Upgrading house to 3 phase supply

[BigBoy]

3-6x for both unit price and standing charge?!

maybe different for region? we always had three phases (100A) coming in to the property but on a single phase meter...had the need to get three phase for some machinery so all that needed to be done was getting a three phase meter installed, I'd have to look but the price increase was more like 10-20% for unit price?


e : maybe even the same unit price, bad memory...

Domestic prices are considerably different to commercial hence the huge difference.

Just because you have three phases available does not mean you pay for them. But when you request the upgrade to three phase the cost and reason for the upgrade is all on you.

 

[builder22]

That seems a lot...will need to double check but the unit price is around 16p, standing charge 20p

That's on a business tariff but with the house included (workshop on same supply as the house)

 

[dirtychinchilla]

Im considering running a new line to put 3 phase in so I can potentially install an electric boiler.
Probably a bit simpler doing it on the farm and just running cable across half of a field.

Why do you want an electric boiler?

 

[soundb0y]

Why do you want an electric boiler?

I don't like paying for oil. Also I generate 100kw/hr on site so electric prices are negligible compared to domestic prices.

I was looking to hook up to the biomass we have but for the length of pipe run I suspect it may be cheaper to go electric.

 

[dirtychinchilla]

I don't like paying for oil. Also I generate 100kw/hr on site so electric prices are negligible compared to domestic prices.

I was looking to hook up to the biomass we have but for the length of pipe run I suspect it may be cheaper to go electric.

Ah OK, fair enough! I'm sure there are ways in which you could harness the biomass. What about filling a thermal store using the biomass and having an electric boiler to top up the heat? That would definitely be more efficient.

 

[soundb0y]

Ah OK, fair enough! I'm sure there are ways in which you could harness the biomass. What about filling a thermal store using the biomass and having an electric boiler to top up the heat? That would definitely be more efficient.

How do you mean a thermal store?

 

[dirtychinchilla]

How do you mean a thermal store?

Basically a large hot water tank. The idea is that when you have spare energy, you heat up the water in the tank. Then, when you need water you can draw it from the tank. It also acts like a capacitor in the sense that you’re storing energy until you need it. However, you might find that it’s not putting out heat at the temperature you need, day only 50C. So then you could use an electric heater to bring the temperature up to where you need it, say 70C. So instead of going from 40 to 70C with electricity, you do some with biomass and then some with electric. That should be a lot cheaper.

Have a look at this:

https://www.gosheating.co.uk/renewable-technology/thermal-store/

seems to me like you already have the heat so use it!

Also, minimise the pipe diameter between the source and the terminal units and insults to **** to minimise heat loss.

Honestly, if you can make use of that I think you’d have a really cool system. You may not even need the boiler, but you will probably need a heat exchanger.

https://www.treco.co.uk/news/article/how-to-store-biomass-heat-in-a-thermal-store

https://www.thebiomasshut.co.uk/heating-components/heat-interface-units/

That’s a crap HIU though. You want Danfoss. If you are interested I might be able to put you in touch with a colleague who specialises a bit. But, it may be a little small scale for them.

I’ve seen this exact setup work at a converted farm where they run a b&b

 

[clv101]

Are you planning to add a big solar array? 3-phase will allow you 12kW instead of the regular 4kW limit.

 

[soundb0y]

Basically a large hot water tank. The idea is that when you have spare energy, you heat up the water in the tank. Then, when you need water you can draw it from the tank. It also acts like a capacitor in the sense that you’re storing energy until you need it. However, you might find that it’s not putting out heat at the temperature you need, day only 50C. So then you could use an electric heater to bring the temperature up to where you need it, say 70C. So instead of going from 40 to 70C with electricity, you do some with biomass and then some with electric. That should be a lot cheaper.

Have a look at this:

https://www.gosheating.co.uk/renewable-technology/thermal-store/

seems to me like you already have the heat so use it!

Also, minimise the pipe diameter between the source and the terminal units and insults to **** to minimise heat loss.

Honestly, if you can make use of that I think you’d have a really cool system. You may not even need the boiler, but you will probably need a heat exchanger.

https://www.treco.co.uk/news/article/how-to-store-biomass-heat-in-a-thermal-store

https://www.thebiomasshut.co.uk/heating-components/heat-interface-units/

That’s a crap HIU though. You want Danfoss. If you are interested I might be able to put you in touch with a colleague who specialises a bit. But, it may be a little small scale for them.

I’ve seen this exact setup work at a converted farm where they run a b&b

Ah yeah I get what you mean. We've already got the boiler on a small district heating setup heating 3 cottages the main farmhouse and some workshops.

Would just be a case of laying the thermal pipe, adding a HIU and potentially upgrading the pumps at the biomass end.
Its about 130m so not too far but pipe costs seem pretty dear at the moment as with everything. The one thing is im sick of dealing with cowboy biomass installers. We fell out with the lot who put it in originally and two other companies I've had out to quote never bothered getting back to me.

Its just I had some plumbers come out one day for another issue and they recommended the electric boiler as a decent alternative if we pay next to nothing for the juice. They said it would need its own small buffer tank in the loft but not much else would have to change.

There is plenty of capacity left in the biomass though so guess it would probably be cheaper in the long run

 

[dirtychinchilla]

Ah yeah I get what you mean. We've already got the boiler on a small district heating setup heating 3 cottages the main farmhouse and some workshops.

Would just be a case of laying the thermal pipe, adding a HIU and potentially upgrading the pumps at the biomass end.
Its about 130m so not too far but pipe costs seem pretty dear at the moment as with everything. The one thing is im sick of dealing with cowboy biomass installers. We fell out with the lot who put it in originally and two other companies I've had out to quote never bothered getting back to me.

Its just I had some plumbers come out one day for another issue and they recommended the electric boiler as a decent alternative if we pay next to nothing for the juice. They said it would need its own small buffer tank in the loft but not much else would have to change.

There is plenty of capacity left in the biomass though so guess it would probably be cheaper in the long run

Oh awesome that you’ve got a district heating setup! To be fair, if the electricity is free then an electric boiler would probably be ideal and you have no heat loss that you would get with the pipes. Sounds very exciting to me tbh.

Unfortunately I don’t know biomass installers but we do sell HIUs so if you ever need one do send me a message.

 

[b0rn2sk8]

Heat pump pulling 50A (11kw!)seems excessive? Given they have a co-efficient of performance of 3-5x that’s potentially 55kw of heat they are putting out. How big is your house?

When I got a heat pump quote I only needed a 6kw unit for a 4 bed detached and that only needs to be put on a 16A supply. Even a massive 17kw heat pump only need a 32A supply.

 

[SimonR]

Heat pump pulling 50A (11kw!)seems excessive? Given they have a co-efficient of performance of 3-5x that’s potentially 55kw of heat they are putting out. How big is your house?

When I got a heat pump quote I only needed a 6kw unit for a 4 bed detached and that only needs to be put on a 16A supply. Even a massive 17kw heat pump only need a 32A supply.

Most (Air to Water) Air Source Heat Pumps have a COP of around 3 (for the best performing units in mild weather, whereas COPs of 4 and above tend to be for Air to Air ASHPs) and when you factor in the Seasonal Performance Factor (SPF) they can drop rapidly down to a COP of 2 in cold weather. In fact the COP can drop well below 1 in extremely cold weather (when you need the most heat). For an ASHP for a 4 bed house, the recommended size is around 9Kw (which would cope with 225m2 of heating in a well insulated house and as low as 90m2 in a poorly insulated house) According to Govt figures the average floor size of a 4 bed dwelling in the UK post 2002 is around 170m2 which equates to a 9Kw ASHP. This will also depend on flow temperatures and outdoor design temp. (which in Scotland will be much lower than Cornwall) as a rough guide on this, Manchester is assumed an outdoor design Temp of approx -2.5oc for ASHP calculations.

 

[dirtychinchilla]

In fact the COP can drop well below 1 in extremely cold weather (when you need the most heat).

That's where you might want to consider a hybrid approach where you combine your heat pump with an electric boiler with a COP of 1. Your SCOP will probably be better for it.

 

[b0rn2sk8]

The thing is, thanks to the jet stream we really don’t get ‘extremely cold’ weather in the U.K. It barely drops below freezing in most of the country and even that’s only for a few days a year.

They use heat pumps extensively in far colder countries like Sweden without issue. It always comes back to cost and **** old houses in the U.K. that no one wants to improve.