Thread: RAPS for a shed

Hi Simon,
Whilst i cannot comment on RAPS for a shed (although i lived on one as a teen) your cost seems reasonable, my shed cost me about $3500, run was about 30m, sub board, 3 15a outlets, 1 20a 3 phase outlet, 8? (thats sad, i don't even know how many GPO's my shed has ) double GPO's and 11 double fluro's.

Living on RAPS was a pain, but that was many years ago, the tech has changed a lot. I think the panels back then were only 60w (1200x600 i think)...we had 8 and ran a household of them. Gas fridge, gas/wood cooking and hot water etc. We found some push button appliances would not work off the inverter, had to run the gen.

Ew

Hi Ueee,

Thanks for the quick reply. From memory you have solar lighting?

WRT lighting, I already have the lighting (double fluro's) installed, but just not connected. Also I would be looking at installing the system myself. Although I'm not sure if being a stand alone system allows me to do that legally or not? Don't have an issue with myself doing the job but not if it would void any insurance policy for fire! If I had to pay someone to install the RAPS then the labour would be a deal breaker and make it much more expensive than paying a sparky to do a "conventional" connection via the house.

I confess that part of the attraction is the DIY bit!

Simon

Aren't parallel strings a bad thing with lead acid?

Stuart

Originally Posted by simonl

Hi Ueee,

Thanks for the quick reply. From memory you have solar lighting?

Nah, just solar extractor fans. 10" car fans mounted under the normal whirlybirds running off a 40w 12v panel with a temp switch so they don't suck all the warm air out in winter....

Ray is messing around with solar lighting. Might be best to wait for him to get back from OS and chat to him about it, he'll know.

Ew

To save money I buy all the wire, powerpoints, switches. conduit, etc, from Bunning or wherever I can get them cheapest. Once I have everything I mount everything run the wires and conduits and then call in the sparky to connect everything. It's perfectly legal and the sparky usually only charges a couple of hundred bucks to twitch a few wires together, check everything and connect to the house. I've done this on four sheds - saves heaps.

I'm with th62, do as much as you can legally yourself.

No point paying electrician's hourly rates to dig trenches and run conduit..

And here's a tip. Make friends with your local electrical wholesaler, open a trade account and you'll pay much less than retail. Trade discount on a lot of electrical stuff is very generous, up to 50% off in some cases.

And don't forget get a sparky to choose the wire sizes.

Regards
Ray

Originally Posted by Ueee

Ray is messing around with solar lighting. Might be best to wait for him to get back from OS and chat to him about it, he'll know.

Ew

Hi Simon,

As Ewan says, I'm going all off grid for workshop lighting.. If I installed a grid connected system the best I could hope for is 8c per kw hour for excess returned to the grid... plus I like the idea of being off-grid...

Basically I'm going 4 panels 250W in series parallel to give 1000W as 100V 10A into a mppt solar charger controller charging 24V lead acid... total AH for batteries is still undecided, but 200 AH would be nice.

The 24V dc is distributed through a control system to constant current buck/boost power modules to provide the 33V 3.5A for the led modules.

Sound a bit complex, but I'll do a much more detailed write up when I get back in a couple of weeks.

Going to CERN next week to research the time machine project...

Regards
Ray

PS Links to bits and pieces..
The Solar charger controller
Tracer 2210RN EP 20A 12V 24V MPPT Solar Cell Battery Charge Controller Regulator | eBay

The LED heatsinks
1 PC UP TO 100W Watt LED Aluminium Heatsink Round XXL 10W 20W 30W 45W 50W 100W | eBay

The LED power supplies
100W Watts High Power LED Driver Boost Step UP Topology Garden Street Light | eBay

The LED modules
100W Warm White High Power LED Panel 9000LM 100 Watt Lamp Light | eBay

Solar panels 250W 48V
250 Watt, High Voltage Solar Panel, monocrystalline, 96 cell

Just a suggestion but If you are looking for advice regarding an inverter or solar in general try having a look at Whirlpool Forum. There are a lot of installers who frequent the Green Tech - Whirlpool Forums . There is a lot of valuable knowledge available there. I have had a number of issues pointed out to me that the supply/install company did not even know about. It was because of this lack of knowledge that I did not go ahead with solar.

Dean

Hi Ray,

The Tracer MMPT controller seem to be pretty good. I have a 12V 10A one for my camping setup and so far it's been good. There is also an LCD display that plugs in via an RJ45 which tells you the charging current, state of charge (an estimate) and a number of other features, which I have too.

The solar modules by low energy developments seem pretty good too. I have one of their 150W. Their prices were the most competitive when I bought mine. I went picked mine up from their shop. It's a no frills tiny shop but they have a bout 4 people working there and I get the impression that they move a lot of stuff. The guy that served me had done either a diploma or degree in some alternative energy course and there was not much he didn't know! I was impressed. Buy from them again no problem!

You mentioned running your lighting off solar, what about your power?

If I did connect to the house, I would certainly do as much myself (legally) as I could. I'd rather put myself to work for free than pay someone to do it!

Hi Dean,
Thanks for the link to the forum. I'll have a look at that.

Hi timeless,
My brain is not working yet. I'll have to re-read your post a bit later!

Hi Stuart,
WRT paralleling batteries. I always thought it was OK as long as they were same chemistry type, same capacity and (if possible) same age. They would also be the same brand if buying all at once. If looked after, they should all degrade by the same amount and their internal resistance should all stay reasonably matched I would have thought.

Just out of interest, the new Toyota Land cruiser 200 series run twin batteries. They are in parallel, one each side of the engine bay just to give enough CCA for their monster V8 diesel.

Cheers,

Simon

I have seriously thought about converting all my house and shed to LED lights running off a small solar backup system. If I use 12v I can do it myself legally except for disconnecting the existing light circuits.

This will have the advantage of saving money on power and light globes and we will still have lights when the lectric goes off which is more often than I would like out here. We have a wood cooking range which also supplies our hot water and we can always cook on the gas BBQ if the range is not going. Water is gravity fed so we have a reasonable supply of that.

Either way we are going to change to LED lights. My step daughter works in a lighting shop and she can get us good prices. They have also done there homework on the quality side.

Dean

Rule of thumb in boats, count on 30% of battery capacity if you want long life from them. Assuming we're talking lead-acid, lithium are a lot better at ~4X the price.

As for running big current draw items like a welder, no.

I've spent a lot of time playing with off grid systems and my strong advice is, pay the money, connect to the grid and have a happy life in your machine shop. The pain of living without the grid connection is going to stay with you long after any possible savings are blown replacing stuff & adding panels, batteries et al.

I do have a welder that works well (well, acceptably). It's a Readywelder and runs fine off of a 24V DC supply - basically a MIG spool gun purpose-designed for in-field repairs etc. Quite a good unit but it wasn't cheap and it's not a patch on my 250A Chinese MIG.

Don't forget the starting current for motors is 5X or more their running current....

PDW

Originally Posted by PDW

Rule of thumb in boats, count on 30% of battery capacity if you want long life from them. Assuming we're talking lead-acid, lithium are a lot better at ~4X the price.

As for running big current draw items like a welder, no.

I've spent a lot of time playing with off grid systems and my strong advice is, pay the money, connect to the grid and have a happy life in your machine shop. The pain of living without the grid connection is going to stay with you long after any possible savings are blown replacing stuff & adding panels, batteries et al.

I do have a welder that works well (well, acceptably). It's a Readywelder and runs fine off of a 24V DC supply - basically a MIG spool gun purpose-designed for in-field repairs etc. Quite a good unit but it wasn't cheap and it's not a patch on my 250A Chinese MIG.

Don't forget the starting current for motors is 5X or more their running current....

PDW

And air cond if considering a house system. One of the reasons I very quickly decided against going off grid. By all reports I have seen the cost of off grid is prohibitive when you consider the ongoing replacements. The price of power will have to go up a long way to match it. Hopefully someone will come up with a cost effective electrical storage medium one day. I keep hearing about exciting developments!

Dean

Don't go there Simon. As PDW says, pay the money and connect to the grid.

I helped my dad set up a RAPS at his property in The Grampians. However, he had no choice. It was quite complex even though his power requirements were very modest. You will require a very large inverter to drive machinery.

Regards,
Chris

P.S. My uncle's RAPS at his house in Gippsland caught fire and burned the house to the ground.

Boy you guys are great at killing the romance! Thanks all for the advice. I was really hoping to try it, be a little inovative and have some fun. I wasn't really considering it as a cheaper option just a diiferent approach but advice so far from people who know more than me is not encouraging!Thanks guys. Simon