Thursday, March 29, 2012

Solar Air Heater

This is a picture of the 24x4 foot solar hot air collector that i fabricated from gutter downspouts, common lumber, foam board insulation, and some corrugated glazing material.  All of these items were purchased at a local big box type lumber store.  It is essentially a dual pass hot air system that runs the length of the collector (within 4 gutter downspout tubes) and than enters a plenum where it turns and makes another 24 foot pass before entering the home through insulated ducting.

You can see the downspouts and the plenums in the close up image.  I use an in line radon mitigation fan that is actuated by a thermal snap disc inside the collector.  When the collector temp hits 110F the snap disc closes and turns on the fan and will run the fan until the temp in collector hits 90F.  The radon fan is centrifugal and is quite powerful and rated at 140F.  (

I keep this system up and running from late September into April.  It is piped into two floor registers in different areas of my main living space.  It regularly runs at 120F output and will generally run 6 hours per day, when sunny.  Of the three systems i have (PV, Thermal, Air) it is the least prone to shading effects.  This system combined with a high efficiency wood stove provides roughly 95-97% of our heating needs in the mtns of WV.

Thursday, February 23, 2012

And than came the panels

I obtained these panels from a company called Sun Electronics out of Miami Florida at $0.78/watt, which is a very good deal.  I payed about $1900 (with freight) for 10 panels at 2100 watts.  I should have bought 10 more at least now that i think about it.  The panels took several weeks to arrive but i was patient, especially at that price.  These are Evergreen ESE 210W panels that are rated to work with Enphase Microinverter systems.
I met the freight driver in town (we live on a narrow dirt road) and loaded the pallet on a trailer, which weighed about 460 pounds.  I was careful to inspect these panels as best i could before signing the shipping invoice.  THIS IS IMPORTANT.  Nonetheless, the panels were beautiful and i was excited to have them in my possession.  They seem very well constructed and are impressively large in size.

I formulated a plan to mount these and asked a friend to assist on probably the coldest sunday of the year, but hey, i was anxious to get them on the mounts.  Unfortunately he was running late so i got to work on my own.

I first installed the Enphase M215 microinverters which i found online for $150 a piece with free shipping.  I bought 10 to match my number of panels.  These are very nicely built with good efficiency ratings to boot and they have a 25 year warranty, which matches the warranty on the panels.  So this system is built to last!
I installed the microinverters and all the bolts for the panels and jumper/bonding cables, which all came together very well.  The ironridge system is very nice and easy to work with.
I heeded Gary's advice and made a board system for the bottom of the mounts to hold the panels while i carefully lined them up.
Once i felt strongly the first panel was squared up and in place i began adding panels.
The panels went on very quickly and and suprisingly easy once the first one was set up really well.  I did this alone in about 2 hours at most.  It was fun and painless.  The panels weight about 45 pounds each.  I torqued all the bolts to specification, using the WEEB grounding washer system.  I used a copper strand through all the microinverters and tied these to two grounding rods spaced 6 feet apart (inspector requested two rods).
I cut the rods off at the ground after pounding them in as far as i possibly could (about 7 feet each).
 looking 180 degrees south.
Here is a picture from my back deck, with the drain back solar hot water heating system in the foreground to the right.  The trencher helped with the 100 or so feet i had to dig to bring the 1.5 inch conduit to the house. It is 18 inches deep in conduit (per code).  I think they look pretty nice out in the field.

Building the PV Mounts

I found the panels i wanted for a really good deal (more on this later) and located specs on the internet to gain dimensions for the panels so i knew how big my ground mount would need to be so that i could get started.  So i got to work digging and setting posts.
luckily my ground is nice and loamy and made for easy digging (all 14 holes).
  I soon had something that looked like this.  All posts in concrete, and i tied them together with 2x4's on either side.  I was very careful to get the angles and posts very straight and consistent, which wasnt terribly hard but did take some time and thought.  Tilt angle is about 38 degrees, our latitude.
I than installed the Iron Ridge racking system, which went on quite well.  I made sure the rails stayed parallel to one another for the length of the mounting system.

Site Survey and Beginning Stages

I knew that i wanted to do this and thought of a couple options for location, one being the roof and the other being a ground mount to the west of my house.  I opted for the ground mount due to aging roof and not wanting to have to mess with taking the system down at a later date.

So i began by doing a solar site survey for the area i thought would be best for the ground mount, and it turns out it was a good choice.

 Here is my setup facing 180 degrees south with all my site survey tools at hand.  this was easy to do.

The area below the plotted line with the highlighted lines represents shading.  Shading is bad.  I will get minimal early morning shading due to a couple locust trees to the south east of the array.  This shouldnt cause too much problem and will only occur in the weeks surrounding the winter solstice, when the sun is lowest in the sky.  Trees can always be removed if need be, but id rather not do that right away if it doesnt pose a problem.  I will keep a close eye on output.  This is easy to do yourself by hand and teaches you a fair amount.  This link is all inclusive on doing this yourself:

So i have my site picked out, time to get to work.

Here is the 2.1Kw Solar Electric system I installed with basic tools and minimal electrical knowledge

Before deciding to take the plunge on designing and building your own solar photovoltaic (PV) system, it is best to try and reduce your electricity usage as much as you possibly can.  There are a number of ways to do this including insulating your house very well, putting electrical devices on power strips or timers, or simply (and most importantly) paying attention to what you are doing.  The following link will help you take hold of some of these things and ultimately, im sure, will help you lower your electricity usage.  You will see me reference this site a lot, basically because it is the best solar diy resource i have found on the internet today.

 This is a "kill a watt" meter, it allows you to see what an appliance is using electricity wise and gives projections for total cost for electricity usage for that appliance for hour/day/month/year.  You program in your kwh rate based off your electric bill.  This is well worth the 30 bucks it costs, especially if you are just getting into energy savings.

IT MAKES SENSE TO SAVE ELECTRICITY.  (and why might that be?)

Well, for some, it might be because they would feel good if they were able to do something environmentally conscious and reduce their impact on the natural world.  For others, and likely the majority, it makes sense economically.  WV is fueled primarily by coal, and yes, it does keep the lights on.  But the problem is, coal is non-renewable, meaning there simply is not enough supply for the demand we are putting on it. What this means to customers of the electric company...rising electricity costs.

Plain and simple, we only have so much coal and the prices obviously are continuing to rise.  The sun will rise and fall daily as it has for eons.  Why not harness some of its free and clean energy.

Here is a little more tell tale evidence that we can continue to expect electricity rate hikes as demand continues to increase and supply continues to decline.  As you can see, we have become somewhat greedy with coal, trying to get it while the getting was good.  Unfortunately, the getting isn't always going to be good.