Setting up semi-off the grid solar array in the jungles of Maui and could use advice

Bootyfunk

Electricity is very expensive on Maui. My fiancé and I rent a small 3 bedroom house in the jungle. We are low income and our electricity bill is hurting us. We would like to set up a solar array to lessen the bill. I’m definitely a newbie at all this, so I really appreciate your patience with my ignorance on the subject of all things solar, as well as your helpful advice.

We don’t want to set up anything permanent (on the grid) as it isn’t our house and we want to take our solar with us when we move. My idea was to set up a semi-permanent solar array and hook some of our electronics to it. We would like our solar to supply the 3 main areas of our home that use a lot of electricity.

One is our entertainment area in the living room. Someone leaving the island gave us their brand new 50” flat screen LCD TV. Yes, we were very lucky. Also came with a sound system. We have a cable box and an Xbox 360 (which functions mostly as our DVD player.) We’d like to be able to hook all this stuff up so they run off solar generated electricity. This area probably draws the largest amount of power.

Aside from our bedroom, which has no electronics, I use a bedroom as an office and my fiancé uses another as her office. We both work from home starting new businesses. I have a desktop computer, our printer and modem/router in my office; my fiancé has a laptop and sowing machines in hers. I will soon be purchasing an industrial large format printer for our new sign business, which will likely go in my office. Both of us have fans in our offices and usually charge our phones there. We’d like to hook everything in our offices up to the solar array as well.

Overhead room lights would remain on the electric bill since they are hard-wired and that’s fine. We turn off everything that uses electricity when we go to bed except for our refrigerator. And I mean everything (including the microwave, cable box/TV, etc.) We plan to keep our refrigerator on the grid, so while we sleep nothing would be draining the solar batteries of juice at all. During the day, we’d probably plug items that are only occasionally used (microwave, hair trimmer, blowdryer, etc.) into grid wall sockets so as not to strain the solar batteries.

I plan to run a few long heavy-duty extension cords from the batteries to the 3 places we want free electricity (entertainment area in the living room and both our offices). Would a different form of wiring be better? Safer? More efficient?

I bought an almost new 1200 watt inverter on craig’s list for $70. I’m hoping this will cover my needs. I have a 2 month old big truck battery (I know deep cycle is optimal) that I was planning to start off with. I know I still need solar panels and a charge controller.

With the solar panels, I have the basic question of how many panels/watts do I need to cover what I listed above? I’ve been told you can keep adding panels, but I really don’t know what a good starting point would be considering the above mentioned needs? 1000 watts?

Also, it seems like there are 3 kinds of solar panels. 1) the big factory kind that a solar installer installs on your roof, 2) portable solar panels, also made by a factory, but usually smaller and cheaper (http://www.homedepot.com/p/Grape-Solar-100-Watt-Monocrystalline-PV-Solar-Panel-for-RV-s-Cabins-and-12-Volt-Systems-GS-S-100-Fab36/203336897#.Uj_lMVMf6J4) and 3) DIY solar panels, like the ones that can be purchased on eBay (http://www.ebay.com/itm/1KW-Nearly-Whole-3x6-Untabbed-Solar-Cells-for-DIY-Solar-Panel-Best-Value-/360618767489); they send panel pieces that you put together yourself.

Can I take a big factory panel that was meant for a rooftop, build a wooden frame to hold it and use it in my makeshift solar array? Does the wiring allow that? I don’t know if those big panels must be hooked to the grid or if can they be hooked into a less permanent solar array?

As for the DIY panels – are they worth the savings if you can do it yourself and build your own panels? I read on a website that the DIY panels are inefficient and sometimes don’t bring in as much power as sellers claim. But others said they worked great and saved money.

Or should I just stick with the company-made portable solar panels? We get a ton of sunshine on Maui, but also a fair amount of rain because we live in the jungle. I’m worried about weathering on whichever panels I choose, especially the DIY setups.

I also need to get a charge controller and don’t know what how many amps I need. I don’t even have a ballpark figure. I believe there is a way to add more charge controllers if you need more amps, but I’m not sure exactly how that works.

I know I wrote a book. Thank you in advance for your advice. Much aloha from the islands!
-- Kevin

Cariboocoot

Re: Setting up semi-off the grid solar array in the jungles of Maui and could use advice

Welcome to the forum Kevin.

Just how bad is the electric bill? How much do you get charged per kW hour?

I ask this because off-grid electric generation is not in any way to be considered cheap, even these days. It will require a substantial investment to acquire panels, charge controller, batteries, inverter, and all the miscellaneous bits to connect it together. Chances are very good that you would be further ahead spending that money on reducing usage.

For example: desktop PC. They can chew through 3 or 4 times as much power as a laptop doing the same work. Adjusting that big screen TV's picture can take 100 Watts off its consumption rate. Turning off everything 'for real' when not in use can bring surprising results too.

The first thing you should buy is a Kill-A-Watt meter. Measure everything you plug in to an outlet and see where all that power is going. Reducing consumption is your first line of defense.

If you still plan on going ahead with the solar, do not buy anything before you've worked up a plan! You would be amazed at how often 'bargain' equipment turns out to not be such a bargain after all; if it doesn't suit the need it's just money wasted. And you can't know what you need in equipment until you have some accurate numbers for how much power you want to supply.

Used equipment can sometimes help, but it can also be a pig in a poke. A "1200 Watt" inverter could be a good ProSine or a piece of junk square-wave disaster. As for panels, DIY will be the most expensive and least reliable. The small, "portable" panels likewise cost a lot per Watt (local place here just had some 100 Watt panels on sale for "only" $3.99 per Watt). By far the cheapest will be the commercial "GT" panels, although they are not always easiest to incorporate in a system (Voltages are not ideal for battery systems).

It is possible to build a portable power system with one or two 'big' panels. Several people here have done it (Mike's solar monolith: http://www.mike-burgess.org/PVinfo_1.html). You could say every RV install is such a system.

But first you're going to need those power usage numbers. Otherwise you're traveling blind.

mike95490

Re: Setting up semi-off the grid solar array in the jungles of Maui and could use advice

PV power is expensive. Your Fridge is likely the biggest hog.

DIY panels are a dead end - steer clear of them.

Your best bet is 200watt class, 80V panels, with a MPPT controller, a 24V battery bank made from 6V golf cart batteries, and a 24V pure sine inverter.

You can mount the panels on a painted wood frame. They need FULL sun, dappled shade or partial sun will NOT work.

ggunn

Re: Setting up semi-off the grid solar array in the jungles of Maui and could use advice

I'm afraid that the news is not all that great. Unless you've got a fair amount of cash to throw at a system, grid tied without batteries is your best option. You are either connected to the grid or you are not; there is no "semi". I understand that as a renter your options are limited and in a large part under the control of your landlord, but unfortunately there is no cheap, easy, and portable way to generate significant PV power. I am pretty sure that even on Maui you won't be able to generate off grid power cheaper than you can buy it from the grid.

westend

Re: Setting up semi-off the grid solar array in the jungles of Maui and could use advice

I know Oahu power is $.40/Kwh. Maui is probably more.
As others posted, the totality of even a small system can get expensive in relation to power delivered. Maybe a good way to knock down your bill and get your feet wet in PV power would be to buy a small kit and hook up just a few devices to it. Something like this. You can pretty well abandon the idea of taking the DC off the module using extension cords. Save those for the AC distribution. A length of MC4 cable is built for the purpose and will have the right connectors. The "big truck battery" will die a miserable death, save it for a vehicle. You will need some battery capacity and you have to establish what your usage is.
Downloadable solar usage calculator
Good luck with your solar beginnings!

mike95490

Re: Setting up semi-off the grid solar array in the jungles of Maui and could use advice

This board's host site has several small cabin kits, up to full off grid house kits.
http://www.solar-electric.com/rvandsmbasoc.html small
http://www.solar-electric.com/ofsokiforho.html larger