Monday, July 29, 2013

July 2013 reports

28 July 2013: The last week of July has been quite mild with a regular mixture of sun and light rain. The most noticeable change is the productivity of the two Sunboxes - the Surya-3 with the ETFE front panels is simply bounding ahead of all previous expectations! When the month ends, I will publish a new energy and ground temperature graph.
Some House figures:
  • House annual 5,415, biennial 5,210 kWh. 
  • GSHP annual 3,427, biennial 3,202 kWh,  triennial 3,245 kWh. 
  • PV annual 3,128, biennial 3,096 kWh, triennial 3,166 kWh. 
  • Sunbox annual 2,922, biennial 2,744 kWh. Sunbox 3 improving rapidly with the help of the ETFE front panels.
  • Ground Temperature 14.0ºC. This used to be the highest peak ever possible, now it is a more consistent temperature over a few weeks.

21 July 2013: Ground temperature dropped back to 13.7ºC after a cool weekend at the end of the July heatwave. Annual PV grew to 3,170, and the annual Sunbox capture increased from 2776 to 2878 after some days of exceptional weather and performance.

14 July 2013: the month started with a week of overcast and rainy spells, but the mid period of July is the longest period of summer heat since 2011. I have had to cope with leaks (which have been fixed), but I still have anxieties. The biggest worry would be a leak underground. Let's not think about that! Glycol solution does not dry off quickly, so there are long lasting tell tale smears if there is one.
  We have had several days this month when the system has packed 59 kilowatt hours in a single day - three times in the last 8 days! This is a combination of electrical and thermal storage. Now, I have a new target, which is to see if we can pack in a full SIXTY!

World News later, here are some metering figures for the midpoint of the month. For the House and the GSHP there isn't much change because it's summer! PV, Sunbox and Ground are on the way up:
  • House annual 5,399, biennial 5,204 kWh. 
  • GSHP annual 3,424, biennial 3,204 kWh,  triennial 3,249 kWh. 
  • PV annual 3,132, biennial 3,081 kWh, triennial 3,163 kWh. Improving - in first two years of operation the average was 3,300 per annum!
  • Sunbox annual 2,776, biennial 2,653 kWh. Improving rapidly with three systems working, and better weather.
  • Ground Temperature 14.1ºC. This went up thanks to a warm sunny weekend. This first time in 4 years that I am seeing ground temperature so high.
7 July 2013: I'm doing house reports on alternate weeks during the summer unless something changes.

Sunday, July 21, 2013

Energy levels restoring

20 July 2013: It is some months since I produced an Energy Levels diagram, and since the tee-piece leak and the repair to the leak, it is time to do another. Just before the leak occurred, there was good sunshine and the levels were on the way up nicely. There was a period of time when I was waiting for the replacement tee, the scaffolding was up for a whole month. (The more recent leak of July was fixed so quickly, it doesn't cause a blip on the curve, because it was just equivalent to a couple of cloudy days.
Diagram: Produced by ArchiCAD, using author's data and algorithm July 2013
I'm not sure why the curve should drop so steeply at that point in May. Although May was cold, it wasn't cold enough to have the heating on, although hot water was still needed. It could suggest that the borehole had warmed up, but without the additional heat being added, the energy level was dispersing outwards because the temperature had risen to higher than would be normal for May without charging.
The Ground Temperature line looks slightly different. The recent winter was not particularly cold, but it was very long and dreary, so the winter curve is very wide, and the dodgy spring (combined with the leak in April May and the heat wave of July meant that there was a strange look to the curve climbing out of the winter into summer 2013. The fact that the ground temperature of 21.7.13 has dropped back to 13.7ºC reflects the energy curve (top), implying that the larger volume still needs more energy to be injected before equalling the energy levels of, say 2011.

Sunday, July 14, 2013

Record capture on sunny days, and another pump exchange

14 July 2013: The ETFE is so effective that the heat can build up almost too quickly in the big Sunbox. I've decided to leave the bottom vents open to reduce over heating risk. Although the black collectors are vertical, the liquid temperature will zoom up to over 70º if the pump is not running. If the pump is running, it is still too slow (at 2-3 litres/minute) to remove this heat and I have been tricking the GSHP into using its pump to work cold, just pumping liquid round without heating or cooling. This brings the Sunbox temperature down to about 40º on hot days.
These show the liquid temperatures in each
of the Surya panels
  I decided that it would be worth investing in a replacement faster pump, so I installed a faster speed Wilo pump this morning (only took about 20mins). This will get the energy down below faster, allowing the panels to accept more solar energy. This pump uses slightly more energy than the previous one, but during the day, it is powered by the PV roof anyway - costs nothing to run!
  Today, the total Solar capture was 59 kilowatt hours! 23kWh of this is Photovoltaic, 7kWh from the tubes (highest ever) and 29 kW from the combined Suryas (also highest ever, Surya-3 was 19 and Surya-4 was 10). The afternoon got slightly cloudy, so we havent yet had a totally maximum performance from the PV roof.
  Ground temperature is holding steady at 14.1ºC, boosted by the good weather, but also by the additional solar thermal systems added since last year.

Thursday, July 11, 2013

Refilling and checking for leaks

11 July 2013: The hosing is now fixed and I need to re-fit the lower louvre. It is a very sunny warm day, so we must not waste any more of this free solar energy 'raining' down on the house!
The ladder is held away from the window with a ladder brace that makes the whole process safer, and enables it to be rested against a window without risking damage to the glass or frame.

Instead of filling through the top-up bottle, it is easier to take off an air-vent and do it through that - about 40 litres being returned to the panels! Every small part of it is run through a strainer. 

Hose is secured!

Looking upwards at the
repaired hose and clips
11 July 2013: After two days of slow draining of the Surya-3 Sunbox panels (which hold many many litres of fluid), I finally moved that piece of hosing 10mm sideways so that it is now equal between the two panels. The Jubilee clips have been retightened and the panels are not leaking. 
This was accomplished by a combination of ladder work and reaching out of the bedroom window. The work has still saved £250 worth of scaffolding, perhaps I should spend something like that on an improved energy meter for the roof mounted Surya-4. 
 I would still like a pop-up platform scaffold or similar for this sort of light maintenance. I think the hosing got moved when I was doing the work to insert the Tee-piece and i had to loosen off the panels and hoses to give some flexibility for fitting the tee. In the end, I used a simpler leakproof tee piece, but must have forgotten to fully check all the other hoses. 
I hope it doesnt matter that the jubilee clip
isnt pefectly lined up :( It is still keeping the
junction leak-free
Now it's time to refill.... Will be a long job. Took 2 days to drain.

Wednesday, July 10, 2013

Improved flow to Tubes heat exchanger

10 July 2013: This is ironic after mean and dispirited things I wrote only a few weeks ago about the Evacuated Tubes. But at this time, when the two Surya panels are closed off waiting for my repair, the valving and circuit design allows the Tubes to continue working, and they are doing splendidly.
   A bit of determination to fix it has fixed it! New pump is working well, and on Monday, I replaced the flexible tap connectors with normal 22mm piping - reducing all restrictions on flow, other than the actual heat exchanger itself. This means that the position of the H/exchanger is fixed, but it hasn't needed moving for a year.
   I still believe that a low temperature collector is more effective for solar earth charging. They really only seem to do anything when there is direct sunshine. But when the sun shines and the tube circuit is not working, the tube manifold temperature rises to dangerous levels, like 135ºC, and I don't want an exploding steam engine in my loft!

Monday, July 8, 2013

Fixing leak - probably needs scaffold

8 July 2013: The gravel on the ground below the sunbox has a distinct pattern of wetness. There's no point in collecting it in the bucket because it will be contaminated, but the bucket shows the 'rate of loss' quite well. 

I'm trying to fix it from the ladder, but it's very difficult and rather dangerous. I am using a lifeline and the ladder is tied on, but one still cannot exert real force on a screwdriver or see clearly what is being done. The hosing between the two panels seems about a centimetre too short, and tightening up the jubilee clip alone may not be enough of a fix (it did feel slightly loose).

Ladder or Scaffold
I have been up the ladder and had a good look, and the problem is the lower hose section connecting the left hand panel-pair. It's not enough to just tighten the jubilee clip, because, somehow (perhaps during the tee piece fixing) the hose got moved slightly, and is off centre. It needs to move 10mm rightwards, then re-tighten. I might be able to do it without scaffolding.
   If you never hear from me again, I am in the Queens Medical Centre after falling off the ladder. Seriously.... I will  use a lifeline and tie the ladder on securely.

Another leak, in a new place!

8 July 2013: Oh dear, I should have left the old scaffolding up a bit longer to test this system in hot weather. I haven't had a problem with a jubilee clipped hose joint before, but I've noticed recently the need to top up the system recently. The leak is definitely happening, and it is easy to detect now because the ground is so dry that one can see where drips are falling. It's at the mid point between the two panels on the left.

Sunday, July 7, 2013

Murray wins!

7.7.13: After 77 years without a British winner, Andy Murray wins Wimbledon in straight sets!
   What has this to do with the Peveril Solar house? well, I had to keep nipping out to reset the GSHP to do another half hour of cold pumping. This being the hottest day of the year caused our house to store 59 fifty nine kilowatt hours of energy in the day - made me wonder how Andy and Novak could do anything in 40ºC heat of Centre Court, let alone play at full stretch for three sets.
    The ground temperature (after some hours of rest in the middle of the night) was 14.1ºC, the highest it has ever been!

Heat pump help with cold pumping

7 July 2013: The hottest day of the year and Murray is slugging it out with Djokovic and Wimbledon! Meanwhile, I am keeping an eye on my solar earth charging circuit.

The ETFE Sunbox fronts are so effective that the temperature in main Sunbox (Surya-3) has risen to over 70ºC! This is far too hot and I need to find a way to reduce it. Liquid flow of 160 litres per hour is just too slow to remove this heat, so I have turned to the GSHP to circulate cold. The pressure of this pumping pushes more liquid up to the loft area if there are two small pumps up there pulling it along.When the powerful pump in the GSHP is cold-circulating, the assistance it gives to circulation is enough to boost the flow rate more than 3 times, to 490 litres/hr. It boosts the kilowatt rate to over three, and lowers the highest temperature in the Surya by 30 degrees - that gets the heat down more quickly and enables the black panels to accept more solar energy. 

The power used by the GSHP is immaterial because in this sunshine, it is being driven by the large Photovoltaic array on the roof!
    I know what my evening project is!
  • I have to swap the recently-purchased faster pump to the Surya 4 circuit
  • Modify the heat exchanger circuit for the Tubes to have less flow resistance, and return the Tubes to using the weaker pump. 

Friday, July 5, 2013

Summer temperatures

Top controller is for the Surya-4 metal radiators
on the house extension. The lower controller showing 64.5º
is for the main Sunbox with the swimming pool panels
Friday 5th July 2013: Warmest day of the year so far, and Saturday is likely to be hotter, and Sunday likely to be hotter still! This photo shows temperatures at about 3pm, and demonstrates perhaps how effective the ETFE is. 
    The vertical panels of the Surya-3 Sunbox have a steep angle to the Sun, so I would expect the metal radiators of Surya-4 to be doing better - at 15º pitch. 
  • On the S-4, the Sun has to fight through 6mm of solid Polycarbonate to get to the radiators. 
  • In the case of 2 ultra thin skins of ETFE on the S-3, most of the solar heat is arriving on the panels, and this photo shows a liquid temperature 34.4 degs C higher than the radiators, and about 40 degs hotter than the ambient air temperature. 

Exchange pump for tubes

Friday 5 July 2013: Circulation in the Tube-circuit is a problem, so Step One, I took all the components off and checked each one in case there was a blocked strainer. Everything is clear, although the flexible connections to the heat exchanger are quite narrow in diameter. 
  The main problem is that the low wattage consumption pump was too feeble to push the liquid through the heat exchanger and the other parts, unless it was at maximum power of 45watts.
  I've taken Step Two which is to replace the Wilo pump with a more powerful model - 6m head instead of 4m head. And in the next week or so, I will probably replace the Flexible Joints with fixed piping. That means that the position of the Heat Exchange will no longer be adjustable, but that is a sacrifice that is needed for improvement to the performance. This is working but needs to be at 72 watts to be strong enough to push through.

On the main Surya Sunbox circuit, I have removed one of the check valves (replacing it with open pipe) as it is not really needed, and I notice that the flow rate has improved, with the low power pump.

On the tubes, I need to remove the flexible connections so that all further obstruction is removed. 

Tuesday, July 2, 2013

Restart the tubes

The wiring includes an energy meter (middle),
the Kingspan solar controller (bottom) and
a 3 switch 2-gang light switch which allows me
to force things on and off. Actually, I could
do with another switch plate for some other
control functions.
1 July 2013: My main problems with the Varisol Tubes are flow rate and airlocks. This was all complicated by the loss of liquid caused by the leak in the main Surya3 Sunbox.
    I've done some plumbing and electrical work in the last few days, and got them working again. Perhaps they can be brought back into use.

1. I removed a check valve to improve flow through the heat exchanger (that works). I put it there to stop 'improper' flow when the more powerful flow from the heat pump is working, but this risk no longer applies.

2. Modified the wiring so that I can force the pump to come on (so that I can check flow rate and working action) - partly done, right->
3. Refilled the system on both sides of the exchanger with fresh liquid so that it can run - and gradually work the airlocks out. I don't have an airlock remover at the highest point of the tubes circuit, but regular pumping around does seem to remove them gradually. I need a sunny day with both pumps working to be sure it works.

By the end of the day, I had a new reading on the energy meter!! Looking at it working now, I wonder why it seemed so difficult before!

The copper heat exchanger is contained inside that block
of pink insulation below the pipework.

Monday, July 1, 2013

June 2013 Reports

30 June 2013: World News later, here are some metering figures for the end of the month:
  • House annual 5,413, biennial 5,209 kWh. 
  • GSHP annual 3,422, biennial 3,202 kWh. Annual dropping very slowly.
  • PV annual 3,071, biennial 3,093 kWh, Triennial 3,160 kWh. Bad two weeks with rain and cloud. In first two years of operation the average was 3,300 per annum!
  • Sunbox annual 2,663, biennial 2,619 kWh. Halted by the cloud and rain of June.
  • Ground Temperature 13.2ºC. This went up thanks to a warm sunny weekend.
23 June 2013: I'm not doing house reports on alternate weeks during the summer.

16 June 2013: World News later, here are some metering figures:
  • House annual 5,420, biennial 5,206 kWh. Annual dropping very slowly. 
  • GSHP annual 3,427, biennial 3,200 kWh. Ditto.. 
  • PV annual 3,087, biennial 3,122 kWh. Rising slowly - not an excellent June yet 
  • Sunbox annual 2,669, biennial 2,631 kWh. Halted by the long time of no action in May-June. 
  • Ground Temperature 12.7ºC. This went up to 13.1ºC last weekend (9th) with some sunny weather, but the rest of the week was rather cool.
9 June: This is the week of no solar capture earlier, but I got the Teepiece fitted later in the week and got the system working. There have been some sunny days, including the weekend, so the ground temperature jumped to 13.1º on Sunday evening. During the summer, it's not really worth posting figures every week as there is so little electric consumption by the house or heat pump that there is not much change. June 2012 was grimly cloudy and rainy, so we will see how the figures improve. June 2013 has started well.
  World news wise.... it was the 60th anniversary of the Queen's Coronation - more horse parades. In the same week, the Queen opened the new BBC headquarters in Portland Place. The Turkish crisis rolls on with the occupation of Gezi Park in Istanbul. Syria dominates the news too with Qusair being recovered by the government.
  The story of global phone tapping has been broken by the Guardian. Who can be surprised that the NSA in US and UK government were performing statistical analysis on trillions of phone calls, emails and messages, Facebook and Google requests and all? With all the worries about global terrorism, and security, this seems inevitable. They claim that they do not read the contents specifically (unless keywords are used), mostly it is to check the linkages and frequency. We shall see.
  Tom Sharpe, novelist, died, and Nelson Mandela is looking dodgy having been admitted to hospital yet again with respiratory infection. Surely they can let him die in peace? LondonDerry (Northern Ireland) has been voted European City of Culture and had a large ceremony - it seems better to do this in June than to do it on 1st of January, as did Liverpool a few years back - having a large music festival in January in bitter winter winds coming off the Irish sea was a bit difficult.
  As an oddity, a man in Bolivia got what many see as a deserved end - buried alive. I am not sure if this was an officially sanctioned punishment, or villagers doing their thing. Having raped and murdered a woman, he was in custody, and the grave was dug. He was flung into the open grave and the coffin of the woman lowered onto him, and the grave filled in. It says something about the culture that rape is punished in this way, compared with some countries where a raped woman is ostracised or even killed because she is no longer 'pure'.
  Sportswise, Rafa Nadal won the French Open Tennis for eighth time, and Vettel won the Formula One in Montreal.
 For the Peveril Solar house, it is only worth publishing numbers every two weeks, as little changes during the summer.

2 June 2013: The month of June has started with very good weather, and it is frustrating that the Sunbox system is not burying solar heat while it remains out of use. I am waiting for one solitary Tee piece. The first one arrived from Anablep but it was the wrong size, a 30-30-30 when I want a 38-38-38 tee piece. I am still waiting for the right ones to arrive. It will only take an hour to fix up, and yet lovely days of sunshine are passing by!
  The ground temperatures chart below is interesting. With negligible heat being drawn up by the heat pump (a tiny bit of hot water only), and no solar heat being put down either, we seem to have settled on a stable summer temperature of about 12.4-12.5ºC. The Sunboxes have been out of use since the scaffolding went up, and while they were working there was a rapid upward acceleration of the ground temperature from 10.6 to 12.5º.

  • House annual 5,460, biennial 5,209 kWh. Annual dropping very slowly. 
  • GSHP annual 3,459, biennial 3,203 kWh. Ditto.. 
  • PV annual 3,026, biennial 3,148 kWh. Very static.
  • Sunbox annual 2,666, dropping fast because nothing is being put down.
  • Ground Temperature 12.4ºC. This seems to represent the summer norm (for this time of year) if nothing much is being put down or taken up. (I would expect it to rise with natural warming to 12.8º by July if the sunbox is not repaired.)
World News? Turkey has come from nowhere to be the biggest story, with the proposal to build a shopping mall (using a pastiche Ottoman style) over Gezi Park in Taksim Istanbul. A peaceful occupation of the park (to save the trees) turned nasty when the police over-reacted, inflicting excessive punishment over the tree-savers. In a more unexpected place, Stockholm has been suffering from riots, youth unemployment, especially in the immigrant communities has spilled over into violence. Beloved actor Bill Pertwee (Hodges of Dad's Army) died. It was the 100th anniversary of Stravinsky's Rites of Spring and of the death of Emily Wilding Davison, who leapt fatally in front of the Kings Horse at Ascot.

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