Purchases of solar panels in the United States?

[darwenn]

I find that the gain is not very significant for the price, but it is only my responsibility. It is true that I will not have a solar panel delivered by post, mine bought in England had been delivered in 5 days with DHL. What I notice, and maybe it's not normal tell me is that my ammeter was rising in September with a great sun (I said was rising because now with a pale winter sun we lose in performance and I only have it since September) at 8 amps with my 100w panel. There as today with the sun, it does not spill the 5 / 6 amps which is the normal power (measured done before the regulator, but I have to review the angle of inclination on my roof to compare), at the beginning I thought of a problem with the shunt resistance of the ammeter and I changed it, same observation, it goes up to 8 amps I then changed the ammeter analog (class 2.5) and it was always the same at that time with a sun at max.

[Forhorse]

Attention with DHL, they are reputed to be boring on customs fees (say that with them it's not even worth hoping to get through they systematically declare everything without waiting for a parcel control by the customs office)

[darwenn]

For England I have not had any problems with DHL (but boin it was in England), but after reflection I will not order anything outside the European Union, I think it's too risky. My purchase is not planned at the moment but I will opt for 200w in England or as Elephant says, in Germany, which are in fact resellers of panels made in China. 500 euros for 200w even with 50 euros plus postage, it seems already very reasonable.


To bounce on my 8 amps with a good summer sun, is this normal? can we exceed in certain conditions, the indicated power of 2 amps? (the normal intensity given for the panel is close to 6 amperes).

[Forhorse]

It is 8A but under what tension?
Because 8 * 12 = 96W; we do not exceed the 100Wc panel (but good 96% yield difficult to believe)
Finally some measurement errors ready and if your regulator is PWM type it shocks me no more than that.

[darwenn]

Let's say that the no-load voltage is more than 18 volts (even 20volts I think of memory, I'll check), but when the panel is connected to the regulator and the battery, the voltage drops to that of the battery, so logically the 8 amps would be normal if we calculate like this 12,5 volts x 8 = 100w but hey it leaves me a little perplexed so I took the opportunity to ask the question parenthetically.

[elephant]

I agree with forhouse: only a switching regulator controlled by μprocessor allows a cost-effective adaptation of the mppt to the load: do not forget that it is especially the available current which varies in case of strong sunshine and there would be too much heat loss in a simple series regulation.

Do not worry too much about the strength of the panels: experience done (by a trainer): I saw walking on it (on a 170 watts). But it is not done to be delivered alone: ​​it is about twenty flat on a pallet, normally.

[Forhorse]

Let's say that me, between buying a "basic" regulator at 30 euros which will shoot my batteries because it has no charge processor then buy another one at the same price a few months later in 24V which will not be better, more at least one voltmeter and one ammeter ...
And immediately put 200 € in a good MPPT integrating a real processor charge (it even has a battery temperature probe) plus basic monitoring indications already integrated ...
I chose the second solution.

After everyone sees noon at his door. I understand that someone who is already equipped does not want to invest such a sum. But first purchase is to consider seriously.
(Some who have made the change say they see an increase in production of 50%, personally I still have trouble believing, but it seems that the gain is still significant)

Currently the problem that I have is the capacity of my batteries, it is too weak.
I'm a bit like you, I have two "auto" batteries of 62 and 70Ah in parallel (i.e. theoretically 132Ah) loaded by a simple PV of 80Wc (for now I have never seen it exceed the 60W) and yet during the beautiful days to 14h the charger is already in charge of equalization (the battery voltage exceeds 14.5V and the charger slams the charging current considerably just to finalize it)
And it's even worse when several beautiful days follow each other (I consume an average of 60Wh per day)
Suffice to say that at the moment I "lose" almost 2 hours of production per day, and that in summer at 10 am my batteries will be charged and the rest of the day will be lost so to speak.

So I say increase the power of the panels is good, but I think it should primarily increase the storage capacity.

Besides I have another project for another local a little bigger, I had originally planned 280Ah of batteries (4x70Ah) I believe I will double this capacity (especially as I predict PV 480Wc)

[darwenn]

Yes, like you I had considered increasing the storage capacity. I had even thought of deep cycle batteries and had launched a subject on it to conclude that in the end apart from better reliability in the long term, these special batteries at 350 euros per 100ah will not increase to equal power, the autonomy I have with car batteries at 30 euros recovered at the scrapyard (which work very well for the moment). But it is especially in winter that I need power, and in winter there is little sun in the north (what? Who said "the rest of the year too !!"? ), the days are shorter and the sunshine less efficient (that's what I noticed in any case, but as I said I'll try to review my angle panel, because it is less inclined than when I put it on the ground at the end of the summer, I put 40 °). The problem is that the more batteries I have, the more power and autonomy I will have, but the longer my panel will take to recharge them and in the winter it will not be won. So it's a bit of a stalemate.

[Energie_Vair]

Attention, there are many amateurs and neophytes in the field of renewable energies. Especially on the internet, because the pseudo-sellers have often not had the experience of the field ...

As for the MPPT regulator, it's true that they make a big difference (15% to 25% more electricity). But again, pay attention to the false MPPT regulator, which are in fact standard PWM regulators, but three times more expensive!

In previous posts, you also mentioned batteries. There is no point in paying a crazy price for supposedly "solar" batteries. This too is a scam! The batteries with the best price / quality ratio are currently 6v deep cycle batteries. These sell for around 100 EUR for a 6v / 210ah.

It's up to you to shop!
Kind regards.

[darwenn]

6 volts 210ah are you saying? interesting. Well it should be loaded in series and use them in series but it should not be a problem is 12v 210ah. Do you have good addresses?