Solar Panels or Solar Energy

47 posts in this topic

1 hour ago, scook17 said:

If one read through all the link above, it will. E mentioned that the Burocracy and electricity grid operator makes things difficult for the end user.

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On 20/02/2021, 17:09:23, vivanco said:

The limit to 600w is by the assumptions that household wiring can handle 600 watt safely. 

If an Apartment cant handle 600w, then it's not fit to rent out... 

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Thank you for the explanations and links. Another thought came into my head, if 600w is the limit, but the PV never achieves that not even at peak, why not get a 800w or 900w, which at peak would maybe reach 600w limit? must I buy only a 600w PV?

 

 

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5 hours ago, wien4ever said:

Thank you for the explanations and links. Another thought came into my head, if 600w is the limit, but the PV never achieves that not even at peak, why not get a 800w or 900w, which at peak would maybe reach 600w limit? must I buy only a 600w PV?

 

One can do this.  Important is that the Inverter used should not exceed 600W rating.

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29 minutes ago, fraufruit said:

Solar panels that don't need sunlight???

 

Article here  for those who are interested.

There are many crazy technologies out there, but most of them fail in one or two key points.

Either they are too expensive, or their efficiency is too low, or they degrade with UV... or other reasons...

 

It's like battery technology: lots of ideas but in the end 99% of them fail on one or multiple key points.Solid state battery looks great, except price is absolutely unnacceptable. Other technologies have charge cycle limitations...

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On 18/02/2021, 16:47:11, Guest said:

just had a visit/appointment from a solar firm...  

16 x 320w panels.

4 KWP batter Pack ( Same idea as  tesla power wall)...

Installation,,,,

18,000 euro!... 

 

I was just curious to work out the DIY costs:

 

200w Amazon Panel (0.7mx1.5m) - 150 Euros.

300w Amazon Panel (2m x 1,5m) - 280 Euros

So 16 panels x 280 Euros = 4.5K for the panels.

320w x 16 panels = 5.12KW inverter needed

5-6K Inverter - around 2.5K Euros plus.

4KWP Battery is around 4K Euros.

Misc parts/wiring - 1K

 

Parts = 4.5K + 2.5K + 4K + 1K = 12K

Add in scaffolding, wiring, time and effort, guarantee, profit the company makes and yes, I can see +6K so therefore 18K installation cost.

Wonder if that 18K was including or excluding MWST?

 

Alternative Balcony System (as was shown in photo), or RV/Camper Van roof system, DIY:

2KW Solar generator (inverter plus battery) - Around 1K per KW, so 2K

2 x 300w panels - 600 Euros

Wiring/connections/fittings - 100 Euros.

Electrician required to fit 'correct' socket - 300 Euros

Total cost 2K-3K Euros depending on battery size.

 

1KWh = ~30c, so 109.50 Euros per year if 1KW is consumed each day.

2K Cost = 2000 / 109.5 = ~18 Years payback.

 

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6 hours ago, scook17 said:

 

I was just curious to work out the DIY costs:

 

200w Amazon Panel (0.7mx1.5m) - 150 Euros.

300w Amazon Panel (2m x 1,5m) - 280 Euros

So 16 panels x 280 Euros = 4.5K for the panels.

320w x 16 panels = 5.12KW inverter needed

5-6K Inverter - around 2.5K Euros plus.

4KWP Battery is around 4K Euros.

Misc parts/wiring - 1K

 

Parts = 4.5K + 2.5K + 4K + 1K = 12K

Add in scaffolding, wiring, time and effort, guarantee, profit the company makes and yes, I can see +6K so therefore 18K installation cost.

Wonder if that 18K was including or excluding MWST?

 

Alternative Balcony System (as was shown in photo), or RV/Camper Van roof system, DIY:

2KW Solar generator (inverter plus battery) - Around 1K per KW, so 2K

2 x 300w panels - 600 Euros

Wiring/connections/fittings - 100 Euros.

Electrician required to fit 'correct' socket - 300 Euros

Total cost 2K-3K Euros depending on battery size.

 

1KWh = ~30c, so 109.50 Euros per year if 1KW is consumed each day.

2K Cost = 2000 / 109.5 = ~18 Years payback.

 

Unless your inverter or battery are failing before.

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6 hours ago, scook17 said:

Alternative Balcony System (as was shown in photo), or RV/Camper Van roof system, DIY:

2KW Solar generator (inverter plus battery) - Around 1K per KW, so 2K

2 x 300w panels - 600 Euros

Wiring/connections/fittings - 100 Euros.

Electrician required to fit 'correct' socket - 300 Euros

Total cost 2K-3K Euros depending on battery size.

 

1KWh = ~30c, so 109.50 Euros per year if 1KW is consumed each day.

2K Cost = 2000 / 109.5 = ~18 Years payback.

 

Problem with this calculation is that 600 wp can never charge the battery to full potential. Moreover balcony system is used by plugging into socket. For quicker return, one need to do it DIY. For 600w panel kit + installation, one can be done in under 1000 euro. With full diy, the total cost will be around 60%.

 

So payback cost will be around 1000/ 109 ~ 9 yrs or 600/ 109 ~5.5 yrs. With proper panel orientation the full DIY installed panel, the payback is within 4 yrs (based on production data from users from Photovoltaik forum) 

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We are all underestimating electricity price increase in the coming years.

 

ONe question I have: for these socket simple installations, on a 3 phase installation, how does this work? Only one phase receives the added power? Or the counter somehow subtracts it from overall consumption?

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4 minutes ago, MikeMelga said:

We are all underestimating electricity price increase in the coming years.

 

ONe question I have: for these socket simple installations, on a 3 phase installation, how does this work? Only one phase receives the added power? Or the counter somehow subtracts it from overall consumption?

 

The only way I know is using a tie grid inverter, but then there are multiple scenarios, because your meter might or might not support going backwards, so when your consume is lower than the production you might have issues.  And then as far as I understood you have to report your tie grid inverter to your electricity provider and get their permission to use it, and some providers do not support them at all.  And even the ones that in paper support them might give you a big headache.  It looks like they want you to give up and not do it, for example requesting everything to be installed by a professional, which will drive the price high and financially it won't make sense anymore.

 

I, like you, have been considering for the past two years to install a small self-installed setup at home, but the bureaucracy seems to be crap and that's the only thing that has stopped me.  I still need to research more about it.

 

You can check this for the basics:

 

https://www.vde.com/de/fnn/arbeitsgebiete/tar/tar-niederspannung/erzeugungsanlagen-steckdose

 

But it seems like if you want to do it yourself you will have to keep it isolated from the net or jump through the loops and headaches.

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1 hour ago, MikeMelga said:

We are all underestimating electricity price increase in the coming years.

 

ONe question I have: for these socket simple installations, on a 3 phase installation, how does this work? Only one phase receives the added power? Or the counter somehow subtracts it from overall consumption?

 

I asked this of the electrician when he setup the wiring. The electricity socket is by default single phase, except for things like cookers and electric cars which are wired for 3 phases. Ironically many of the EV can actually only use single phase, even if you bothered (as I did) to have them wire up 3 phases in the garage.

 

The other sockets in the house are wired to a single phase. I had several wired individually for units which took a considerable amount of power. Here the phase is rotated. So washing machine on one phase, dryer on the next, and so on.

 

With a balcony system, you are putting 600w into a 3.6KW socket, so it matters not what phase it is connected to.

The meter I have is bidirectional, so records 1.8 and 2.8 figure which records the amount consumed and the amount given back to the grid.

 

If you have one of those very old mechanical meters, the wheel (I miss this as it was easy to see actual consumption) would go backwards if you generate too much electricity.

Now that might seem fair, but it would be then 1:1 for consumed vs 'sold' electricity, like returning your unused electricity.

That's the simplest system possible, but this is Germany, so no, we cant have simple.

We could have a system where you get a credit on the bill for the amount you gave back.

No, here you need to become a 'seller' of electricity, which is taxable and needs registration, blah blah.

 

It seems to me everything is done make things as complex and as expensive as possible.

Take for example needing an intelligent meter where >10KW system is installed. At an additional cost to the consumer of course...

 

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Ok, then it might be down to the meter, so if I check the specification I should be able to guess if I get "credit" for the injection?

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I had a couple of folk around to quote for PV last week. The first quote (the one expected to be cheapest) has just arrived, and I'm struggling to see how it can be even close to cost effective. The total cost (inc Mwst) is 32k to supply and install a 14.8kwp system with wall box and battery, guaranteed for 12 years. There is a possibly 1.5k subsidy in relation to the wall box, but apparently nothing else is available. Given my electricity bill has been less than 1.5k for the last few years, even allowing for a price increase, it doesn't appear to me that PV makes economic sense, as I'd be out of guarantee with a drop off in panel/battery performance way before it had paid itself back.

Am I missing a key benefit here, or is there some other sort of subsidy that they have failed to mention?

I suppose the battery and wall box (combined cost just under 10k) make a difference, particularly if I change to an electric vehicle. Can't think of anything else though.

Anyone else receiving similarly priced offers?

 

 

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Depends. I spend over 2000€ of electricity per year. If I had a heat pump instead of a gas boiler, I would probably save 3000€ a year. That means the system would pay itself in 11 years. If I had a second EV already, I could probably save 4000€ per year, which would pay the installation in 8 years,

which is quite good. This of course assuming either a 100% usage or some money made from selling.

And with expected price hikes, it definitely makes sense in my case.

 

Still, I was expecting a cheaper price, but perhaps inflation has a play.

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On 27/06/2022, 12:59:57, dstanners said:

I had a couple of folk around to quote for PV last week. The first quote (the one expected to be cheapest) has just arrived, and I'm struggling to see how it can be even close to cost effective. The total cost (inc Mwst) is 32k to supply and install a 14.8kwp system with wall box and battery, guaranteed for 12 years. There is a possibly 1.5k subsidy in relation to the wall box, but apparently nothing else is available. Given my electricity bill has been less than 1.5k for the last few years, even allowing for a price increase, it doesn't appear to me that PV makes economic sense, as I'd be out of guarantee with a drop off in panel/battery performance way before it had paid itself back.

Am I missing a key benefit here, or is there some other sort of subsidy that they have failed to mention?

I suppose the battery and wall box (combined cost just under 10k) make a difference, particularly if I change to an electric vehicle. Can't think of anything else though.

Anyone else receiving similarly priced offers?

 

 

 

I wonder if you really need 14.8kwp? How did you (or someone) work this demand? You don't say what exactly the system is, but you may want to ask certain questions:

 

1. Do I need a 14.8kwp battery? Presumably you are looking at the Powerwall from Tesla. This will contribute around 8.5K plus installation to the overall cost. Personally I like this product, but I don't own one (yet).

2. How can this 14.8kwp demand be reduced? Presumably most of it will be for heating? What is the SCOP rating of the heat pump (seasonally adjusted multiplier (the COP) for the electricity averaged over a year). If it's not already installed, can you buy a different heat pump with a higher SCOP? How about a ground source heat pump? 

3. How old are appliances like fridges, freezers and things which run 24/7? Do you know which appliances take the most energy? Buy a cheap (15euro) electricity plug and it will tell you.

4. Hot water heating can mostly (~8 months) be 100% completely solar.

5. What other sources of heating could you easily use? Is wood or wood pellets available.

6. Around 75%+ of this electricity is for heating the house and water. Adding insulation can serious drop this demand.

 

The salesman will surely sell you everything you could need to have plus much more. There is one subsidy you didn't consider. There is a tax deduction for labour costs (20%) on your property. There is also one for installing certain 'green' modernizations using approved suppliers. 

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Thanks for the feedback. I agree that 14.8 is too much. Our current consumption is under 3.5kwp. Admittedly, we don't heat with electricity, we don't have an e-auto yet, and our consumption may rise as our kids get older, but my understanding is that there is an economy of scale to having a "too large" system, which can sell back to the grid. Nonetheless, the other company has quoted for just 10kwp (albeit the overall price is unchanged, due to higher labour costs and a supposedly better battery) which already seems generous, even allowing for moving some of the heating to electricity (we are also having a pellet oven installed later this year).

Neither company is offering a Tesla Powerwall. One is offering Senec (a German brand) and the other is Huwawi and BYD (no idea who they are): all coming in at around 6.5-8k of the cost.

The 35k costs do not include a heat pump.

Amortisation from the various offers runs at between 12 and 15 years (allowing for their own assumptions of me having an EV on day 1, and electricity costs increasing by 6.5% year on year).

I was speaking to neighbours about this (all of whom have been quoted or paid similar sums), and there is a feeling that this might be a very local issue, as so many houses (well, towns and villages to be precise) were destroyed in the floods last year, that companies are overrun with work and able to charge top dollar.

My view is that 35k wasn't such an unreasonable price whilst there was a substantial (30% or more) subsidy from the state, but prices have not reduced now the subsidies are no longer available (at least, not for the lion's share of the cost).

I will go back to the salesman and see if they can reconfigure based on a lower power demand. I'll update if that has a significant impact on price.

 

 

 

  

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49 minutes ago, dstanners said:

Thanks for the feedback. I agree that 14.8 is too much. Our current consumption is under 3.5kwp. Admittedly, we don't heat with electricity, we don't have an e-auto yet, and our consumption may rise as our kids get older, but my understanding is that there is an economy of scale to having a "too large" system, which can sell back to the grid. Nonetheless, the other company has quoted for just 10kwp (albeit the overall price is unchanged, due to higher labour costs and a supposedly better battery) which already seems generous, even allowing for moving some of the heating to electricity (we are also having a pellet oven installed later this year).

Neither company is offering a Tesla Powerwall. One is offering Senec (a German brand) and the other is Huwawi and BYD (no idea who they are): all coming in at around 6.5-8k of the cost.

The 35k costs do not include a heat pump.

Amortisation from the various offers runs at between 12 and 15 years (allowing for their own assumptions of me having an EV on day 1, and electricity costs increasing by 6.5% year on year).

I was speaking to neighbours about this (all of whom have been quoted or paid similar sums), and there is a feeling that this might be a very local issue, as so many houses (well, towns and villages to be precise) were destroyed in the floods last year, that companies are overrun with work and able to charge top dollar.

My view is that 35k wasn't such an unreasonable price whilst there was a substantial (30% or more) subsidy from the state, but prices have not reduced now the subsidies are no longer available (at least, not for the lion's share of the cost).

I will go back to the salesman and see if they can reconfigure based on a lower power demand. I'll update if that has a significant impact on price.

 

 

 

  

 

For comparison, before I moved into a house, consumption was around 4.5KWh. We selected a 5.8Kw system. It generates around 6.5Kwh per year.

You might think, great, we're covered. In year one 29% of the electricity was covered by solar. Five years later, it's around 38%, mostly due to load shifting (using expensive things when the sun shines!). 

 

The money I get from the feed in, is not worth the effort. With a >=7Kw system you will be the 'lucky' guy who will be forced to have a 'smart' meter, for which you will have to pay many times more in rental than the dumb meter of today.

 

Personally, given the choice all over again, I would have installed a slightly smaller system than 7Kw, and had panels facing east, south and west. The south facing panels I would have angled for best production in winter. You will get way to much energy in summer, that this trade off is a good one. I would have also bought a power wall rather than a bigger solar system, i.e. taken the 14.8kwp, dropped it to 6.99 kwp and spent the money I saved on a battery.

 

For heating, I have gas. For water heating gas + heat pump (selectable). Opting for just gas heating (or just heat pump heating) was a mistake. With EEG dropping out this year and gas massively spiking in price, electricity from the grid via a heatpump is now equal, and I am sure will be a lot cheaper come this winter. Three years from now, it may well be the other way around. Who knows. So I should have also invested in a heat pump or some alternative heat source at the time.

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Most people think heat pumps are crap, they do not produce a hot water, which means, you need a large surface area to get enough heat from them. This means installing under floor radiators, to get the surface area and the radiators on the walls become use less, uneless you want to power them from GAS again.

 

Heat pumps, have a fan running all the time, so should not be mounted on the house or near the bedrooms, as you will hear them all night long, put them in the garden, and lose some heat moving the water from garden to the house.

 

I only got this info from youtube, so maybe ist crap, it it all sounds reasonable to me

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1 hour ago, yesterday said:

Most people think heat pumps are crap, they do not produce a hot water, which means, you need a large surface area to get enough heat from them. 

 

My water heater needs replacement and the plumber said he can install a heat pump so it must produce hot water. 

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