Who is using solar?

Just to get the ball rolling, who is using solar?
I am curently building a garage that will have approx 15m2 flat panel collectors heating a 2000litre buffer tank, also there will be a wood/biomass boiler connected to the same tank. From here the Hot water will go into the house via an insulated pipe.

There is also a backup oil boiler (currently the primary heat source).

smooth operater

Who advised the 2000 litre tank?

smooth operater

smooth operater wrote: »

Who advised the 2000 litre tank?

It's a DIY project and I'm building one of these http://builditsolar.com/Projects/SpaceHeating/SolarShed/Tank/Tank.htm
it's capacity is approx 2000litres. estimated cost €500.
Im using the principle of, bigger the tank (& insulation) the longer it will hold the heat. With our variable climate we could go several days without usable sunshine.

ircoha

DB: nice idea, it is sort of the lead acid version of PV,using more output from the panels.
Just wondering will it be direct or indirect?

I am planning to use a direct configuration for the solar & wood burner and a coil in conjunction with the oil boiler.
Here is a basic sketch showing how it's intended to go together.

bertie1

Is there antifreeze in the solar loop ,& is there seperate coils in the buffer tank for the solar & the wood burning

sculptor

Is there any way you could store it in or under the house that way any heat loss is not 'lost'. I vaguely remember seing a whacky seventies system where they had a tank under the house.

smooth operater

Deleted User wrote: »

It's a DIY project and I'm building one of these http://builditsolar.com/Projects/SpaceHeating/SolarShed/Tank/Tank.htm
it's capacity is approx 2000litres. estimated cost €500.
Im using the principle of, bigger the tank (& insulation) the longer it will hold the heat. With our variable climate we could go several days without usable sunshine.

I would nearly half the tank size. A 2000 litre tank will never be heated up to your desired temp by the solar, therefore if you wanted hot water your boiler would have to come on, and then the boiler has to heat up the 2000 litres?

mad m

Doing an extension at present and have Solar in on the planning. What is the best to go for? Its a mind field!!! I was out at the RDS today and seen Solar Panels which are recessed into roof with flashing. A company does them and takes 2 days to install,so they say...My house is terraced and south east facing.

Can someone tell me from experience what is best system....

Many thanks.

smooth operater

smooth operater wrote: »

I would nearly half the tank size. A 2000 litre tank will never be heated up to your desired temp by the solar, therefore if you wanted hot water your boiler would have to come on, and then the boiler has to heat up the 2000 litres?

I'm planning to fit 15m2 flat panel collectors and the tank is also a heat dump for the wood burner.
The house is connected to the system via an insulated pipe in the house is a thermal store running the UFH & DHW via mixer valves. The cold return from the house goes into the "preheat coil" then via the oil boiler if the tank is not at 60c + else it bypasses the boiler. The wood burner will also be supplying heat to the tank, having such a large store means that I will only need to light the wood burner every couple of days.

bertie1

bertie1 wrote: »

Is there antifreeze in the solar loop ,& is there seperate coils in the buffer tank for the solar & the wood burning

It will be a drainback system therefore no antifreeze, both the solar & wood burner circuits are direct only the oil boiler & pre-heat coil are indirect.

bertie1

I cannot see you having hot water when you need it , it will take for ever to heat 2000 lt tank

bertie1

bertie1 wrote: »

I cannot see you having hot water when you need it , it will take for ever to heat 2000 lt tank

I intend to bring the hot water from the solar panels into the tank via a defuser pipe fitted in the top of the tank, thus allowing for stratification.
Therefore hot water will be fed and remain at the top of the tank, rather than trying to heat the whole tank from the bottom. Cold water feeding the solar will be drawn from the bottom of the tank.

Same for the wood boiler

smooth operater

Half the size of your tank...

Looks like the consensus is for half a tank, OK thanks.

mrs aol

we have 12 sq m panels and a 1000 lt tank seems to be working out well.

Deleted User

Deleted User wrote: »

Looks like the consensus is for half a tank, OK thanks.

The above is true if I only use it for solar, but I intend to use it as a buffer tank for a wood burner and several websites by wood boiler companies are advising that you use a much bigger tank.

Maybe I should look into building it vertical and using just the top part to store solar and the whole for storing wood heat?

or two tanks??

mrs aol

Our 1000 litre tank is used for our solar panels and our wood pellet stove ie hotwater and heating.

Mothman

6 sqm solar panels installed 10 years ago, coupled with 300l tank. Rest of hot water is suppplied via wood burning range, which also heats house and on which we do our cooking.
Now that days are getting longer, the gas cooker and electric kettle are starting to get used again

MM, for how much of the year would you get 100% hot water from your system?

Mothman

Deleted User wrote: »

MM, for how much of the year would you get 100% hot water from your system?

Usually beginning May through most of Sept bar one or 2 cloudy periods. Last summer was different story with more periods needing backup.

The reason Sept is better than April is that the incoming water temperature is much lower in Spring than in Autumn.

Usage is daily bath, showers, washing up and hot feed washing machine.

Sunny day in winter brings temperature up to 40C. Today is sunny and temperature at bottom of tank just after midday is 59C.


My system is not ideal being integrated into 30 deg roof. Too much hot water in summer, not making best use of winter sun.

Also installation costs have not risen hugely during the 10 years and I assume they are more efficient as well.

I didn't mention that the panel I have are flat plate. At that time for same money, I would have only got half area of tubes and smaller tank. It was no brainer, despite the sales talk saying it would be better.

smooth operater

Mothman wrote: »

My system is not ideal being integrated into 30 deg roof. Too much hot water in summer, not making best use of winter sun.

Also installation costs have not risen hugely during the 10 years and I assume they are more efficient as well.

I didn't mention that the panel I have are flat plate. At that time for same money, I would have only got half area of tubes and smaller tank. It was no brainer, despite the sales talk saying it would be better.

30 degrees slope is ideal for the solar....the flat plate are still cheaper and have a quicker payback period. You did good man. If you did go for the tubes it would have been a bit more efficient in the winter alright, but flat plate are still the more popular

AckwelFoley

smooth operater wrote: »

30 degrees slope is ideal for the solar....the flat plate are still cheaper and have a quicker payback period. You did good man. If you did go for the tubes it would have been a bit more efficient in the winter alright, but flat plate are still the more popular

Actually.... ive found a few suppliers that are cheaper with the evacyated tube systems

I find the flat plate is more popular because many ppl that buy solar panels are unaare of the tubes and because they dont look aswell on the front of a home.. to some ppl.. i could care less tbh.

..but the tubes do have a shorter life span and can need replacing of individual tubes.. but one advantge is that, if a single or a few tubes are not working the system still works, whereas if one panel fails, the entire system doesnt work

I'm going for flat plate as well. mainly on the grounds of cost (home made). The roof is almost due south pitch 40deg, hopefully optomised for the early & late summer periods, if it works correctly should extent the season by a couple of weeks both ends. I did consider a steeper pitch for winter optomisation, but costs were too high (as would have been the roof!)

AckwelFoley

Deleted User wrote: »

I'm going for flat plate as well. mainly on the grounds of cost (home made). The roof is almost due south pitch 40deg, hopefully optomised for the early & late summer periods, if it works correctly should extent the season by a couple of weeks both ends. I did consider a steeper pitch for winter optomisation, but costs were too high (as would have been the roof!)

Whats the saving €€ on home made panels?

<50% (hopefully) will know the real answer when I've finished 'em.

Watch this space!

smooth operater

snyper wrote: »

Actually.... ive found a few suppliers that are cheaper with the evacyated tube systems

I find the flat plate is more popular because many ppl that buy solar panels are unaare of the tubes and because they dont look aswell on the front of a home.. to some ppl.. i could care less tbh.

..but the tubes do have a shorter life span and can need replacing of individual tubes.. but one advantge is that, if a single or a few tubes are not working the system still works, whereas if one panel fails, the entire system doesnt work

Would you remember off hand which supplier? Could be good for future reference.
I never actually looked into the maintenance of them, any idea how often one of these tubes are likely to go? Or how often they'd have to get the system serviced?

smooth operater

Deleted User wrote: »

I'm going for flat plate as well. mainly on the grounds of cost (home made).

When you say home made, are you buying the panels and installing them yourself?

As in constructing them myself.

Mothman

smooth operater wrote: »

30 degrees slope is ideal for the solar....

From my own observations, I don't fully agree. Ignoring last summer (it really was awful) I have an abundance of hot water during Summer. I'd rather the panels were at a steeper angle, (40 degree +) and have more hot water out side of summer.
Got to point out though that the extra installations costs of not intergrating the panels in my roof would probably not be recouped by the extra returns.

I do often wonder is the optimal system be extra panels but at an angle of 60 degrees?

Last year as a trade off for the poor summer, the back up was hardly used during the exceptionally sunny April

Mothman

snyper wrote: »

whereas if one panel fails, the entire system doesnt work

How likely is it that a panel fails? There is very little to go wrong.

and to other readers that don't know what a flat plate panel is, its quite a simple construction. Basically the principle is,
A box, with insulation. On top are lengths of copper pipe with black flat metal welded to them, topped off by glass.

The black flat metal plates collects the heat and the liquid in the copper carry the heat away.

smooth operater

Deleted User wrote: »

As in constructing them myself.

Fairplay. Well keep us updated.

smooth operater

Mothman wrote: »

How likely is it that a panel fails? There is very little to go wrong.

and to other readers that don't know what a flat plate panel is, its quite a simple construction. Basically the principle is,
A box, with insulation. On top are lengths of copper pipe with black flat metal welded to them, topped off by glass.

The black flat metal plates collects the heat and the liquid in the copper carry the heat away.

Ye the impression i was under was they had very little maintenance, if any.
Cheers man

Mahatma coat

I use solar for electricity, anyone else doing this??

I also run a generator on BioDiesel, anyone doing this?

gsxr1

Mahatma coat wrote: »

I use solar for electricity, anyone else doing this??

I also run a generator on BioDiesel, anyone doing this?

What is Bio Diesel? Is it a mix with a percentage of diesel for cold start.

I read somthing about the new saab/ford petrol mix. Im wondering if its the same principle.

How well does it heat?

Mahatma coat

OK right I live in Australia, so Heating isnt really an issue, I'm more concerned with generating electricity to keep me Beer cold, drive the aircon etc

Biodiesel is fuel made from vegetable oil, I use it to run a 2Cyl Lister generator, tis a conventional type generator, I also use the same fuel in the tractor and the Landcruiser.

I was discussin the ins and outs of diesel Boilers with me Da ( he's a plumber ) and we think that the fuel might drive a diesel burner as it is, but at worst case scenario we'd just have to mix in a bit of Kerro

homer911

smooth operater wrote: »

Would you remember off hand which supplier? Could be good for future reference.
I never actually looked into the maintenance of them, any idea how often one of these tubes are likely to go? Or how often they'd have to get the system serviced?

You are more likely to need to get the system re-pressurised - any less than tight connection will lower the pressure in the system over time - this is the only maintenance i have had on vacuum collectors since installation

sculptor

Being offered a solar system with 40 57mm x 1800mm tubes, 300lts stainless cylinder, controller and all the bits for just under 5k plus 1k fitting. It seems reasonable what do ye think?
Its not a plug Muffler.

homer911

I paid just over 5k gross a couple of years ago for a similar setup with a 300l copper cylinder - the stainless cylinder is very expensive, but copper prices have also gone up lately so there may now be little in the difference

mad m

Getting 3 flat panels next week and it comes with a 300ltr steel cylinder I think,and the usual bits and bobs. Getting the panels recessed with a flashing kit...All in, it was €6500 and I get back €1500 from Gov....

Mothman

Just to follow up to postings earlier in thread when I said 100% supply by solar panels was usually from early May onwards.

I haven't needed to use back up to solar panels at all this month. (April)
It has been quite sunny, 7hrs a day instead of a more typical 5hrs a day

10 yo system
6sqm flat plate. 300l tank

Daily usage includes bath, couple showers, washing up, hot feed washing machine and the usual wastage with kids running hot tap needlessly :rolleyes:

ircoha

DB:
I met the guy behind this company
http://www.jenni.ch/index.html?html/English/english.htm

might have some ideas: the basic tank is 28k litres
The idea is to spec it so as the tank does all the heating for the house; heat up in summer, use in winter

AckwelFoley

Mothman wrote: »

How likely is it that a panel fails? There is very little to go wrong.

and to other readers that don't know what a flat plate panel is, its quite a simple construction. Basically the principle is,
A box, with insulation. On top are lengths of copper pipe with black flat metal welded to them, topped off by glass.

The black flat metal plates collects the heat and the liquid in the copper carry the heat away.

Well, its unlikely, but i was making the distinction between the two.

As it happens i was out at a site in Monaghan where an installed panel on a loop of 3 had failed. The glass completely shattered.

It wasnt thermal shock, as the system has been comissioned for some time, and there are no cases of where panels in use simply shatter, it seems to be that it was struck with a heavy object or a possibility that the panel was fitted with stress on one corner.

AckwelFoley

smooth operater wrote: »

Would you remember off hand which supplier? Could be good for future reference.
I never actually looked into the maintenance of them, any idea how often one of these tubes are likely to go? Or how often they'd have to get the system serviced?

There is not alot of maintainance. If a tube fails.. with the systems we supply, the tube blackens from the bottom up. Most Suppliers will guarentee them for 10 years but the expected lifespan seems to differ depending who tells you.. 15 yrs upwards.

The only servicing would be to check the glycol levels in the system, the liquid will stay weather proof for 10 years but needs to be chabged after that period.

sculptor

irocha, Do the Americans not have anything bigger;)

AckwelFoley

Mahatma coat wrote: »

I use solar for electricity, anyone else doing this??

I also run a generator on BioDiesel, anyone doing this?

Have you any spec for us on the pv panels? What size, cost and output?

ircoha

Anybody doing this, most lightly via a buffer tank?

AFAIK all the A rated washers have only a single feed so u would be rinsing with warm water

Mothman

ircoha wrote: »

Anybody doing this, most lightly via a buffer tank?

AFAIK all the A rated washers have only a single feed so u would be rinsing with warm water

10 year old Bosch washing machine with hot feed. I think at the time it was A rated energy.
Works very well particularly with the 60C washes (sheets, nappies etc), but even with 40C, the cold water is about 8C at moment, and takes a lot of energy to heat this to 40C.
There is heat loss from hot water standing in the supply pipe, so depends how long the supply is from the tank.

If hot feeds arn't available now, then this machine is going to have to last me a lifetime!

Cuauhtemoc

10 year old Bosch washing machine with hot feed. I think at the time it was A rated energy.
Works very well particularly with the 60C washes (sheets, nappies etc), but even with 40C, the cold water is about 8C at moment, and takes a lot of energy to heat this to 40C.
There is heat loss from hot water standing in the supply pipe, so depends how long the supply is from the tank.

If hot feeds arn't available now, then this machine is going to have to last me a lifetime!

I was looking into this the other day. LG apparently are one of the only companies(haven't found any others yet) doing washing machines with a hot water intake. They look quite good. Just have to check reliability and actual energy usage.
I think it makes sense if you have a good supply of hot water from solar.

Edit: Link to A++ washing machine http://uk.lge.com/products/model/detail/steamdirectdrive_wm14445fds.jhtml

C.

Time for an update, Finally got around to installing the panals a couple of weeks ago, with the current weather and near constant overcast conditions, the tank (1000litres) is still cool

I'm looking forward to September as there is a better chance of seeing a bit of sunshine.

Chimpster

Deleted User wrote: »

Time for an update, Finally got around to installing the panals a couple of weeks ago, with the current weather and near constant overcast conditions, the tank (1000litres) is still cool

I'm looking forward to September as there is a better chance of seeing a bit of sunshine.

Dolan,

Do you have any idea of the exposed surface area of the solar coil in that tank?

I am looking at something similar to what you've done.