Solar Energy, anyone?

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Solar Energy, anyone?

Postby Digit » Wed Jan 30, 2008 6:26 pm

Subsidy on Solar panels is back.
Anybody planning to do something with solar panels now or in the near future?
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Postby Lennart » Wed Jan 30, 2008 8:14 pm

Hi Digit,

Well, we currently have around 5700 Wp (Watt peak) of solar panels on our roof. We bought several systems back in 2002 and 2003 when there was still a subsidy on the panels (ranging from a reasonable half of the price in 2002 to a crazy EUR 95,- for 4 panels with a value of EUR 2800,- in 2003...).

Although the panels are not optimally positioned since we moved to our current house (the roof is tilted very slightly to the North, where South is optimal), they should approximately generate our anual power consumption of 3000 - 3500 kWh. (If positioned optimally, this would be around 4500 kWh.)

I installed them last October - after going through a lot of research to find a good mounting construction for our non-standard situation - so it's too early to say.

I have an RFXmeter lying around for monitoring all three systems, but didn't come around to installing it yet.

If you have any specific question about solar panels, just let me know. The new subsidy is a nice incentive to buy some (or many) panels, but note that saving energy is more efficient; that should always be the first step.

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Postby Lennart » Wed Jan 30, 2008 8:23 pm

To give you an impression, here's a picture of our roof, showing 2 of our PV-systems (the third system is at the front of the house, not in the picture).

Image

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Postby Snelvuur » Wed Jan 30, 2008 8:38 pm

Is this just a thing of "i buy 4 panels, hook it up to the main powers" and i'am done? Since thinking of this, i'am getting a flat roof. Now i stil have a few more days to decide if i want extra tubes and stuff (maybe to roof too) so please let me know, i can better make something allready there then to do it later if you know what i mean.

http://www.ad.nl/binnenland/article2011794.ece <- article dutch.

// Erik (binkey.nl)
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Postby Dowser » Wed Jan 30, 2008 8:43 pm

How do you feed that to the house?
I have seen a lot of solutions only forcing the power in to a regular wall-socket, after an inverter. While that might work it is a single phase solution and might fry a poor unsuspecting electrician during a power-outage if your house is connected to the grid.
(And it is probably illegal in a majority of countries...)

I have been searching for a 3-phase inverter that can have grid-power as one "feeding-point" together with other power-sources, but hasn't found any yet.

//Markus
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Postby Bwired » Wed Jan 30, 2008 8:51 pm

Wow Lennart I envy you, great solars and gives you a lot of benifit! I was stupid and did not think about it in 2002 :-(
I think you are not paying that much anynore for energy?
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Postby Lennart » Wed Jan 30, 2008 9:09 pm

Hi Erik, Dowser,

Up to 600 Wp (3 or 4 panels, depending on panel size), it's just a matter of connecting the panels to the inverter (usually supplied with a set of panels) and connecting the inverter to a (any) wall outlet (which then becomes an inlet :-).

The inverter is needed to transform the DC power coming from the panels to AC mains power. The inverter is usually located inside your house and + and - DC cables run between inverter and panels. Cables are usually 4mm^2. Note that most systems have several panels in series to increase the voltage, lower the current and thus decrease cable losses. Depending on the number of panels, inverters and strings you might need to run several + and - cables.

If your system is larger than 600 Wp, you need to connect the inverter, or inverters, to a dedicated group (groep), otherwise it's basically the same (although I would cut of the plug of the inverter and connect it directly to the group in that case). Up to 3600 Wp, it's possible to use a single group. Above that, you need 2. If you go beyond 35 Amps (you need a roof full for that :-), it's time to switch to 3 phases (3 x 25 Amps). I have a 3 phase installation and added an extra group to each of the phases, one for each PV system.

You won't easily fry an unsuspected electrician, as all inverters continuously monitor the mains power and shut down within miliseconds as soon as the power goes down. Contrary to popular believe, solar systems don't continue to work if there's a power outage (unless you build in a battery backup circuit, but that means less efficiency and a different price tag; it's only an option where there is no mains power available, or power outages are very frequent). Island operation - as it is called - is a risk only if you don't use a dedicated group (i.e. connecting a vacuum cleaner to the same group that the PV system is connected to on a sunny day might let the inverter think that it can still output its power if there is a power outage). That's why they put the 600 Wp limit on using existing groups for PV systems.

Systems above 600 Wp need to be checked by a certified electrician before being put into use.

(Note: this is the Dutch situation; your mileage may vary)

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Postby Bwired » Wed Jan 30, 2008 9:21 pm

I dived in the Solar world several times and believe me a solar system consisting of 4 panels and giving up to 600 Wp does not make a difference at all. It only cost you a lot af money and gives you almost nothing back. A system like Lennarts is the real stuff but by today's standards its costing you a bundle!
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Postby Digit » Wed Jan 30, 2008 9:22 pm

Saving energy is what i'm already trying to do these days; walking around the house, finding the latest overlooked devices that consume energy, etc.

I've always been interested in having Solar Energy; back in early 2005 i already did some 'research' on this subject.
Our house has a completely flat roof, total of >100 m2, just waiting to be populated by solar panels ;-)
I already had thoughts about buying solar panels somewhere in the future, but maybe this is a good trigger to get things started.

For starters, here are some links i used back in 2005 on this subject.

http://www.polderpv.nl/ (Dutch)
http://www.zonnepanelen.wouterlood.com/ (Dutch & English)
http://www.olino.org/articles/category/zonne-energie (Dutch)
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Postby Snelvuur » Wed Jan 30, 2008 9:31 pm

some nice information http://www.zonnestroomproducenten.nl/ dutch..

Still i have a few computer running 24/7 but nothing fancy besides some lights.. and i still use +- 5600 kWh a year (i checked it now, but thats pretty high)

// Erik (binkey.nl)
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Postby Snelvuur » Wed Jan 30, 2008 10:17 pm

I know get why he got them back then.. http://home.wanadoo.nl/jvdkrift/zon2/zonneset2.htm as you can see: (dutch)

Actieprijs 2720.=
EPR subsidie 1750.= (3.50 per Watt Piek)
EPA subsidie 175.= (we bezaten al een positief EPA-advies)
ENECO subsidie 750.= (1.50 per Watt Piek)
Te betalen voor de levering (2720 - ( 1750 + 175 + 750)) = 45.=
INDERDAAD Voor 500 Watt-piek dus maar 45.= excl. montage


// Erik (binkey.nl)
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Postby Bwired » Wed Jan 30, 2008 10:36 pm

That was then :-) Tonight it was on the News that the Dutch government has decided to give 35 euro cents back for every Solar kWh.

Pieter Knuvers
www.bwired.nl Online House in the netherlands. Domotica, Home Automation.
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Postby Snelvuur » Wed Jan 30, 2008 10:46 pm

I cannot read anywhere that if you go beyond 600Wp that you need a seperate group. At least not on the sites i visited in this short period of looking around. Only found out that http://www.duurzame-energiesystemen.nl/ for example, offers 3420Wp and it costs (hold your horses) 16.860,00 euro's.. might be better to go on marktplaats then, http://www.vergelijk.nl/?cat_short=veil ... nnepanelen gives a lot of hits..

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Postby Digit » Wed Jan 30, 2008 10:52 pm

This afternoon i heard on the radio that the subsidy is limited: the government expects to give subsidy to ca. 40.000 houses; after that, the subsidy stops again (?). Another thing mentioned was they're targeting the bigger installations; not those with just 1 or 2 panels.
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Postby Lennart » Wed Jan 30, 2008 11:12 pm

Hi all,

Some comments on the recent posts:

- I can especially recommend the site by Floris Wouterlood, as mentioned above (http://www.zonnepanelen.wouterlood.com).

- @Pieter: a small sized solar array (4 panels) does make a difference, in my opinion. It will generate 10 to 15 % of the annual consumption of an average household. It may not seem much, but it's all linear; 10 times as many panels will cost you 10 times as much and will generate 10 times as much. If you can only afford a small system, I'd say: do it anyway, as the experience and the fun you'll get from the technology will definitely make you want & buy more panels :-). However, 4 panels won't make a serious difference if you don't start thinking about saving energy first (switch lights of, use CFLs, use a low power 24/7 server or even better: turn it off, etc.). My experience is that even a small set of panels will make you much more aware of your energy usage and saving options. It will become a new hobby, which combines well with the home automation thing. And yes, in my case, the electricity bill will be almost zero (unfortunately, I still have to pay the connection fee ("vastrecht")).

- @snelvuur: unfortunately, I bought most of my panels in 2002 when the subsidy was roughly half the price of the panels; my motivation was mainly the environment, not the financial argument. I bought some extra panels in 2003 at an over-subsidized pricepoint (as I said, EUR 95,- for each set of 4 panels...), and so did the rest of Holland. The consequences are well know: the subsidy which was budgetized at EUR 75 million turned into EUR 175 million, leading to a subsidy stop which lasted for 5 years... All in all, my panels need to be on the roof for another 12 to 15 years before I a reach a full return on investment, financialy speaking. More important though, is the CO2 reduction that comes with it.

- If I take into account all the hours I put into the whole subject of solar panels, including all the research for a large scale array, getting price quotes, getting the stuff delivered, installing it, filling out many many forms for the subsidy, moving it and finally solving all the problems I've had with inverters (don't ask), it's been a very bad investment; but hey, as I said, it's another hobby now! :-)

- As far as the new subsidy is concerned: note that the 35 cents is on top of you using the kWh yourself, as I understood it. Usually it would cost you around 20 cents, so the total earning per kWh would be around 55 cents. This is comparable to the German subsidy that works out very well.

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