Very instructive - we have 100 solar panels and no storage capacity so will be very interested in these discussions!

The drilling companies were both local. The first driller, whom we sued and who had to refund in full, is still operating and saying that they are GHPA borehole drillers - although they aren't a GSHPA member. The second driller was and still is an MCS certified installer and GSHPA member; they had to redrill the borehole. At the time, neither mentioned clay as any kind of a problem, nor did the local MCS certified installer. I believe that everyone has learned - but I still see that water quality is not considered as as a major parameter in the MCS or other guidelines on designs using boreholes for GSHPs. I'd like to have some evidence of this, as I can't access some of the documents.

We have so few MCS-certified installers in our area that we have nearly run out of options - we had a dispute with our original installer over faulty maintenance and now work with another installer. We don't know how to determine who to use based on track records, other than using the GSHPA and the MCA databases. Any suggestions would help as there are few online reviews of these companies.

You have a Hythe Environmental Community Group near you, which seems to be working proactively in a number of projects, including energy.

I suggest you make direct contact and draw this discussion topic to their attention.

If I wasn't 300 miles away, I'd be dropping in at their next meeting to discuss the their future energy strategy, heat-pumps and battery storage.

There is no requirement for members of the public to simply follow the paths suggested by government subsidies.
We are free to implement our own local/cheaper approaches if we have the knowledge and expertise to do things better.

And I'd be very interested to understand how you've managed to have 100 solar panels installed without storage!

a: I can't see how your DNO agrees to such a high export current on sunny days

b: I think you have a listed building, which constrains what you can install at roof-top level.

Don't worry if those PV panels also appear to breach regulations.
We have more solutions here on this Forum than you have problems! 😉 

@transparent It looks like you have got a bad deal from your contractor, driller etc.

Firstly, I presume you have an extraction licence from the environment agency? Any heat pump above about 7 Kw (2500 litres extraction per day)will require the licences or you are breaking the law.

An open loop system cannot be connected to a standard based plate heat exchanger(which the Swep unit is) without significant filtration being installed to remove the particles' normally associated with open loop. The clay particles are normal, in other areas it will be sand. You should have a different type of heat exchanger (co-axial type) or a separate shell in tube heat exchanger and a glycol loop to the heat pump.

The secondary heat exchanger can be cleaned, and we have done it many times with acid (patio cleaner) or alkaline (dishwasher tablets), however both are very corrosive, can be dangerous, and you need a very large high pressure pump, so it is NOT a DIY job.

Very good. I just sent the Hythe group an email saying we want to participate in discussions - although it would be much better if you could get here!

We installed the 100 solar panels in 2013 when there were still subsidies for solar generation. We had to struggle to get planning permission for ground-based PV, as we're in an AONB, but we finally achieved that.

We had to install a 3-phrase network connection - without it, we wouldn't have been able to install GSH either - we're in a rural area that had a really bad network. We had major problems with UK Power Network, which initially quoted £3000 to install 3-phrase. After we had taken out a bank loan for the solar installation, contracted with the installer and gone through 9 months of back and forth with UK Power on the application, they sent an engineer to site and said it would cost £25,000 to install. This is when the government decided to suspend the subsidies and when various organisations took them to court. After the court decided that the subsidies had to be reinstated (for a few months only), we wrote to the CEO of UK Power Network and accused the company of misquoting and of completely mucking up the installation of renewables. Within 3 days, three high-level UKPN executives were at our property and we negotiated a network installation that would take place in January and that would be completed in 3 weeks, just in time to be able to qualify for the subsidy. We paid them £10k and they absorbed the rest of the cost as long as they installed by the deadline (they did). They also reformed their quotation system and promised to get up-to-speed to facilitate renewable installations. One big advantage of this is that our parish now suffers very few power outages - before, we had about 10-12 per year - every time the wind blew, and we could install more than a 4kw heat pump, or it would have overloaded the network.

I'm an environmental scientist and my husband is a 'green' agronomist. When we began our project, we were trying to demonstrate how a small farm with Grade II listed buildings in a dilapidated state could be converted to 100% green energy while sustainably managing water, improving biodiversity, managing gardens/agriculture organically, and conserving ancient buildings. We got special planning permission based on a whole-site approach, where one of our buildings was meant to be used as a demonstration centre to disseminate knowledge and exchange experiences. We had to bring together a lot of different knowledge holders and sources to achieve our goals - some of that worked, and some of it didn't. At the end of the day, we realised that it is just too costly for most people to do this (including us), so we didn't proceed with the demonstration functions.

The cost of installing batteries for the system was prohibitive. We've tried to keep on top of this since that time but haven't heard about the DIY options. Maybe it's because we are so absorbed in trying to keep our GSH system up and running, and we hadn't found this forum!

In any case, we still clearly don't have the knowledge that we need to successfully/economically manage our renewable energy system - it seems like it requires more of an engineering / technical background than we have.

What I would most like to have is someone who would help us to revamp our whole energy system...we are still importing too much energy and having too many problems with the GSHP.

ALSO: We switched from Good Energy to Octopus Energy in November, as Octopus pays a lot more for export. This itself was a nightmare, as Good Energy wouldn't allow us to switch contracts and I had to fight them for months to achieve this (if anyone wants to know how I managed it, write to me; we were also actively misinformed me about government conditions on export payments).

When Octopus installed their Smart Meter last November, it started registering 2 x the electricity imports that are normal. We complained in early December and they recognised the discrepancy and promised they would act. They charged us nearly £1000 for 3 weeks of import, and then reversed the charges. When our GSH system went out completely, there was no decrease in electricity import - and when the system was repaired, no increase in import was registered. Octopus has done absolutely nothing about the meter discrepancy so far. They again charged us £1200 above our normal usage. I went to The Energy Ombudsman today and started a complaint - when I informed Octopus about this by phone, they said they would schedule an engineer immediately. Apparently they perk up when the Ombudsman is invoked.

If you know of anyone who might be able to support us, please contact me at phowardstutterheim@me.com

@heacol We have no extraction licence as our extraction is below 20 cubic metres per day (we have the calculations of how much we use for heating and they were done correctly) - the Environment Agency was of course notified. We discharge to a local stream, which is permitted. 

We investigated heat exchangers as I said in an earlier post - we learned that our system is too small for co-axial. Do you know of a supplier of a co-axial heat exchanger for a 17kW system? If so, please do advise...

We clean our SWEP 14243-046 B28 heat exchanger regularly using high-pressure water only - no acid (my husband has an industrial factory and we use factory equipment), which seems to do the trick. The pump is regularly flushed with high-pressure water and occasionally (3-6 months, depending on the weather) demounted and treated with formic acid. We know this will shorten the life of the pump some, but it's cheaper than installing a horizontal system or trying to filter the borehole water.

The worst problem we had was that we were forced to replace the secondary heat exchanger twice as the MCS-certified installer didn't adjust the temperature settings in the GSHP correctly, which allowed the system to freeze. We also changed MCS installer for our servicing as a result.

@phowardstutterheim

Correct me if I am wrong, but I assume that you are drawing water out of the bore hole, passing it through the heat exchanger in your GSHP, and then discharging the water elsewhere. Where does the discharged water go?

I tend to try to think outside the box when problem solving.

There are GSHP systems that use water flowing through a suitable pond as the heat source. You already have the flowing water, so would it be possible for you to create a suitably sized pond? The idea being that by placing suitable heat exchangers within the pond itself, be it loop piping or something similar to standard radiators, heat energy could then be absorbed by passing a sealed brine solution through these heat exchangers. The bore hole water would flow around the heat exchangers, rather than through them, so would not be able to block your present plate heat exchanger.

Since water is at its most dense at 4C, provided there is sufficient bore hole water flow, and the pond is of suitable size, it should not freeze solid.

Let me know what you think.

Hi Derek,

That's an interesting idea that we haven't entertained, and might have entertained if we were at the initial stages again. The question of water temperature might be important - how large/deep would the pond have to be to ensure that the brine temperature doesn't drop compared to the water temperature in the borehole at 40M deep?

However, we have decided not to take further action - backflushing the heat exchanger and the pump, and demounting the pump and flushing it with formic acid every few months is enough to keep our system running. Again, it is economics (as well as whether experiments will produce better results) - we don't want to invest more than we have already invested (which is a LOT). If we're spending 50 person-hours and £300 per year to maintain it as we are, how many years would it take to recoup an investment in another ground source system?

@heacol Sorry, I made a mistake. My husband told me that he doesn't use high pressure - he backflushes (we had valves installed for that purpose).

Sheesh @phowardstutterheim .... this story keeps growing in size!

You are raising so many points that really need comment and discussion not just within this Forum, but in your local Hythe Environmental Community Group too!

Let's see how much of what you've posted I can explode into an array of other subjects before @editor finds out and divides them off into separate topics 😀 

1: If you've got 3-phase available, then why has a single-phase (240v) pump been installed for the borehole water?
That introduces phase imbalance needlessly, and there is a 3ph version of your pump available.
Even with 3-ph, a heat-pump still causes additional losses on the Distribution Grid due to harmonics. Ofgem requires UK Power Networks to reduce these losses.

2: If you've got ground-mounted solar panels, then have you and your husband considered using your combined professional knowledge to arrange them as part of a hot-house roof, within which you could nurture a range of experimental or exotic plants such as Citrus Australasica sanguinea (caviar lime)?

3: Smart Meters are one of my 'specialist subjects'. Which company first installed yours, and what was the approximate date?
I'm trying to work out if it's a SMETS2 version, or a SMETS1 which has subsequently been migrated to the National Smart Meter Network.

4: I have particular understanding about inconsistencies in Smart Meter readings, and possible billing errors.
I studied that matter extensively about 18 months ago whilst I was with OVO Energy.
I have discussed it with Octopus, and sent an update to a senior member of their technical staff just before Christmas ('22).

5: There seems to be an inherent failing in the way that LPAs 'approve' Building Control Notices which are filed with them by 3rd party professionals under the Competent Person Scheme.
There are no checks as to whether the installation actually complies with the requirements.
This needs to be raised with the relevant Councillors. How well do you know Cllrs Hollingsbee and Carey?

6: Now you're with Octopus you can install (large) storage batteries, and run the GSHP off-grid for most hours of the day.
UKPN will prefer that because off-grid use removes their losses through harmonics.
You'll need to change to a variable Time-of-Use tariff with Octopus, who are the only national Energy Supplier to offer them thus far.

@phowardstutterheim

Should you decide to go down the battery storage route, if you had possible 1 extra solar panel installed, which I do believe are VAT free at the moment, and also install battery storage at the same time, that is also VAT free. I think to qualify the system would need to be installed by a MCS accredited installer, not DIY.

@transparent

The borehole pump is a Rovatti 4ES8 - it is a .75 kW, 2A 3-phase. The circulating pump that I mentioned, Grundfos, is single phase. We've been advised on all of this equipment by irrigation specialists/installers, and our (industrial) electricians were involved in the initial installations as well. I don't know if what you mention bears specific investigation, but we can call on our electrician to find out.

When we installed our solar system, there was a major gap in the domestic /small-scale greenhouse market, at the same time that large-scale greenhouses (a sector my husband works in) were being completely revamped for energy efficiency. Together with a renewable heating engineer who worked for Danfos, we initially designed a modular, self-heating greenhouse system that uses GSH and solar for lighting and heat. The idea was to market 'kits' that can be installed for domestic or small-scale nursery use. However, we would have had difficulty getting planning permission (AONB) for a demonstration / experimental model, our heating engineer went out of business, and we didnt' have the means to go ahead on our own. We were also missing an architect who would help with planning permissions. Things have changed a lot since then, and we haven't kept up-to-date. Perhaps there is or should be a discussion on this forum?

About our Smart Meter: it's an EDMI ES-30B. Do you have any knowledge of this model? We've also had completely chaotic billing since the SM was installed - I just stuck it all in a spreadsheet yesterday and sent it to Octopus, together with the complaint about the meter discrepancy and their failure to take action, as well as their failure to communicate. The 'high level' technician at Octopus that is communicating with me speculates that the problem is that our export is getting added to our import - this is nuts, because we've had virtually no export due to cloudy conditions, and because our import went up when our GSH system went down, and has not gone up after our GSH system came back on. I'm really fed up with this mess and any suggestions you could give in our dealings with Octopus would be extremely useful.

I'm a close colleague of Jenny Hollingsbee, who lives very close to us. We've had dealings with her relating to Ukrainian refugees in Folkestone-Hythe (we host a family), where I am quite active advocate. I'd need to understand the issue better to raise it with her.

A question about the batteries and Time-of-Use Tarrif: we're on a fixed tarrif until September 2023, which has protected us against increases in energy prices - so wouldn't it be best to wait until that expires before switching? And, the installation of storage batteries would be even more beneficial if we could store excess solar generation...?

A final thing we're concerned about is the efficiency of our GSH system. We have felt that we are not getting the full benefits out of the system since it was installed - our electricity import seems too high overall. We didn't have a Smart Meter (our new one is completely stupid), and we don't have any way to measure the total electricity use of the GSH system we have installed - from borehole to GSHP/boiler). If you have any suggestions on how to go about this, we would be very happy to hear.

@phowardstutterheim 

Looking at the data sheet for your Smart meter (link below), the most obvious thing that I notice under 'Billing Data Log', is that whilst there is 'Active Import Registers', there is no corresponding 'Active Export Registers', so I would question whether the meter is actually recording separate export totals.

EDMI-METERS.COM "https://www.edmi-meters.com/wordpress/wp-content/uploads/2018/05/ES-30B-Factsheet-English.pdf"

The link below is for how to read your actual meter, which may indicate what data is actually being measured and stored.

https://www.google.com/search?q=EDMI+ES-30B&rlz=1C1OPRB_enGB514GB552&oq=EDMI+ES-30B&aqs=chrome..69i57j0i22i30i625j0i390l4.8073j0j7&sourceid=chrome&ie=UTF-8

I also have a solar PV system and Smart meter, though only single phase. Although the indoor display shows export power as negative values, it does not subtract from the total import value displayed. I would therefore suggest that you monitor your display for a period of time and see if this is also the case with your meter.

I am also with Octopus on their standard tariff, so only get billed for imported energy, and get no payment for exported energy. I am not certain how Octopus utilise the data coming from my Smart meter, since I am on a single rate tariff, it could be that they just take the final import total at the end of the day, and record this until the end of the billing period when the total bill is calculated.

For those on a ToU tariff, Octopus would need to record the amount of imported energy every 30 minutes, and calculate the cost based upon the tariff rate for that period of time. How Octopus would deal with negative meter readings (if they receive them when you are exporting), you would need to clarify with them.

Since you are contact with someone within the technical department at Octopus, I would suggest that you ask them to confirm what data they are receiving from your meter, and how they are calculating your bill based upon that data.