forums energies: society, ecology and clean technologies

Hello

We would like to be autonomous on plots belonging to us in the woods (wood + meadows).
The goal is to supply year-round equipment such as refrigerator, portable computer, compact fluorescent bulbs ...
Estimated requirements are in the range of 1.5 kWh / d. minimum.

I have covered many topics of this forum, who taught me a lot of things, I also made my own investigations, including the different kits available on the internet ...

Questions and uncertainties persist ....

1) the calculation of the PV potential of the place where we are gives me for January a daily average of 1.66kWh (JRC / PVGIS): does this mean that with the equivalent of 1 kWp in PV panels, I can count on this estimate?

2) what about batteries ....? what capacity needed to hold 3 days (4.5 kWh?) without discharging them too much?

3) in the case of hybrid installation, it seems that it is necessary to install a regulator by system ...? Are wind regulators specific to wind?

And other questions that will surely come later ...

Thank you in advance for your invaluable help! ;-)

If your batteries are low voltage (12 or 24V) then LED lighting will be more efficient and less consumer than compact fluorescents.

Ditto for the portable computer, with a car adapter, you avoid a double conversion, so less losses.

There are fridges in 12 / 24V.

So, you have to decide what voltage you will use for batteries and panels, if you are going to have a big inverter or a small one, which charge controller, and so on.

For example, for the fridge. If you put in a stock of phase change liquid to 3 ° C, and the solar panels produce enough to freeze the liquid in the day, you will not need to power it at night ... so a calculation to do on the price of batteries etc.

That is true !

Your advice is good! But having already done (roughly) the trick of this question (low voltage or 230V), my choice is definitively on the 230V, for several reasons besides.

Thank you

Very delicate, the problem of capacity.

I quite agree with your 1,5 KWh / day.
The problem is to calculate the PV peak power to have enough power in the winter.
The other day, I was with a client on a "dreary winter day" in the early afternoon (and this kind of situation can last 3 to 10 days in a row). Its roof
10 KWc produced royally .... 180 Wh / hour, so a big max of 1 KWh / day.
Over 10 days, that would produce a deficit of 5 KWh, not to mention that your "lighting" request would be more intense, because you have to start lighting around 16:30 pm.
Let 21 A / h under 240 volts, but it is quite rare that we store under high voltage: usually we store under 24 or 48 volts, the converter is not what is the most expensive (do not forget no more than the batteries are in direct current, and that most devices are designed for the alternative.
To store 5 KWh under 24 V, about 200 Ah of batteries.

Now, you may have to reconsider your consumption calculations: a good domestic refrigerator actually consumes about 1 KW / h / 24h, but is it a permanent place to live or a vacation spot? In which region ?

Thank you elephant

"To store 5 KWh at 24 V, or around 200 Ah of batteries."

It seems to me very little .... do you mean that only one battery of 200Ah would be enough for my needs as stated in the subject?

"Now, you may have to review your consumption calculations: a good domestic fridge actually consumes around 1 KW / h / 24h, but is it a permanent place to live or a vacation spot? region ? "

in the trade I found a refrigerator 248l which consumes 175kWh / year + a freezing of 215l which consumes 120kWh / an .... known and relatively reliable mark ... which makes a total of 295kWh / year is about 0.81kWh / day!
We want the site to accommodate 3 people minimum permanently if needed ... and we are around 45 ° North and 1 ° East to the ladle .... is in the Périgord black ;-)

In the basis of the Photovoltaic Geographical Information System, in PV Estimation, there is a modifiable criterion: Estimated system losses [0; 100] .... it is automatically set to 14% .... someone knows- what does it mean?

Thank you

Hello,

Parameters to know:
Region Poitou-Charentes monthly performance of existing installations:
January => 45 Wh / Wc July => 170 Wh / Wc installed

Battery efficiency: about 80% or 800Wh returned for 1000Wh provided

Efficiency of an inverter: 95% maximum

In this example:
1.5 kWh / day => /0.95 /0.80 = 1.97 kWh / day to draw panels
About 60 kWh per month
In January you need 1.333 Wc panels, in July 355 Wc are enough.
For 400 Ah batteries in 24 V will provide sufficient autonomy (about 5 days)

Obelix

Hello and thank you !

We are not in Poitou Charente! But I imagine that it is the same with us a little bit near here .... I have to dig up here!

So I summarize, for needs of about 1.5 kWh / day:

1) for an autonomy of 3 to 5 days, 400 Ah of batteries in 24V would suffice!?!?

2) for production: 540 Wc in PV + 500W wind turbine ...! ???? (1 regulator by system?)

3) What about regulators: MPPT? Amperage?

4) What about pure sinus converters: how to calculate the required power (W)?

Thank you very much for giving me some of your time!

Hello,

I was wrong on the region!
It is aquitaine so it changes a little and better!
December and January => 55 Wh / Wc and July => 155 Wh / Wc and this for a standard orientation.
There is scratching for a fixed installation by maximizing the yield for the two winter months.

Otherwise for:
The 1) ok
The 2) I have never had good returns with a wind turbine. The investment is not profitable even in the long run.
In panels this makes: 1000 Wc to install. It's playable!
The 3) MPPT regulators imperative if one wants a reliable and efficient installation with a good performance.
The amperage: power panels 1000 Wc battery voltage 24 V that makes 50 A.
The 4) everything depends on what this converter feeds.
If there is a bit of electronics it is pure imperative sine, otherwise it is a wise choice that avoids a lot of trouble. Its maximum power is that of consumption on the 220 "while on the road"!
(in my opinion in 1000 W)

Obelix

Hello

You can have real productions in your area on BDPV: http://www.bdpv.fr/index.php

knowing that you will produce better in unintegrated ..

pay attention to the reserve not to exceed for the discharge of the batteries not to the guns .. see also that it is slow discharging batteries (gel) it is worth ..

I agree on the position D'Obelix on the wind ... in default it must be on the ground mat after wind study .. otherwise not worth thinking about it.

and do not hesitate to invest in reliable / known from the depart ..

attention to the term "hybrid" which in solar concerns mixed modules (water / electricity) is that correct?