Choice of intelligent switches ?

InVestor_2

jeepjunkie wrote: »

The export is worth 1.65p per unit.

So considering I have to buy it back at 10p a unit is just madness.

For me the export is worthless when compared to the value of the on-site generated electricity and the 46.81p FIT.

Indeed when the sums were done for the viability of PV on our roof the export payment was not even taken seriously it's so low.

I know some people opject to using devices to use all the generated power but looking back everyone from installers to the EST encouraged using all the generated power and little mention of the export was ever made...

With the arrival of smart meters, that will change. I think it will make these devices much less attractive (on a financial basis).

I considered getting one over the Winter, but I'm lucky in that I have a system that often generates a spare 3kW, and I'm able to switch my immersion on to use it. Today it was on for 4.5 hours or so, all free

For me, personally, I don't think it's worth getting one. I have no objection to people using their generated electricity. I try my best to use my free electricity too

OffGridLiving

InVestor wrote: »

I considered getting one over the Winter, but I'm lucky in that I have a system that often generates a spare 3kW, and I'm able to switch my immersion on to use it. Today it was on for 4.5 hours or so, all free

For me, personally, I don't think it's worth getting one. I have no objection to people using their generated electricity. I try my best to use my free electricity too

I think the value of these devices comes in when you don't have full sunlight all day in order to generate a spare 3kw for the immersion heater. All it would take is for the sun to go behind a cloud and instead of your water being heated for free, it could be taking some power from the grid.

[Deleted User]

It's very easy to underestimate the value of these devices until you have one.

Cheers

InVestor_2

OffGridLiving wrote: »

I think the value of these devices comes in when you don't have full sunlight all day in order to generate a spare 3kw for the immersion heater. All it would take is for the sun to go behind a cloud and instead of your water being heated for free, it could be taking some power from the grid.

I was just making the point, that for me, I don't think it would be worth it to get one.
I only need a good 2+ hours every 3/4/5 days to have enough hot water. I can go weeks even months without the boiler heating my water. It's still considerably cheaper. If needed I just put on my gas boiler.

With the introduction of smart meters I can't see how they could pay for themselves in any reasonable timeframe.

[Deleted User]

InVestor wrote: »

With the introduction of smart meters I can't see how they could pay for themselves in any reasonable timeframe.

It may be different for recent [ish] pv installs but for those of us on the original rate import [in my case] is six times what the export rate is so will always be worth it. I'm all electric but i'm sure the same would hold true for oil/lpg users and even mains gas.

Besides water heating alone does not stop all export.

Cheers

InVestor_2

jeepjunkie wrote: »

It may be different for recent [ish] pv installs but for those of us on the original rate import [in my case] is six times what the export rate is so will always be worth it. I'm all electric but i'm sure the same would hold true for oil/lpg users and even mains gas.

Besides water heating alone does not stop all export.

Cheers

For all electric it clearly makes sense, but the majority of people in this Country are on Gas, which is considerably cheaper per kWh than electricity.
Anyway, I'm happy I decided to not get one, others may well find they are worthwhile. I still think much less so when smart meters roll out.

[Deleted User]

InVestor wrote: »

For all electric it clearly makes sense, but the majority of people in this Country are on Gas, which is considerably cheaper per kWh than electricity.
Anyway, I'm happy I decided to not get one, others may well find they are worthwhile. I still think much less so when smart meters roll out.

I totally understand where you are coming from which why I myself hummed and hawed until a device came out at the right price coupled with simple install.

The Ebenezer Scrouge inside still grumps whnn the wife runs a bath... then I have to check myself that it's free

Cheers

silverwhistle

When I get back to the UK this summer I plan to get PV whilst blowing a raspberry at the bank my cash ISA has been stuck in: even at post July rates it makes economic sense, but I would need to use as much as possible of my own generation.


Given, as a language teacher, I'd be working from home or in the evening I reckon I'd be able to make reasonable use of the power, but although I haven't bothered with any payback analysis the automatic switches seem too expensive.


Although I'm fit enough, running down the garden and up and down stairs to the airing cupboard to switch the immersion off or on everytime the clouds pass over seems impractical. I've seen some cheap remote wireless controlled switches which might make manual switching easier. Thoughts anyone, or do I just rely on the sunny south coast weather and getting an occasional bit of exercise? :-)

InVestor_2

silverwhistle wrote: »

When I get back to the UK this summer I plan to get PV whilst blowing a raspberry at the bank my cash ISA has been stuck in: even at post July rates it makes economic sense, but I would need to use as much as possible of my own generation.


Given, as a language teacher, I'd be working from home or in the evening I reckon I'd be able to make reasonable use of the power, but although I haven't bothered with any payback analysis the automatic switches seem too expensive.


Although I'm fit enough, running down the garden and up and down stairs to the airing cupboard to switch the immersion off or on everytime the clouds pass over seems impractical. I've seen some cheap remote wireless controlled switches which might make manual switching easier. Thoughts anyone, or do I just rely on the sunny south coast weather and getting an occasional bit of exercise? :-)

I have a home monitor in my office, with the immersion switch just a few feet away in a cupboard.

Cardew

zeupater wrote: »

Hi

I suppose that the answer to the above really relates to the structure of the op's energy supply contract. For example, in our case, having a tiered tariff gas supply, the energy cost offset from our thermal system is calculated at tier1 rates.

Our gas supply tier1 bracket is ~7.5p/kWh for the first 670kWh/Qtr, so considering that our gas use over the past 12 months has been <1100kWh (almost all in winter months) - March totalled ~55kWh, April 5kWh ... £80 would therefore relate to somewhere around 1067kWh of supply(80/0.075), or around 850kWh (01067x80%) of heat, that's the equivalent to ~4.7kWh/day over a 6month summer period (850/180), so not unreasonable from a 3kWp system with an automated control system.

With a solar thermal system the direct heat provision efficiency drops away as the differential between ambient & cylinder temperature rises (a form of automated modulation) whereas direct element-heating wouldn't, however, our system is amply capable of providing double the heat provision calculated above ... if we used more water the average lower storage temperature would cause system efficiency to rise and we could save even more gas and still have enough HW on tap, but using more water in order to show a better payback isn't really consistent with the reason for having the system!! ....

HTH
Z

Hi,

Agree, but your situation, and ultra low gas consumption, which justifies using Tier 1 rates is atypical.

In any case virtually every company is stopping the Tier1/Tier2 tariff and having a daily standing charge; so 4p/kWh for gas would be a ballpark figure.