PV panels installed on new build

stamjoe

On a new house I purchased it came with 6 200w PV panels, but if it is not stored and is only used on the fly and I'm at work when they are generating and only return when they are not, how do I even get some use out of these? Seems like such a waste manufacturing panels that can never be used.

dathi

you can install a solar pv diverter which diverts the excess electricity to the hot water cylinder

sydthebeat

dathi wrote: »

you can install a solar pv diverter which diverts the excess electricity to the hot water cylinder

probably the best option.

also realise OP, that there is a constant draw on your electricity during the day even when you are not around. Things like pumps, fridges, alarms etc are drawings constantly and you can also have pretty significant vampire draw by items left on stand by, gadgets plugged in charging etc.

its actually quite easy to build up a 2.5 - 3 KW draw down for the 8 hours youd be away from your house

your panels could be generating on average about 800w / hr... so in reality about 40-50% of the electricity generated by the panels could be going into keeping the dwelling running while vacant as it is.

Effects

Can you set your washing machine or dishwasher on delay? Newer models often do this.

My engineer worked out that a diverter to the cylinder wasn't a great option given how long payback would take.

Gumbo

Fit divertor to get hot water in your return home.
Also set your dish washer and washing machine on delayed starts every morning before you go to work.

unkel

Effects wrote: »

My engineer worked out that a diverter to the cylinder wasn't a great option given how long payback would take.

He is right. But since the OP has the panels installed already, it's not a lot of additional costs to have a diverter bought and installed (maybe €500?) and it will save maybe €30 or €40 a year compared to gas heating or night immersion. Hard to say, depends on your other use as well

Or you could just give it back to the grid. Helping everyone out a little bit. And hope maybe one day (soon) we will get a FIT which would save you more than a diverter would ever save you per kWh that you don't use. Particularly given that you don't have to make any investments for this

I'd go for the latter option myself (do nothing)

As others said, try and run as many applicances as you can staggered from about 11AM / noon until about 3/4pm

There is no point running 2 applicances at the same time as even on the sunniest hottest day of the year, your panels can only supply one moderate applicance at a time with solar at best, or part of one

Gumbo

unkel wrote: »

He is right. But since the OP has the panels installed already, it's not a lot of additional costs to have a diverter bought and installed (maybe €500?) and it will save maybe €30 or €40 a year compared to gas heating or night immersion. Hard to say, depends on your other use as well

Or you could just give it back to the grid. Helping everyone out a little bit. And hope maybe one day (soon) we will get a FIT which would save you more than a diverter would ever save you per kWh that you don't use. Particularly given that you don't have to make any investments for this

I'd go for the latter option myself (do nothing)

As others said, try and run as many applicances as you can staggered from about 11AM / noon until about 3/4pm

There is no point running 2 applicances at the same time as even on the sunniest hottest day of the year, your panels can only supply one moderate applicance at a time with solar at best, or part of one

I would argue that the cost of heating water for a family over the course of a year is a lot more than €30-€40 Unkel.

unkel

Of course it is!

But the contribution of the diverter to this cost is no more than about €30 or €40 (in terms of competing with night rate immersion or gas boiler use) for his 1.2kW solar PV system

Calculation: his 1.2kW panel nets about 1100kWh per year (south facing, in ideal circumstances). Let's say he uses about half of this directly in his household, so it leaves about 550kWh per year to go into the diverter. Let's say he doesn't have gas (which is cheapest), then this will have to compete with using a standard immersion at night rate (not as cheap as gas, but a decent second) @6.65c / kWh, so saving is 550 * €0.065 = €36 per year

If he does have gas, the saving is more like €20 per year or so

unkel

And for the record, I am not a pessimist or a nay sayer. And I am very much in favour of renewable energies. I have an EV as my main family car and I have solar tubes for my domestic hot water. I try to be neutral, even critical though and I do my sums rather than act purely on beliefs

I would very much like to have solar PV too, but the sums are unfortunately very much stacked against it at the moment

rolion

@ OP.my friendly advice go get a IBoost+ from a local supplier like HERE.
Installation, should be not more than 1 hour by any electrician OR simple as DIY, check YouTube for lots of videos.
No matter cost, plus or minus and despite that your PVs are quite small in capacity, the main advantage of not being day time in the house will pre-heat the bottom of the cylinder with few good degrees, giving a boost to the overall water heating process...now, very important step,what kind of cylinder do you have as UNLESS you have a big, good insulated one is pointless to get the diverter.


@Unkel...sorry to cut short your hopes but I don't see soon any type of FIT in Ireland...if we have to follow the global tendency of scraping payment due to corporates and healthy positions afraid of losing the control of the market... Also, not lastly, as you may know, FIT with current weather just doesn't work, the impredicability of the generation just dunno how to say it, just not working...

Have fun.

unkel

I still remain hopeful of a FIT

The unpredictability of the generation of solar (and wind!) will become much less of an issue once there is grid attached storage and real time value pricing of elecricity. You won't get paid much for your solar when the grid is fed while there is abundant sunshine. You won't get paid much for your wind electricity when all the windmills are running fast in the middle of a windy night. And electricity will be very expensive at about 7-9PM at peak demand when there is no sun and no wind. But you will get paid if you provide valuable grid storage! As in your house attached batteries, your EV, etc.

quentingargan

I wouldn't recommend just any type of immersion divert device. Some of them badly corrupt the sine wave on the grid. See attached.

Gumbo

quentingargan wrote: »

I wouldn't recommend just any type of immersion divert device. Some of them badly corrupt the sine wave on the grid. See attached.

Have you got a top list of diverters to use?

rolion

And here again step forward from 2013 to 2017 ...i have the iBoost for almost a year...and is so much noisy here,all neighbours and supplier and all my electrical appliances are going so fcuking corrupted... Wife looking for a new fridge,hope she doesnt read there.

kceire

kceire wrote: »

Have you got a top list of diverters to use?

PWM type;

• ImmerSun
• EMMA 4G

There are lots of ELVDC alternatives that are far more efficient, however they are not suited to standard grid tied setups.

rolion wrote: »

fcuking corrupted... Wife looking for a new fridge,hope she doesnt read there.

It's probably killing MOVs and line filters, death by transient generator.

rolion

Not sure how all the offtopics will help our happy owner of a 1,200W of PV power...

Acording to manufacturer website FAQ HERE ... looks ok to me as been listed PWM ...
The only complaint i have to iBoost is that doesnt have an aplication which tells you how it performs.
I have to rely on my Egenie to monitor the usage and/or on the small LCD build-in .

Thanks for sharing the concerns thats how we learn here !


And shes not getting a new fridge,i'm saving for a new Viessman gas boiler .

rolion

@stamjoe
MOST important thing to check is if you have a ESB analog meter or a digital type.
If your meter doesnt look like one below,call your provider and ask to replace it A S A P.

Perhaps they changed the topography recently.

[EDIT]:
iBoost = phase angle fired
iBoost+ = PWM

Gumbo

Sir Liamalot wrote: »

PWM type;

• ImmerSun
• EMMA 4G

There are lots of ELVDC alternatives that are far more efficient, however they are not suited to standard grid tied setups.


It's probably killing MOVs and line filters, death by transient generator.

I heard ImmerSun went bust?

my guy is recommending this unit : http://myenergi.uk/product/eddi/

Its PWM Tech also.

quentingargan

kceire wrote: »

I heard ImmerSun went bust?

my guy is recommending this unit : http://myenergi.uk/product/eddi/

Its PWM Tech also.

The company that owned Immersun went bust, but it has been bought out and is running again.

The Mynergi product is designed by the same people as far as I know. Not sure if it is on the market yet. I haven't seen them, but would be PWM as well.

stamjoe

Some fantastic tips here, yes I do have gas, and have started using it for heating the water, currently I have my meter readings set to the 24hour reading rather than day and night, but I was thinking of switching to day and night and turning on the washing machine etc at night for the cheaper rate, but I hadn't thought of setting a timer for those devices to come on during peak sun light hours.

Lots of options here.

macgabhs

For those of you with Daikin Heat Pumps and solar PV panels there is a new accessory coming out which will optimise the heat pump usage to make the most of available excess solar generated power.

http://www.daikin-ce.com/news/recent/2017/daikin_online_controller_offers_on_demand_home_comfort_from_a_distance_new_gateway_to_give_homeowners_heating_control_convenience.jsp

stamjoe

One thing I read in the brochure for my house it said the PV would provide power to the house and hot water.

When I finally got into the attic the inventor was switched off but since I turned it on the gas zone for hot water doesn't seem heat up as fast l feel.

If I wanted hot water during the day is it cheaper to turn on the gas zone or the immersion thinking it'll draw from the panels?

Cheers

unkel

stamjoe wrote: »

If I wanted hot water during the day is it cheaper to turn on the gas zone or the immersion thinking it'll draw from the panels?

Immersion is 3kW. You can expect a bit over 1kW at most from your panels around mid day on a very good sunny day, so you will still pay paying for almost 2kW at the expensive day rate. Don't do it. Using gas will be many times cheaper. Even using the immersion at night at night rates while you have zero solar will be a lot cheaper than heating the water while the sun is blasting down.

Sorry if that sounds cynical, I'd love solar PV to do more for us all, but this is the way it is for now.

Gumbo

Depending on the system I suppose, I had 2.3kw coming from my Panels last week at 2pm. I haven't moved in yet so cannot consistently monitor it and I will need my wifi to get the app to monitor it without crawling into the attic eaves.

I don't think the divertor sends the full power to the immersion either, I think it only sends a couple of hundred watts and it uses it as a kind of trickle heater?

*i may be wrong on that so I will look into it to confirm.

The premise of heating water from pv is it works passively all day that there is surplus to do so and offsets the gas/utility electric demand by reducing the load on conventional water heating systems by having the tank temp sitting at a higher starting temp and sending a luke-warm hot feed to other systems.

Every little helps it's not an all or nothing situation...or at least ought not to be.
The larger the pv array the less demand conventional sources will have to meet (as long as they can take a hot feed which is not a given).

unkel

Sir Liamalot wrote: »

The premise of heating water from pv is it works passively all day that there is surplus to do so and offsets the gas/utility electric demand by reducing the load on conventional water heating systems by having the tank temp sitting at a higher starting temp and sending a luke-warm hot feed to other systems.

Indeed. But the benefit for the OP is about €20-€30 per year. Installing a €500 system for a return as poor as this wouldn't be my idea of a sound investment.

My interest is more from an engineering point of view and the merit of cleaner air Unkel.
People will and do have to remind me that it's more important save quids.

I've spent more on power electronics than some people do on cars.
I often wonder why RE can't have merit on it's own why it has to pay for itself. Do toasters pay for themselves....I know I'm odd that way no need to explain it...

€500 is more than I'd spend for a grid tied jobbie. I'd go DC diversion anyways...

unkel

Sir Liamalot wrote: »

the merit of cleaner air Unkel.

Aye not everything is always about money. But you can make choices that give a lot of cleaner air, yet are not bad at all on your pocket.

My main family car is a full EV, that I bought brand new and it cost me no more than a similar size, similar spec petrol or diesel car would have cost me. And the running costs are almost zero. So big win for clean air and big win for my pocket

An immersion diverter for a 1kW PV system? Not much of a win for clean air and certainly no win for your pocket. But as a gimmick / toy / something that pleases your technical interest, surely it does have merit

Yurp.

I can't argue with electric drive, 3 times the efficiency of the infernal combustion engine and ⅓ the energy cost.

I'd happily spend €15k on a fit for purpose electrical system for a tiny home/barge/remote cabin/etc and roll out my own services than spend €80k on a site and ticky boxes. I think RE in Ireland is stiffled with lack of accord by the powers that be and investment in developers at the cost of Joe Public.
Until that changes I can't advocate grid tied for nine to fivers.

I have to agree also on the gimmic aspect, most of what I see on the market these days I'd call fashion over function.

My rule no. 1; don't believe the sell sheet until you have your own data.

I can live outtov a camper for months with 150Wp on the roof, but I wouldn't hang less than 4kWp on a gaff.

unkel

Sir Liamalot wrote: »

I can't argue with electric drive, 3 times the efficiency of the infernal combustion engine and ⅓ the energy cost.

A bit less that that. I've driven the car for 7,000km and it has cost me about €7 in electricity

(a very efficient diesel car would have cost €500 in fuel)

Sir Liamalot

Sir Liamalot wrote: »

rule no. 1; don't believe the sell sheet until you have your own data.

:pac:

unkel

Sir Liamalot wrote: »

infernal combustion engine

Infernal, LOL, took me a few seconds to get that. I'm a bit slow. I wish Irish people were only a bit slow like me, not like the extremely retarded people who keep buying diesels. No other country in the world buys more diesels than us. For shame.

7000 km on 52kWh?
7.5Wh per km?

What's yer kerb weight Unkel?

unkel

Fast charger is just round the corner from me. Beside McDonalds, Starbucks, local library, supermarket, my favourite take away, barber, etc. etc. Charges my car up in 20-30 minutes while I visit any of those fine establishments.

And public charging is free

Have home charger but only used it a few times...

unkel

unkel wrote: »

And public charging is free

Start powering your house from yer car.

unkel

Haha, some people with Nissan Leafs do that

https://www.youtube.com/watch?v=ADqk4IjzjXs

But seriously, V2G is the future. Load up all the EVs with cheap solar during the day and cheap wind during the night when electricity wholesale prices are near zero

Then use the EVs to help power the grid at times of peak demand

Simples...

unkel

Interesting calculation is that an average Irish household uses 3,500kWh per year. This means I could charge for 30 minutes and then power an average household for 72 hours from my car. Some Teslas would power a house for 10 days.

unkel

unkel wrote: »

But seriously, V2G is the future.

Disagree. Batteries, chargers & electrical installations are not 100% efficient. The kWh you sell to the utility grid will cost you ~1.1kWh 1.2 > 1.3kWh to replace and reduce the lifespan of your battery.
Mary down the road making tea is taking incremental miles off yer range.

Also bare in mind Li-Ion as we know it is not 10 years old yet so anyone claiming they will last that long has no data to prove it.

Remember a warranty is not an assurance of quality but a gamble that you charge X amount extra for a product expecting X amount of customers to push it to the limits of it's design and warrant that return.
It is a very difficult thing indeed to prove a battery capacity and providence. Especially when the fox is guarding the hen house in terms of your "test gear" being supplied by your battery manufacturer.
I run several battery systems you're doing it right when you're not using the battery.

Let micro-generators charge utility batteries.

unkel

Nobody knows for sure how batteries will fare long term, but all EVs these days come with 8 year battery warranties. If you buy Ioniq in the USA, you get a lifetime warranty. So the problem (if there is any, quite likely there isn't) is with the manufacturer, not the owner of the car. And it is quite likely the car is end of life and worthless before the battery has lost 15 or 20% capacity after say 10 or 15 years or so

I foresee that household electricity pricing will soon enough be variable. As in say €0.01 / kWh during a very windy night and €1 /kWh during an exceptionally heavy peak demand. EVs (and to a lesser extend home storage) will come in very handy to buy cheap and sell expensive

unkel

unkel wrote: »

Nobody knows for sure how batteries will fare long term

I get good results from lead acid. But they're not fashionable and I have to build my own systems because nothing I can buy works very well.
I don't think 10 years is an issue but I'll let you know in another 6.



Had a look at the neo-Tesla car data a while back and it confirmed my suspicions that not a lot of their customers were running them anywhere near their limits in terms of extracted energy or cycle life.

Portable devices upset me no end because I can't set the charge parameters to limit charge and discharge to give me 6x the lifespan with more confined thresholds, another thing we are beholden to product engineers and their bean counters with these modren proprietary systems.

Variable pricing would be interesting at the moment most providers sell far higher than they buy to end users.

rolion

offtopic i know but i have 2 cars, big turbo diesel engines in the front of the house.
I prefer reliable and proven cars that suits my work needs and safety/security/comfort of my family.

I have no plans to sponsor early develpment of those electrical vehicles, aka EVs, i just let the richer and enthusiasts of the free side road charging to test them and once technology matures in around 10 years ,well, then i may be forced to replace the family car if i can justify it.

stamjoe

Would you say it is better to switch to a day and night meter, or is it better to use the PV panels during the day on the cheaper 24hour rate, or not use them at all and use most of the electricity at night?

unkel

rolion wrote: »

offtopic i know but i have 2 cars, big turbo diesel engines in the front of the house.
I prefer reliable and proven cars that suits my work needs and safety/security/comfort of my family.

I have no plans to sponsor early develpment of those electrical vehicles, aka EVs, i just let the richer and enthusiasts of the free side road charging to test them and once technology matures in around 10 years ,well, then i may be forced to replace the family car if i can justify it.

You have a weird idea of the economics of renewable energy! You spend all that money on solar PV for very little gain while you could have saved yourself a fortune by having at least one EV

Be it either a first gen Leaf second hand for about €5k or a brand new Leaf for about €18k or an Ioniq for about €25k. These new cars cost less to buy than equivalent diesel cars after the €10k subsidy!!!

And then there is the near zero running costs of them. I've spent about €7 in electricity in the 7000km since I've had my EV. There is virtually no maintenance, €120 motor tax and insurance is cheaper than any other similar size car

rolion

unkel wrote: »

You have a weird idea of the economics of renewable energy!

d

It's called necessity and common sense !

Day time,drive a nice big commercial,all paid by the taxman.
Weekend,love the comfort and safety of my family MPV.
Not lastly,i love big and powerful engines.

I want to see who comes out in one piece:me,from a diesel car OR someone trough the fire of the batteries.

But,you can be right !

unkel

rolion wrote: »

I want to see who comes out in one piece:me,from a diesel car OR someone trough the fire of the batteries.

Another misconception about EVs. Do a google and you'll find that the battery packs stay intact in even the worst accidents and fires. If they didn't, I'd have to agree with you

Don't try sticking a knife into the battery of your mobile phone, folks

I like big and powerful engines too. Nearly bought a 5l V8 Mercedes this week, have had several high powered and big engined cars in the past

Electric drive is more reliable and proven than the ICE. It is the same age more or less, cooler, less complex, faster, torqueyer, more efficient, cleaner, simpler, longer lived and more versatile.



The battery is the strongest part of the car and the bus bars are made of fuse wire.

quentingargan

stamjoe wrote: »

Would you say it is better to switch to a day and night meter, or is it better to use the PV panels during the day on the cheaper 24hour rate, or not use them at all and use most of the electricity at night?

I would get a day/night meter anyhow to have the option for winter. If I was pretty sure of good weather, I would run the washing machine during the day. I always charge my car at night unless it needs a top-up.

quentingargan

If all cars were electric, and someone came up with the idea of an ICE with injectors, cams, valves, and squillions of moving parts, AND wanted to run it on flammable liquid petrol, they'd be laughed at!:eek:

stamjoe

quentingargan wrote: »

I would get a day/night meter anyhow to have the option for winter. If I was pretty sure of good weather, I would run the washing machine during the day. I always charge my car at night unless it needs a top-up.

Only things I'd be running is a dishwasher once a week, washing machine and dryer, only one of those has a timer to run at night, but might look into switching to day/night.

unkel

I run the diswasher (it's old and it uses 1.5kWh) about 4 times a week at the night rate. That's all I do and it still saves a little bit of money over having a single meter (I checked this before I bought my EV). If you do anything else (washing machine, immersion, electric vehicle, etc.), getting a free night meter is a no brainer.