Water worse then better

Last week we had a new water tank fitted that was bigger and had a safety switch to turn off the pump before it could run dry. We have been having a bit of a nightmare with it. Or not exactly with the tank, but because of the change to the flow rate through the system - mainly due to a filter being added. When the filter is new in and clean it can just cope with the flow, but as soon as it starts to get a bit dirty the spring starts backing up in the channel causing a muddy pond (at A in the diagram) which then overflowed down the bank. As soon as this happened the filter became pretty much entirely blocked as the water got muddier. We were also concerned that the wall holding the spring back was going to collapse on the water but breaking the whole system. We ended up cleaning the filter several times a day to keep the water flowing. We could have removed the filter from the system, but we didn't want the new tank to fill with mud (although it does have a tap to allow cleaning) and we didn't want to drink such muddy water.
This diagram shows the system from above and then from the side. Sorry if it is not clear - but it will help us remember in the future what we have done!

We have had to made an emergency improvement to the system so that the water from the source can overflow safely without creating a muddy pond. While doing the modifications we discovered the little flows of water shown as thinner blue lines which flow out of the bank and were carrying mud in to the water. The new solution excludes these too and allows them to flow safely round the tank.

We added a small dam (shown as a grey curve) to collect the water in to some drain pipe. The drain pipe has a T junction in it and the pipe in to the filter is connected to the end of the drain pipe (that bit was a bit tricky - there don't seem to be 80mm to 25mm connectors but we drilled a hole in a drain pipe cap for the pipe to go through). When the water can't flow through the filter fast enough it backs up the drain pipe (no mud) and flows down a pipe attached to the T junction.

The diagram makes it look all lovely and neat, actually it is a big mud swamp due to the water having been going everywhere it shouldn't for a while and the ground is pretty uneven too. We hope it will dry out now it is mostly in pipe.

Close up of the pipe section

There is a good youtube video here about how to capture a spring. We might do a more thorough and buried in the hillside solution sometime in the (far and distant) future. We still need to improve the covering of this solution as the spring before the pipe is just covered in pieces of slate which could let runoff water in.

Another interesting thing this video mentions is ram pumps - they use only the power of the water to pump a portion of that water up hill (ie no electricity needed). Possibly an interesting solution to our need to get drinking water for the animals (and for the potager) higher up the land. Doug calculated the spring provides 21,600l of water a day. We only use a few hundred so we need to find more uses for it!!
Doug did look in to hydro electricity, but apparently we would generate something like 86 watts... so not so useful.

New water tank

About a year ago I mentioned that we needed to replace the water tank the spring water flows into before being pumped up to the house. A while after that we ordered the new tank. The plumber and the earth excavation man have finally managed to coordinate and appear to install the new tank!
We cut down a tree yesterday and strimmed to give them access. They disappeared down there all morning with their mini digger and made lots of crashing and bashing. They reappeared briefly to say 'eerm do you want to keep the old tank??' and looked very relieved when we said no. I guess they broke it up to get it out.

When we ventured down at lunch time to take a look they had dug down to the rock underneath to sit the new tank on that and created a giant trench to allow the area to drain. They say we need to maintain the trench otherwise it will fill with mud and the tank will float away. Nice! We are thinking about what plants we can plant down there to stabilise it. Would need to be shade and wet loving.
The tank is much bigger than it looks in this photo. 750l. Another improvement on the old tank is a filter on the water inlet, the old tank used to get all silted up inside from time to time - resulting in lovely brown drinking water and a fun day trying to clean it out.

It all looked good. Until we started fiddling with it! The plumber told us we needed to clear the pipe above the tank as we did last summer (it is a lot wetter and muddyer now given all the recent storms) and put back the slate roof of the water channel - they had removed it during their work. He told us we needed to remove the pipe from the tank so the mud we would stir up wouldn't go in to the tank. All good - until we managed to get some stones and twigs wedged in one of the pipes. We did  eventually get them out with the help of some wire, but in the mean time water was going everywhere and we were worried it was going to undermine the foundations of the new tank. We then had a very trying time getting the pipe we had removed back on. We didn't really understand the mechanism of the bolts (still don't) and the water flooding everywhere didn't help. We were sure we would lose one of the little bits... but luckily didn't!

Funny story - Last time the plumber was here - last autumn - he managed to catch a branch of the plum tree at the top of the drive on his van. He drove off at high speed and didn't seem to notice, dragging it half way down the drive before it fell off.
This time just after he arrived another branch went creeeaaaak crash and fell off just behind his van. We think the tree has been waiting to get its revenge, but just mistimed it!

It is a shame as it was laden with soon to ripen plums. C'est la vie as they say!

More on central heating and hot water

Ages ago I rambled on about our thoughts for central heating and hot water. It is an expensive part of the rennovation, plus it will make life expensive, hard work and uncomfortable if we get it wrong. Oh the pressure!
Since then we have read even more on the internet. It seems that a lot of systems like we are thinking about have two water tanks, an accumulator for the heat from the wood burner, which is used for central heating, and a smaller tank for DHW (domestic hot water - got to speak the lingo you know) that is heated by the solar thermal panels. The DHW tank also has an electric emersion heater for when the sun doesn't shine enough. We are keen to have free heating and hot water so this arrangement doesn't exactly suit us. It is not clear whether we could heat the DHW tank with heat from the accumulator in the summer. It is possible to do as I described before and have the solar and wood burner feed the accumulator and not have the other tank, however because the accumulator is something like 2000l (the DHW tank is smaller at maybe 200l) the solar panels are unlikely to heat it hot enough so you have to burn wood all summer. This isn't terribly efficient for just hot water as you are heating a much larger volume than you need. Another alternative is to use solar to heat the accumulator as much as possible (which is likely lukewarm) then have further heating as you use the water, called 'on demand' or 'in line' - this can be electric or gas.
While reading about all this I came across people who, rather than use solar thermal for their DHW, use solar pv. The solar pv generates electricity and this is used to heat water either via a heat pump (ground or air source) or via an immersion heater - or more likely a combination  of the two. There are a lot of discussions about whether solar pv used like this is in fact more cost effective now (as it gets cheaper to install) than solar thermal. This is interesting to us because it would mean we could harness the effort free energy from the sun rather than the effortful energy from wood and it could provide the heating as well as DHW. However of course these systems have their complexities (and costs). In general heat pumps are better suited to creating warm rather than hot water, which means they are well suited to underfloor heating (which we have assessed to be too expensive) but not so much to radiators or DHW. It seems though that they can do higher temperatures as the systems get more sophisticated so we are investigating further.
My head is spinning after reading so much on the internet. It is hard to find people in the same position as us. Most people are happy to use some electricity, as the system will still work out cheaper than gas or electric heating. However for us our most basic heating is wood which is free, so the other solutions aren't saving us money - only effort. But that is important too, as there is only so much work it is realistic to think we can do each year with the animals, the growing things, the maintaining the property, perhaps the earning some money, and hopefully the having some time off and enjoying ourselves! There are of course people out there doing similar things (I am not a beautiful or unique snowflake) but I haven't managed to find any very detailed descriptions of the systems they have settled on.
I am sure you will be hearing more on this subject.

What have we been up to?

For the last few days we haven't been doing anything too exciting. We have been skiing on our own and with some friends, we went out to lunch with friends, we raked leaves off the drive (big job given number of leaves and 600m of drive), we put more gravel on the drive (feels like futile never ending task, but maybe it will stop sinking without trace at some point) and we have spent time searching for various things (bigger duvet, waterproof jackets, tax documents) in boxes.
Poppy was sick in the middle of the night. Seems to happen from time to time. Last time it was worse and we took her to the vet where she proceeded to barf giantly three times on his floor and scales. He was most impressed. He gave her an anti emetic injection (expensive!) which fixed her up quickly. luckly this time just seems to be the once so no need for a repeat visit.
The weather has been very cold with heavy frost over night (forecast was -7°C our thermometer said -2°C but it is close to a window). So far nothing has frozen solid and the pump has kept running. Water coming in to the house is REALLY cold though and makes washing hands etc a painful experience (as the hot water is only on when we shower). Showering is not very attractive idea either but we have been maintaining standards and braving it despite the freezing conditions. One day we didn't collect an egg and it stayed in the egg box overnight and froze and cracked, was fine when defrosted and fried.

Central heating and hot water

Yet another thing we have been thinking about is the central heating and hot water. We are keen to have something that uses wood as we have a 'free' supply (the quotes being because it takes a lot of labour, so it doesn't cost money but it does cost time and there is some investment in saws, fuel, oil etc). We are also interested in solar hot water (rather than PV) as it would reduce the amount of wood we needed to provide and it would seem a waste of a perfect south facing roof not to have it.

Our current thinking is that we will have a wood gasification boiler in the garage with an accumulation tank. The solar panel would then also feed the accumulation tank. The idea is that you burn the wood furnace very hot (which is efficient) every day or every other day and heat the water in the tank up to 90C at the top. The water in the accumulation tank is kept stratified (ie hot at the top and cool at the bottom) and the tank is very very well insulated so it can maintain close to that temperature for a couple of days.
Hot water (DHW) for showers etc is taken from the top of the tank via heat exchange (ie there is a coil of pipe in the accumulator through which your mains pressure water is run to heat it up- often there are 2 coils, one low down in the cooler part of the tank and one in the hotter part)
The heating runs using water directly from the tank. Radiators would take water from the top and return it cool to the bottom and under floor heating would take it from the middle (as it runs cooler than radiators) and return it to the bottom. We are thinking underfloor heating downstairs and radiators upstairs (although possibly underfloor in the bathroom upstairs too)

The wood furnace would provide the main amount of hot water and the solar would feed in to this to reduce the amount of wood needed. In the winter the solar wouldn't be doing much and you would need to fire the wood furnace perhaps every day. In the summer the solar would provide a higher percentage but you would still need to fire the furnace every once in a while (every few days???)

It seems that the complex thing in systems like this is keeping the tank properly stratified as you feed hot water in (from your furnace and solar panels) and take hot water out (for heating and DHW) plus feeding cooler water back in (returning from the heating system). To make this work there are also some controls outside the accumulation tank which decide whether to feed water in or not. For example if the water returning from the radiators is above a certain temperature it would be recirculated rather than being fed back in. If water that is too warm goes in to the bottom of the tank it will rise mixing the whole tank up meaning the top of the tank is no longer hot enough to work the heat exchange which is providing your DHW.

I have read a lot on the internet about this and my mind is boggled as there are so many varieties of the different components. We have also spoken (not yet at great length) with the plumber (who specialises in renewable and green heating) - as you can imagine this is a bit of a challenge in French. He is an agent for a company called De Dietrich who do provide solar panels, wood furnaces and accumulation tanks, but as far as I can understand from their very unhelpful website they don't plan on them being configured as we want. In their view the wood furnace is only for use in the winter and only provides hot water for heating not for DHW. You then need an electric immersion heater to provide the DHW when solar is not enough. I think they are a French company and we have noticed the French use electric for heating and hotwater unlike in the UK where electric is considered too expensive and the most common I suppose is gas. We are not keen on this solution, we would have an immersion heater but only for use once in a while when one had failed to run the furnace or something.

It is hard to get a vision of what such a system might cost. The wood burning furnaces are not cheap and nor is a solar hot water system, but the idea is it would then be very cheap to run. Virtually free infact. Once we have the floor plans sorted (if that ever happens) we can speak in more detail to the plumber and get an actual quote (1 million EUR perhaps).

Akvaterm seem most common accumulator in the UK

Alternatives might be to use one of the wood burning stoves in the kitchen or living room to provide hot water, this would be cheaper to install, but would leave us more dependent on electric heating for hotwater in the summer when solar wasn't enough and in the winter if we wanted hot water when we didn't want the stove lit.

Next episode in the water saga

I suspect this is going to be a long running story.
The current water basin holds something like 160l. The average daily (indoors) water usage is something like 250l (varies a lot depending what source you look at). Which would be fine if the inflow rate to the basin is fast enough.
We managed to run the basin dry recently and went to have a look at the inflow rate as we had not used the full 160l just prior to it going dry. We discovered that most of the water from the spring was running out down the side and not making it in to the basin, this meant that to fill the tank once it was dry was taking many hours.
To fix this we needed to have a look upstream of the basin, to do this we needed to excavate to find the channel. Having done this we found that some plant roots were in the channel and had blocked it by trapping small particles of mud. Once we scooped this out (gross and slimey) the water started flowing in to the basin again. We then needed to syphon the water out of the basin as it was all muddy from us digging around in the channel.

The water basin (with excavation above)

The excavation (it is deeper than it looks in the photo)

 We measured the inflow rate, after the recent very heavy rain it was approx 160l in 30 mins. We are not sure what the rate will be when it hasn't rained for a while. We need to wait and see.

We have spoken to the plumber about getting a bigger tank (rather than basin), probably 750l. This will allow us to use a bit more water in quick succession (eg a couple of showers and the washing machine) but it will not solve the problem if the inflow rate becomes much slower when it hasn't rained for a while.
This tank will also have a sensor in it like in toilet cistern but in reverse to detect when empty rather than when full. This would be a great improvement as the only way we have of telling whether the basin is empty at the moment is either going and looking at it (not practical during a shower for example) or when the tap runs dry - which means the pump is already running dry which will damage it if it runs for more than a very short period like that (very expensive mistake).
Ultimately we can connect to mains water as the next house down the valley has it (maybe 500m away), but it will be expensive to do as we have to pay for the channel to be dug and the pipe laid. If we did this we could continue to use the source water and only use mains when it ran out, as water is metered and (even) more expensive in France than the UK. Whatever happens having the source improved is a worth while investment.