Insulating the roof

[sonjack2847]

54 minutes ago, Arizona Kid said:

Most of the roofs here in the Phills are a dark color. Don't know if it would make much of a difference. Might be worth trying. I rent so I don't have a choice

Apparently, it makes a 5c difference, remember light colours reflect heat and dark ones absorb it so they get hotter.

[jimeve]

1 hour ago, Viking said:

Is it not when you are off-grid you need batteries??  assuming you want to use your electrical things when the sun gets down.

lol, wrong way round. grid-tie you don't need batteries. 

[jimeve]

57 minutes ago, Dave Hounddriver said:

I have battery back up for brownouts

Dave, how long will the batteries run? Say load for 50 inch TV and cignal box, ceiling fan, fridge/freezer.?

[Dave Hounddriver]

30 minutes ago, jimeve said:

Dave, how long will the batteries run? Say load for 50 inch TV and cignal box, ceiling fan, fridge/freezer.?

That is a harder question than it seems at first glance.  I can tell you that mine will last for a 12-hour brownout.  What I cannot tell you is whether I am discharging them to the point where I am damaging the batteries.  Smarter minds than mine will have to tell you how many amp-hours of battery you need and how long you should run them for.

For anecdotal evidence, I can tell you that my 4 x 150 amp-hour batteries have lasted close to a year and will power all those things and more during a 12-hour brownout.  If I had to do it again, I would spend the extra for 4 x 200 amp-hour batteries as they will not discharge so low during those long brownouts. (Of course, it also depends on the type and quality of inverter/charger you are using.  Mine comes in a pretty box and seems to do the job but one can never tell what is going on inside that box.  I cross my fingers and enjoy the brownouts but I don't recommend it to people who are not willing to take the risk of the whole thing burning out or burning up.)

Edited June 23, 2019 by Dave Hounddriver

[jimeve]

21 minutes ago, Dave Hounddriver said:

That is a harder question than it seems at first glance.  I can tell you that mine will last for a 12-hour brownout.  What I cannot tell you is whether I am discharging them to the point where I am damaging the batteries.  Smarter minds than mine will have to tell you how many amp-hours of battery you need and how long you should run them for.

For anecdotal evidence, I can tell you that my 4 x 150 amp-hour batteries have lasted close to a year and will power all those things and more during a 12-hour brownout.  If I had to do it again, I would spend the extra for 4 x 200 amp-hour batteries as they will not discharge so low during those long brownouts. (Of course, it also depends on the type and quality of inverter/charger you are using.  Mine comes in a pretty box and seems to do the job but one can never tell what is going on inside that box.  I cross my fingers and enjoy the brownouts but I don't recommend it to people who are not willing to take the risk of the whole thing burning out or burning up.)

Seen them for sale solar batteries in Dumaguete, For 200 amp hour 14,000 pesos. seen them cheaper on FB but this guy gives 2 years warranty. I got an inverter (pure sine) not solar compatible. I hooked it up to two12v car batteries last 3 hours. 50 inch TV Not the best solution. At least the inverter keeps my car batteries topped up.

[Gary D]

Choice of batteries is critical, you need deep discharges batteries. Standard car batteries will fail in short term.

[Tommy T.]

They are expensive, but I believe gel-cells are the best batteries for deep cycling. I used them on my yacht - they outlasted "wet cells" like golf cart batteries, "dry cells" like used in aircraft. They can withstand rather brutal treatment - like running them down to near zero volts - and come back up very close to new condition. They are best used if drained to no less than 50% capacity before recharge. I have not shopped for them here. Brand name in USA and elsewhere are Gel-Tech and I believe West Marine also may have them. I had three "4D" batteries on my yacht for "house" use. These powered refrigerator, lights (all incandescent - before the time of LEDs), computers, short-wave radio communications (at 150 watts), TV, stereo - all for up to 3-4 days when the sun wasn't shining on my solar panel array.

[hk blues]

21 hours ago, Viking said:

I have been thinking of this too, I found a complete "package"  of 3,7 kWp Grid tied solar system  that will generate savings of 5000+ pesos/monthly on your electric bills. Cost for this system is 220k pesos, meaning it will be generate a profit in less than 4 years.  I will not do this as a first step, but probably in the future if we decide to stay there long time.

That's pretty much what I was quoted for a grid-tied system i.e. it doesn't work during brownouts!  For me, the main problem, in addition to the brownout issue,  was our bills are only 2,500php  a month so payback would be in 8 years.  i estimated that during that period, the system would require maintenance and perhaps upgrading etc so the numbers didn't add up for me.   

[jimeve]

12 hours ago, Gary D said:

Choice of batteries is critical, you need deep discharges batteries. Standard car batteries will fail in short term.

I know, I have the spare car batteries already. going to buy some deep cycle solar batteries.

[Viking]

4 hours ago, hk blues said:

That's pretty much what I was quoted for a grid-tied system i.e. it doesn't work during brownouts!  For me, the main problem, in addition to the brownout issue,  was our bills are only 2,500php  a month so payback would be in 8 years.  i estimated that during that period, the system would require maintenance and perhaps upgrading etc so the numbers didn't add up for me.   

If my bills was only  2500 monthly, I dont think I would bother with solar panels at all. If I did, it would be an off grid system so I would not get affected by the brownouts.