Getting my feet wet with a small scale solar project.

Our "pub" where you can post about things completely Off Topic or about non-silent PC issues.

Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee

Post Reply
aristide1
*Lifetime Patron*
Posts: 4284
Joined: Fri Apr 04, 2003 6:21 pm
Location: Undisclosed but sober in US

Getting my feet wet with a small scale solar project.

Post by aristide1 » Wed Nov 14, 2012 2:18 pm

Rains the last few summers have resulted in far more cellar moisture than before. I added a dehumidifer and promptly noted increased electrical consumption, quite a bit for what used to be my cheap months. What's a viable alternative? Well I can run a fan to vent the cellar, but how do I control it?

So my first thought is a small solar setup without batteries, run the panel directly to some 12 volt fans. That won't work, voltage from solar panels is AOTP all over the place. Even if a panel has an 18 volt max hooked up to a 24 volt fan (fairly common) the panel may produce less voltage than required to make the fan spin, but sill feed it to the fan which would produce nothng but heat after any length of time.

OK, so step in the charge controller, the device that converts solar cell output into a more useful format. Huge voltage swings can be regulated to produce voltage to charge 12, 24, 36, or 48 volt batteries, meaning they produce a little more than the battery rating itself. You can connect loads to some of them, and it would be inexpensive to have the controller simply power the load in daylight and to not bother with the battery (I don't need or want these fans running after dark.) But it doesn't work that way, charge controllers require batteries.

The only option over a charge controller, which few would be aware of, is the PICO PSU. The lowest cost one has a max of 8 amps on the 12 volt line. This would run my fans, but not much else.

----------------------------------

Stage 2 of my project would be to vent the attic as well. There are some self contained solar attic vents, most commonly the 10 and 20 watt sizes. They are feeble. There are 30 to 50 watt units available, they can be quite costly. None are very long term oriented, very high durability. Other attic fans of interest would be the smallest from Jet Fan US. It comes in under 200 watts but is AC. This could be powered by a small inverter.

There's really no such thing as a solar power inverter, they just can not accomodate huge voltage swings so charge controllers are still be required. Like the cellar fans I really don't need to run them if there's no sunlight, and hence I really don't need the batteries, but the charge controller makes that impossible.

-----------------------------------

Having a battery backup, even without the extra cost of an inverter, allows to 12 volt lighting, LED or flourescent, which frankly would not really pay for itself, but would add convenience. This is viable for the rear entrance to my home, since it doesn't have any lighting now and it really should.

-----------------------------------
Other passing thoughts:

It's a shame the charge controllers can't do their thing without the batteries. I would not have minded a 1000-1500 watt setup that would create AC only on sunny days to power an air conditioner. Large storage amounts to many batteries, very large gauge cables, added complexity.

I'm not overly impressed with large gridtie systems, the power you sell back to the power company is purchased at a far lower price than what you pay to buy it from them.

Boy there's a lot of crap out there, and by that I mean inverters and other electrical equipment that is not UL approved. I already own equipment that's not UL approved, but all of it is high end audio and built like a brick outhouse. No UL rating becomes an issue if there's a fire in the home caused by non-UL approved equipment. It may give an insurance adjuster a reason not to pay a claim. The super cheap inverters, without any seals of approval, well I wouldn't want to use them anywhere near their maximum rating. And I don't want any inverter that's relying on a 50 cent 12 volt fan for survival.

Vicotnik
*Lifetime Patron*
Posts: 1831
Joined: Thu Feb 13, 2003 6:53 am
Location: Sweden

Re: Getting my feet wet with a small scale solar project.

Post by Vicotnik » Wed Nov 14, 2012 2:40 pm

Me and a friend have a slow "produce you own power" project going. It's very basic and we plan to use mainly stuff from the recycle bin, so progress is very slow. We will probably use wind, not solar.

Anyway. We (or my friend, rather) will probably build a simple charge controller from scratch. They are not that complex are they? The simple ones are not that effective though; perhaps not enough for your needs?

andyb
Patron of SPCR
Posts: 3307
Joined: Wed Dec 15, 2004 12:00 pm
Location: Essex, England

Re: Getting my feet wet with a small scale solar project.

Post by andyb » Wed Nov 14, 2012 4:29 pm

What is the cause of the moisture.? Is it water leeching through the porous cellar lining or is it washing machines and tumble dryers that are removing moisture from clothing that is causing the issue.?

If it is coming through the walls, would prevention not be a better solution than a cure.?

If the moisture is created in the cellar would it not be possible to have the excess moisture pumped out of the building.


Andy

CA_Steve
Moderator
Posts: 7650
Joined: Thu Oct 06, 2005 4:36 am
Location: St. Louis, MO

Re: Getting my feet wet with a small scale solar project.

Post by CA_Steve » Wed Nov 14, 2012 6:04 pm


aristide1
*Lifetime Patron*
Posts: 4284
Joined: Fri Apr 04, 2003 6:21 pm
Location: Undisclosed but sober in US

Re: Getting my feet wet with a small scale solar project.

Post by aristide1 » Wed Nov 14, 2012 9:12 pm

andyb wrote:What is the cause of the moisture?
It's multiple issues.
1. Last year or the year before our total rainfall was 25 inches above normal. That's severe. More moisture is working its way in through the foundation, not so much the walls but the floor. And I'm talking about overall dampness, not puddles.
2. The local public sewer system for our street is now overloaded, not only because of the extra rain, but because a large residential development up the road was added to our already heavily taxed system, it's overwhelmed on a regular basis.

I routed the water from my down spouts through some underground plastic piping I installed a while back. That was a marvelous change but the current rainfall is just nuts. I've filled in low spots in the lawn with more soil, and next year I will bring in a small truckload of top soil and put a slight slope on the soil away from the house. Given all that the solution with the lowest up front costs would be to simply install a gable fan in a cellar window on a humidstat, but if it's very humid outside it then runs for no reason. And I'm in a river valley, humid by nature.
andyb wrote:If the moisture is created in the cellar would it not be possible to have the excess moisture pumped out of the building.
I'm trying to mitigate the cost of running the dehumidifier. It runs mostly in the summer and adds heat to the cellar as well. And it's running a lot.
CA_Steve wrote:No access to a microinverter?
http://enphase.com/explore/enphase-technology/
You know that seems like an option. They're $200, about the same price as a 100 watt solar cell. No charge controller to buy, but it appears to be a grid tied inverter, whch means they require AC to synch up to so they can pump it back into the grid, else they won't ouput anything. So now we're talking AC home wiring and local codes. Add to that power companies don't like to discover their meters are running backwards, some may even haul you into court if they find out you're doing it in secret.

But the micro inverter strikes me as a strange option. It converts DC to AC immediately, which means there's no way to store it. The thing I don't like about selling power to the power companies is they pay only fraction of what they charge when they buy it from you.

Don't get me wrong I like the Enphase unit. If it wasn't grid tied it would be perfect for the attic application.
Thanks and keep the conversation going.

andyb
Patron of SPCR
Posts: 3307
Joined: Wed Dec 15, 2004 12:00 pm
Location: Essex, England

Re: Getting my feet wet with a small scale solar project.

Post by andyb » Thu Nov 15, 2012 12:06 pm

It was really concrete/brick waterproofing sealants that I was thinking about, but I assume that you have already done that. It also sounds like you have done a couple of the other tricks on the following guides as well, they are worth looking at regardless.

http://www.wikihow.com/Waterproof-Your-Basement

http://www.handymanusa.com/articles/drybasement.html

As far as moisture producing machinery is concerned I was thinking along the lines of products such as the following ones.

http://knowhow.com/article.dhtml?articl ... country=uk

A condensing Tumble Dryer will usually have a built in sealed plastic container that you simply take out of the machine and pour away when you have done a cycle, so all of the water from the machine is contained and does not become airborne, which has obvious ramifications for the air/moisture levels. My brother has one in his garage, you would not know that it waqs there, the air/moisture levels are exactly the same as the rest of the house.


Andy

aristide1
*Lifetime Patron*
Posts: 4284
Joined: Fri Apr 04, 2003 6:21 pm
Location: Undisclosed but sober in US

Re: Getting my feet wet with a small scale solar project.

Post by aristide1 » Thu Nov 15, 2012 12:39 pm

Andy,
As a winter project I should probably address the joint where the cellar floor and the cellar walls meet next. It doesn't sound like as much fun, but it would probably return the greatest benefits.

Another problem is that Drylock was painted on my cellar walls over 30 years ago, now it's falling off. I can't just paint over it, I need to remove everything that's loose.

Thanks for your input.
Aris

andyb
Patron of SPCR
Posts: 3307
Joined: Wed Dec 15, 2004 12:00 pm
Location: Essex, England

Re: Getting my feet wet with a small scale solar project.

Post by andyb » Thu Nov 15, 2012 2:35 pm

Good luck, it sounds like a project that is going to be hard work and almost certainly wont go smoothly.


Andy

Post Reply