Newbie from Philippines with a 300W setup

**Sunking** · 03-01-2014, 12:44 PM

Originally posted by workpod

Okey so what I have are:
3 units 100W solar panels, Pmax 100W, Vmp 17.4V, Imp 5.76 Voc 22.0V, Isc 6.06A, Max system voltage 600V
PSW (Pure Sine Wave) Inverter rated at 1000VA/700W - I thought 1000VA stands for 1000W as VxA = W
30A PWM charge controller
2 units 100Ah Motolite Solarmaster FLA, deep cycle batteries
Other things I already have:
1 unit 20ft 1x1-inch square tubes - cut in to 6 to secure the 3 units of solar panels via stainless bolts and nuts
1 unit 20ft 1x1-inch angle bar cut in half to secure the solar panels with the square tubes with stainless nuts and bolts and to the roof and secure with tex screws
20 meters #10 weather proof dual Royal cord
10 meters #8 automotive wires
battery lugs, nuts and bolts, volt panel meter (0V to 30V), ampere panel meter (0A to 50A), 30A circuit breakers

My objectives are:
1. To at least save a third or half of what I'm paying to the power company
2. To get rid of the nuisance of getting frequent brownouts especially during my work hours

Background:
I'm an online web developer/programmer with work hours at 7:00AM to 3:00PM. Having power interruptions can be quite a nuisance as some of my clients (although they didn't say it, I know) are stressed when I suddenly went offline because of unannounced power fluctuations.

I have an isolated work area converted from a store room with the wiring separated from the house wiring and ready to be energized by the solar power setup. I have a 2W LED light, a 65W electric fan, a desktop with a 700GB and 500GB harddrive with AMD Radeon 7500 video card, dual monitors AOC 2236V and Acer P241W, Intex 1500VA/900W UPS, generic 600VA/300W UPS, modem/WIFI router

My goal is to make my work area powered by the solar setup and make it power fluctuation free from 7:00AM to 4:00PM. After the 4:00PM period, I either reconnect my computer system to the mains or turn it off as the work hours is over. Then optionally/probably divert my solar setup to provide power to the lights only until the next day. The lights would be a total of 10Watts max from 6:00PM to 6:00AM and again transfer the lights to the mains after 6:00AM.

OK you are already making huge mistakes, making wrong assumptions, and wasting money.

First to do what you want requires no solar power what so ever because you already have commercial power. May not be reliable commercial power but a lot more reliable than solar and does not come with limitations. You can do exactly what you want with just rectifiers > batteries > inverter. In other words a dual conversion UPS. Ever hear of a UPS used in IT Data Centers? It will run circles around solar and a heck of a lot less expensive.

Secondly using a PWM controller and battery panels is a waste of money and energy. Battery panels cost about twice as much as grid tied panels. It take a 300 watt PWM system to generate what a 200 watt MPPT system using grid tied panels. A 300 watt PWM system cost roughly $700, and 200 watt MPPT system cost roughly $500.

So tap the breaks and rethink this because you are fixing to make a huge mistake going solar. FWIW anything you take off-grid will cost you roughly 10 times more for power the rest of your life vs buying it from the power company. Ihave no idea where you came up with it is cheaper to make your own power, but it is FALSE.

Just based on what little info you have provided of using 12 volt 200 AH batteries and a 700 watt inverter you can build a dual conversion UPS for less than $800 USD. All it takes is a 24 volt 75 amp rectifier, 24 volt 100 AH AGM battery, and a 700 watt inverter.

**workpod** · 03-01-2014, 07:44 PM

Thanks for the advise Sunking. Much appreciated.

I'll look that up and do some more research.

Meanwhile as you pointed out and as I already wasted money, I'll put these equipment/items to good use and continue setting this up as intended. The only appliances left to the grid will be the TV and the ref. And if another batch of "scheduled power interruptions" for "system maintenance" comes along that often takes between 4 to 8 hours, I'll still be working on my computer, stay online and make my clients happy. To make things more wasted that it is, I'll be using a 12V setup. Setting the 3 panels in parallel to the controller to the batteries to the inverter.

Already done and connected the panel board with the panel meters, charge controller, batteries, inverter and wirings on the ground floor. I'll be securing the solar panels on the roof today. Just 5 meters distance to the panel board. I already had the two batteries recharged overnight with each having 13.5V with no load.

Total wasted money for this by the way is about US$1,280.

3x 100W solar panels = US$277.67 @ about US$92.56 each
30A 12/24v PWM charge controller = US$81.40
1000VA/700W Pure Sinewave Inverter = US$151.16
2x Motolite Solarmaster 100Ah Deep Cycle batteries = US$348.88 @ US$174.42 each
Others (plyboard, shelvings, panel meters, wirings, cuicrcuit breakers, fuses, battery terminals, terminal blocks, bus bars, nuts and bolts, square tubes, angle bars, etc) = US$420.89

I'm consuming an average of 320kWh with the amount between US$73 to US$75 a month. And If I could save at least US$25 a month or US$300 a year on my electric bills, the ROI to my wasted money would be fully paid within the next 4 years. In time to waste another batch of money to replace the batteries of about US$350 in cost or upgrade my setup. And if I could save more than US$25 a month, it will be an earlier schedule to waste more money. At least the future US$350 will have an ROI of at least 1 year and 2 months. With plenty of years in between for the next battery replacement or other equipment that may fail.

**Sunking** · 03-01-2014, 08:33 PM

Originally posted by workpod

Total wasted money for this by the way is about US$1,280. I'm consuming an average of 320kWh with the amount between US$73 to US$75 a month. And If I could save at least US$25 a month or US$300 a year on my electric bills, the ROI to my wasted money would be fully paid within the next 4 years.

Wrong, it is impossible to ever achieve ROI on an off grid system. Battery replacement cost alone will be at least 5 times more than what the POCO will charge you.

You average a 5 Sun Hour day and with a 300 watt PWM system if you utilized every single watt hour of energy the system could generate works out to roughly 1 Kwh of electricity per day or 30 Kwh per month in the USA that equates to $3 month or $180 in 5 years. A good 5 year battery in the USA sized to provide 1 Kwh per day cost $1000 USD. Now with that said a 12 volt 200 AH battery like you have if used every day can only supply you with 500 watt hours per day or 15 Kwh per month, If these are low quality batteries like I suspect you will be replacing them every year or two. If you discharge them to using 1 Kwh per day or 50% DOD that match your panel production, you will be replacing them every 6 months. So I have no idea how you came up with 4 years ROI, it is not possible.

That last thing you have not accounted for is you cannot utilize all the power, lucky if you use half of it.

Sorry not trying to bust your chops, but your assumptions are all wrong leading you to false conclusions. You are an IT weenie and should know garbage in gets garbage out.

**workpod** · 03-01-2014, 10:07 PM

Probably depending on how large one's off grid system is and how much one has spent on it. That's why I started relatively small which I actually have gone overbudget by US$280.

If I overestimate my consumption and have spent a lot of money for my over producing setup it might be probable to achieve the "impossible to ever achieve ROI" that you have in mind. If I ever do overproduce might as well sell my excess power to my neighbors in half the cost to what the POCO is charging. Easy to sell out my excess since my next door neighbor is my brother in-law.

Bear in mind that this setup is 90% utilized during the day from 7:00AM to 4:00PM and the rest of 10% is for nighttime where the lights with a total of 10W max if turned on at the same moment. The only lights that will stay on all night will be the front gate with a 2W LED light and the 2W LED light at the back of the house.

The sun is way over the sky by 7:00AM. The 5 Sun hour day you're pointing out maybe around 9:00AM to 2:00PM. And if you have lived in the Philippines you know that 3:00PM is still very hot even until 4:00PM.

The POCO is charging about an average of Php10.00 or US$0.23 per kWh with all the usual generation and transmission charges, distribution charges, subsidies, goverment revenues, universal charges, and adjustments. Yes it's a small price to pay indeed but I won't have the money to pay it with if I lose my clients because of just one critical time that I should be online and there's a power failure on my area. Worse if it's an island wide like what happened during the typhoon Yolanda/Haiyan with the power getting on and off for several hours for a few days.

The reason why I did decided to setup a solar powered work area is that while working and there was a power interruption, my 1500VA/900W UPS will stay up for 30minutes before shutting down. It's an Intex brand with 2 units of 12V9A in series making it a 24V9A. I reasoned that if a 24V9A will stay up for 30minutes give or take 5 minutes, how long will the setup with 2 units of 12V100Ah battery in parallel with 3 units of solar panels in parallel just barely producing an average 12V12A to a 12VDC to 220VAC PSI? That's what I'm going to find out in the next few days.

My last February billing was 319kWh. My January billing was 304kW. December 2013 was 332kWh. Might be because of Christmas lights and since the nephews and nieces were at my house for the Christmas season. So I'll have to see mow much the kWh will drop on my next March 2014 bill. Which will be inconclusive since I'm starting to energize my work area just by today. And the POCO meter reading has a cut off date every 16th of the month. Meaning my February billing has the period covered January 16 to February 15, I think.

The solar panels are now on the roof and sun power is now juicing my work area while doing this post. Yehey! Reading on the volt panel meter is between 13V and 14V with the ampere reading is between 18A and 20A with the needle barely touching the 18A mark. The time now is 10:02AM.

I understand that the volt meter is between 13V and 14V because I turned on the inverter this morning while not yet connected to the panels and let it supply power to the TV and electric fan while my wife and kid are watching. Hehe just to prove to my wife that "You see? Even if there's a brownout you can watch TV and turn on the fan". Talking about justifying the expenses to the wife

For now the solar setup is supplying power to my work area and to the TV and fan to the living room. By this afternoon, I'll be letting the batteries charge up while we go out and spend the weekend. By tomorrow the official experiment and observation on how everything goes starts. To avoid the "getting conscious" knowing that we have solar power systems juicing our home, I told my wife and son to use the electricity as we normally do.

By the time my next bill arrives which probably a week before the month ends, I'll see how much kWh has reduced from my bill while still utilizing the electricity as though I have no solar setup connected. And then finally conclude the effect by June 2014 billing after I have 3 electric bills to compare with.

By that time I shall prove that Sunking was right all along that

it is impossible to ever achieve ROI on an off grid system

and that

with a 300 watt PWM system if you utilized every single watt hour of energy the system could generate works out to roughly 1 Kwh of electricity per day or 30 Kwh per month

And when that time comes, I'll surrender to the fact that my

assumptions are all wrong leading you to false conclusions

and will know what that garbage got in so I take that garbage out.

**workpod** · 03-01-2014, 11:25 PM

While re-reading this post I remembered something and is actually out of topic but pertaining to justifying expenses and never achieving ROI.

I used to own a motorcycle when I was a Systems Analyst/Programmer of a local company. My wife would backride when we go out to malls, outside town to visit the in-laws, eat out. Not to mention the heat, sweat, smell, pollution what we have to endure. And have to find shelter when rain comes when we were out riding. When our son came it was hard as it's very dangerous to bring along a baby on a motorcycle (as if riding in tandem is not dangerous enough).

So my wife and I agreed on a project to take on a car loan and bought a 7-seater Toyota Avansa. Why a 7-seater? So we could have plenty of spaces for the in-laws and the nephews/nieces. It was my wife's idea actually. I had already quit my local job at that time was already working as an online web developer/programmer. Also sold my motorcycle since I was already working at home.

At first I was very reluctant as the downpayment was about US$4,700 at that time and the monthly payment of roughly US$302 for 5 years. That's a total of US$22,820. And the gasoline is now is around US$1 per liter. And I wont be using the car everyday since I'm working at home. This investment I truly believed was impractical, waste of money, and will never achieve ROI. But still I looked at the beautiful pleading eyes of my wife and even the eyes of my baby son seemed to be saying "pretty please...." and was surprised to hear myself saying "What color would you like Honey?"

Okey so we now comfortably riding our car with the aircon on to keep out the heat and pollution. Plenty of space with the baby comfortably cooing. Never minding the ever rising fuel cost and car maintenance. And just enjoy the comfort and safety more than when we were out riding in tandem in a motorcycle.

And guess what? I still bought a cruiser type motorcycle because I love riding a motorcycle. And even eyeing for that low end Harley I saw in a mall last few months ago.

Update:
It's now 11:44AM and the panel reading is 13V 20A. Is this normal? Should not I be reading the amps close to 30A. Or at least maybe between 24A to 27A?

I guess so as the computer work area is still connected with the 42" Samsung TV with satellite receiver and 65W electric fan at the living room feeding off the inverter. But still I'm not quite sure. Maybe because it's a PWM charge controller?

When I switch off the circuit breaker between the panel meters and the charge controller, the reading goes to midway 17V and 18V with 0A. Understandable since there's no load.

The 3 solar panels are parallel connected to a weather proof combiner box at the roof via a #10 weather proof Royal cord wire and a single 5 meter #10 Royal cord leading to the panel meters to the panel board. The panel meters are connected to a 30A circuit breaker using a #8 automotive wires before connected to the 30A PWM charge controller which is then connected to another 32A circuit breaker. Then wired to the batteries in parallel still using #8 automotive wires. Then another set of #8 automotive wires are connected to the Pure Sinewave Inverter. A DPDT 60A knife switch connects my workarea to the inverter output. I'm using a #10 PDX wire for the AC side.

The TV and electric fan are temporarily connected to a 7 meter #10 extension wire connected to the inverter's second AC output. This is where I'm going to connect my light wires at night, to the second AC output of the inverter. Until I fix my light's wiring on a more safe and permanent setup with safety circuit breakers.

**workpod** · 03-02-2014, 05:14 AM

Just got off from a computer game I was playing. Didn't noticed it's already 4:45PM

Still have my workarea on solar, while my kid is watching Toonami with the TV also on solar. Checked the panel reading and it's 12V8A.

Now have switched the workarea and TV back to the grid and let the batteries rest overnight to see the actual no-load voltage.

Batteries without load are 12.6V to 12.7V on the multimeter with panels switched off, disconnected from the charge controller and inverter turned off. I guess that means it's still on 100% charge as stated here: http://www.solarnavigator.net/battery_charging.htm I'll check again tomorrow morning on the voltage.

Have researched on the rectifier-batteries-inverter setup. The setup still needs to connect to the grid to convert the AC to DC and charge the batteries. Useful during a heavy cloudy day the whole day or perhaps half-day. But won't be using the rectifier though as the inverter has a built-in charger that can accomodate 500Ah and up. All I have to do is just plugin the AC input line of the inverter to the mains.

Perhaps a grid tie/offgrid hybrid would do. But I won't get into that yet. Still very early to get into another mess.

But the way things are I'm quite happy that I was offgrid since 10:00AM this morning until 5:00PM this afternoon. And still have my batteries on full charge.

By the way, is it okey to leave the panels disconnected from the charge controller? And the batteries also disconnected from the charge controller?

**axis11** · 03-02-2014, 11:35 AM

Voltage reading on the battery to determine state of charge is very inaccurate. At least let it rest for 3 hours before you take voltage readings.
It's fine to leave everything disconnected. But why do you intend to do that?

Now that you have your system running, you might as well check how many dc amps is the inverter requiring when you have everything hooked up. Then compare your PV amps input. You can have an estimate which is greater between production and consumption at different times of the day.Keep in mind there are conversion losses.

During the rainy season, it will be a different story. Sunkings assumption of 30KWH/ month production is more than likely to be near the actual data you can get if you count it as a monthly average for the whole year.

Let's not go on a debate about ROI. Just let us know how it turns up after 4 years.

Whatever the result is, you still win because you succeeded in your primary goal to keep your business running with or without the grid.

If you include the possible losses in downtime due to power failures in your ROI computation, you could break even earlier.

**Sunking** · 03-02-2014, 12:24 PM

Originally posted by axis11

Whatever the result is, you still win because you succeeded in your primary goal to keep your business running with or without the grid.

Well here is the point, it is a very bad way to go about it. Get a inexpensive 24 volt 50 amp rectifier, connected to a 24 volt 200 AH Deep Cycle AGM battery connected to a 24 volt 1 Kva inverter and he gets exactly what he wants for a whole lot less investment. It is called a Dual Conversion UPS. It uses grid power when avaialble, and switches to battery when grid fails. When restored it the battery recharges and inverter is back on the grid. There is nothing to do as it is automatic. He is not going to save any money with solar. POCO charges him 23 cents per Kwh, and anything he takes off grid is going to cost him $3 Kwh in his location. He is just fooling himself with wrong assumptions.

**workpod** · 03-02-2014, 07:14 PM

Originally posted by axis11

Let's not go on a debate about ROI. Just let us know how it turns up after 4 years.

Okey I got it. I give up on the ROI thingy. I forgot all about it already.

Yes that's what I'm afraid of, when rainy season comes the solar production will be drastically affected.

BTW, just checked the batteries, the voltage as 12.4V to 12.5V. Reconnected everything now. Kindly bare with me, a really total noob on this.

At 6:00AM voltage is halfway between 12V and 13V. Amps is 0A.
7:00AM reading is 12V 4A. Workarea on solar.

How can I determine the DC amps the inverting is requiring when everything is hooked up? PV amps I'll know since I have an ampere meter from the panels to the controller. Should I add another amp meter from battery to the inverter?

@Sunking
I'll dig deeper n the possibility of using a Dual Conversion UPS or a rectifier thingy.

Is this what you mean? http://www.ebay.com.au/itm/50AMP-AC-...-/120741122246
Or this? http://www.ebay.com/itm/Siemens-rect...-/200805535824

Forgive the guy for being dreamy in the allure of going solar. Have to wake up at some point.

Thanks for the guiding me to the right direction. Really really appreciate it.

**Sunking** · 03-02-2014, 08:23 PM

Originally posted by workpod

At 6:00AM voltage is halfway between 12V and 13V. Amps is 0A.
7:00AM reading is 12V 4A. Workarea on solar.

OK SOC voltages are kind of useless on a working system but that would indicate your battery was around 50% which is an area you want to avoid. Ideally you never want to go below 75% capacity. Otherwise cycle life goes out the door.

Originally posted by workpod

How can I determine the DC amps the inverting is requiring when everything is hooked up? PV amps I'll know since I have an ampere meter from the panels to the controller. Should I add another amp meter from battery to the inverter?

Yes that is the most important measurement to determine what is really going on and how everything should be sized up. Anyone doing battery work is going to need a good DVM and amp meter, plus a hydrometer and thermometer to measure battery health

Originally posted by workpod

@Sunking
I'll dig deeper n the possibility of using a Dual Conversion UPS or a rectifier thingy.

Is this what you mean? http://www.ebay.com.au/itm/50AMP-AC-...-/120741122246
Or this? http://www.ebay.com/itm/Siemens-rect...-/200805535824

Something like the Seimons unit in your second link. Problem I see with that one is it is 3-phase. You will need one that matches your electric service.

There are a lot of telecom surplus 24 volt battery rectifiers out there for cheap. Look or search
Lorain 24 volt Rectifier
Reltech 24 Volt Rectifier
Surplus Telephone 24 Volt Rectifier
24 Volt Float Rectifier

You are looking for something like this.

**workpod** · 03-02-2014, 08:31 PM

@Sunking
Great. Thanks for the search keywords and links.

Panel reading update as of 6:30PM:
6:00AM -12V+ 0A
7:00AM -12V 10A (connected the workarea and the living room with TV, satellite receiver, light and fan)
8:00AM -12V 10A
9:00AM – 13V 16A
10:00AM – 13V+ 18A+ (more like 19A)
11:00AM – 13V+ 20A
12:00NN – 13V+ 20A+ (more like 20.5A or 21A)
1:00PM – 13V+ 20A+
2:00PM – 13V+ 20A
3:00PM – 13V 16A+
4:00PM – 12V+ 10A (a bit of clouds are on the west)
4:30PM – 12V 4A (sun is hiding behind the clouds at the west)
5:00PM - 12V 4A
6:00PM - 12V 0A+ (sun is well over the horizon. Orange clouds can be seen on the west)

At 4:30PM I already disconnected my workarea and the living room from the solar but left the house lights connected to the inverter.

I decided to leave the house lights to the inverter 24/7 since the total consumption of the lights would only be 10W max when turned on at the same moment.

To avoid posting my reading updates and more details on the progress you can visit the topic here: http://www.workpod.org/renewable-energy/going-solar/

Most of the post I'll put up shall be quoted from this thread to also help out some guys who are into this.

**axis11** · 03-02-2014, 10:52 PM

Based on your voltage readings, it's showing that your battery never gets fully charged. You should see more than 14v when charging and more than 13v a few minutes after the charging has stopped.. You are consuming way more power than the panels can replenish. You just can't see it immediately because of the size of your battery bank.

Its good to have an ammeter between the battery and inverter so you have an idea what is the power draw for each device and the combined power your system is using. I used a cheapy ammeter like this

Error Page | eBay

http://www.ebay.com/itm/New-200V-100A-DC-Digital-Voltmeter-Ammeter-LED-Amp-Volt-Meter-Current-Shunt-/350919680206?pt=LH_DefaultDomain_0&hash=item51b47160ce

Plus a digital dc clamp ammeter to be able to know what is going on on different parts of the system.

**workpod** · 03-02-2014, 11:21 PM

@axis11
Nice one. Thanks kabayan

**Sunny Solar** · 03-03-2014, 03:33 AM

Workpod save yourself headaches and frustration.. sell all the equipment you bought to someone that will believe he will save money going solar.. .. Don't even think grid tie as there are no incentives to do so and the way 90% of the meters work here you would end up paying the power co. for all the power you generate.. Not good on the pocket..
Do a much more reliable simple system like I use.
1 X 1000 w 12v TSW invereter
1 x 25a 12v battery charger. (one with at least 4 steps of charging)
2x 12v n100 truck batteries. (about p6000 ea motorlite are best)
You don't need expensive deep cycle batteries for what you are going to do.
Connect the battery charger to the batteries the batteries to the inverter and then to the computer. Simply turn on the battery charger before using the computer.. Connect a room light to the inverter also and you will never know you are having a brownout until you look elsewhere.

Using the above system permanently to power your computer will be far cheaper than buying a built UPS and with far greater capacity and easy expansion.
Iseriously doubt you can buy grid tie solar panels cheaper than 12v panels..As they are virtually unknown and not easy to obtain.. Mabe any you do find would have been made by a Barangay Captains elementary school kids as a project..

Seriously you simply cant save even one centavo on going solar.Even if you are buying from one of the worlds most expensive electricity suppliers Meralco.

Newbie from Philippines with a 300W setup

Newbie from Philippines with a 300W setup

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