Have you been waiting for PV panels prices to drop?

[Xringer]

Originally Posted by gascort

Question - with the grid tie systems, I'm assuming when the electricity from the grid goes down, so does your house, otherwise there'd be live lines out there with the risk of backfeeding and killing linemen.
A big advantage to solar as I see it would be the ability to have electricity even when the utility is down - all your neighbors would be envious!!

The grid-tie systems that I've been reading about (like these tiny units),
Enphase Micro-Inverters


Shut right down if the grid power starts acting up. If the grid goes dead,
so does your system..

For home backup power during a blackout, you would need a more complex system.
One that includes a battery system and a mains disconnect.
Or a disconnect box similar to those used with gas generator backup.

[Xringer]

Originally Posted by roflwaffle

Here are some Kaneka 60W thin film silicon panels for ~$3.50/Watt, so prices look to be dropping. If ya wait, there may even be some in the neighborhood of $3/Watt in a year or so.

Solar Cell, Solar Panel, Solar PV, Solar Products, Charge Controllers, Solar Trackers - Kaneka 60 60W Thinfilm Solar Panel K60 (GSA-60)

Here we are 10 months later and we see the K60 is now $99 or, $1.65 a watt.

Not too shabby..

[smokeyj]

Not to hijack the thread or anything but.
Before you consider solar panels please consider reducing you demand.
You will most likely find you can drop your consumption for lower expense than generating the same power with solar panels.

Light you use frequently should be CFL (payback is under a year)
If your refrigerator is over about 12 years old a new high one should be cost effective
Caulking
Insulation
Water heater blanket
Pipe insulation
Pay attention to parasitic loads (ie always on TV's and computers)

Dropping your consumption is entirely equivalent to maintaining your consumption and generating some extra. Dropping you consumption will consume fewer dollars than going into the electricity business.

But hey its your money (Oh and some of mine via tax subsidies)

[Xringer]

Just about everything (within reason) has been done. I've been getting down to the last of the wall-warts.
One of the main reasons for this 'greenness' is the new Sanyo heat-pump that we just installed to heat our home this winter.
Sanyo 24KHS72 AC/HP DIY install project - EcoRenovator
With this thing running up the NStar bill, we need to watch all of our usage.


I was thinking of buying 1 or 2 of the K60 panels to charge 12V batteries.
I've been looking at the Steca Solsum 5.0C 5A 12/24V Charge Controller
and wondering if it will handle the high DC voltage from a K60 panel.

$ 123.96 for a 60 watt charger isn't bad and that should be enough
to meet all my hobby and backup-lighting needs..
It can charge two 12V batteries in series, which is nice..

With two K60s in parallel, maybe I could use it to take some of the DC parasitic load off the line.
Items that are on 24/7 and use 12VDC..

Anyways, solar PV isn't going to be a big investment right now.
But, playing with some small scale stuff might be a good learning experience.

[brucey]

If the output voltage on those panels are 60 volts how are you going to charge a normal 12 Volt battery?

[cfg83]

brucey -

Originally Posted by brucey

If the output voltage on those panels are 60 volts how are you going to charge a normal 12 Volt battery?

I don't know, but here is the charge controller he's talking about :

Steca Solsum 5A 12/24V Charge Controller - Steca Solar Charge Controllers(Pwm Type) @ AltE

Steca SOLSUM
PWM Charge Controllers
5.0C / 6.6C / 8.0C / 8.8C
12/24 V Systems

The Steca Solsum "C" model is one of the most sold charge controllers on the market. It is optimally suited for use in solar home systems with load currents of up to 10 A at 12 V/24 V and up to 240 Wp module output.

Max. module input short circuit current for the Solsum 8.8c is 8 Amps.

Here's the K60 :

K60 60W Thinfilm Solar Panel Pallet QTY 25 - Solar Panels by the Pallet @ AltE

Volts:  48 V
Amps:   0.9 A
Watts:  1500 W

Sooooo, it appears that the output Amps are well below the charge controller's tolerance, but I am not really sure.

CarloSW2

[Xringer]

If you look down at the bottom of this page, Solar Cell, Solar Panel, Solar PV, Solar Products, Charge Controllers, Solar Trackers - Kaneka 60 60W Thinfilm Solar Panel K60 (GSA-60)

You will see some chargers. I kinda like the one for "only $24.96", but I'm unsure about it's survivability when used with a K-60.
The other one I like is the $118.75 unit, since it does higher current & voltage..
But, it only 12V, not 12 & 24 volts..

I sent an email to the dealer (Solar Blvd) and asked them, so maybe next week I'll know.

[Ryland]

Originally Posted by brucey

If the output voltage on those panels are 60 volts how are you going to charge a normal 12 Volt battery?

to charge a 48 volt battery pack you need to get them up to 60 volts to equalize the batteries and my parents system is 24 volts altho the panels are wired to 72 volts with a maximum power point charge controller that drops it to 24v right before the batteries so they could use smaller wire under ground, it also allowed them to get more total watts out of the array.

[brucey]

Ahhh, that makes sense then. But then you have to buy a 120$ controller for a 100$ panel?

[Xringer]

Originally Posted by brucey

Ahhh, that makes sense then. But then you have to buy a 120$ controller for a 100$ panel?

In that case, it would be best to buy two panels and wire them in parallel..