Adding some solar to my greenhouse

[Chris1948]

First of all, glad I found this site. I've written to several solar panel companies, even those that I used to deal with when I was working and none have replied. I live in Central Texas, lat and long - 31.11°N 97.89°W (sorry if I have that reversed). I'll do the introduction here then ask my question(s) in the appropriate forum, not sure which one it is yet, but I'll find it . I'm 66, have lived here full time ever since I retired from the Army in '90 after 22yrs. After my Army retirement I worked on the Ft. Hood tank ranges for another 23yrs where we used quite a lot of solar panels in the last 10yrs or so to keep the batteries on the target equipment charged and retired from there in June of 2013. My main interests include reading, mostly science fiction, SteamPunk, and Techno-Thrillers; collecting antique and vintage glass such as depression glass, Early American Pattern Glass and cut glass. My newest hobby since full retirement has been plants. Prior to my 2013 retirement we'd bring all the plants we could into the house for the winter, that just wasn't possible anymore as I started collecting more and more and they kept getting larger and larger so last September we bought a 13X10X8 greenhouse for everything. I also picked up a small propane heater that I used over the winter to help keep the chill off and this is where my questions are going to come in. So my new friends, in what forum would I post some questions I have about using a solar panel with inverter to run a fan and possibly a few light bulbs inside the greenhouse?

Chris

[LETitROLL]

Welcome, as far as posting your upcoming questions, I would say either the General Discussion, or the Off Grid Solar threads would be acceptable?
(It sounds like you want your Greenhouse off-grid?) I will tell you now in case I do not see your future post, that they do make some good 12vdc, and 24vdc, etc. fans that would save you from needing an inverter (cost & reliability), but depends on your needs, we will save that discussion for your future question when there is more particulars about your needs.
have fun

[Mike90250]

Hiring a crew to trench 600' to your greenhouse, and installing a power feed to it, will cost less than even a small PV system and battery replacement.

If you want something to "play" with, 200W of PV, a 100ah deep cycle battery, charge controller and small pure sine inverter would be a useful starting point. Plan on replacing the battery every other year.

But pricewise and reliability, running power is going to cost less, or just grabbing a half dozen solar path lights.

[Chris1948]

I guess I was trying to do this the hard way. After doing some thinking today I've noticed that it's less than 100' from the back of my house to the greenhouse. I don't have an outdoor outlet but I wonder if I took an outdoor certified cable, ran it out of one of the rooms closest to the greenhouse, ran the cable through PVC in the ground to the greenhouse. I think that would more than likely be the cheapest way for me to go.

[russ]

Run the new cable from a breaker in your main panel - get electrical help and do it right

[Sunking]

Hire an EC

Hire an Electrical Contractor to run you a 20, 40, or 60 amp circuit from your Main Breaker Panel. A lot cheaper than solar both short and long term. You can shave some bucks off by digging the trench for the EC. Most likely the EC will use a contraption that looks like a big Rotor Tiller that will trench and bury the cable at the same time in a hour. A Green House needs real power and solar will not cut it.


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[Chris1948]

Thanks Russ and Sunking, I'm beginning to quickly realize that now. Thanks for all the ideas everyone, much appreciated.

Chris

[Sunking]

Thanks Russ and Sunking, I'm beginning to quickly realize that now. Thanks for all the ideas everyone, much appreciated.

You are welcome. I understand your passion as I am an avid gardener. I lived in North TX just on the north side of DFW area and had a Green House. Initially it may not seem like a Green House needs much energy, especially to a layman who really does not understand how much energy things in a Green House really uses.

I always start my tomato, pepper, melons and other warm season crop seeds day after Xmas. Well that take heating mates which are electric, and of course some propane heating. Dallas is really kind of an arid climate with low humidifier, and in a Green House requires a humidifier when using heat. Even in winter it can get too warm, and that requires a swamp cooler and ventilation. For AC power all those toys are fairly low power. A 100 watts there, 200 watts there, and another 100 watts over there. Added all up what any 15 amp AC circuit can handle day and night. But for the length of time they need to run like 24 hours adds up to some serious Kwh. I can use up to 10 Kwh per day, less than a dollars worth of electricity from the POCO. Probl;em is it cost some $3000 per Kwh or $30,000 to replace that with solar, plus a generator for those long cloudy spells we got in winter and spring.

Well I have moved, still grand a lot year round and do not need a Green House anymore in Panama. Everything I grow now grows year round down here. Seriously thinking of doing what I seen at Epcot Center Disney in Orlando, a fricken Tomato Tree as a canopy for the back porch. It is fricken awesome with a canopy diameter of over 100 feet. Wished I knew what variety they are using.

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[Chris1948]

I live here in Central Texas, 60 miles N of Austin and 60 S of Waco. Using my little propane heater on low most of the winter I managed to keep the temp right around 50 though there were several days I had to turn it up to medium. And, like N Texas we have really low humidity, I think most of the time it was in the 18% range according to the gauge I have in there. Of this summer, as you know being from Texas we have no Spring, most all the plants are outside except for a few like my African Violets and Orchids. What I plan to do for humidity is I have four large black tubs from Wal-Mart (I also grow my tomatoes in them) put one in each corner and fill with water and let evaporation provide the humidity inside. The only downside of getting a contractor to run wiring out to it is that the house is pretty old and I'm afraid the first thing they'll say is that all the wiring in the house needs replacing. That's why I was thinking of just running an outdoor 16/3 cable from the room nearest the greenhouse in some buried PVC conduit. It probably won't be a run more than 75' at the most, probably less.

Chris

[inetdog]

I live here in Central Texas, 60 miles N of Austin and 60 S of Waco. Using my little propane heater on low most of the winter I managed to keep the temp right around 50 though there were several days I had to turn it up to medium. And, like N Texas we have really low humidity, I think most of the time it was in the 18% range according to the gauge I have in there. Of this summer, as you know being from Texas we have no Spring, most all the plants are outside except for a few like my African Violets and Orchids. What I plan to do for humidity is I have four large black tubs from Wal-Mart (I also grow my tomatoes in them) put one in each corner and fill with water and let evaporation provide the humidity inside. The only downside of getting a contractor to run wiring out to it is that the house is pretty old and I'm afraid the first thing they'll say is that all the wiring in the house needs replacing. That's why I was thinking of just running an outdoor 16/3 cable from the room nearest the greenhouse in some buried PVC conduit. It probably won't be a run more than 75' at the most, probably less.

Chris

There is not much risk of an inspector requiring an upgrade of the whole house wiring system, but he would be justified in requiring that the wire that runs to the greenhouse be connected to your house wiring system originating at a safe point, such as the main breaker (fuse??) panel.
If you just tap into a branch circuit that runs on the side of the house facing the greenhouse you could get into serious trouble.
Probably the most important requirement would be that the feeder would have to be four wires, namely L1, L2, Neutral and ground/EGC. If the house wiring is old enough there may not be an EGC in any of the original branch circuits, and just connecting to ground rod or water pipe would not be safe.

An electrician will know (but not necessarily understand) those requirements and will produce something that is as safe as possible.

[Sunking]

The only downside of getting a contractor to run wiring out to it is that the house is pretty old and I'm afraid the first thing they'll say is that all the wiring in the house needs replacing.

They cannot do that. A dishonest contractor may tell you that, but no. Inspectors can only inspect what work was done. They cannot and will not say anything about any other wiring. If they did would open them up to thousands of law suits. They already inspected and approved what was done earlier. They cannot say what was done earlier is wrong now because you could sue them and make them pay for the upgrades. Trust me, been doing this for 35 years. They will not go there.

[Living Large]

I built a garage 100' from my house, and when I looked into the NEC, I seem to recall there were options for grounding and the kind of circuit. What worked out easiest and most straightforward, was to run a dedicated circuit on its own breaker. This setup relies on the ground rod in the main building, and there is no GFCI requirement for the circuit breaker. I was going to go 60A with a flat copper cable of gauge I can't remember (6 or 8), that would fit in a 1-1/8" grey plastic conduit, and an electrical inspector pointed out I could go to aluminum wire, the next larger gauge, and have a 100A service for about the same cost. I paid the guy $40 to come out first and give me advice, wired it as he suggested, and then he inspected it with flying colors. I guess I am saying a couple of things - but mostly get the advice/help of a professional - it is worth it.

[Sunking]

I built a garage 100' from my house, and when I looked into the NEC, I seem to recall there were options for grounding and the kind of circuit. What worked out easiest and most straightforward, was to run a dedicated circuit on its own breaker. This setup relies on the ground rod in the main building, and there is no GFCI requirement for the circuit breaker.

That would be the option afforded in 250.32. It boils down to if there is any common metallic connection to the two structures. What you did is install a basic 4-wire feeder, rather than 3-wire.