Getting started in solar - some advice would be greatly appreciated

[Carl Elias]

G'day there,

I'm after some information regarding a solar setup. At this stage I'm not really sure what's involved, but I'd like to get into solar energy and start taking my house off the grid as much as I can. The main issue is that I rent, so I can't make modifications to the structure, however I do have space outside where I can erect my own rig if need be.

Ideally, I'd be interested in putting together some kind of solution that is portable (or at least, can be dismantled and rebuilt elsewhere), that doesn't require being wired into the mains (instead, electrical could be powered directly from the solar array and batteries themselves) and is scalable, so that I may add more panels or batteries (or whatever else is required) in the future. One day, if I ever own my own home, it'd be nice to take this solar setup and have it mounted permanently on the roof.

I'm unsure of if this is achievable, where I should start, and what hardware I require. Does anyone have any ideas here?

I really see that any device I can power from solar is a step it the right direction, and a win for the environment. I'm prepared to take it slowly and start off small, perhaps shifting some devices off the mains onto this array in a controlled manner.

Any help or advice is most appreciated, I really have no idea where to get started!

Cheers,

- Carl

[Dale Sheler]

The first question would be is what kind of access do you have to the sky? Do you have a yard?

[Carl Elias]

G'day Dale,

I sure do - it'd be about 5 m x 20 m, so not the biggest space, however we get a lot of sun where we are. I'm prepared to build scaffolds or whatever else I need to mount panels in the back yard or in a temporary arrangment on the side of the building.

Cheers!

[Rob Beckers]

Carl, take a look at the ballasted mounting systems that are used on flat roofs (such as http://www.preformed.on.ca/PDF/BRMbrochure.pdf). This is something that can be quite easily made as a DIY project. The downside is that the panels are close to the ground. The trouble with mounting them higher is that the overturning moment (forces) caused by the wind will increase rapidly, and with it the need for either large amounts of ballast weight, or some way of anchoring to the ground.

-RoB-

[Carl Elias]

Those mounts look interesting.

I'd like to learn more about an array I could build though. I might be over-simplifying the configuration, but basically I'd like to have panels on one end, batteries in the middle, and a power outlet on the other end that I could plug devices into. Would you have any tips on where I should look for this kind of setup?

Cheers!

[Rob Beckers]

Carl, while a picture could say a thousand words, I'll try the latter since time is short and drawing pictures takes lots of time.

PV panels hook up to a charge controller, which in turn hooks up to batteries. Depending on what you want to do with it, common battery voltages are 12V/24V/48V. You could leave it at that and run lights etc. directly off batteries (there are 12V CFL and LED bulbs, and freezers, fridges etc.). If you want grid voltage (not sure what it is over there, we have 120V and 240V over here), an inverter connects to the batteries to turn DC into AC.

PV modules come in (broadly) two types; those meant for direct battery charging, with a voltage suitable for batteries, and those meant for grid-tie. The latter are much cheaper "per Watt" vs. the former, and can be used for battery charging too: A type of charge controller named "MPPT" (stands for Maximum Power Point Tracking) will take a higher input voltage and convert it down to battery voltage. Also, you can use regular 60-cell grid-tie modules to charge 24V batteries with a regular charge controller (you loose a little in the process, but the voltage is close enough to make it work). Take a look at the Morningstar brand for various charge controllers, they are well-made and don't break the bank.

Home Power Magazine had a great article on batteries in their current issue (Feb./March), you may be able to pick that up locally.

More in general, there are lots of good books on off-grid power, and how make such a system. Take a look at Amazon; the reviews should point you to something that works for you.

-RoB-

[Joe Blake]

Hi Carl,

I started out in the mid '90s in the way you are considering (I was renting) and I've now got 1600 watts of grid-tied power plus about 2-300 watts of non-grid power available via 150 AH of batteries.

I found these portable panels a couple of years ago

http://www.jaycar.com.au/productView.asp?ID=ZM9134&keywords=portable+solar&form=KEYWORD

They come completely set up with everything in place (wiring, alligator clips, thermal probe). They are self-regulated so they won't overcharge your batteries. Quite literally a case of carry the panel(s) to the desired location like a fold-up picnic table, open up, drop the legs down, face the sun and clip onto the battery(ies).

Even 120 watts I found I could carry on my motorcycle (awkwardly) using a rigid framed back pack to get them home from the shop.

Under $700 (Australian).

They are moderately fragile so can suffer damage if handled too roughly.

Joe