Designing a solar UPS

[Lee72]

Hello All,

I just started a blog about a project I am working on since 2 years. My project is called "One Fridge off the Grid" and deals with distributed energy production. I am about to design a PCB that will have a ATMega2560 and various sensors on it - it will also have the Arduino Proto-shield connectors to be compatible with any other shield.

I am looking for feedback and suggestion about the usability for other purposes - maybe small modifications will open up new use cases?

I am also looking for beta-testers. If you have these items:

• Power Inverter 12/24V
• SLA Batteries
• Sharge controller 12/24V
• Solar panels

and if you are interested in receiving a test unit please send me an email!

And this is the link about the "bigger picture" of the project: http://solar-trap.com/?page_id=83

Looking forward to your feedback
Markus

[Mike90250]

Some smarts need to be integrated into the fridge.

Most new fridges, on power up, initiate a power sucking defrost cycle, heaters and all. WTF !

It would be GREAT to have a controller that could tell the fridge, the sun has set, and to relax the temperatures, so it does not drain the battery at night, and conversely, when battery is full, to power the fridge into a defrost mode while power is abundant, and then chill it a few extra degrees in preparation for the night. This should save a lot of power in the system.

[Naptown]

What Mike said makes perfect sense

[FloridaSun]

and if you are interested in receiving a test unit please send me an email!

Looking forward to your feedback
Markus

No thanks, I don't plug anything into my elec outlets that's not UL listed.

[Mike90250]

....
I am also looking for beta-testers. If you have these items:

• Power Inverter 12/24V
• SLA Batteries
• Sharge controller 12/24V
• Solar panels

and if you are interested in receiving a test unit please send me an email!...

If you have something for 48V systems and flooded batteries. I think you will need to make it
scalable to a wider range of systems, to get much market penetration, 12 & 24V are generally low end or RV setups. Full blown houses generally are at 48V for better efficiency.

[FloridaSun]

If you have something for 48V systems and flooded batteries. I think you will need to make it scalable to a wider range of systems, to get much market penetration, 12 & 24V are generally low end or RV setups. Full blown houses generally are at 48V for better efficiency.

Full blown houses usually have more than a 1000w inverter, 24v-35Ah battery bank, one 235w panel with 6amp controller as his links recommend on his blogsite. That's a recipe for trouble, very misleading as far as components and cost involved not to mention unsafe as he shows no recommendations for fuses/breakers or wiring gauges. The whole 'one fridge off the grid' idea seems more of an advertising scheme for his future product than any safe, reliable way to save money or make the world more 'green'.
His youtube clip asks if we will help him reach his goal of taking 1,000,000 fridges off the grid to replace a nuclear power plant. I hear that as, will we help him design, test and sell 1,000,000 of his transfer switches.

back to your fridg rant... I agree, wish they would make fridges with a switch to disable defrost cycles.

[SunEagle]

Maybe the "off grid fridge" idea will be a little hard to accomplish since their electric load is sizable. Finding something with a little smaller "load" may be easier.

The decision to take a constant energy user off grid on a vast scale is admirable but to do it to eliminate a Nuclear generating plant is plain dumb.

You can build all of the RE type generating systems you want but until a reliable and cheap way to "store" the excess energy is designed and installed you still need your "base" generating systems. Hydro carbon based fuel prices can vary greatly and run into a lot of environmental push back which can raise their cost dramatically. There is Nuclear technology that is relatively cheap with low fuel costs that is available and is still the cheapest best bet way to generate electricity. One area to stop worrying about is storing "spent" fuel rods. They are still a good fuel source and should be recycled like the rest of the world does.