Legislation affecting solar thermal

[Ric2013]

Yeah. Fortunately I left my ladder behind when I looked at the system. Went back in the evening so I could look at the system pressures while it was cold and met the customer's family. Turns out there was poor communication but one member had found someone who specialised in solar and was relatively local but I think it took me to convince them it needed doing (particularly when I discovered the blow-off had previously actuated). So now someone else will be sorting it out. Hurrah!

 

[Chrisjones.7976]

Why does it need flushing mine has the same water & special antifreeze mix for the last 10 years. It has a filler from mains water via a double check valve to top up if necessary but in all honesty has never needed doing . Original antifreeze was pumped in via small hand pump before water from mains supply.

 

[townfanjon]

Why does it need flushing mine has the same water & special antifreeze mix for the last 10 years. It has a filler from mains water via a double check valve to top up if necessary but in all honesty has never needed doing . Original antifreeze was pumped in via small hand pump before water from mains supply.

After 10 years Chris , it wants changing .

 

[Chrisjones.7976]

Out of curiosity, why if everything is working fine? All the pipework is stainless steel apart from the coil & the panels heat exchanger. The pump packed up a couple of years ago and the fluid mix was nice & clear that came out of the pump.

 

[Rob Foster]

Why does it need flushing mine has the same water & special antifreeze mix for the last 10 years. It has a filler from mains water via a double check valve to top up if necessary but in all honesty has never needed doing . Original antifreeze was pumped in via small hand pump before water from mains supply.

out of pure professional curiosity whose solar fluid have you used ? assuming its equvalent to Sentinal R100
Rob Foster aka centralheatking

 

[Chrisjones.7976]

I think it came from someone called secon solar, bright pink. It said long life, but that's about all I remember. Ta Chris

 

[Rob Foster]

I think it came from someone called secon solar, bright pink. It said long life, but that's about all I remember. Ta Chris

They all put fancy colours in to solar fluid to
make it ...'special' in fact the same stuff give or take cooled the Merlin Engine in the Lancaster, all types of Spitfire until after WW2 its not rocket science, it was then, it tastes just like pear drop sweets
I know
centralheatking

 

[townfanjon]

Out of curiosity, why if everything is working fine? All the pipework is stainless steel apart from the coil & the panels heat exchanger. The pump packed up a couple of years ago and the fluid mix was nice & clear that came out of the pump.

Do you change the oil in your car ?

 

[Rob Foster]

Do you change the oil in your car ?

Anybody would be a fool not to
in my opinion , I meet every service schedule on my vehicles
why not....but we are engineers and understand the ramifications of not servicing ,,,just like planes, etc and the armed forces machines
domestic folk do not...my friend has a Honda with over 400,000 on the clock, another is just passing 295,000
centralheatking

 

[Chrisjones.7976]

I think from reading various articles that the thing that makes the fluid break down is allowing it to boil. On mine when the temperature in the cylinder reaches 85C the solar heat is diverted to a dump radiator. I think in the whole time it's been installed it's only done it a couple of times as its quite a big cylinder & people in the house tend to use the hot water with showers etc.

 

[Brambles]

The issue generally is the glycol absorbing oxygen (that is why overheating it can become a problem). Depending upon how “tight” the system is it can last a long time (8 years plus). However, in time with the absorption of oxgyen, the inhibitors mixed with the glycol starts to convert to acetic acid. If you leave it in long term you should monitor the PH - obviously every time you monitor the PH you let a little bit more oxygen into the system.

 

[Ric2013]

I think from reading various articles that the thing that makes the fluid break down is allowing it to boil. On mine when the temperature in the cylinder reaches 85C the solar heat is diverted to a dump radiator. I think in the whole time it's been installed it's only done it a couple of times as its quite a big cylinder & people in the house tend to use the hot water with showers etc.

I was thinking a dump radiator is probably a really good idea.

Conventional thinking is it's better to heat a lot of water to a low temperature and then use gas to top-up than heat a little water and risk overheat, but that line of thought means that your solar will be insufficient even on the hottest days.

I must say I do like the idea of a solar system that dumps the heat on very hot days and is sufficient without gas top-up more of the year.

 

[Rob Foster]

I was thinking a dump radiator is probably a really good idea.

Conventional thinking is it's better to heat a lot of water to a low temperature and then use gas to top-up than heat a little water and risk overheat, but that line of thought means that your solar will be insufficient even on the hottest days.

I must say I do like the idea of a solar system that dumps the heat on very hot days and is sufficient without gas top-up more of the year.

We are learning alot about solar at present, in fact I am non exec dir of a Solar Thermal
Roof company. Barnsy at Sentinel tells me R100 goes down to -28c and up to something silly many times boiling point of water...because
solar thermal system overheat...so the trick is to keep getting the heat away..there is a fella I know who is dev a set up to cool down ...voltaic panels to keep them efficient and then use the removed heat to bang it into a cylinder ...Its all protected by UkPlumbing & Heating Innovation Centre which is open to anybody with an idea at any stage...its a not for profit set up. Rob Foster
aka centralheatking

 

[Chrisjones.7976]

Back to solar PV. I have this also, I bought a bit of electronics from someone called Optimersion (I think they have gone bust) there are others around. It detects what would go back into the grid & diverts it to an immersion heater, so on average sun I get a reasonable amount of hot water 50- 55C ish, hot enough for most things. On the rare days as I said previously it can go up to 85C at which point the dump radiator kicks in, not that it hardly ever does. There is a thermostatic valve on the hot water outlet that limits the output water to 60C so it doesn't scald people.

 

[Rob Foster]

Back to solar PV. I have this also, I bought a bit of electronics from someone called Optimersion (I think they have gone bust) there are others around. It detects what would go back into the grid & diverts it to an immersion heater, so on average sun I get a reasonable amount of hot water 50- 55C ish, hot enough for most things. On the rare days as I said previously it can go up to 85C at which point the dump radiator kicks in, not that it hardly ever does. There is a thermostatic valve on the hot water outlet that limits the output water to 60C so it doesn't scald people.

There are a few units like this one, and clever people with pv time their hot water usage for lunchtime , so its back to cylinders out with the combi if you have space...mind you pre warming mains cold before the combi can save loads of uplift energy...there is a few latents going thro on this at the moment...would not know whom tho !
Rob Foster aka centralheatking

 

[Ric2013]

Back to solar PV. I have this also, I bought a bit of electronics from someone called Optimersion (I think they have gone bust) there are others around. It detects what would go back into the grid & diverts it to an immersion heater, so on average sun I get a reasonable amount of hot water 50- 55C ish, hot enough for most things. On the rare days as I said previously it can go up to 85C at which point the dump radiator kicks in, not that it hardly ever does. There is a thermostatic valve on the hot water outlet that limits the output water to 60C so it doesn't scald people.

Back off-topic, you mean?

This shows exactly why the FIT is wrong. The idea was that the lower efficiency of the PV cf. thermal would be compensated for as the owner was doing the network a service in exporting high-quality electricity at the demand side of the grid where it is needed rather than have to pay a power station and lose a lot of the energy in conversion and transmission. But, of course, instead of subsidising the cost and making it a requirement that any unused energy is exported, they decided to pay people to generate and then pay them again for exporting half (even if they don't export any at all). The divert-to-hot water method is a consequence.

Problem is that, while solar PV is better environmentally than gas for creating heat, it's not as good as solar thermal by a long margin. PV is also less efficient in terms of kWh per square foot, but the energy is more useful as it can be transported off-site (via the national grid), used to run motors, electronics, and even run heat pumps. Thermal may make more energy, but you have to store that energy, it is very low-grade energy (heat), and you can't do anything with it except use it as heat which may not even be very useful in hot weather.

As a friend of mine once put it, '[t]he government could have put the panels up for free and given the householder some incentive for the use of the roof and we would all have benefitted. Instead of which they decided to buy into, and promote, people's greed...'.

Much as I regret the near-demise of the FITs, they were all wrong anyway.

 

[Brambles]

Ric,

All very good points ( with which I agree ).

I think that there is a much bigger picture there too. If you look at it ( solar PV ) as a bit of a quirk. On the face if it, it was easier to instal than thermal solar, it took off and then got caught up in the embedded power debate. The level of uncontrolled generation grew quickly to such a level that it (embedded power) impacted (negatively) peak power prices for the major generators. That quickly moved on to large private investors shunning the UK power sector for future investment.

Sadly ( in my view) the consequence appears to be that all forms of power generation ( even coal) now seem to attract a Govt. subsidy of one sort or another.

As with all these issues, the consequence is that those who can least afford to pay their power bills are those who are impacted most.

If you couple that with the proposed (?) ban on gas fired domestic heating for future new builds - people are being burdened with using an energy source ( grid electricity) that is currently three times the price of gas to heat their homes.

That is not intended to be a political statement, but I earn a very good living and cringe at my power bills. How do those not so fortunate deal with it?

On the heating side - we really need a small, but knowledgeable lobby group, to educate and promote the benefits of solar thermal with the Dept for Business, Energy and Inovation.

Apologies if the above is not appropriate for this forum.

 

[Welder]

Ric,

All very good points ( with which I agree ).

I think that there is a much bigger picture there too. If you look at it ( solar PV ) as a bit of a quirk. On the face if it, it was easier to instal than thermal solar, it took off and then got caught up in the embedded power debate. The level of uncontrolled generation grew quickly to such a level that it (embedded power) impacted (negatively) peak power prices for the major generators. That quickly moved on to large private investors shunning the UK power sector for future investment.

Sadly ( in my view) the consequence appears to be that all forms of power generation ( even coal) now seem to attract a Govt. subsidy of one sort or another.

As with all these issues, the consequence is that those who can least afford to pay their power bills are those who are impacted most.

If you couple that with the proposed (?) ban on gas fired domestic heating for future new builds - people are being burdened with using an energy source ( grid electricity) that is currently three times the price of gas to heat their homes.

That is not intended to be a political statement, but I earn a very good living and cringe at my power bills. How do those not so fortunate deal with it?

On the heating side - we really need a small, but knowledgeable lobby group, to educate and promote the benefits of solar thermal with the Dept for Business, Energy and Inovation.

Apologies if the above is not appropriate for this forum.

Once again, the UK examines this issue from the ar5e end up while the civilised world laughs up its collective sleeves.

The UK & USA are the only places where one gets a subsidy for literally wasting energy.

Instead of fixing the millions of leaky buckets we call homes, and only at that point investigating alternative generation (which of course would then be hugely reduced), we do the pathetic job we do pouring hard earned energy into sh1te housing so the big energy cos can keep their earnings up.
Makes me ashamed to be a Brit.