Newbie Advice Sought

[Paul_F]

• How much does the EV use? Alternatively, how many miles per year do you drive in it? If it's an i-MiEV that's ~4 miles/kWh so 16 MWh would be equivalent to 64,000 miles a year. It's not really worth including EV electrical consumption in domestic use since there isn't much you can do to improve it.
• Washing and cleaning is where I'm interested. It uses lots of hot water, and that's a large consumer of energy which if I understand correctly you're producing at the moment from electrical resistance via an Immersun? Shifting to an alternative source (heat pump or solar thermal) would potentially save a lot of energy, and if you're already on Octopus Go then it's cheaper to heat up at night and export solar during the day - Octopus Outgoing Fixed is 5.5p/kWh and Outgoing Agile has been ~12p/kWh during the day recently. If you've already got a heat pump and can get on Agile Outgoing, you're saving ~10p/kWh on the cost of hot water as well as reducing your total consumption for the cost of a couple of valves and some pipe.
• Depending on where you are, 3-phase may be relatively simple. If you're planning on charging 2 EVs, electrical heating and hot water via Go/Go Faster then you're likely to find it tricky to charge everything at once and take advantage of a narrow cheap-rate slot. You're likely only to need to make alterations as far as the meter box, and then connect any new PV arrays directly up to it - no reason not to leave the house wiring on a single phase as it is at the moment. Really depends how you connect to the local grid and whether it's single or 3-phase at that point.

[kla456]

[/quoteI told you we were from a parallel universe, done all that and got the T shirt.

Yes, but do you have inside and outside shoes?
Do you have upstairs and downstairs shoes?
Top and bottom of our stairs is like front of the mosque!

[Bugtownboy]

I sense a Venusian competition coming on

[kla456]

Reply yo Paul_F

• I understand your point, but my target is net-zero for all consumption. As far as I understand we don't yet have performance criteria for net-zero? The Dutch recently introduced Benq standard (net-zero) for all new builds but we are still building new houses that will have to be refurbed before 2050!

• Re. washing and cleaning, as I said, my first object is to net-zero my consumption

• Your point regarding 3-phase could be useful. However, I extended and the incoming main is now 3m from the external wall. Too much disruptive work to contemplate.

[kla456]

Reply to Bugtownboy:

Been and gone!

[kla456]

Further reply to Paul_F

Apologies Paul for my earlier reply which did not do justice to your post. My main interest is to get to net-zero but of course I want efficiency and low running costs.

The car is a VW e-UP - similar to I-Miev I think. It charges at about 3.5 kW/h and does about 6k miles/annum

I've just observed 3 clothes washing machines, 1 dryer, 1 dish washer (all Miele - one 20 years old) operating concurrently and together using approx. 7 kW/h with a 2-hour cycle. Far as I know, these machines are cold water connected. I'm generating hot water jointly by heat pump into the primary HW tank, the Immersuns divert PV energy into the secondary HW tank that feeds into the primary (Daikin installer would not allow another arrangement). I don't yet have Octopus Outgoing (minimal export paying something (5p?) by FIT. I expected to switch to Octopus Outgoing after a 10kW PV extension (rejected by DNO, since resubmitted for 4kW).

• I get it regarding 3-phase, and this is probably the best way around DNO restrictions. I'm planning a further small front wall extension next year and might be able to bring in 3-phase then, together with a fire-proofed electrical cabinet - my electrical cupboard is scary full of kit and more coming.
  
  Thanks for your posts.

[Ken]

Does not seem that your wife is logged in ?

[Bugtownboy]

I've just observed 3 clothes washing machines, 1 dryer, 1 dish washer (all Miele - one 20 years old) operating concurrently and together using approx. 7 kW/h with a 2-hour cycle.

How many of you are there ?

Admittedly we’re retired, two of us at home, but have really pushed/focus on useage/consumption which has meant killing some lifelong habits.

Everything gets washed together on a 30o, quick wash, dried outside, not ironed. Lucky position that we bought a 30’s house and renovated that allowed us to change all the white goods.

Don’t have a lot of electric things - got rid of the separate freezer.

Our daily electric useage is 3.5-4kWh per day (1400 kWh pa).

I know it’s a battle you probably don’t want to have, but I think your route to net zero would be cheaper, and simpler, by reducing useage.

[Stinsy]

Further reply to Paul_F

Apologies Paul for my earlier reply which did not do justice to your post. My main interest is to get to net-zero but of course I want efficiency and low running costs.

The car is a VW e-UP - similar to I-Miev I think. It charges at about 3.5 kW/h and does about 6k miles/annum

I've just observed 3 clothes washing machines, 1 dryer, 1 dish washer (all Miele - one 20 years old) operating concurrently and together using approx. 7 kW/h with a 2-hour cycle. Far as I know, these machines are cold water connected. I'm generating hot water jointly by heat pump into the primary HW tank, the Immersuns divert PV energy into the secondary HW tank that feeds into the primary (Daikin installer would not allow another arrangement). I don't yet have Octopus Outgoing (minimal export paying something (5p?) by FIT. I expected to switch to Octopus Outgoing after a 10kW PV extension (rejected by DNO, since resubmitted for 4kW).

• I get it regarding 3-phase, and this is probably the best way around DNO restrictions. I'm planning a further small front wall extension next year and might be able to bring in 3-phase then, together with a fire-proofed electrical cabinet - my electrical cupboard is scary full of kit and more coming.
  
  Thanks for your posts.

Sorry to be nit-picky, but there is no such thing as "kW/h", Watts are a rate of energy, 1W = 1 Joule / second.

My washer (Beko) and dishwasher (Neff) each pull 3kW but only for a few mins to heat the water, although they are frequently on together, I've never seen them both heating at the same moment, then for the vast majority of the 3hr wash they only pull a few 100W, the washer goes up to 600W when on full-power spin. I have a Beko heat pump drier and that only pulls a few 100W throughout the cycle.

Maybe you should evaluate buying new, energy efficient, appliances?

[Paul_F]

The car is a VW e-UP - similar to I-Miev I think. It charges at about 3.5 kW/h and does about 6k miles/annum

I've just observed 3 clothes washing machines, 1 dryer, 1 dish washer (all Miele - one 20 years old) operating concurrently and together using approx. 7 kW/h with a 2-hour cycle. Far as I know, these machines are cold water connected. I'm generating hot water jointly by heat pump into the primary HW tank, the Immersuns divert PV energy into the secondary HW tank that feeds into the primary (Daikin installer would not allow another arrangement). I don't yet have Octopus Outgoing (minimal export paying something (5p?) by FIT. I expected to switch to Octopus Outgoing after a 10kW PV extension (rejected by DNO, since resubmitted for 4kW).

• I get it regarding 3-phase, and this is probably the best way around DNO restrictions. I'm planning a further small front wall extension next year and might be able to bring in 3-phase then, together with a fire-proofed electrical cabinet - my electrical cupboard is scary full of kit and more coming.

No worries.

• e-UP charges at 3.5 kW on single phase, 7kW on 3-phase. Probably only of interest if you start to drive further - 14 kWh/day at cheap rate is the limit for single-phase -> 60 miles/day -> averaging >22k miles/year.
• 7 kWh is a LOT - but probably not surprising, particularly for old appliances. Dishwasher for hot fill is pretty easy, quite a lot take water coming in at 60°C and from my experience that gives improved cleaning and reduced wash times. If you want to hit net-zero then you're much better off at looking for ways to reduce consumption first. More efficient appliances and considering hot fill is a much cheaper way to go than more PV, and avoids any embedded emissions in making the PV.
• If you're heating the first hot water tank in the chain with Immersuns, that will mean the majority of the time your hot water comes from electrical resistance heating of PV that you would otherwise be exporting to the grid. Turning that off will mean - assuming that you don't run out of hot water - a reduction of about 50-70% in the amount of electricity used for hot water over the course of a year.
• Octopus outgoing is 5.5p/kWh exported for the fixed rate version, they also offer an Agile-equivalent. Over the last week that's been averaging about 12p/kWh although historically it has been lower - that's reflecting electricity prices being high at the moment.
• Easiest way to bring in 3-phase is probably to put the 3-phase meter box on an outside wall wherever the power comes in at the moment, and then run a single phase from it to the current electrical cupboard. Unless you have an existing electrical safety issue there is no need to re-wire the rest of the house.