Solar VP - Lots of questions - Rebates and Feed In Tariffs, Past experience ???

I wouldn't bother with the hassle and expense going to the grid for such little wattage!

As a project you could keep to 48 volts, and charge a 48 volt battery bank. 48 volts won't hurt you. Get a few deep cycle gel batteries, and 500-1kw of solar panels and charge controller so you don't over charge. Get a 48 volt to 220 volt inverter, a pure sine wave is much better!

Get a 500-1kw inverter, continuous rating not peak. make sure your wiring can take the currents. The battery to inverter being the highest currents and run your appliances off of that, that way you are doing nothing wrong and any excess you can dump into a 1kw heater and it will get rid of it very quickly.

The best way is to connect to grid, but only worth while if installing 2kw or more!

liamolaighin

Hi I'm a little off topic here but the posters here seem to have all of the experience needed to advise me. I'm building a low energy house. 8Kw ground source heat pump provideing heat. Thus although oil costs are zero I will have additional ESB costs. My plan is to wait a year or 2 until PV panels get cheaper and more efficient and then install a few KW to offset my ESB costs.

My query is regarding what I should do at the build stage to make the addition of PV panels as simple as possible for a certified installer as possible down the road. i.e I am getting the 16Kva connection capacity due to heat pump. Should my electrician run particular cable to meter and attic when house is being wired? Is there anything else obvious that I should ask be done during build/roofing to make addition of PV panels simple down the line?

liamolaighin

liamolaighin wrote: »

Hi I'm a little off topic here but the posters here seem to have all of the experience needed to advise me. I'm building a low energy house. 8Kw ground source heat pump provideing heat. Thus although oil costs are zero I will have additional ESB costs. My plan is to wait a year or 2 until PV panels get cheaper and more efficient and then install a few KW to offset my ESB costs.

My query is regarding what I should do at the build stage to make the addition of PV panels as simple as possible for a certified installer as possible down the road. i.e I am getting the 16Kva connection capacity due to heat pump. Should my electrician run particular cable to meter and attic when house is being wired? Is there anything else obvious that I should ask be done during build/roofing to make addition of PV panels simple down the line?

Why don't you consider a 5kw wind turbine ? I believe the kestrel turbines are about the best you will get for Irish conditions. Combine that in the future with solar, that would give you the best of both worlds. Granted wind turbines are very expensive, but if you have the space then it would be a shame to waste the abundant power source!

freddyuk

Deleted User wrote: »

I wouldn't bother with the hassle and expense going to the grid for such little wattage!

As a project you could keep to 48 volts, and charge a 48 volt battery bank. 48 volts won't hurt you. Get a few deep cycle gel batteries, and 500-1kw of solar panels and charge controller so you don't over charge. Get a 48 volt to 220 volt inverter, a pure sine wave is much better!

Get a 500-1kw inverter, continuous rating not peak. make sure your wiring can take the currents. The battery to inverter being the highest currents and run your appliances off of that, that way you are doing nothing wrong and any excess you can dump into a 1kw heater and it will get rid of it very quickly.

The best way is to connect to grid, but only worth while if installing 2kw or more!

In all honesty to buy, set up and maintain successfully a battery based system is a lot more hassle than getting grid tied. You cannot just charge deep cycle Gel batteries like ordinary lead acid as you will kill them. The capacity needs to be 3+ times the actual usage to prevent early failure and if there is no sun for a few days you need to plug into the mains to get a charge anyway and pay full whack. You need to know the demand to get enough battery reserve and it all gets very complicated and expensive. A house will use 300 -400watts when no serious loads are being used so it can be very satisfying to see the meter has stopped. If you are out then the power is sold back even though it is only cents at a time. Once installed PV just does it's own thing without any "tending" like a battery system.

freddyuk

liamolaighin wrote: »

Hi I'm a little off topic here but the posters here seem to have all of the experience needed to advise me. I'm building a low energy house. 8Kw ground source heat pump provideing heat. Thus although oil costs are zero I will have additional ESB costs. My plan is to wait a year or 2 until PV panels get cheaper and more efficient and then install a few KW to offset my ESB costs.

My query is regarding what I should do at the build stage to make the addition of PV panels as simple as possible for a certified installer as possible down the road. i.e I am getting the 16Kva connection capacity due to heat pump. Should my electrician run particular cable to meter and attic when house is being wired? Is there anything else obvious that I should ask be done during build/roofing to make addition of PV panels simple down the line?

How low energy?
First thing is to make sure the house faces the right way and you have the perfect roof space available. Angle the roof at 35 degrees. Any vent pipe, aerials, or other protuberances should be moved to the north side and avoid fitting lots of roof lights. (Any shade across the PV will be a disaster). Dormers are a complete no, no. Make sure the roof is strong enough (never a problem). Have a conduit from roof space or other way down to the meter area. Depending on the roof covering you will need to install bracketry so it is worth considering how these can be installed neatly without compromising the roof later. If you want to "integrate" the panels you could design a tray so there is still a largish air gap under the panels as they will get very warm but keep them at the same roof line level. Maybe you could take warm air from under the PV and feed it into a air to water heat pump system? (don't think that has been done yet).
Ensure there are no trees to the south
If you want to wait for the panels to get cheaper - consider that currently there is a lot of surplus in the market in EU due to the cutting of the customer subsidies. There is a lot of subsidy from certain far east governments to produce the panels. We are in a massive recession right now. When the market adjusts there will be less supply and inflation will kick in so you may well be at the bottom now. There will be other producers opening up in South America and India but currently the regulations driven by government cash incentives keep the quality assurance at a very high level. When that support disappears what happens to the QC? I suggest the government will not care what you put on the roof as they will not be paying for it. I think PV will get more efficient but I also think it will get more expensive as the inflation cycle kicks in, which it surely will.
You don't mention solar thermal? You may find your heat pump is guaranteed up to 55c (winter may be a problem). Good for UF but solar will get you way over that for DHW so you just need to store it correctly.

I'll get my coat.....

BrenCooney

Has anybody here imported PV panels from Germany, if so from whom, and what was the ballpark price for the panels, and for the inverter if you got it there also?

Having travelled through Germany last year, it was heartbreaking looking at all of the houses with banks of PV on their roofs, and I have none!

Over the past few months we have gotten our electricity usage down to 6-7 kWh per day and I would like to get a few kWs of PV on our roof.

PM me if necessary.

I used an EU website to do up some calculations and the figures are begining to look not bad (see below).


BrenC

quentingargan

The main reason why you will find solar PVs in Germany, and increasingly in the UK, is because the feed in tariff is about 5 times what it is in Ireland. If you use electricity during the day, then it may stack, but if you are in a house where there is nobody at home all day, and you are selling your surplus production to ESB for 9c per Kw Hr, the payback time goes into orbit.

Germany doesn't have a monopoly on production, despite the various incentives. You will find solar PVs, mounting systems and inverters from various countries, all with good certification and quality.

jobrok1

Hey! All...

I'm a bit late to this party, but sure better late than never.
And thought I'd throw my tuppence in if may help any bit.

I just had a 4.5kW (well... almost 4.5) solar PV system installed at home.
Just over €11.5k installed. Very efficient and tidy installation too, I might add.
I was quoted for 17 x 265w panels but the available roof space only allowed for 16 panels so the supplier used 275w types instead.
No idea of the varying performance data between the 2 types or if will will have any real benefit over all, but I thought it was worth a shot.

I don't have a directly south facing roof but the layout and position of the house allows for 2 sets of arrays to be installed.
6no. panels are on the front South-West facing roof and 10no. panels on the South-East facing roof. so obviously I'll only be getting the full benefit from the Sun for a slightly shorter time period than normal. But again! Better than nothing.

The inverter is a Sunny Boy 4000TL-21

Plus! We're hoping that the recent tax relief incentive on domestic renovations will help knock a nice chunk off that overall price.

Here are some quick pics and short video of the invert from the other day. Late afternoon and quite hazy.
https://plus.google.com/photos/108055220638046678237/albums/5971300303914019937?authkey=CK740Y-6i-zRggE



Also! The above South-West and South-East arrangement has worked out very well for our already installed solar hot water panels which heat an 800l storage tank (600l connected to our central heating and 200l tank inside again for clean domestic use). This system is more than enough for our hot water needs for most of the year, with some supplementation from an immersion which I know this new solar PV installation will pretty much make it completely self-sufficient.
The solar isn't enough to heat the water for the colder months, obviously! But combined with our wood burning stove we've managed to remain completely independent of oil and gas since the house was built about 8 years ago.

11.5 K seems extremely excessive to me for just 4.5 Kwp ?

Did you get an itemised price list ?

if so how much did you pay for the panels and the inverter ?

freddyuk

I do not know which panels you had installed but I can see that one string is very close to the minimum MPPT voltage limit.
You have string 1 = 10 panels in series = 330v
and then string 2 = 6 panels in series = 180v

You may find in summer when the temperature is higher that string 1 will drop close to or below the MPPT limit. The amps will be dictated by the sunshine level and will rise in summer but if the voltage drops below 175v the MPPT may stop working and you lose efficiency and generation.
Higher temperatures = lower voltage.
Probably not a problem but maybe you can keep an eye on the voltage for string 2 out of interest.

jobrok1

A similar sized system placed on the ground would have cost considerably less, but that wouldn't have been a viable option for us. So the roof was the only location we could do it. If I were to do it DIY then, 'Yes', it would have cheaper also. But getting up to install the panels on our roof wasn't going to be an option for me. Two roof areas meant twice the scaffolding to hire, so that's a good chunk of the cost right there.
And scaffolding certainly isn't cheap to hire out.

It's not all just about the cost of the panels, inverter, etc... The installation and safety in doing it has to be accounted for also!

As for the MPPT limit on the string with 6 panels... The installer was aware of this also and said that at least 5 panels were needed for it to be considered. On his initial site survey it was difficult to properly work out the area so he roughly worked out that 5 would most likely be possible but asked me to send on any plan drawings for him to do a better measurement. 6 panels were fitted in the end.

And as I said above! The tax incentive on home renovations will hopefully knock the 13.5% VAT off it, so cost will be €10k

jobrok, how much did you spend on leccy a year ? or how many kwh do you need ?

According to the online calculators a 3kwp system in ireland is capable of generating something like 7 kwh a year in Ireland. So you got huge potential there. EV perhaps ?

What was your main reason for installing solar ?

jobrok1

Our reasons...?
Primarily financial! Our only utility bill is with Airtricity with their fixed monthly billing which fluctuates between €80 - €110 for the month. No idea why it varies so wildly but I presume it just depends on when they actually come out to read the meter. If I took regular reading myself I'm sure it would be fall somewhere in between.

Anyway! We'd always planned on going down this road eventually. Wind was the main option for a good while but was always way to expensive to it right. Plus regular maintenance would only add to the cost over time.
I have a small off-grid turbine on-site already but it's pretty knackered at the moment. Bearings on the mounting swivel are shot and it's now stuck facing north permanently. Another reason not to go with wind!
I'll get it sorted come the Spring and set up my shed and back garden as a simple off-grid system (for the craic, mainly).

So! gradually solar started to come down in price and quickly became our primary choice. We got quotes for various sized systems, both ground and roof mounted. Ground installation was much cheaper but needed extra work to be done, such as concrete pad to be laid beforehand which ate into the savings compared to the roof system. Then the budget came out with the tax relief on home renovations which tipped us in favour of finally biting the bullet. Whether it will qualify for it is another question but worth the shot, in my opinion.



Why did we go for 4.5kW system?
Well! Firstly... It's the maximum we could fit at this point. If we had room for more, I would have got them.

And secondly... As I mentioned above, we're not directly South facing so getting the maximum out of two arrays (South-East and South-West) was our best option. This has worked out very well for our solar water heaters for the last number of years so no reason why it shouldn't for the PVs also. I realise that the full benefit will be for a slightly reduced time during the day, but one array will get exposure from the first crack of dawn till well into the evening while the second array will have to wait a while in the morning but then get the sun right up until sunset.

An EV isn't on the cards at this point in time but down the line maybe. We have 3 small kids so an EV isn't very practical at the moment.

freddyuk

Deleted User wrote: »

jobrok, how much did you spend on leccy a year ? or how many kwh do you need ?

According to the online calculators a 3kwp system in ireland is capable of generating something like 7 kwh a year in Ireland. So you got huge potential there. EV perhaps ?

What was your main reason for installing solar ?

Which calculator are you using? I think that is way out. SMA comes out at 4031 for the 4.4kw system using Suntech modules. In my own experience that is not far off although I am still tweaking. I always aimed for 5-6 kw capacity to cover the average annual usage of around 5000kWh.

freddyuk

freddyuk wrote: »

Which calculator are you using? I think that is way out. SMA comes out at 4031 for the 4.4kw system using Suntech modules. In my own experience that is not far off although I am still tweaking. I always aimed for 5-6 kw capacity to cover the average annual usage of around 5000kWh.

Yeah think you're right Freddy, now that I think about it I think it was around 3500 kWh because I remember it was more than out 2100 kWh needs per year, and that include losses.

Jobrok, I think the ESB only allow 5.5 kWh max on single phase, and I don't know how much a 3 phase supply is in Ireland, ?

freddyuk

Single phase is 6KW maximum installed capacity. There have been massive arguments about how you define the limits because if there is money involved this matters. Officially installed capacity is what comes out of the inverter which may be quite a bit less than the total panels nameplate output. You can probably install 6.5kw of panels and stay within the rules in Ireland as the monitoring is ad hoc. In UK they will photograph your generation meter to check if you are over generating. It is closely monitored.

These are the rules: (Conditions Governing the Connection and Operation of Micro-generation)

1.2.1 Micro-generation
For the purposes of this document, Micro-generation is defined as a source of electrical energy and all associated equipment, rated up to and including
􏰀 25A at low voltage[230V], when the DSO network connection is single-phase 􏰀 16A at low voltage [230/400V], when the DSO network connection is three-
phase, and designed to operate in parallel with the ESB Networks LV system.
Where multiple generating sources [of the same or varied technologies] are on the same site and share access to the same ESB Networks connection point, the aggregate rating must not exceed:
􏰀 25A at low voltage, when the DSO network connection is single-phase 􏰀 16A at low voltage, when the DSO network connection is three-phase.
This definition makes no explicit reference to any specific form of generating technology but the interface with the ESB Networks LV system must not be capable of connecting the generation source, to the ESB Networks LV system, if the ESB Networks grid supply is not present and within parameters given in Table 1 below. Any form of generation whose interface with the ESB Networks System does not comply with this provision, is considered outside the scope of this policy.

fclauson

freddyuk wrote: »

Which calculator are you using? I think that is way out. SMA comes out at 4031 for the 4.4kw system using Suntech modules. In my own experience that is not far off although I am still tweaking. I always aimed for 5-6 kw capacity to cover the average annual usage of around 5000kWh.

yup - that's about right - mine did 4200Kwh on a 4Kwp system for last year in southern Ireland

jobrok1

Yeah! 5.5 - 6kWh is the limit.
If I had a little more roof space I'd have gone the whole hog and definitely put in at least 4 more panels to get the most out of it. If you're doing it at all, then do it right! (or as close as possible)

I'd estimated about 3500kWh/y but if I can get over 4000kWh/y like 'fclauson' then I'll be well chuffed!

freddyuk

Just had my second year ESB/IE export credit. Once again I am given some numbers and amounts but no meter readings. I took the readings off my meter at the anniversary and they do not tally with IE calculations. However to add to the confusion the IE calculations are taken from anniversary date to end of the year whereas the ESB portion (support payment) is the full 12 months from anniversary date which is 13/01.
Anyone know why and how we are supposed to track this? Did they take 2 different reading on 2 days? Not sure they did as I was there.
I have asked yet again for some readings as I am monitoring over 200kWh more exported. Not good as I should be using it all but that will be sorted well before the support ceases in 3 years.

freddyuk

Now had a new email from IE and the anniversary dates for ESB and IE credits are now the same....which makes more sense! But I still await the notification of the actual meter reading numbers and when they were taken. IE told me to speak to ESB and ESB told me it was IE who had the information.
So far I am being ignored.

Rogue_art

Hi Freddyuk,

Have you tried getting your answers by corresponding with microgen@electricireland.ie

Though it depends on who actually deals with your query, i generally find that such queries are dealt with satisfactorily.

regarding your difference in readings; this may down to an inaccuracy in how you are monitoring your export. There can often be a difference between the kWh logged on your inverter and measured elsewhere. The only way for you to get an accurate reading is to measure it on an accurately calibrated kWh meter. You can buy a fairly decent one for about €30.

hope this helps.

freddyuk

Yes I have.
I have the export meter that is a prerequisite to getting the net metering payments so export is measured by that. Unless IE read that meter I do not know how they can assess my export. The Inverter will not help you as it measures generation only.

Rogue_art

Apologies freddyuk, I misunderstood you. I thought you were saying that there was a difference between your recorded export and their recorded export.
Yes of course they have to read your meter in order to assess what payments you are entitled to. Do you think they are not reading the meter? Bear in mind that in the majority of cases they are reading the import/export meters remotely! You can check if yours is enabled for remote reading by checking in your meter box for a little antenna.

Where are you seeing the 200 kWh difference? Perhaps it is just a time difference between the reading date you are working off and the reading date they are working off?

I'm out for the night now. seeya

freddyuk

Shouldn't be hard to tell me the reading then! I am still waiting.
Would you pay your IE bill if they just said you owe us X€ this period? Of course you would not. You get an old reading and a new reading and a price per unit. It is, I guess, a legal obligation to provide a fully itemised bill that can be verified by the customer for any metered supply.

murphaph

Here in Germany the Heat Pump + PV combination is pretty popular. Even in summer you can make use of it if you have your thinking cap on...

In winter you obviously use the PV juice to charge the UFH slab and also the buffer tank (and your DHW tank of course) for when you get home in the evening. Some heat pumps can be reversed in summer to act like air conditioners. Viessmann make accessory boxes for some of their heat pumps that add passive cooling (just the circulation pump reverses, everything else stays off or active cooling (heat pump compressor fires up but operates in reverse, actively cooling the property through the UFH). Viessmann make a control panel for their heat pumps that intelligently monitors PV generation and can be set to use as much PV as possible when the sun is out.

There are surely other manufacturers with similar products.

What would be really cool is an EV with an easily removable battery (using some sort of dolly) that can be removed and charged during the day without the car. You then swap batteries in the evening when you get home and so on.

air

Charging a battery in that manner wouldn't make a lot of sense as you'd end up having to buy 2 batteries instead of one.
One would be better off feeding the electricity onto the grid and getting paid for it and then charging up your car over night.

air

air wrote: »

Charging a battery in that manner wouldn't make a lot of sense as you'd end up having to buy 2 batteries instead of one.
One would be better off feeding the electricity onto the grid and getting paid for it and then charging up your car over night.

Exactly, the electricity network becomes your giant ultra cheap battery. And you buy back at night rate.

This only works though as long as they continue to pay the feed-in-tariff.

murphaph

air wrote: »

Charging a battery in that manner wouldn't make a lot of sense as you'd end up having to buy 2 batteries instead of one.
One would be better off feeding the electricity onto the grid and getting paid for it and then charging up your car over night.

I'm assuming batteries get cheaper of course. Someday they will. Agree that at current prices it doesn't make sense even if it were easily possible to slot batteries in and out of cars like a mobile phone.

Batteries for houses are now being marketed in Germany as the FIT falls and it makes more sense for anyone installing today to use as much of their self produced electricity as possible. There are online calculators to help you decide if a battery makes economic sense (they cost around €10k at present).

I calculated that it doesn't make sense for us on our planned system (PV + Ground source HP) at current prices but if/when the batteries fall in price enough, we may add one to the mix.