Best modules for use in low light

lowlight

The site is on a South facing hill (New Zealand, 38 degrees South) and is surrounded by trees. So little direct sunlight in winter. Apparently thin film amorphous silicon and CIGS modules do better in these conditions. Any comments or links regarding this?

mike95490

Yes, they do better.   But not nearly enough to make you happy.  And they have a short panel lifetime ( 5 years)

If you are not able yo place your panels in a sunny spot, they will only produce about 5-10% of their nameplate rating.
Amorphous silicon and CIGS might give you 10-15%.  a 5% improvement is not very much.

BB.

Solar panels, to be "useful", need direct sunlight.

Is there any way you can access direct sun with a "remote" mounted array (run a cable 100+ meters back to your place)?

-Bill

Dave Angelini

Solar can also be useful if there is alot of it! Probably 4 times or more of what would be normal. This is not that hard to do if you have the space. I do this for a few of my clients. Ends up around 8kw of panels, or more!

 If space is an issue, it will cost you even more as you will have to use high efficiency panels which can be 2 X  the price.

Cut the trees and do it in a way that protects from fire. Build a firebreak that is good for you and others for a fire. We have plenty of wildfires much farther from the equator than you are. Agree with the 2 previous posts!

Hard to do anything if the hill is the problem in winter! Get to the top of it!   Good Luck!

NANOcontrol

I have extreme shade and overcast at my site.  I run 3,000W of panels into a 500W controller.  I wish it were better, but it suits my needs perfectly.  Adding reflected light could be a possibility like placing near a white wall or building.

Dave Angelini

Bifacial from Canadian Solar. Many of my installer buds are using them. Not to mention, they are just beautiful sitting underneath them.





 

lowlight

Thanks for the input. Because it is a covenanted bush block, I can't cut the trees down. Will get some good sunlight in summer, but very little in winter. May be able to combine solar with wind. The wind blows at night and during winter, so would make sense. The wind turbine would have to be at the end of very tall pole, though.

Any of you tried this?

Dave Angelini

Very few places are actually good for wind. People think it is good until they measure it. I have clients up in the high country above where I live that have used wind. The problem and the reason most have abandoned it, is high wind. The secondary reason is the companies who make wind gens do not stay in business long. I would say 90% get wind damage to the turbine, can't get a replacement, or do not have access anymore to the guy who went up the tower. You can look in the marine world or at some of the cheap and poorly made gear on amazon. That might be a way to test if there really is any meaningful power in your winds. A genset probably is the way to go for you.

clockmanfran

Hi Lowlight, 

We are a Independent non commercial Sustainability & Renewable Energy Project, and been doing the research and development for over 20 years now.   And NO we do not just throw money at this stuff, and if necessary we will re-invent the wheel if it works out more cost effective.   Our Mantra ........ Keep it Simple, Make it Robust, and keep it Cost Effective.

Amorphous silicone panels, I tested these with some Monos and Polys and in 2006 the amorphous silicone panels were very much better in ambient light conditions. However, over the past 10 years or so Monocrystalline manufacturers have got better and more efficient in the manufacturing process for output in ambient light conditions. 

Our PV collection started in 1987, with amorphous silicon, in fact i still have them up and operating at just 400 watts max output.  If i replace them with the same modern Monocrystalline panels, then for the same surface area i will get a good 1100 watts. Yep technology and quality have sure moved on and the real PV prices have fallen sharply.

With the latest LONGI 120 cell split panels giving a good 20% of there rated 380w output in just ambient light.   In winter and rainy days this all adds up.   LONGI panels are made in China as are most of the PV panels, and i can obtain the New 380 watt panels at about $130 each. 

We now have 63 Big Mono PV panels, from Panasonic, Sharpe, German manufactured SolarWorld PV, etc, down to a couple of bottom quality KNIVE. panels. 

Wind Turbines, We have 3off 4m (12 footers) diameter made by us to the Hugh Piggott design, these went up in 2008.  Every year they need servicing and blades re-balancing, so i have to give a complete week for all 3.    Material cost for one is now about $1500 for a TRUE RATED output of 1kW.   When asked I now say, "DONT BOTHER with domestic wind turbines as PV is way more cost effective, and they just sit there with no moving parts"

I will keep my 3 flying as long as possible, as I say to folk "Its a very visual Statement". 

PHOTO ....... 2007 Mrs with a set of our carved blades.

Orbital_Truth

Hi,

is there a solar panel that also works with wind, or do I have to buy them separately?

BB.

Welcome to the forum Orbital_Truth,

Solar panels themselves, are just "flat panes of laminated glass + solar cells". Completely different from the typical wind turbine which is usually a 3 phase alternator + rectifier (just like the modern car which has an alternator to charge the battery and run the car electrical system).

The big difference is the charge controllers used for solar panels vs wind turbines....

Solar Panels, the charge controller can pull current or stop current as needed to charge the battery bank and power your DC loads. (there are two major types of solar charge controllers--PWM and MPPT... PWM are cheaper and best for smaller systems. MPPT are usually used on larger systems and the MPPT controller costs a lot more--But is much more capable).

Wind turbines are "different". The typical Horizontal Axis Wind Turbine can directly connect to the battery bank (through an AC to DC rectifier) to charge the battery... And a typical solution to limit charging is a "dump controller" which, when the battery is full, turns on and dumps current to a resistor bank to prevent the battery bank from over charging... Wind turbine charge controllers--There are lots of options out there (including MPPT type controllers) to better control and harvest energy from the turbine.

With wind turbines, there are lots of issues with safety and reliability. More or less, most HAWT will over speed and can even self destruct in moderate to high winds if there is no electrical loads on the turbine (i.e., battery bank is disconnected). So, wind turbines have other methods to limit maximum RPM... Furling out of the wind (sideways to wind), Mechanical brake, Electric brake (controller shorts out alternator), and feathering blades (among others). So you need to "pair" the proper charge controller for "the wind turbine model" you will be using.

What is coming out of China these days are "all in one" units... Such as AC inverter/charger, with solar and wind turbine inputs. Look interesting--But I do not know anything about them--Just there seem to be quite a few options out there.

More or less, Solar panels + charge controllers + battery bank + AC inverter (or inverter-chargers), for the most part "work". There are some very sophisticated systems that require some advanced knowledge and tech support to address special issues and problems.

Wind turbines--They seem to be much more difficult to get functioning correctly (Many spin and don't charge, some don't even spin). The turbines themselves are (relatively) cheap--However the towers, concrete, hoist turbine to top of tower, yearly maintenance (and hoist/crane rentals, etc.) as well as the support equipment (controllers, wiring, possible lightning or ice damage, etc.) makes wind a bit more "iffy". Having a real local support person/company can be a big help. However, be aware that installers and mfg. simply "walking away" from projects with "issues" is not uncommon.

My typical answer is to design and install a solar panel powered system first (with backup genset power, if needed) first... And then if you want to try--Look into wind--Find wind installations near by you--And how much energy they generate per month (Watt*hours, kWH) by month for the last 12 months and see if it is cost effective or not for you.

If you wish--Please feel free to start your own discussion/thread and we can discuss your needs and site details--And not derail "lowlight's" tread.

-Bill

PS: You can "parallel" charging systems to a single battery bank... But you can run into issues too... For example, a solar and/or genset charging your battery bank works fine--But add Wind + Dump load--You have to make sure your dump load is not wasting energy supplied by the solar or genset (i.e., genset simply dumping its output into a dump load).