what do you think?

[ron17571]

Any experiences with solarkits.com?i was thinking about their cabin kit,kyocera 130 panel,17.6 volts with a BZ240 14 amp controller with mounts and wiring.i thought of using this with 4 crown batterys 225 amps for 900ah.739.00$and no i dont have any connection to them and im just looking for a system that makes it a little bit easier to put together.oh and hi to everyone.

[BB.]

I don't know about the exact BZ 240 controller--but in general, the BZ controllers are not worth the money (or probably any money). You can read about the BZ MPPT250 in this thread.

And, don't expect 650 to 780 Watt*Hours out of a 130 watt panel setup... That is almost twice what the "real numbers" will be for a long summer day (with fixed mounted solar panel), and less during the winter.

In the end, you have to know what your power requirements are and what such a system would generate in your area. I ran some numbers for an 130 watts system running a derating factor of 0.62 (for DC off-grid system) with default values, and I would guess you will generate a minimum of ~432 Watt*Hours (~36 Amp*Hours at 12 volts) a day for around 6 month of the year (note PV Calculator program requires 1kW minimum for solar panel... Multiply the results by 0.130 for your 130 watt system).

I can't comment on the rest of the pieces (other than Kyocera is a fine panel mfg.).

Sizing a system is always a tough problem the first time through. Most people really don't know how much load they will need to support. If you are running a few 13 watt DC CFL lights and a portable radio:

195 WH = 13 watt * 3 lamps * 5 hours a night
60 WH = 12 watt * 1 * 5 hours a day radio (~1 amp load @ 12v for 5 hours a day)
==========================================
255 Watt*Hours per day for above loads

Do you have more questions?

-Bill

PS: Fixed numbers to 130 watt panel... I saw the 85 watt kit first and did the calculations on those numbers.

[icarus]

Please, please, please,, heed the warnings about BZ controllers.. Do a search and read before you buy an expensive mistake!

Tony

[icarus]

Let me add this,

Aside from the BZ issue, I think there are other issue with this Kit.

I think on balance, it is filled with cheap generic components, and when you put all the items together you could do at least as well by buying the components separately .

Take for example, 85 watt panel, from NAWS site is ~$435. A simple (good quality PMW) controller (Sunsaver ) for ~$40. Modified Sine wave inverter like one in the "kit" ~$25 from your local auto parts store,,, making a total of $500. Toss in a few buck for wire and stuff and you are still ahead. Add in a real inverter and you would rival the cost of the "kit"

I agree with Bill that the real world yield from an 85 watt system is going to be way less than advertised. I always use a 50% factor. That is by the time you derate all the components for efficiency you end up with ~50% net/net.

So in your example, your panel might put out 85 watts for 6 hours (average, and that would be a good average!) would yield ~255 watt/hours/day, enough to light a 15 watt cfl for ~17 hours,,, or less.

Avoid the perennial "ready, fire, aim!" Do your math, do your reading before you make expensive mistakes. This site is a very good source for unbiased, real world experience. Smart guys who have done smart things.

Tony

[ron17571]

Of course i read the warnings about bz controllers after i posted.

[BB.]

Ron,

Don't worry, the only bad questions are those that are "unasked".

Just an FYI--most people underestimate their loads and costs of a good quality solar PV system. And overestimate how much power a solar PV system can supply.

They then find that they are having problems "dead" batteries in a couple weeks--and a few weeks or months later, the batteries will not hold a charge.

A "good" solar system will last decades (and the batteries some 3-10+ years if properly sized and maintained) with little work.

But, because solar systems are expensive (really, expensive ), it pays to understand your loads and requirements by season.

What usually makes sense is to size the system to run your average loads for at least 9 months of the year. And plan on having a small generator to make up for winter/stormy weather.

Also, a solar system makes the most sense with continuous use for some 9 months of the year at a minimum. And can make pretty good sense for a weekend place if used most of the year.

Normally, it will not make much economic sense for a larger system used only 3 month a year. There, perhaps having a few panels to keep batteries charged (during the off season) and a small genset (run in the morning to run heavy loads and recharge the batteries after a night of use) is a better solution.

Just using rough numbers, grid power costs around $0.10-$0.30 per kWhr. Off grid systems (year round occupation) will cost you (very roughly) $1.00 to $2.00+ per kWhr (assuming 20-25 year life)--so conservation and sizing your loads to the minimum amount needed is very important.

Icarus/Tony is a year-round off-grid user and frequent poster (especially when he is away from home and has grid power ). His system is not too large (see his "sig") and he is in Canada (not in sunny Arizona) and seems quite happy with his installation. He has a few appliances (washer--gasoline engine powered; fridge--propane powered; backup generators--he collects those ) which help reduce his needs. Plus--just don't use electricity unless it is needed. It is a lifestyle choice.

I have a Grid-Tied system in a major metropolitan area--So, my suggestions are more from reading and common sense.

-Bill

[icarus]

Bill,, I resemble that remark!

I don't collect generators,, they seem to collect me. The Lister and the Vintage Onan I inherited. The two of the Honda's came from cast offs, the EU I found nearly new for ~$300. The 2.8 kw Mitsubishi was a steal,, a cast off from my neighbour who grew tired of replacing control boards. (Turns out it was a flaw in his Solar DC grounding that was frying the boards. Mitsubishi send me a new board gratis! I even offer the genny back to my neighbour but he had bought a 2kw Eu to replace it and didn't want it back!)

The rest our antiques cast off from various bush camps, including a 1929 Kohler DC Auto start. I long for many of the items that were cast off in my lifetime before I could grab them. Big Onan 10kw Continental engine genset. Big water cooled Lister,, a handful of others. Not to mention the outboards! We used to have one from the 1920's that said on the side "Made by Ole Evenrude" Somebody stole that one!

My expertise (if you could call it that) was keeping the mechanical side of these beasts running. The electrical side was never my long suit. Aside from brushes and grease, if the engines ran, then the gennies worked!

Tony