. To provide some power to house when light is available 2. To provide all power to the house and sells the excess back to the utility when light is available. In both cases the utility still provides power to the house either during the day or definitely at night. For your long list the house would be drawing power from the utility. But the usage would be, on average, outside of daylight business hours because business uses along with just more people doing things at day use the most power during the day. But even so most of the time you would not be using all of those. The third install type is more complex, costs more to install and maintain and often only exists in locations without utilities. Those installs require both solar and batteries. Solar charges the batteries during the day and batteries provide the power for the rest of the time. Any system would of course be sized to the house and with the last option one choose as a lifestyle to make certain trades offs to lower costs. Such as limiting when laundry is done (turning off other appliances completely when running the washing machine.) Obviously for any of the above additional back up power supplies could be in use such as gasoline/diesel powered generators.
C-P-User-3 wrote:
Now then, if we can get 85 Lumens per watt from these new fangled bulbs, and if we can get a solar system that delivers lower voltage (e.g. 12 volts; whatever)
Lights are not the biggest power users in a normal house. However they are not normally trivial either. But on average I suspect load estimates for an install would not change substantially if all bulbs were the most effective possible.