Most reacted posts

A hot water system doesn't know or care whether it's AC or DC being supplied. In Australia we can get second hand 250w panels for about 20 bucks a piece. The way you connect is directly to the heating element. You need to use ohms law to match the resistance of the heating element to the...

This thread has become so complicated with expensive hitech solutions to what is a simple problem. Yes...you CAN connect your series/parallel combo of used solar panels that you got for 5 bucks each to heat hot water directly in your el-cheapo resistive element hot water unit. Yes... you will...

Never, ever put 4 batteries in parallel....they will not last very long at all. If you must then have the positive pickup at one end and the negative t the other so that each battery has same length to charger...really important! Consider a 48v charge system, far superior to a 12v or 24v...

To connect a resistive hot water heating element you need to factor in maximum power transfer to the equation. Basically the resistance of the panel needs to roughly match the resistance of the heating element. (remember, we put 8 ohm speakers on our 8 ohm amplifier?) How do you determine the...

Please prove that the components will fail ? The heating element is a passive resistor. It doesn't care what type of voltage is applied to it, AC is simply instantaneous DC. Directly connecting solar panels, with care to match panel resistance to heating element resistance, is by far the...

A lot of fear mongering and negativity here.

Put a 10uF/450v capacitor across the thermostat terminals if using a DC voltage....else contacts will fuse together and hot water will never turn off. Then there will be a big...BANG

48v battery bank needs significantly thinner wiring than 12v. When you parallel more than two batteries you create imbalances that shorten your battery life significantly. It's all about the wiring, the wiring determines the Amps, the amps determine the losses in the wiring. Thick wiring is...

what voltage is your battery bank?

Do not do an off grid setup based on any 24v component, it is a fail from the word go. 48v or don't bother...truly.

@Tictac.....it is indeed a novices section, the exact reason I made my comments regarding paralleling batteries. (this has been covered with practical examples extensively on forums outside of the US) Your link to the smartgauge article (which I am familiar with) supports my comment that it...

What size battery?

Nahh..sorry..that does not even come close to the world renowned SMA off grid kit.

Put a diode in series with the PSU as well....12v LEDS on a 24v source?

I use the SMA Sunny Island 8.0h with normal SMA grid tie inverters. Everything connects at 240v except the 48v lithium or LA battery bank. It does all this and has been around for years (is the industry benchmark) Looking at this unit it looks not quite as elegant or simple to install. But...

Without any interface between them? No RS485...no CANBUS? Without balancing it's just a fact, 2 in parallel is fine, but as per his schematic 4?....nope unless NASA or Spacex did his cabling Experience? Been off grid for 30 years...have setup an entire grid on an island...got a...

Tesla versus Chevy Volt...LOL

Oooh….really? an arc can be sustained by any voltage indefinitely as long as it is applied indefinitely. Absolute nonsense buddy.

Mate....noone is saying use 600v from the panels...the formula is to use the same voltage as the element and hence the whole hot water unit is rated at. You are scaremongering either through self promotion or ignorance.

Do you know why? Hint: RMS versus Peak to Peak.

Absolutely agree with you about the twin Sunny island setup....The problem with DIY setups is they need constant monitoring...the Sunny island and SMA stuff just works..year on..years on.....

If you had used three SMA Sunny Island inverters for your 3 phase project you could just have used the generator input to charge the batteries from a single utility grid phase. this is exactly what we have been doing for years....and it just works. And...you could charge at 6kw/hr per Sunny...

how do you switch the heating element off and on?

So-o-o-o-o much easier to do all this with Sunny island inverters.... everything just works and is scaleable to the asteroid belt.

I predict a fire...a BIG fire.

Just buy a ne w 240v fridge with one of the new electronically driven compressors. My samsung 280 litre fridge uses 40 watts on full sing and makes ice cubes in an hour. My Toshiba laptop uses more...