New system on the horizon...

      Okay, so I am coming into a bit of money I didn't expect. Which is great! Sadly though as is the story of my life... it enough to get a good start but not enough to get it done. Which means I will have to do things in piece meal again.

      But that's not the reason for this post! No siree Bob! This post is to talk about a new system I will be building for the cabin and eventually moving to the main house. If you have read my other posts you already know what I have in place right now. But this new system will be a 24VDC system (increase efficiency of the system overall) with a custom fridge and DC water heating.

      I have been shopping around for a DC refrigerator for some time now and while I have found some great fridges out there... I can't afford them! So in my searches I found this link:

http://www.raycotechnologies.org/build_your_own_battery_powered_r.htm

      And since I have an AC fridge already as well as the majority of the materials I need to build with... why not? The great thing is I have an HVAC technician that is going to help me with sizing the refrigeration components that work with 24VDC current. The fridge I have is a 19CuFt. Kenmore so I have to have enough capacity to maintain 35F. And that's where my friend / co-worker will come in. right now I am looking at a Dan Foss compressor (actually 2 of them) one will be set for lead and the other as lag.

      More on the refrigeration set up in a bit, I want to focus on the power side of the house. So to power this up I will be investing in two Suntech STP180S-24/Adb+ 180W 24V Solar Panels from the AltE store. That will give me 360W of power production there. The next element will be a 600W 24V 7 Blade Raptor Wind Turbine. Since where I live is literally the prime place for both solar and wind it's a good fit.

      The batteries will be Trojan T105 6V 225AH and I will have a total of 8 set up in series / parallel so I will have a total of 450AH capacity. And as a load diverter as well as a more efficient means of heating water I will use a 600W 24VDC hot water heating element. The wind turbine and the heating element will be purchased from Missouri Wind and Sun and the batteries will also be purchased from the AltE store.

      How the system will be set up is pretty simple. The wind turbine and solar panels will be installed to charge the batteries, the how water element will work as a load diverter in the event I am producing more power than the batteries can handle. This will prevent the batteries from being damaged. So my load characteristics will change.

      On top of my existing loads I will be adding my custom made refrigerator and a hot water heating element. But I will also be adding to my charging capacity with the wind turbine. Which is perfect as during the winter months solar is a bit of a bust. But during the summer it's perfect and wind is minimal. Now the whole reason for using DC on the refrigeration and water heater is to save money long term. Right now our current refrigerator is propane fired and only about 7CuFt in size. And one issue we have run into is that when the propane runs out we sometimes don't notice it until just about everything is defrosted and warmed up. Not a very healthy or efficient way of keeping food cool and fresh. The other problem is the cost of propane is prohibitive! Right now based on my usage tracking and cost analysis we are spending about $200.00 a month in propane for refrigeration, heating water, cooking and space heating. Now that may not seem like a lot to you... but to me, it's too much especially with times being tight the way they are.

      I figured out that with the DC refrigeration and water heating we will see a pay-back on our investment in about 28 months. Now that may seem too long. But in the world of cost efficiency it's not, especially when you look at the fact that the payback time is when the system will have paid for itself in propane sales not made. After the payback period you are ahead. And since the solar panels I have opted for are rated with a 12-18 year life expectancy I will get far more production out of them than my payback. Next the wind turbine is rated to survive about 5 years, again I will see over 2 years of production AFTER payback has been made. And the life span is theoretical, it could be longer or it could be shorter (which means it will take longer to see my payback).

      Next the batteries I have selected are also rated for about 5-7 years, but with the fact I am always on top of my battery maintenance and the fact that with the combined sources of power, the batteries will rarely be driven past 70% which translates to longer life spans. There are two families close to where I live that are using the same batteries I will be using and they have both exceeded the life expectancy of the batteries by 1 year and 19 months respectively. So again, the payback is well worth it.

      Okay now the home made refrigeration unit. So talking with my HVAC mechanic I will have to look at the current compressor in my refrigerator and see what the BTU rating is on the existing AC compressor then match that to a comparable 24VDC compressor. Right now we are looking at a Dan Foss BD350GH model 24VDC compressor. We believe I should be able to use the existing condenser and evaporator so that will save me some $$$ right there. I will have to get 24VDC fans for cooling as well as a 24VDC LED for the interior of the fridge. I can use existing extra wood and insulation we have on our property to increase the outside insulation aspect of the refrigerator. This is crucial as it will increase the efficiency of the system over all and prevent excessive run times on the compressor.

      Hopefully in my next post I will have the final fridge design and components list available for anyone that reads this. Peace, Love and Led Zeppelin!