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Carbon Negative part2

large_ghostman

Well-Known Member
Most Helpful Member
Some good questions were raised in the first thread, so i thought i would do a part two at look at some of things raised, and maybe give a little background.

Edison cells were good, they had some issues but nothing time and research couldnt improve. The problem was in 1975 (or 74??) A battery company brought the technology (I cant remember the company off the top of my head but wiki has the answer), they sat on the technology and closed down all research on it. Now there are no end of theories as to why they did this, everything from they wanted to protect what was then there own new alkali battery technology, to they brought it and realized it wasnt going to work.

Now things move on tech wise, lithium took over from nickel cadmium and became the gold standard. So Edison and his cell was forgotten about from a research view point. But look back in these forums, things we struggled to do 5 years ago we now buy a extremely cheap arduino shield to do.

Home automation was expensive and difficult and a bit niche,the goto at one point was the X10 system, 5 years later home automation is very easy and X10 has become the betamax of this tech, outdated and rarely used.

In the alternative energy field, actually lets not call it that! Its green renewable energy or some forms are simply renewable energy, we are talking here about truly Carbon neutral systems that can be taken to carbon Negative. So first point to clear up.....

Not all green tech is Carbon Neutral, despite the claims! Like many things you can manipulate the figures, this was one point that someone kindly raised in the part 1 thread. So lets take a quick abridged look at the EU regs and specifically UK regs and what Carbon Neutral means.

I the UK new houses have to reach set standards of insulation and Carbon points, new houses are virtually hermetically sealed, letter box's that lead into the house loose you points. One of the tests involves pressuring or depressurizing the house, then they watch the sensors and see how long it takes for the pressure to reach that of the outside.

From this they calculate how much the house leaks, there is a minimum figure for this, currently most dont meet the top level standard, i know of one self built house that actually beats the standard, so it can be done.

All new houses are supposed to have some form of solar water heating, and so the list goes on. We also have a target for affordable housing, this we currently fail at completely! One answer being looked at and one i am also involved in, is the use of modern Log cabins, these have no end of advantages.

First you need fast growing sustainable wood OR composite wood made from wood waste, the heavy effective insulation. One the big advantages however is our obscure planning laws, it is extremely easy to get planning permission for log cabins, in most places they are almost treated like garden sheds.

So building houses this way is quick and cheap and the red tape much less. Once you seal them up and insulate its a question of how to go from 1 (the point at which a house/building is considered Neutral) to 0 or - x. I dont understand the system of numbers or how that side works, its complicated and not my field. But i do know if you get a house to 1 i can get it to neutral.

First glance it looks easy, just add Solar electric panels! But if you do the carbon calcs on solar PV cells (photo voltaic) then your carbon foot print goes up. The reason is the solar cells take energy and resources to make, the foot print of the manufacture,installation,delivery etc etc should all be taken into account when working out how much energy was used to make them.

My pet peeve with this is some Governments like my own have pet schemes like wind power, they seem to think its ok to bend the rules. What they actually do is work out the foot print then offset it against the energy the turbine 'COULD' produce in best case scenario, without topping and without needing maintenance, they then add in a life span that is unrealistic.

If you do all that then yes wind power does come out neutral, in reality however wind turbines dont EVER get near the figures used. I am not anti wind power as such, for example its better than oil being used in a power station or coal. Same with solar PV cells, they use unrealistic figures for the sun etc. Solar water with evacuated cells is however a great idea, especially if you add a heat sink in.

The reason i like solar heating is the energy it can save, unfortunately there is so many figures given for each 1C its hard to give you an exact figure. But the normally excepted figure is turning down your thermostat by 1C save you between 1-3% a year on your energy bill, there is alot of different scenarios and things to consider, so for simplicity its excepted that every 1C you save = a fair amount of energy.

So adding solar with say a decent hot water tank or even a underground water heat sink, can raise the temp of the boiler input water significantly, you cant give a figure because you cant guess how much sun your going to get. But our own system was filled recently because we had a new heating system fitted free, it was done under a special keep Scotland warm scheme.

So it gave me a chance to measure the effects of our system...

NEXT post i will go into what systems we have etc, first i got to go do some things
 

large_ghostman

Well-Known Member
Most Helpful Member
sorry i keep getting trolled! so didnt back in time, i have a busy week ahead, so will add to this thread in snipits like above. I will explain what we currently have at home (its recently been changed) and what i am going to alter it to.

Then i will answer some the question that were raised in more detail and go a bit deeper into the modern world of Bio Digesters and some the research i am doing.
 

Western

Member
Solar water with evacuated cells is however a great idea, especially if you add a heat sink in
Are you talking about some sort of heat sink (aluminium .. fins) up with the evacuated cells ... or the later mentioned underground storage for that solar heated water?

I can envisage a tank buried with lots of foam insulation.

Evacuated tube solar water heaters are becoming more popular here in Australia ... but they are stand alone units generally with a roof mounted tank. Even though our climate is pretty mild, at least compared to yours ... I can see advantages in not keeping the uninsulated storage tanks on the roof in the cold.

You mention the water from yours feeding a 'boiler' ... we don't have them ... unless you're talking about just a standard hot water system ... either gas heated or electric.

... but then we either have one or the other ... not both.


I will explain what we currently have at home (its recently been changed) and what i am going to alter it to.

Then i will answer some the question that were raised in more detail and go a bit deeper into the modern world of Bio Digesters and some the research i am doing.
Thanks ... looking forward to it.
 

large_ghostman

Well-Known Member
Most Helpful Member
I got some work to do but will answer a couple of your questions first, then come back and give more detail. I am still being trolled in another thread:rolleyes:, but its a chance to make sure i dont miss something out i guess.

Are you talking about some sort of heat sink (aluminium .. fins) up with the evacuated cells ... or the later mentioned underground storage for that solar heated water?
No that isnt what i meant. We dont have it connected at the moment because as you will see in the next part i do, we had the entire heating system changed and i havnt had a chance to reconnect some the things we had.

I better post a old google map pic of the house or some of this wont make sense.
house.png
Sorry its a rubbish pic!! The newer google maps pic has an error on!!
Anyway the buildings that are L shaped and the white building are stone and slate 'outbuildings' These are where I have my Labs etc, its also where the solar panels are mostly, most of the building is single floor except the end part i have marked, thats two floors. I mention that not for you but others who wont understand why it works because of the double floor bit and being a partly gravity fed systems and partly a pumped system.

As you can see the house is pretty big, it has a commercial 42KW oil boiler outside, that feeds the house and the other buildings, the heat sink is literally a thick HDP tank! I got it from a far supplies and it holds roughly 1,600 ltrs of water. Its sunk into the ground in a concrete pit thats heavily insulated. It also has a waterproof lining and a sump pump, but i have never seen any water outside the tank. The tank has a tight lid thats also insulated. It has a 2 foot gap from the top of the tank to the top of the hole its in.

There is a wooden decking cover over the concrete hole thats got kingspan insulation under it, there is a gap so you can get to the tank and the valves ect, i also mae sure the king span insulation panels can be removed (not sure what i though was going to eat a hole in that plastic!!). In this heat sink are the water coils, some from heat sources like the solar and some to the hot water storage tanks in the house (2) and the other buildings (3) and 1 smaller coil out to the poly tunnel and a lorry radiator!

The rest of the coils are heat inputs from solar, the generators etc. The pipes are mostly PVC with a funny kind of insulation on, no idea what its called but its designed to be buried and its high insulation, i used this stuff because copper would have cost a fortune, it dosnt look it so much on the pic, but that is a pretty big area. So we opted for PVC to the Tank etc then its joined to the copper heating coils. The joins use ('johns fittings??or whaterever they are called).

All the coils etc are fitted with electric 2 and 3 way valves, this is so we can switch say the solar heating in the winter directly to the house hot water storage tank or the Boiler feeder tank so the water is pre heated a bit (normally around 30C - 90C depending on time of year and what source we are using).

The idea for the boiler feeder is to try and make the water entering the boiler as warm as we can, being 42KW it drinks oil! even our Bio fuel oil!! so every degree C less it has to heat the water at start up the better. Actually we had the boiler fitted a few months back, its already saved a fortune. When they first fitted the boiler none of our heat systems had been connected to it, it was January and we got through 2000 ltrs of heating oil in 3 weeks!!

Using the heat sink and/or direct solar etc we use alot less oil, the boiler isnt on much at the moment as its warmer, but late feb we had dropped from 2000 ltr in 3 weeks to around 600ltr.But we also had the bigger generator running and the cooling system and exhaust system on it feed the water heat sink, the generator is in the out buildings about 20 feet from where the tank is buried. The generator is water cooled and also has a water jacket on the end of the exhaust system just before it enters the exhaust gas collection part.

I should have mentioned the heat input coils are all at or near the take bottom, the take off coils are at the top. I am sure you are aware but for others benefit, you do this because warmer water rises. So inputs go to the bottom and out puts at the top, you then get a temperature gradient within the tank.

Now i am going to skip back a bit to the solar tubes, like yours ours are single tubes, but they are built into wooden frames with old double glazing panels sealing them in front and back (or top and bottom depending how you view it), the bottom double glazed panel has a steel matt black painted panel on stand offs on it (big mistake!!). I will link a video to a similar way we built the actual take offs from the vac tubes. We also used acetone first but now use a different solvent inside the copper tubes (you will see what i mean from the video), the other difference is ours wasnt welded at first, i tried to use the quick fit things (another mistake) but they sure are welded now, like the video the solvent is under Vacuum inside the copper tubes.

One word of warning to anyone going to try this, when you fit the copper tube inside the evacuated glass tubes, even before you get them inside the sealed glass box, wear welders gloves and keep your hands/fingers well away from the nipple bit. Its not too bad once you weld the nipple bit inside the main copper feed (again this will make more sense after the video), the reason is those tips even in fairly overcast weather get EXTREMELY hot!! Thats why sealing them in a double glazed box was a bad idea. We often need to pump water through the tubes or it boils rapidly!! In feb when we had snow it reflected the light onto the panels, those tips were reaching 90C while the outside temp was -4C.

Heres the vid, watch that then i will continue for a bit.

Please note i didnt add my solvent the way he did!! Our system is different in a few other ways but the video is close enough to get the idea. Also ours are Brazed not soldered!! I would trust solder on a hot day.

DO NOT add too many tubes to a single manifold!! Even in Scotland its very very easy to boil the water rapidly in those manifold pipes. Also those evacuated glass tubes need protection water getting in or on the inside lip, they shatter which is why i first decided to use old double glazing glass panels to box them in. Anyway....

Ours have solenoids and are controlled by a control unit (self built), With all heat sources on like generator and solar and boiler etc, it dosnt take long to heat your house hot water tanks up. So we switch the valves to the main storage tanks first, once the house ones are at 85C at the top of the tank we switch the solar to the water heat sink in the ground. If the water in the house storage tanks (we are talking your normal insulated hot water storage tanks) drops below 65C say at night time, then if needed warm water is pumped from the water heat sink tank into the bottom of the house tank.

Or if the water heat sink dosnt have enough heat (normally does) the warmest water (might be house tank or heat sink) is switched to the main boiler coils, this way we always have the warmest water going into the boiler in put, this saves you the most energy as the boiler dosnt have to raise the temperature of the water as much. Then the boiler heating coil obviously goes to the normal boiler coil inside the house tank.

Incase anyone isnt aware, you dont use a standard one coil storage tank in your house! You can get away with it with some electric valves and clever plumbing, but go and buy a multi input coil tank. These days you can get ones with upto 4 heating coils inside them, more common are 2 or 3 coils. We have 4 because of the solar and heat sink but also we have wood burning stoves with back boilers on, these go directly to the house storage tanks, one of our input coils is used as an output or input (depending on the tri valve position).

The reason i had to do this was over heating the house storage tanks, my mum likes the wood burners but they put out alot of heat even with radiators on upstairs. So when the tank reaches around 80C (might be 85C i need to check later), one of the coils in the tank switches to output and goes back to the water heat sink, if needed i can dump the heat into the out building radiators or the polly tunnel. Its all simple look up tables on a quad micro controller board, yes quad micros is way over kill, but the entire system was kind of organic in as much as it grew over time, i didnt plan it in one go. I added bits over the last few years so i ended up having to add micros to do different jobs. (maybe a bit lazy, maybe i will redo the controller to a dual micro system).

But basically the controller you simply set up via a menu, you decide what the max and min temps are and where they are, then decide a hierarchy of importance. so the heat get switched to where you/need it most. My fall back is the poly tunnel, its common with systems that have oil/gas boilers and or wood burner/solar heating, to have a fail safe way to release heat, often these are things like a heated towel rail in a bathroom thats always on. Its job is mainly to bleed away any excess heat, they normally have a thermo valve on them.

If everything was on that produces heat here, a towel heater isnt going to cut it!! so first bleed off is the system simply turns on the radiators in my labs etc, if they are already on and the heat valves set low (the ones on each radiator), then the fall back is the huge lorry radiator in the poly tunnel with a dual fan on it. I might stick another in, but mainly because i am a bit paranoid and also in winter i tend to heat the poly tunnel via the water heat sink if i can.

Anyway I will give more detail later. Hopefully thats answered some your questions, I use a coolant in the closed system, but i am looking to change it. I am going to talk to Gophert on here about whats best to use, i want something a bit more enviro friendly. Also although i use a large water heat sink, i have seen gravel ones and all kinds like ball milled pumice, but i use water with a additive like anti freeze in it.
 

large_ghostman

Well-Known Member
Most Helpful Member
Sorry i have to shut down this thread, pm me your email to this account if you would like more info on this topic.

Because this is connected to a commercial project i am legally not allowed to continue with it under the new terms and conditions we have had to agree to. Sorry but i cant sign rights over on commercial material
 

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