Divert excess PV energy to "heat" hot water cylinder

rolion

Hello,

Installing a 2.5Kw PV system now and, taking in consideration the non FIT status (and not lastly,the bad weather) i'm looking at a device that will divert excess produced PV energy to my 300L cylider,powered also by a 40 tubes solar panels.

Found the "solar iBoost+" here...anyone using it in and any feedback ,please !?

Thanks

quentingargan

I have been testing a number of these units. They each have various ways of turning on a dimmer switch on your immersion. I haven't tested this particular unit, but I think it uses phase angle. This causes distortion on the grid. That may or may not pose a problem for your neighbours. The devices generally work well, but might cause your inverter to become more noisy.

rolion

Thanks,good and valid point.

According to thier FAQ...
"The Solar iBoost+ uses a special switching method to switch power into the immersion heater, this technology does not cause flicker on electrical circuits."

Which device do you recommend, please !?

quentingargan

rolion wrote: »

Thanks,good and valid point.

According to thier FAQ...
"The Solar iBoost+ uses a special switching method to switch power into the immersion heater, this technology does not cause flicker on electrical circuits."

Which device do you recommend, please !?

Last week I would have recommended Immersun, but they just went bust. That's why I'm testing other models....

rolion

quentingargan wrote: »

Last week I would have recommended Immersun, but they just went bust. That's why I'm testing other models....

Seen that too ... with regrets, any idea the reason behind it ?

quentingargan

rolion wrote: »

Seen that too ... with regrets, any idea the reason behind it ?

I guess the problem was that their high frequency switching made the unit a lot more expensive...

rolion

Ive searched online ideas on how to do it properly but nothing good.
I dont think the 3Kw immersion element in the hot water cylinder could create an efficient solution that will cover my PVs production,nonFIT payment and the house comfort zone.

I'm inclined to go with a Aquarea HeatPump that will be "powered" day time by the PVs and keeping hot water at a constant temerature in a dedicated stainless steel cylinder,dedicated for heating and ufh.

quentingargan

rolion wrote: »

Ive searched online ideas on how to do it properly but nothing good.
I dont think the 3Kw immersion element in the hot water cylinder could create an efficient solution that will cover my PVs production,nonFIT payment and the house comfort zone.

I'm inclined to go with a Aquarea HeatPump that will be "powered" day time by the PVs and keeping hot water at a constant temerature in a dedicated stainless steel cylinder,dedicated for heating and ufh.

Problem with using solar of any sort for space heating is that it works best when you need it least. Solar is great for summertime hot water when the oil boiler or whatever is on holidays, but you will struggle to run a heat pump on solar in the winter, and it would be cheaper instead to run it at night on off-peak power. Maybe a boost at noon on the PV, but not the whole day.

quentingargan

quentingargan wrote: »

That's why I'm testing other models....

Find anything interesting yet?

quentingargan

Sir Liamalot wrote: »

Find anything interesting yet?

Yes - found one model that just switches the immersion on and off every few seconds. Seems the meter rounds up or down to watt hours, so this works with the meter. However, it causes flicker in tungsten filament light bulbs. Why you would have those on at the same time as a solar panel is a question, but it doesn't happen with LEDs.

Also, there is a product coming to market in 3 months time which will function much the same way as Immersun, or so I am told.

quentingargan

quentingargan wrote: »

Seems the meter rounds up or down to watt hours, so this works with the meter. However, it causes flicker in tungsten filament light bulbs. Why you would have those on at the same time as a solar panel is a question, but it doesn't happen with LEDs.

Which meter? Import / export or it's own? Incandescents have always been very telling of power quality. Fitting leds is addressing the symptoms not the problem.

quentingargan wrote: »

Also, there is a product coming to market in 3 months time which will function much the same way as Immersun, or so I am told.

Can you send me a link please Q, if you don't want to post the name in the public forum. I'm looking for 6 x 3kW or 3 x 6kW proportional controllers preferably PWM.

rolion

Taking in consideration that no FIT payment, I suggest to connect the output of the inverter directly to the cylinder'immersion.
In that way,direct unconditional supply of electricity towards hot water,for heating and/or for washing.

As a backup maybe,a Solar iBoost that is powering immersion only all the time !?

Not sure whats happening when FIT in,but Q is when !??

quentingargan

Sir Liamalot wrote: »

Which meter? Import / export or it's own? Incandescents have always been very telling of power quality. Fitting leds is addressing the symptoms not the problem.



Can you send me a link please Q, if you don't want to post the name in the public forum. I'm looking for 6 x 3kW or 3 x 6kW proportional controllers preferably PWM.

We were only testing to ensure that the import meter didn't show imports to power the immersion. And we put a meter onto the inverter and the immersion to ensure that all the power was going to the immersion. There is a small amount of spilled export - about 50W.

I'll PM you with brands. I don't think I would put 18kw on PWM. My inclination would be to design something that measures current and fires up 5 of the 3kw immersions with triacs / SSRs and the sixth one only would be proportional. Would require a bit of logic. All the PWM units I have seen thus far are inclined to distort the sine wave which might upset local ham radio enthusiasts in the area....

quentingargan

rolion wrote: »

Taking in consideration that no FIT payment, I suggest to connect the output of the inverter directly to the cylinder'immersion.
In that way,direct unconditional supply of electricity towards hot water,for heating and/or for washing.
....

Not sure whats happening when FIT in,but Q is when !??

Re FIT, Minister yesterday said 2017. Didn't say which end of it. Anyone here in his constituency? (Roscommon).

You can't do what you suggest and just connect the inverter to the immersion. It need a grid and proportional control of some sort.

quentingargan

quentingargan wrote: »

We were only testing to ensure that the import meter didn't show imports to power the immersion. And we put a meter onto the inverter and the immersion to ensure that all the power was going to the immersion. There is a small amount of spilled export - about 50W.

I've noticed my GTI leeches current too. It wakes up with the panel producing 1W but takes 30W to operate...

quentingargan wrote: »

My inclination would be to design something that measures current and fires up 5 of the 3kw immersions with triacs / SSRs and the sixth one only would be proportional. Would require a bit of logic. All the PWM units I have seen thus far are inclined to distort the sine wave which might upset local ham radio enthusiasts in the area....

I thought the Immersun was/is PWM?

I'm looking at a prioritising islanding system so I'm disinclined to hard switch anything and I'd rather avoid spikes and dips.

quentingargan

Sir Liamalot wrote: »

I thought the Immersun was/is PWM?

I'm looking at a prioritising islanding system so I'm disinclined to hard switch anything and I'd rather avoid spikes and dips.

Yes - Immersun was/is PWM. I meant any device that uses phase angle and a triac. Immersun is more sophisticated than that

rolion

Hi,
I think im going to take my chances with the iBooster once i get the panels fitted.
They specified on their web site that is not creating flickering(s).

What can go wrong when i know where to find them here !?
Or,their local Irish distributor speaking some unknown language here ?

quentingargan

rolion wrote: »

Hi,
I think im going to take my chances with the iBooster once i get the panels fitted.
They specified on their web site that is not creating flickering(s).

Phase angle doesn't cause flickering lights, but does distort the grid. A few comparisons with their bankrupt competitors HERE.


Scope of our grid when operating 2kw load on phase angle at half throttle see attached.

mr chips

Could something like this also be used to divert power to storage heaters as well as the immersion? Just thinking that the array could be put to better use than heating more water than we need each day.

quentingargan

mr chips wrote: »

Could something like this also be used to divert power to storage heaters as well as the immersion? Just thinking that the array could be put to better use than heating more water than we need each day.

Yes, you can heat any load. Some of these devices have two relays, so when the cylinder is full of hot water and its thermostat cuts out, the device sends electricity to a storage heater.

However, on months when you have meaningful amounts of surplus electricity, it will tend to have been sunny and heating may not be required. I always caution against using solar anything for space heating.

mr chips

Thanks for the quick reply. We have a boiler here and a traditional plumbed central heating system with radiators, but with a 4kW solar array in place already I'm wondering whether the addition of a few second-hand storage heaters would be worth doing, not as a replacement for the existing system but as an addition. I'd happily divert power into three or four storage heaters if it helped to meaningfully reduce our net use of oil - as time goes by, the power we'll need for lighting even in winter will gradually diminish as bulbs are replaced with LED/energy-saver equivalents etc.

On a related topic, recently I've seen a number of micro wind turbines online with a claimed output of e.g. 400W. Some of these seem ludicrously cheap, with prices in the few hundreds or even less (this is no doubt reflected in the quality of product), but I'm intrigued by the notion that it might be possible to enhance the output of the solar array, especially in wintertime, without having to spend thousands more on kit. Is that essentially a pipe dream, or are there reliable versions such turbines out there?

quentingargan

mr chips wrote: »

Thanks for the quick reply. We have a boiler here and a traditional plumbed central heating system with radiators, but with a 4kW solar array in place already I'm wondering whether the addition of a few second-hand storage heaters would be worth doing, not as a replacement for the existing system but as an addition. I'd happily divert power into three or four storage heaters if it helped to meaningfully reduce our net use of oil - as time goes by, the power we'll need for lighting even in winter will gradually diminish as bulbs are replaced with LED/energy-saver equivalents etc.

On a related topic, recently I've seen a number of micro wind turbines online with a claimed output of e.g. 400W. Some of these seem ludicrously cheap, with prices in the few hundreds or even less (this is no doubt reflected in the quality of product), but I'm intrigued by the notion that it might be possible to enhance the output of the solar array, especially in wintertime, without having to spend thousands more on kit. Is that essentially a pipe dream, or are there reliable versions such turbines out there?

The heat you would get in the winter is really insignificant. See attached simulation of the output for a 14 panel system. The energy from Oct to March wouldn't really do a lot for more than one storage heater.

Micro wind was once cheaper than solar PV, but that has changed as PV fell in price. A 400W turbine isn't going to produce much - particularly in a built up area. Even trees 100m away have a drastic effect on a small wind turbine. In the USA, they mount small turbines on towers 30m high but that'll cost yer.

mr chips

Ah, ok. Thanks for the data sheet, that's really useful. I was looking at some Dimplex XL18N storage heaters, advertised at 60 each second hand (compared to 491 brand new off Amazon!!), but looking at the ad their power rating is 2.5kW so I guess even a couple of them would struggle to work just off the array alright.

I'm out in the sticks with just one neighbouring house about 40m away and have a bit of ground in the form of a 2 acre field, most of which is empty space. It consists more or less of two flat levels linked by a shallow slope, with the upper section roughly 20 feet higher than the lower one. The solar panels are ground-mounted at the top of the slope and face due south with no shading at all, so they are in as good a location as it's possible to get in terms of maximising efficiency etc.

In terms of any possible effects of tree coverage on a wind turbine, there's a mature hedgerow at the boundary around the upper section, consisting of hawthorn trees which are about 15-20 feet tall, and I've also planted about 10-12 tree saplings in that upper section, but most of those are still under 5 feet tall. I had some idle thoughts about erecting a 10-12m tower for any micro turbine - that would have it quite a bit higher than any trees, roof ridges etc for hundreds of metres in any direction. I've seen this turbine rated at 2kW priced at just under 1500, but I wouldn't go near it till I knew more about the supplier.

Food for thought, anyway ...

mr chips

Having had some feedback from the installer, he thinks that small-scale wind-turbines like the sort I'm thinking of haven't yet reached the level of reliability that would justify the risk/outlay.

In terms of using power from the panels to contribute to heating the house, he said that infra-red panel heaters may be a viable option as they draw a lot less power. Simplistically speaking, they work by raising the temperature of the solid objects in the house rather than heating the air, so are more akin to sunlight (if I understand correctly). The type of unit I'm talking about can be seen at http://www.infraredpanelheaters.com/shop/categories/Standard-Panels/ or at https://www.herschel-infrared.com/product/inspire-white/

Anybody used this sort of thing before - is it effective?

quentingargan

mr chips wrote: »

The type of unit I'm talking about can be seen at http://www.infraredpanelheaters.com/shop/categories/Standard-Panels/ or at https://www.herschel-infrared.com/product/inspire-white/

Anybody used this sort of thing before - is it effective?

Yes, I have seen these and they give a warmer feeling for a lower air temperature, BUT they only work if they are on while you want the heat. So if you use PV during the day, they are no more efficient at heating the house for evening use than a Dimplex heater.

I generally don't see how space heating can work with solar. Its the wrong mix. Hot water is better and can be produced during the day for use later. If you have a 2kw solar array, you generally will use most of the power produced, either for running appliances during the day, or hot water storage.

mr chips

Thanks for that. Several times a week I spend part of the day at home, so it might actually be worth having one in the room I mainly use. That would at least mean I wouldn't have to heat a whole floor of the house just to be comfortable, assuming it's effective! Going by the links above, I'd probably need one of the 850 watt versions.

As mentioned, my solar array is 4kW and getting the best out of the panels has simply meant changing when to run the washing machine, immersion etc so as to get it all done earlier in the day. In fact, using the immersion to heat water for later use has meant we burn significantly less oil, which is great. But despite all that, during daylight hours there's nearly always a surplus of power, even on the days when I'm at home for the afternoon and am using the PC, kettle etc (obviously, with light & TV etc being used in the evening, we still import power from the grid when it's dark).

While the array is very effective at providing hot water, there's no point in devoting all the surplus energy primarily to that, even through the winter months - ultimately we would end up with much more hot water than we need, as there's just the two of us in the household. Rather than export surplus energy to the grid, I want to figure out the best way of using the power in a way that's useful to us, rather than e.g. heating a lot of water just for the sake of it. This is why I was wondering about the possibility of storage heaters, infrared heaters etc, as it'd be nice to further reduce the amount of oil we go through, especially when the solar power is "free".

I'll have a think about other possibilities for over the winter, such as how to dry laundry when hanging clothes outdoors isn't an option - it'd probably be more efficient to put wet clothes in a small room with a dehumidifier, rather than running a load through the tumble dryer.

rolion

Lads,i need your avice please : if i have solar tubes on the roof that does a great job ..do i still need / justify these diverters !?
I mean,doing the maths,a proper diverter cost me around €400 by the time is fitted...how much im i going to gain OR lose with/without it ?
Thanks.

quentingargan

rolion wrote: »

Lads,i need your avice please : if i have solar tubes on the roof that does a great job ..do i still need / justify these diverters !?
I mean,doing the maths,a proper diverter cost me around €400 by the time is fitted...how much im i going to gain OR lose with/without it ?
Thanks.

I think if you have tubes, you can't justify that diverter. I'd just time the washing machine etc., and try to maximise daytime use.

Conor20

mr chips wrote: »

On a related topic, recently I've seen a number of micro wind turbines online with a claimed output of e.g. 400W. Some of these seem ludicrously cheap, with prices in the few hundreds or even less (this is no doubt reflected in the quality of product), but I'm intrigued by the notion that it might be possible to enhance the output of the solar array, especially in wintertime, without having to spend thousands more on kit. Is that essentially a pipe dream, or are there reliable versions such turbines out there?

Out of interest, what are the turbines you're looking at? I've been meaning to implement a project on a farm for water pumping - most likely Solar PV or a small wind turbine. Intermittecy is fine - using a big enough tank means it could just fill it up when there is wind / sun available.

mr chips

Sorry, I probably won't be much help to you here - I've put the wind turbine idea on hold for the time being, as the consensus opinion I've had from a couple of different sources is that microturbine technology hasn't become reliable enough for the sort of scale I'm looking at. If you want to look into it more closely yourself then on the face of it, one of the better value ones I had come across was the one I linked to in post #23 above -

https://www.amazon.co.uk/Tumo-Int-Blades-Turbine-Generator-Controller/dp/B01JFU7IQO/ref=lp_10648601031_1_1?srs=10648601031&ie=UTF8&qid=1473863641&sr=8-1

... which claims to produce up to 2kW of power and is priced at under 1500. But I hadn't delved any deeper into that one in terms of checking out the supplier etc, so I'm not in a position to make any recommendations about it - for all I know, it could be an expensive ornament.

The key advantage of solar over wind is that it's solid-state, i.e. no moving parts, which means the potential for wear & tear is virtually nil and you won't face much in the way of costs & hassle over the lifetime of the array - in 20 years' time, mine is expected to still be operating at 80% efficiency at a minimum. As one person I spoke to said, "Wind is great when the power output you're looking at is measured in megawatts, but the reliability for small-scale projects just isn't there yet."

mr chips

mr chips wrote: »

... which claims to produce up to 2kW of power

in 20mph wind.

rolion

Despite my plan to abandon buying a diverter..if today with this bad sunny coverage, i export free to the grid almost 1Kwh...i think i may have to order one just to get the last watt of sun !??
The sums numbers on the dashboard are wrong ... according to supplier i fitted wrong a clamp/sensor and it added the PV energy to grid consumed one.

rolion

Found a nice explanation of how these diverters works HERE.

M question is ... if the diverter is switching / powering on and off so often the immersion electric element,how is this build to resist to so many frequest and non-constant on/off sequence !? Im i not risking of burning off with so many cycles !??
Thanks

Rossdarragh1

Hi, looking for advice on whether to install pv panels or not. As part of a grant scheme I have installed an air to water system. As part of the scheme I have the option to install 6 PV panels under the below conditions. I'm not very educated in this area but according to my research the pv can save up to €200 a year and will cost me €1800 which I'm aware is cheaper than normal. Obviously after 9 years it will have paid for itself. This is all that I'm basing my reasoning off at the moment. What do people think? I know that any excess power will be used to heat the water but wondering is it worthwhile?




The offer includes the installation of the Electric Ireland Connected home and an immersion diverter for any excess power you may have unused and 1.5kW (6 panels) of PV. Our installer will show you how to maximise the use of the PV by timing appliances and hot water heating to use power when it is sunniest. The Solar offer is included in the brochure attached. And would see a total of 6 solar panels (1.5kW) installed on your roof and you would repay in 36 monthly installments to repay the capital cost of the installation.

The offer is for a monthly direct debit payment of €50 per month if you are an electric Ireland customer or €70 euro per month if you are a customer of another supplier. This offer is a hire purchase agreement with Electric Ireland and includes a 35% discount from SEAI, a further discount of €900 from the cost of the solar from Electric Ireland and the Electric Ireland connected home worth (€300).

What’s the catch? The PV offering is a pilot to understand consumer behaviour and collect insights for the purpose of rolling out the project further. You will have a number of small obligations:
- As part of the project, you will have already signed an agreement that allows the team and related parties use the data from your installation for research and development purposes.
- You must allow Electric Ireland to use pictures, optionally and at their sole discretion, of the completed installation at your premises for their marketing and public relations purposes.
- The hire purchase agreement will need to be repaid or transferred if you sell your home.
- You will need to sign a direct debit mandate.

noel100

Rossdarragh1 wrote: »

Hi, looking for advice on whether to install pv panels or not. As part of a grant scheme I have installed an air to water system. As part of the scheme I have the option to install 6 PV panels under the below conditions. I'm not very educated in this area but according to my research the pv can save up to €200 a year and will cost me €1800 which I'm aware is cheaper than normal. Obviously after 9 years it will have paid for itself. This is all that I'm basing my reasoning off at the moment. What do people think? I know that any excess power will be used to heat the water but wondering is it worthwhile?




The offer includes the installation of the Electric Ireland Connected home and an immersion diverter for any excess power you may have unused and 1.5kW (6 panels) of PV. Our installer will show you how to maximise the use of the PV by timing appliances and hot water heating to use power when it is sunniest. The Solar offer is included in the brochure attached. And would see a total of 6 solar panels (1.5kW) installed on your roof and you would repay in 36 monthly installments to repay the capital cost of the installation.

The offer is for a monthly direct debit payment of €50 per month if you are an electric Ireland customer or €70 euro per month if you are a customer of another supplier. This offer is a hire purchase agreement with Electric Ireland and includes a 35% discount from SEAI, a further discount of €900 from the cost of the solar from Electric Ireland and the Electric Ireland connected home worth (€300).

What’s the catch? The PV offering is a pilot to understand consumer behaviour and collect insights for the purpose of rolling out the project further. You will have a number of small obligations:
- As part of the project, you will have already signed an agreement that allows the team and related parties use the data from your installation for research and development purposes.
- You must allow Electric Ireland to use pictures, optionally and at their sole discretion, of the completed installation at your premises for their marketing and public relations purposes.
- The hire purchase agreement will need to be repaid or transferred if you sell your home.
- You will need to sign a direct debit mandate.

Have you got the link I can't find it on electric Ireland
Thanks
Noel

Rossdarragh1

Its through the scheme I'm participating in, not open to people outside the scheme

noel100

Can anyone join the scheme

I consider €1.20/watt excellent value

Rossdarragh1

The scheme is now closed, was operated by an agency through county council. As I participated in it originally this is an add on that was offered. Not well informed in this area so just came on here to see what others thought. Any questions I should be asking before going ahead with it with regard to installation or the future addition of more pv panels?

noel100

Rossdarragh1 wrote: »

The scheme is now closed, was operated by an agency through county council. As I participated in it originally this is an add on that was offered. Not well informed in this area so just came on here to see what others thought. Any questions I should be asking before going ahead with it with regard to installation or the future addition of more pv panels?

Will they allow you a larger Installation than the 1.5kw
I would definitely go for the option over 3 years.
Life span of modules 25years you'll have 16years free electricity ..
I would ask do they have optimizer in the panels stop panels voltage dropping from shadowing.

Rossdarragh1

Thanks for the advice. They only mentioned 1.5. Is it easy at a future date to add extra panels or has it to be rewired to cater for more panels? Are their estimates right it predicting that 6 panels equates to roughly €200 a year saving? I presume 12 panels equates to €400 saving etc? Am i right in saying that the house used the electricity created on demand and the sensible thing to is to have it linked directly to hot water to ensure no electricity is wasted? If selling back to the grid is re introduced it there anything specific that needs to take place in the installation process in order to future proof against it? Sorry for all the questions , I'm not very educated on the matter and don't understand a lot of the associated jargon.

noel100

I know that the micro generation scheme is still available on the esb website open till 31st dec 16.

They will probably put in a 1.5. -1.8kw invertor to change electricty from DC to AC 240v output.

If you have a smart meter ,that will allow you to use the power generated offsetting the higher price paid . Sending power to the grid is 9c kW.

Sending excess power to immersion is good but you mention that you have solar tubes.

Electric car could soak up excess but you won't be generating alot of power.

noel100

You can use this calculator work out how much electricity you can generate

http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php

Place the pointer on Ireland and 1.5 in to size of array. Give approximately what you'll generate.

air

noel100 wrote: »

I know that the micro generation scheme is still available on the esb website open till 31st dec 16.

The scheme is closed to new customers, it's just that they're paying existing participants up to the end of 2016.

noel100 wrote: »

If you have a smart meter ,that will allow you to use the power generated offsetting the higher price paid . Sending power to the grid is 9c kW.

You have to pay €340 for the smart meter which would take 3 years of output to pay back with a 1.5kW system.
For a lot of people an immersion diverter would make more sense than spending the money on the meter.
Given that at present they're not even paying the 9c to new customers there is no benefit to having a meter installed.

air

Rossdarragh1 wrote: »

Is it easy at a future date to add extra panels or has it to be rewired to cater for more panels?

Very easy but you'll likely need a new inverter.

Rossdarragh1 wrote: »

Are their estimates right it predicting that 6 panels equates to roughly €200 a year saving?

No, it's not an accurate estimate, it assumes the system would produce around 1200kWh (which is reasonable) but that the energy produced is worth full retail price to you (18c/kWh).
In order to realise this saving, your average electricity consumption would need to be over 1.5kW continuously in order to guarantee that you would self consume everything that it produces.
In reality if you work during the day you are unlikely to self consume any more than 30% of production in which case the payback will be more like €60 a year.

Rossdarragh1 wrote: »

I presume 12 panels equates to €400 saving etc?

No, in the absence of a feed in tariff a bigger system makes a lot less sense, even with a FIT at less than the retail price, the marginal return on the extension to the system will be less than on the original portion. As the system increases in size self consumption as a proportion of total generation is reduced. This is because self consumption is the only part of generation that is worth anything to you without an export tariff.

Rossdarragh1 wrote: »

Am i right in saying that the house used the electricity created on demand and the sensible thing to is to have it linked directly to hot water to ensure no electricity is wasted?

It's a reasonable approach in the absence of an export tariff.

Rossdarragh1 wrote: »

If selling back to the grid is re introduced it there anything specific that needs to take place in the installation process in order to future proof against it?

You'll just need to have a smart meter installed at that point. Keep the certs and other paperwork for your installation as they will be required for the application.

Rossdarragh1

Would you be inclined to take up the offer on those terms air?

air wrote: »

Very easy but you'll likely need a new inverter.

No, it's not an accurate estimate, it assumes the system would produce around 1200kWh (which is reasonable) but that the energy produced is worth full retail price to you (18c/kWh).
In order to realise this saving, your average electricity consumption would need to be over 1.5kW continuously in order to guarantee that you would self consume everything that it produces.
In reality if you work during the day you are unlikely to self consume any more than 30% of production in which case the payback will be more like €60 a year.


No, in the absence of a feed in tariff a bigger system makes a lot less sense, even with a FIT at less than the retail price, the marginal return on the extension to the system will be less than on the original portion. As the system increases in size self consumption as a proportion of total generation is reduced. This is because self consumption is the only part of generation that is worth anything to you without an export tariff.


It's a reasonable approach in the absence of an export tariff.


You'll just need to have a smart meter installed at that point. Keep the certs and other paperwork for your installation as they will be required for the application.

air

Rossdarragh1 wrote: »

Would you be inclined to take up the offer on those terms air?

Not personally to be honest, it wouldn't represent good value to me.

nice_guy80

quentingargan wrote: »

Re FIT, Minister yesterday said 2017. Didn't say which end of it. Anyone here in his constituency? (Roscommon).

You can't do what you suggest and just connect the inverter to the immersion. It need a grid and proportional control of some sort.

I might email him

Effects

Hi, I'm looking for feedback on using one of these systems for a 1.5kW array. Mech Engineer tells me the payback on them is quite long.
It's for a compact house build. I'm currently thinking of switching systems to a combi-boiler to eliminate the need for a hot water cylinder and save the space.
Any thoughts on this?

Also, there seems to be an extension to the micro gen scheme from Electric Ireland at the moment. Can I apply if my supply might not be fully up and running by the cut off date at the end of this year. For me, selling back to the grid might seem like a better option than a hot water diverter.

quentingargan

Effects wrote: »

Hi, I'm looking for feedback on using one of these systems for a 1.5kW array. Mech Engineer tells me the payback on them is quite long.
It's for a compact house build. I'm currently thinking of switching systems to a combi-boiler to eliminate the need for a hot water cylinder and save the space.
Any thoughts on this?

Also, there seems to be an extension to the micro gen scheme from Electric Ireland at the moment. Can I apply if my supply might not be fully up and running by the cut off date at the end of this year. For me, selling back to the grid might seem like a better option than a hot water diverter.

If there is an export tariff (and there may well be by the time your house is built) then it depends on the tariff. At the moment, one of these devices is about €300 plus VAT and installation. A smart meter is €350 fitted. So they're more expensive than a meter.

On principle, I would prefer to see electricity exported as useful power rather than wasting it on an immersion heater.

There isn't any extension to the micro gen scheme that I know of.

I think these devices are very marginal on systems of less than 2kw of panels. Your system will produce about 1400KwHrs per year. If you use half of this and send the other half to your immersion, replacing gas at 9c per KwHr, the savings are .09*700 or about €63 per year, provided you use the hot water. Not sure I would switch from a Combi boiler over that.

But on another note, I have found Combi boilers are heavily penalised in DEAP. Anyone else finding that?

Effects

quentingargan wrote: »

There isn't any extension to the micro gen scheme that I know of.

You're right, I made a mistake and read the extension for existing customers to 31 Dec 2016 as applications for new customers!

But on another note, I have found Combi boilers are heavily penalised in DEAP. Anyone else finding that?

Ah, I'll have to check that with the engineer and architect so. Hard to see how heating on demand is less efficient that heating a cylinder.

Thanks a lot for your help and feedback!

rolion

Hi All,

Still looking at this option.

However,taking in consideration the "feedback" from OWL sensors ,i am wondering how fast this system scans / samples the grid power versus PV generated power AND switches off the power going to immersion !?

Is there a slight chance that actually i will pay more on the consumed energy from the grid by te tme the sensor realises the realtime flow of the electricity ?

Thanks.