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George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 08:45am 29 Apr 2018
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You are right but I think that's hardly the point.
From what I have researched, the things are not economically Viable anywhere in the world. They are cheaper in the US then here but so is their power on average so they still are not able to save their purchase price over their life time in power costs.
People ( misguidedly) always say the price will come down. It just went up on Tesla Power walls by $500 US. As the demand goes up ( and they can't make the things fast enough now) and the resources they make them from becomes more scarce or expensive ( lithium) then it is ridiculous to think they will go down in price.
There are a whole range of different " Modern" batteries from People Like LG and others but from what I have seen, they are still not economically Viable for the great majority of households.
Because it's going to cost me more to store it using a tesla battery than its worth and I don't have a Dam up the hill from me to make a MH system.
If I do go off grid, it will be plain old out of fashion and non trendy Lead acid storage for me because that STILL delivers the best bang for the buck and will continue to do so as long as I am still walking around on the face of the earth.
As far as Tesla goes, my accountant brother in law and I watch what is happening with them very closely. We and many others would never invest in them and I certainly don't trust Elon far as I could throw him.
Their figures are hidden, skewed and maligned so many ways that are not in with normal business and accounting practices, it isn't funny. That goes beyond the endless broken promises and hype that the gullible fan boys lap up and defend like idiots.
It will be a miracle if they last the next 12 Months.
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 09:15am 29 Apr 2018
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I did say on-grid battery is not cost effectve, but neither were solar panels back a few years, it will change.
I am using a secondhand 770AH Lead Acid Forklift battery with off grid solar only ATM, I reckon I would need a backup generator 10 days a year. I do have grid now also but avoid using it as much as possible. When I move there will be no grid ever. It would be more economical to use a generator for the times when the sun is not shining. But making my own power is my hobby and I enjoy the satisfaction I get from it. So I will be building my dam and installing micro-hydro and a wind generator because I can and because I want to. Also I am going to build my own home for the same reasons, I suspect you and are alike in at least one way, we like to do what we want not what others tell us.There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 12:52pm 29 Apr 2018
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Yep, same as me.
Always lived where the grid was annoyingly reliable but always had this thing for power independence and self sufficiency which is one of the hangups I said I understood people have with the way they want to do things.
Bucking the system is another favourite along with finding loopholes to do things and save a buck.
You got that right! I have built VERY successful businesses and made a lot of money from doing what everyone told me wasn't possible. Even when I had done it for a couple of years people were still saying it couldn't be done and I was lying out my backside till others confirmed what I was doing. Of course some still stuck by their position threatened by the fact they may be wrong and probably loose face.
It's fun to go against the grain and pull rabbits out of hats as I say. Lot of satisfaction in that.
yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166
Posted: 07:19am 30 Apr 2018
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so what else can we tell from the boring ol data. Well quite a lot as it happens.
As you will recall the yellow is measuring the water heater and no hot water was used this day. we can see a 2.4 kwh charge followed by two 700 watt boosts EXACTLY 210 minutes after the first one finishes.
some simple arithmetic tells me this heater is losing 9 degrees C over a 24 hour period and it is losing 200 watts per hour from midnight til morning and less than 100 watts per hour during the day.
so how are we going to improve it. first item is distribution, there is a 24 meter uninsulated copper pipe going to the bathroom, the temperature of the water drops massively.
The second is to insulate the inlet pipe there is about 1.5 meters of pipe that is exposed and it feels like it is 60+ degrees. The tank has already had the original insulation replaced with rockwool and it sits on an insulated plinth that saved around 2.3 kwh when we did that upgrade. We have got some polyurethane insulating sheets we may even box the heater in with that as the rockwool is a little tight for perfect insulation value.
We done some decanting of hot water at the kitchen and at the bathroom and measured a few temperatures At the kitchen tap it takes 0.67kwh to deliver 25 litres of hot water and at the shower it takes 2kwh to deliver the same amount at the same temperature.
If we can get the bathroom water temperature high enough then it might be possible to wind the thermostat back, that would save a lot of energy because the temperature differential inside and outside the tank would be lower.Edited by yahoo2 2018-05-01 I'm confused, no wait... maybe I'm not...
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 11:33am 30 Apr 2018
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Ummm.....
Midnight to 6 ? Am = 1200W, 6-6 = 1200W so your heater would be loosing 2.4Kw of heat just sitting there? Substantial!
When I put the water heater on the Voltage monitor so it heats through the day the rest of the family said the water got hotter. I dismissed this at first although realised they were right. Your figures would seem to bear it out. We all tend to shower at night so the water may have been heating n hour or 2 before we used it. With the off peak, it would have stopped heating closer to 18 hours before. that could have made a significant enough difference to notice as we did.
Does not change the losses or the energy input, just the water is used soon after it has been heated reducing the cooling in the tank. As thermal losses are larger with more temp differential, it may turn out to be fractional more efficient this way. The water in the tank after we shower is cooler so the differential and the amount of heat loss may be less with the cooler water.
Wow. If you weighed what that pipe and then looked at the BTU required to heat it to the temp of the water, I think you'd see some substantial heat loss. My heater is no where near that far from the kitchen sink but it still takes a good while to get to the tap. I was wanting to install a little 25L heater under the sink but everyone told me wouldn't be worth it. Maybe not but all that cold water irritates me. I'd do it but Mrs does not want to loose her cupboard space. Of course in summer, wherever the pipe runs, the cold water is that hot for a while you have to be careful to let it run to cool so you don't burn yourself.
I'll never forget years ago I was on a maniacal green washed forum. These guys were over the top about everything. One of the most ridiculous posts I ever saw was from this guy that wanted to Circulate the hot water through the pipes all the time so he wouldn't waste the less than 2L of water that was cold when he turned on his taps. So hell bent on saving water they couldn't see what I was saying about the energy losses in pumping the water around the pipes which would act like radiators. Guy was still hell bent on saving that water.
I suggested he run it into a jug, let it sti till it cooled, put it in the fridge and there was his drinking water. Genius!
Mine are bare and clearly radiating heat all the time. Going to get some of that split foam from my fridgy mate and enclose it. I know on AC they are particular to insulate the pipes because the thermal losses can be significant.
I was thinking when you mentioned cool room panels before, the way to really insulate a heater would be to box it in with the panel then fill the cavity with that expanding foam. Cut out the foam for the valve, heater element and anode and you'd have a heater that lost 2o in 24 hours or even less. I hate to think of the cost of that much foam though. I don't think it's cheap stuff.
Plastic pipe instead of copper coming from the heater may also make bit of a thermal break but I'll bet some of the heat travels in the water in the pipe itself.
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 11:43am 30 Apr 2018
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I don't know if different insulation is used in the Solar Rheem tanks but with 3 of us in our house we can go 3 days with no heating before the hot water gets to a point where it is too cold for a shower. There is no lagging apart from 1 metre of the outlet pipe that turns downwards as soon as it leaves the tank and the pipes going to the panels.There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 12:27pm 30 Apr 2018
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That has been my experience also with conventional heaters. I found they tend to go cold after 3 days whether you use the water or not pretty much.
3 days is exactly what I was calculating when I put my heater on the voltage monitor with the solar. I am only running the heater element at 700W atm as a test for cloudy days but it seems to be OK. Even if it does not heat all the way up, every day it gets some power is another day in the buffer. I reckon it should take at least 5 days of constant rain before I need to bypass the relay and change it to draw on the grid.
Been here over 6 Months now and not seen even 3 days in a row of cloud let alone rain. It will come though. Eventually.
yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166
Posted: 02:53pm 30 Apr 2018
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comically, from dead cold this heater would take more than 18 hours to reach full temperature and it would consume 36 kwh. I'm confused, no wait... maybe I'm not...
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 09:11pm 30 Apr 2018
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Heating up water takes a lot of energy, I make my own distilled battery water and it takes at least 45 minutes to boil away 5 litres of water with a 1800W jug element in my boiler although it is not insulated.There are only 10 types of people in the world: those who understand binary, and those who don't.
yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166
Posted: 10:04pm 30 Apr 2018
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evaporation is a whole nother level of cooling. Shoot I dont even remember the formula, this coffee is a dud! I'm confused, no wait... maybe I'm not...
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 10:29pm 30 Apr 2018
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Too bloody early for trying to do formulas, anyway Google is your friend.There are only 10 types of people in the world: those who understand binary, and those who don't.
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 12:17am 01 May 2018
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Near enough requires 0.5kw/hr to completely evaporate 5kg of water from room temp
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 12:48am 01 May 2018
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Electricity is very weak for this sort of thing. I use a waste oil burner for bulk heating. Can easily throw 300Kw at something. I can boil a 200l drum of oil in 17 minutes without too much effort at all.
Oil has about 10 KwH worth of energy per litre. When you consider the size of a 10 Kwh battery and what it takes to generate that amount of power, you can see the immense energy density of Liquid fuels and what electric cars have to overcome.
I Played around with cracking oil a while back. Had a keg I put some fittings on and half Filled it with oil. Had a tube coming out the top to take off the vapors that ran back underneath through the flame as a super heater. That was the key to getting good product. Did away with a condenser and just bubbled the vapor up through a column of water which condensed it very effectively.
Resulting output which was half way between diesel and petrol condensed and floated on top of the water then ran off into another vessel. Was a great product for adding to oil to run my vehicle on in winter.
The same sort of setup would be perfect for purifying water. You could do 50L an hour with a little effort and not so big a burner. My best output for a burner so far is 1200KW. That's burning 2L of oil a minute. Needs a Couple of Big Blowers to supply enough air and a good Pump to feed the oil.
Pretty hard to put all that power to any efficient work though. Be ok in an industrial boiler or a brick Kiln but you need something sizeable that's for sure.
A little burner doing 200Kw would be really effective for distilling water from a Keg or a 44 gallon drum. Probably want a 3/4" output pipe to keep the pressures down and run it through a car radiator with a couple of electric fans to condense it.
When I want distilled water, I just put out a plastic sheet or tarp and run the rain water into a drum or make a solar still.
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 01:08am 01 May 2018
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Cheers, Tony.
Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1664
Posted: 09:28pm 01 May 2018
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Have you considered Solar Stills?
Googled them a bit at one point, just out of curiosity.
Plenty of examples about.
Phil
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 10:03pm 01 May 2018
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Yes I did and if I was starting over knowing what I know now I would build a solar still instead. The main reason, with the solar still you can just put some water in and forget it.
However the electric version has another use I have in mind for it that is not related to solar power.Edited by Madness 2018-05-03There are only 10 types of people in the world: those who understand binary, and those who don't.
kanchana Regular Member Joined: 08/05/2018 Location: Sri LankaPosts: 56
Posted: 02:19am 13 Apr 2019
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What kind of system you use to monitor the energy?Regards kanchana
Keith Johnson Newbie Joined: 25/04/2019 Location: AustraliaPosts: 4
Posted: 06:17am 27 Apr 2019
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My solar is grid connect with no battery. Most of my demand is during then day to cool the house. In Australia a direct solar hot water system is a no brainer.
You only need solar to supply your average demand. So if you use an average 5 kW a day then that is what you must put back into the system. Work out how many no sun days you need to allow for and that is how big a system you need to collect the power and to store it.
However some appliances take vastly more power than the watts noted on the label to start so you need a bigger inverter than the average demand to ensure that the appliances are not damaged by under-voltage on starting. There are more refrigeration units killed by under-voltage than by spikes or over voltage. Most modern power supplies used in computers and such like can take a surge current on starting more than 10 times the rated power. I repeatedly have generator back up systems tripping over current circuit breakers because after a power fail the generator starts reconnects power and every computer in the place wants its bit simultaneously. Simple solution is to fit a drop out contactor to every computer. Power fails and it stays off until a human pushes the reset button. Simple trick spreads the load out over time.
In an area with erratic and unreliable supply it gets very tempting to add another 5 kW solar and a battery bank. Disconnect the grid and fly solo. The problem is on a lovely sunny day the mains supply goes down and takes my solar down as well.
Australia's extremely restrictive electrical rules make any cost effective solar installations impossible as everything needs to be overseen by the electrical union people. That is even if it does not connect to the grid.
Keith Longreach
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 08:03am 27 Apr 2019
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I thought our prices were high for solar installs, until I started hanging at a solar forum that has a lot of US posters My gridtie system cost $4000 fully installed, and that included the removal of the old asbestos backplane in the fusebox and a complete new 'guts' for the existing tin box (its been built into the brick wall, so not an easy straight swap)- it's go a wireless gridtie 5kw dual channel mppt inverter and 6kw (6050W) solar install- 2x 3kw wings facing east and west
In comparison there are 3 other US posters who had comparable systems installed in the states, the cheapest one was $18000!!! both of the others were over $20000 Remember that's US dollars, that's $25574.4Au for the cheap one and over $28416Au for the other two...
Even including the solar rebate in the total cost, our solar installs are remarkably cheap in comparison to what seems to be the normal price in the US
To add insult to injury, in many parts of the US, grid ties are simply not allowed at all....
Can't really comment on the UK prices as I've only seen one guy mention his systems price, and his panel array was wildly larger than mine, with 10kw feeding a 5kw inverter, but he is in Scotland and the insolation there is pretty low,even in summer, his panels are at 45 degrees for winter! even then he only paid just under 6000 pound, about $11g AuEdited by Boppa 2019-04-28
BenandAmber Guru Joined: 16/02/2019 Location: United StatesPosts: 961
Posted: 12:12am 28 Apr 2019
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For us in the US it is very expensive
if you're handy and want to go completely off the grid
don't mind using used equipment and are lucky enough to find this form
you can build your own inverter use used solar panels
then it is possible for a very poor person to go solar
The way I see it the poor person is the one that needs to go solar
So he or she can have a better life with fewer bills
Whether you guys on here or know it or not
you guys are helping with the thing I just mentioned
yes with sharing your wisdom at no cost you are helping the poor
And the Australians have already been there done that with the solar thing
so it seems they have the most experience and knowledge
you know it is just an opinion just the way I see it and appreciate it
Others May see it in a different light and that's just fine
I mean no disrespect to no onebe warned i am good parrot but Dumber than a box of rocks
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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