Posted by: @editor

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@transparent, excellent observation... my issue with batteries is still the massive capital expense... I'm still struggling with the maths. Maybe in the next house when we have a smart meter.

Next house?

After all that renovation, don't tell me you're thinking of moving again....

Posted by: @editor

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[...] this is where my DIY inability hampers me... would definitely consider the cheapo route and install myself, but don't have the skills

If only there was some sort of online help-forum where people could offer you advice 😉 

Just how do you think the rest of us worked out how to build/install a battery?!

Domestic electricians aren't necessarily in a better position than you.
Except they do start by having a selection of tools and a multimeter.

The only point at which you need a qualified electrician is the final step to connect the inverter back to your consumer unit.

For everything else, you'd be working below 75v and following what others post here.
That includes being told which tools or additional components you need, and where to get them from.

Think of it as a New Year's Resolution, and start a new topic so the whole world can follow your progress.

@transparent 

As easy as putting sparklers in champagne glasses (thought I’d start the new year in bad taste). 
My first house purchase was from a budding DIYer. The first time the gas board came round to read the meter, before they had left had condemned the boiler as a risk to life and turned off my supply. That was just the first week and it got worse. Sold it on to some other muppet like me as fast as I could.

@transparent 

I was surprised at how easy it was to install our battery setup.

Granted I am pretty competent at building/fixing things and was confident around the electrics.

The regulations talk about "competent person", which I'd say I'm in that bracket, so I am well within my rights to do the installation.

I probably would have got an electrician to do the final step with the CU, however as it was in our garage and connected to the garage CU which could be completely isolated in the house, I was able to complete the installation myself.

I do believe that an electrician wouldn't have done a better job and maybe in some cases not as good a job (looking at some of the installations online on some big installers Facebook pages).

I have to live with the installation and so took extra care to ensure it was installed above and beyond an safety needs.

@papahuhu With OvO withdrawing their Heat Pump Plus tariff I'm suddenly interested in alternatives but I had rather assumed that a time of use tariff wouldn't work based on the following arguments:  A heat pump works best when providing a gentle heat 24x7. My house was pretty much designed to radiate heat despite my best efforts so if the temperature goes down too far, my heat pump doesn't have the capacity to drag it back up again in a reasonable time and I have no way of storing heat (underfloor heating would be the most obvious way of achieving that). How do you make it work for you?

I have an alternative that most people don't - when I was planning my system (winter 2023/24) electricity prices were going crazy and also we weren't 100% sure that the biggest domestic heat pump could cope on the coldest nights (it can) so the system here is a hybrid with a small supplementary modern oil boiler and a buffer tank. On full price electricity it starts to cost more when the COP goes below 4 (at about 4 deg C ambient) so in extremis I can set the crossover point to 4 C and revert to oil to some degree below that. It'd not be my choice but it would be waaayyy better than my CO2 output before I put in the heat pump. I'd prefer alternatives and prefer it even more if the Government could start to be serious about mandating affordable sustainable heating tariffs.

@dr_dongle I’m not @papahuhu but, if my offering is of any interest, you are welcome to it. We are with Octopus and are on the Cosy tariff; this allows for a total of 8 hours per 24 hours at the rate of ~15 pence per kWh. Unfortunately, the rate for the other hours is much steeper. To make the most of such a TOU tariff, one usually needs to store energy for the ‘steep’ hours at least. We have 27 kWh of Tesla Powerwall storage which enables us to only draw from the grid during the 8 cheapest hours. Yes such systems are convenient but expensive (but getting a little cheaper) You will find topics about installing your own setup from the likes of Fogstar, so if you are feeling competent, you may well be able to equip yourself with a system so that the cheapest TOU tariff is your friend! Regards, Toodles.

@toodles I'm running at 4.5 kW just now. Assume two parallel 13.5 kWh Powerwalls, they would charge in 2.7 hrs @ 5 kW each and the heat pump would need to run at the same time so 14.5 kW for the 3 x 3 hr cheap-rate windows. The heat pump would then drain the Powerwalls in 6 hrs so it would all work, just. As you say, the capital figures are scary - £15k by my reckoning for the packs and switching/control electronics which must all depreciate in at most 10 years as the technology improves and the battery degrades (to no more than 70% on repeated deep discharge cycles if what I read is true). All noted though 🙂

@dr_dongle 

we put in a single PW3 and cycle the battery 3 times in 24 hrs. It’s a good, 10 year unlimited cycles warranty, so I figured if I flog it to death and they replace it after 9 years then all the better for me. 
I’ve got it outside as I’m a wimp and worry about fire, but it’s been good as gold at 40 to -7 last night. 

We run on the cosy fixed tariff, I think it’s 14.3 p, three times a day, I’ve never had to use anything other than low cost power other than 30 minutes yesterday. I did the calcs and although there is a penalty fee for exiting the fixed cosy, even though I switch in March to intelligent flux ( the export finances my entire power for the year). We have zero power costs, this year we should finish the winter with about £800 in ”profit”. 

so it all depends upon your power demand and any solar you might export and whether you have an EV. A high mileage EV changes everything, as that will always use the most power, we don’t have an EV so is not a consideration. 

I had another quick look at agile prices this morning, it still didn’t work better for me. The heat pump optimiser I use can, theoretically, optimise on the agile tariff. But it doesn’t work if you have a battery in between the 2 systems, they don’t coordinate. 

Hello, nice to see some New Year posts.

We've had our system about 14 months.

5.2kW solar, PW3 & Samsung 8kW (?) ashp.

We use octopus go & outgoing lite as we have an EV. Upgraded the PHEV Prius to an MG IM5 - yes, quite an upgrade but I didn't want a boxy EV but I wasn't quite prepared for the 0-62 in 4.6seconds! 407 bhp and 411 miles.

Over the last 364 days our electricity bill has been £330. Of which half is standing charge (don't get me started). Agreed it was an unusually hot summer and it's only a small bungalow with just us two. Having lived on a narrowboat we are very frugal with water & power . So overall I'm very pleased with the system. Better than the £10/day on coal as well as oil & electricity!

Steve

Posted by: @bash

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I probably would have got an electrician to do the final step with the CU, however as it was in our garage and connected to the garage CU which could be completely isolated in the house, I was able to complete the installation myself.

I do believe that an electrician wouldn't have done a better job and maybe in some cases not as good a job (looking at some of the installations online on some big installers Facebook pages).

I have to live with the installation and so took extra care to ensure it was installed above and beyond an safety needs.

Depending on what 'Standards' existed when you made that mains connection, it may or may not be "safe".

Have a look at the Safety Warning discussion on the need for bi-directional RCBOs which I posted here in Spring'24.

If in doubt, post a photo here of the trips in the garage consumer unit, and we can talk it through.

@profzarkov 

bet you don’t miss the constant aroma of the chemical toilet, although I otherwise love the idea of living on the water. We did a holiday once, the Cheshire ring, bloody nightmare going through some of the roughest parts of Manchester and back out to some very beautiful areas. 

@papahuhu ah yes, you're right although we had a pump out system. I do miss the life - the freedom. But not the "third class citizen" image or the something's always not working or broken or dripping! Plus it's getting too busy and not looked after by CRT.