Some solar help at home
 

I've been messing around with some solar ideas around home for the last few months. I thought I'd share some of the things that I've started doing.

The biggest project that is almost finished is a small pv array.
I traded my little electric scooter for 4 older used solarex utility grade PV panels from a local aquaintance. I'm told they were originally off a library in Oklahoma city. They were 6 volt and 70 watts each when new. Age has degraded them closer to 60 watts and I figured out how to convert them to 12 volts. It was important to convert them to 12v so they would be compatible with the grid tie microinverter I had in mind (like this one Enphase Micro-Inverter M200-32-240-S02, MC4 cables) . I will probably buy one of these in the next few days. I found this model as cheap as $185.

Here is a pic of the 4 panels on the rack I made. The rack will soon be mounted on the south side of my yard out of all the tree shadows.

I was reading about solar drapes while researching my other big solar air heater project. Solar Heating Drapes, Solar heating drapes - Solar Electric

So I thought I'd try using some materials I had lying around on some windows that catch alote of sun.

Too bad I only have two small windows that face south.

In one room we use for storage I coverd a double window that faces east with some black plastic weed control fabric. Also, on the stationary part of my patio door that faces west I put up a big piece of leftover pet screen material that I used for the seat of my recumbent bike project. Both set-ups seem to warm up nicely when getting full sun. The weed control fabric doesn't allow a view though.

More to come when I get time :).

Very cool. I didn't know you could get inexpensive grid-tie inverters. Thats great!

Nice. Better than the old OK4U inverters that disappeared years ago. I like the comm via the power wires. Too bad this comm technology isn't used more in other applications.

I ordered a grid tied inverter yesterday. Need to paint the solar rack and then place it outside. Then I can start hoping for some sun :(, haven't seen much sun here lately.

The solar air heater I plan to build is like the one shown in this link.
atlanticenergy.ca > projects > Wayne Langille - Solar Air Collectors

I have bought all the materials except the glazing material. I'm having trouble finding cheap, light, and heat resistant material. I'm thinking of using the corrugated polycarbonate roof panels. Tuftex Polycarb, 8' x 26", Clear Polycarbonate Panel, V
My local hdw has this stuff for that price, but they won't order less than 10 items and I only need 2. All the other home improvement stores can get it only in wierd sizes, like 3ft wide or 7 ft long, and thier prices are quite high.

I haven't had time to start building it yet anyway. I'll figure something out.

Holy cow thats an expensive solar air collector. I'm much more partial to this design:

Build a Simple Solar Heater

Very cool project!

I agree it is expensive the way they show it. I'm definitely not spending anywhere near as much as they are showing :eek:. I looked at many diy designs and this one stands out for me. It seems well researched and developed with great performance.

I'm just going by the basic design. I'm using things I already have, or I substituted certain materials for cheaper easier to get items. I'm using a wood frame instead of aluminum and hopefully getting a much cheaper glazing. My foil faced insulation was way cheaper too. I will be using a fan from one of the many I already have, and come up with a controler from stuff lying around. I found 3" flex aluminum duct for cheap. My cost isn't going to be anywhere near what they list. I estimate around $150- $200 in the end, depending on glazing.

I recieved my new Enphase inverter on monday. It is very well built and so far I'm very happy with it. I have pretty much figured out how I"m going to lay out the system. I just need to get some wire and finish painting the wood frame pv rack.

If you decide to use plastic glazing be careful about thermal expansion. I had a window pane addition project unravel due to this issue.

Cool project :)

Thanks for linking that Enphase inverter :p

It's got the wheels spinning on alternative uses :D

I suspect that your 70 watt panels still put out 70 watts, there isn't any sign of aging that I see from the photo, even our 25 year old panels put put nearly the rated output.

I have been looking into the Enphase set up for a few months now. I have several used BP panels that I would like to put to use. The problem is that they are different wattages. If my understanding is correct though the Enphase micro inverters don't care what the individual panels are rated at. What I am still a little confused on is the Enphase EMU. Did you need one with your installation? Is it required?

I've heard of one system where the owner rewired his four panels to make the total
output voltage look like just two panels. So, he only needed 2 Enphase inverter units.

You really don't need the EMU, but it's a real nice gizmo to have.
Each of your Enphase inverters has a built-in AC-line communications device.
Each inverter can send it's status info (via 230VAC lines) into the EMU.

That status info tells you how well it's PV panel is working. How many watts it's producing.

The EMU has a network socket that you can plug into your router or directly into your PC.
Allowing you to read-it-yourself, or pay for an on-line Enlighten monitoring service that will
store status/power history data on-line.
ART TEC - Solar Power - Real Time performance stats

Go down the page and click on '7 Days'.. It's neat software..

What are the working voltages of your panels? If they are a high enough voltage individually to be compatible with one of the Enphase inverters, then It would be OK to put then in parallel as long as they are all the same voltage and the combined power is within the specs of the inverter. If they are lower voltage, It probably wouldn't be a good idea to put panels of different wattages in series to increase voltage. Mine are each 12volts and are all in series to make 48v (which my inverter likes), but are all similar wattage. The max current of my array is also within spec of my model inverter. I don't use the EMU, I rigged up a Kill-A-Watt to keep track of power production. Check this thread out for more info on my set-up. my diy pv set-up - EcoRenovator

Enphase is doing well during these hard times..

Enphase Energy Ships 100,000 Solar Microinverters

"[October 05, 2009]

Enphase Energy Ships 100,000 Solar Microinverters
PETALUMA, CA, Oct 05, 2009 (MARKETWIRE via COMTEX) -- Enphase Energy, the leader in solar microinverter systems, shipped its 100,000th unit in September 2009, reaching this remarkable milestone just over a year after the product's launch in July 2008."