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Solar powered greenhouse fans — The Grow Network Community
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Solar powered greenhouse fans

Marc ThomaMarc Thoma Posts: 77 ✭✭
edited September 2018 in DIY Tutorials
great idea and great job!

from a photovoltaic engineer :) At our last house we had 54- 175 watt solar panels (installed back in 2004) powered the entire house and all of my growing operations.

Heather

Comments

  • StacyLouStacyLou Southern WisconsinPosts: 89 ✭✭
    edited September 2018
    Awesome! We have a bunch of those fans - now I know what we’ll use them for once we get a greenhouse!
  • peppypoblanopeppypoblano Posts: 92
    edited September 2018
    I like this idea.  We have a spare solar panel and have been trying to figure out what to do with it.  Thank you for sharing.
  • Marc ThomaMarc Thoma Posts: 77 ✭✭
    edited September 2018
    Bonus is we can charge our devices for free from inside the kitchen (it took some guts to drill a hole from the outside to inside!).

  • Marc ThomaMarc Thoma Posts: 77 ✭✭
    edited September 2018
    Batteries will be the next acquisition so we have power when the sun doesn't shine.
  • H_DH_D Posts: 384 ✭✭✭
    edited September 2018
    how many solar panels do you have?
  • Marc ThomaMarc Thoma Posts: 77 ✭✭
    edited September 2018
    Just the one 40watt panel for now. It just barely meets the needs of my greenhouse fans and charging an iPhone or iPod touch at the same time.

    When my local hardware store (Canadian Tire) has two 100watt panels on sale again, I'll consider getting two. But then I'll really need to get batteries as well!
  • H_DH_D Posts: 384 ✭✭✭
    edited September 2018
    Thats a great plan Marc..keep us posted on your progress
  • Marc ThomaMarc Thoma Posts: 77 ✭✭
    edited September 2018
    I've now posted a more in depth article on my blog for my setup. Admins, would it be okay if I post a link to it?
  • bmaverickbmaverick Posts: 175 ✭✭✭
    edited September 2018
    Marc,

    Nice work!  Love the solar use in the DC realm.  Why? because you get more power and lower costs for a DC solar setup.

    Our last farm in Nashville-TN was run off all DC powered solar.

    Now, I have not made any green house yet.  So PLEASE blog here your work.  I did bring up to southern WI all my solar gear.  The panels are the ones used on the Space Station made by the original UniSolar Corp that later got absorbed by Kyocera solar.
  • Marc ThomaMarc Thoma Posts: 77 ✭✭
    edited October 2018
    Here is the link to the article: https://tranquilgarden.ca/free-greenhouse-ventilation/

    If you have any questions about the setup that is not covered in the article, let me know. ?

    Eager now to get some batteries - just debating whether to go with regular deep cycle lead acid or lithium.
  • H_DH_D Posts: 384 ✭✭✭
    edited October 2018
    that depends on your needs..saltwater batteries are better for the planet, environment and less chance of an "accident" during maintenance of traditional lead acid batteries
    for those wanting to know the different kinds of batteries to use with a solar system
    Lead acid

    Lead acid batteries are a tested technology that has been used in off-grid energy systems for decades. While they have a relatively short life and lower DoD than other battery types, they are also one of the least expensive options currently on the market in the home energy storage sector. For homeowners who want to go off the grid and need to install lots of energy storage, lead acid can be a good option.

    Lithium ion

    The majority of new home energy storage technologies, such as the , use some form of lithium ion chemical composition. Lithium ion batteries are lighter and more compact than lead acid batteries. They also have a higher DoD and longer lifespan when compared to lead acid batteries. However, lithium ion batteries are more expensive than their lead acid counterparts.

    Saltwater

    A newcomer in the home energy storage industry is the saltwater battery. Unlike other home energy storage options, saltwater batteries don’t contain heavy metals, relying instead on saltwater electrolytes. While batteries that use heavy metals, including lead acid and lithium ion batteries, need to be disposed of with special processes, a saltwater battery can be easily recycled. However, as a new technology, saltwater batteries are relatively untested, and the one company that makes solar batteries for home use (Aquion) filed for bankruptcy in 2017.
  • H_DH_D Posts: 384 ✭✭✭
    edited October 2018
    Marc
    When we moved from NJ to NC we brought all our panels too..they were initially installed 15 years ago and when we took them down and tested their energy output they were still at the same watt/amp output they were when we recorded them being installed, no degradation at all so re-stringing them won't be an issue. That was 54 Solar World panels..then we had 70 or so BP solar 200 watt panels still in the shipping boxes..one day soon my entire life will be solar powered again :)

    Its sad that panels unfortunately have not evolved in technology since the 70's maybe some more output but the technology has not changed (or at least what us consumers have access too)

    Heather
  • Marc ThomaMarc Thoma Posts: 77 ✭✭
    edited October 2018
    Thanks for the info on the batteries - will have to do some more research!

    New technologies in panel composition are constantly being made, so I am quite confident efficiency will go up as well as the price going down. And hopefully one day we will simply be adding solar to every new roof in new construction and re-roofing without thinking twice about it.
  • H_DH_D Posts: 384 ✭✭✭
    edited October 2018
    Marc,
    Ive been saying those same things for almost 2 decades..full disclosure.. I am/was a photovoltaic engineer, ran my own EPC for over a decade and was involved with the legislation and rule making for the NJ Renewable Energy program on both the photovoltaic and energy efficiency sides...even when places like New Jersey made deals with solar panel manufacturers that if NJ installed and implemented a solar rebate program that eventually the prices would come down that was back in 2003, the rebate program went from paying a $5.30 rebate per watt installed to $1 per watt and I dont think its even offering rebates anymore (i left the program and closed my business in 2012 because the program rules changed on a dime and you simply cant run an efficient business that way) and panel prices have come down somewhat we used to pay wholesale $5 per watt, now I think I can still get them for about $1 per watt but have not seen good quality panels lower than that in a long time.. they havent come down enough though, not a rate that is equal or less than what you pay to install traditional electricity. Its all bureaucracy bullshit
    Ive rattled enough lol
    heather
  • bmaverickbmaverick Posts: 175 ✭✭✭
    edited November 2018
    Marc, I've had so-so luck with Deep Cycle batteries over the past 15 years.   Prior to 2000, they were made with better materials and technology.  Today, they are higher price and cheaply made.   This is for the Groups of -31, -27 and -24.  AND not all deep cycle batteries are the same either.   These batteries hate temps below freezing.   Below freezing kills these types of batteries.

    AGM batteries are a bit better, but you have to spend much time looking for a great deal of Ah and size.   These are a little more forgiving at colder temps down to 24F.

    As for lithium, these are great for colder operating temps, best for recharging, BUT prone to their own issues.  Heat is a BIG issue.  And water is another BIG issue.   Also, I've looked high and low for devices to recharge them that don't cost and arm-n-leg.   I've talked with a few electrical engineers at work.   With using those 3Ah Dewalt/Black-Decker lithium rechargeable batteries, using an H-bridge and some other electrical components it can be stepped down to 12VDC.  Some call this a DC-DC converter.  eBay and other places sell those too.   Depending on those fans for Ah load at 12VDC, these batteries could last a few days before recharge.

    The very best batteries to have are Edison batteries.   However, they cost sooo much, but last 50+ years, can over charge, can drain them down to 2% and recharge back to 110% with no issues zillions of times.  There are instructions on the web on how to DIY make them too.
  • bmaverickbmaverick Posts: 175 ✭✭✭
    edited November 2018
    Heather, that is so cool you're into the engineering with solar.  Looks like we have a great resource from you to ask questions. :)  I'm just an Electro-Mechanical Design Engineer in mobile climate control systems.  Thus, a great deal of my background is in 12, 24 and 42 VDC systems.  I've dabbled in 120 & 240 VAC HVAC roof top units at one job for 1/2 year, but it was sort of like learning a whole new language.

    You are so right, solar panels sold to the average person have not really progressed in technology.  We read about article published by universities all around the world with new materials and better power generation, but nothing seems to make it to the market place.   And the best panels I have ever owned came from UniSolar.   They use triple junction technology.
    http://uni-solar.com/uni-solar-difference/technology/index.html
    http://uni-solar.com/contact-us
    Now, it's inventory is just AMAZING .... https://en.wikipedia.org/wiki/Stanford_R._Ovshinsky
    Today we take so much for granted of what this man brought to our world.  Some say he was the Edison of our era.  He made batteries more earth friendly too.   What is wild is this ... Ovshinsky is also distinguished in being self-taught, without formal college or graduate training.  Without him, we would still be using computer technology from the 1980s.  He is the inventor of the rewritable CD/DVD optical devices.  It was his technology that cave us LCD flat screens for smart phones, laptops, tablets, etc.  This technology that is non-silver based was the foundation to lower cost and high energy gathering solar cells. Even the flexible types!  He is best know as ...
    Environmental Hall of Fame 2008 Award, Solar Thin Film Category, Father of Thin-Film Solar Energy
  • Marc ThomaMarc Thoma Posts: 77 ✭✭
    edited November 2018
    Thanks for all the additional info on batteries and solar panels. Now that I am officially urban homesteading (my blog has been rebranded as such), solar and wind power is very interesting to me. I eventually hope to get a Tesla Powerwall but those are obviously pricy and not as available yet as we'd like, especially here in Canada.

    As with everything battery technology will change and improve. Especially now that Battery Electric Vehicles (BEV) are becoming more popular. We are leasing a 2018 Nissan Leaf and loving it. If I could charge the car with solar during the day and then dump that power back into my house at night at least for lighting, I'd be really happy. It's coming and some enterprising DIYers are experimenting with ad-hoc ways of doing it.

    For now I'm just happy to have the solar power in summer to keep my greenhouse cool and charge up my iDevices when the sun does shine, even in winter as it is right now. ?
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