View Full Version : Solar power for fun (and profit? ) Charging up your EV

08 September 2010, 1753
The Mission,
To run 1/3 to 1/2 half of the house and charge the bike (and now the ZAP!!) with off grid Solar power at a reasonable price.

Some of this information may be redundant, but note worthy.

The Parts:
6 - Evergreen ES-A-195-fa2b solar panels mounted on a Shed 80 feet from the house.
3 - 30 amp Sun Force 12 converter/ battery chargers
8 new Duracell 6 volt 220 AH golf car batteries set up in 12 V strings
6 used Exide 6 volt 200 AH golf car batteries set up in 12 V strings
1 - SunForce 2500 Pure Sine wave inverter
Lots of size 4 welding cables connections

Each of the solar panels put out over 13.5 amps of 13+ volts through the converter/chargers. That is over 80 amps of battery charging power!

So why are these on the shed and not in the house? No permits were needed and I did not want the batteries in the house or garage.

So why did we not do grid tie in system? The inverter/cutoff for that setup is much more expensive and we can use both the solar and grid systems as back ups for each other.

Cost rebates.
30% of the project will be paid back by the Federal government.

25% of what is left will be paid back by the SC government

We installed the NEW Sun Force 2500 watt unit (Thanks Terry!!) today and we turned on ALL of the items we had wired into the system.

These Items are OFF grid, but can be but back on with a flick of a switch.

35" LCD TV
Satellite Dish
Dvd player
Kitchen lights.
Kitchen Sink Light.
Dining room light
Fish tank pump
Fish tank air
Fish tank heater
Living room light and ceiling fan at full blast
Bed room light and ceiling fan at full blast
Bed heater
Bed air pump (sleep number bed)
Main bathroom lights
Guest bath room lights
2 clock radios
phone chargers
EV bike charger
RV battery charger (batteries and refrigerator)

Total - 1916 watts. Right where I wanted to be.


Question? Ask away!!!!


08 September 2010, 2157
And I still have shed envy........

09 September 2010, 0222
Start off small....got a dog house?

10 September 2010, 1658
Just a baby shed. Just received a pair of 225W panels at 7PM today!:D Will be making a ground based mount next to or leaning against my small shed. As you said, better to start somewhere than wait.....

10 September 2010, 2022
Great....need photos!!!!


12 September 2010, 0429
Changes since the original post.

The RV batteries and refrigerator had to be changed to a small separate battery charger only. The system was getting drained down too much during extended cloudy days.

We thought it was the refrigerator, but it turned out to be the charger/inverter unit when it kicked in. It makes for a very inefficient stand alone charger.
So we added a 12V 6 A Guest water proof charger and now all is well!

11 November 2010, 1710
Pictures of my solar panels. Now feeding 460W to my house.....
(Picture taken tonight at sunset and shown in summer inclined position.)

11 November 2010, 1720

Um...who is the infidel in the photo trying to steal all of your new found power?

Great stuff!!

11 November 2010, 1727
My little brother was helping me mount the panels today. Pretty low on the food chain, but not quite an infidel......

11 November 2010, 1751
So, that picture was taken around 7PM? It's pitch black here at that time. Still, I do want to get myself a couple of panels this summer. If I got enough batteries I could store all the power until winter. :D

11 November 2010, 1818
My little brother was helping me mount the panels today. Pretty low on the food chain, but not quite an infidel......


No disrespect intended.... :):):)

11 November 2010, 2234
I took the NABCEP EL certification (http://www.nabcep.org/) and learned how much partial shading drastically reduces a panel's output. Inside each panel is a string of individual cells. Panels are then connected in series strings (sometimes multiple strings but there are strings nonetheless). So you've got a series of series cells. Partial shading on one cell can almost take out the entire array. Micro-inverters help isolate the power cutout, but the shaded panel is out regardless.

Ed - the satellite dish looks innocuous enough, but for a good portion of the day it's disabling at least one panel (or the entire array if you don't have micro-inverters). It'll be especially bad in winter months when the sun is lower. If you want to prove it to yourself, get a kWh reading with and without the dish. Unless your tree line is blocking the satellite, I'd recommend moving the dish below the solar panels.

Rob - the fence will take out your panel(s) for probably half the day. It looks like you might have trees close by that will also shade the panels.

To the layman it might not seem like a big deal, but [partial] shading is a big deal with solar PV. A solar pathfinder (http://www.solarpathfinder.com/) is an invaluable tool will pay for itself in energy return. With one glance you can easily see where the sun & shade will be at any time for any month.

11 November 2010, 2328
Thanks for the insight. It was moved a while ago. It is an older photo.


12 November 2010, 0922
I like trees - they look nice and they keep my house cool enough in the summer that we only use the A/C about twice a year.

I hate trees - I can't get a solar array at my house


EVCycle - I'm impressed with your setup. Just out of curiosity - what did it all cost? (tell me to pound sand if you don't want to answer)

Chef - Thanks for confirming that I shouldn't even bother with solar pv. I suspected this was the case - but I didn't know for sure.

12 November 2010, 1136
A pound of sand? :):)

$4300 before rebates (we did all the work). That is for Batteries, Solar panels. Hardware, controllers/chargers, wire and inverter.
$2650 after rebates. It should pay for itself in about 6 1/2 years.
Last months electric bill from the "Grid" people, $121 Normally (Before the solar add on) it is around $180 since we have electric AC/Heat.

12 November 2010, 2302
jdh2550 - I'm in the same boat, "too much" shade around my house to qualify for the local rebates which are substantial. About half the day is shaded thanks to a 4-story tall ash tree on the south facing side. I'm hoping to find another spot in the yard for a small array but there's too many trees even after clearing out many of the old rotting ones. On the bright side, trees reduce AC consumption by 25-35%.

Generating one's own power is way cool. For now though I'm content buying green energy from the wind farms in west TX. The capital expenditure for solar PV is pretty steep. I just looked at this month's power bill and I can barely believe the rates -- 7c per kWh for the first 500 kWh. That seems lower than the last time I checked (if memory serves me correctly which isn't something I can count on these days).

Sand... it's what silicon PV cells are made of ;)