Sharing our experiences with Solar

I had been contemplating a solar panels installation for our house for considerable time, doing my research and trying to get a grasp of what would be possible.
At first I thought that maybe our roof (because of its shape, too many triangles and a rather steep angle) was not suited for solar panels at all but as I collected more information those suitability thoughts got adjusted a fair bit.
Yes, a roof with a 35 degree angle/incline will negatively affect the expected production from your panels, just like installing some panels on a roof facing north, or with some partial shade, but panels have gotten so much better (higher efficiency and cheaper) that these aspects no longer need to be a deal breaker. Yes I'm losing around 11% in electricity production compared to an ideal installation (all panels facing south, at an optimal 9% incline) but because we're so close to the equator, panels facing east, west or even north will still produce decent amounts of electricity.
A really good website with a freely usable good calculator that allows you to fiddle around with the details of your intended setup is found here . Just enter your location (barangay and town) and start fiddling around.
Another aspect that their calculator covers is the variability of electricity production through the year. Yes it's still averages per month, but to know that the worst months of the year (nov/dec/jan) will still produce around 2/3 of what you'd see during the best months (mar/apr/may) will help you to choose the size of the installation for your house.

So, how did I go about it. I started off with our monthly electricity bills, which showed an average use of around 600-700 Kwh per month. 600 Kwh per month translates into 20 Kwh per day. In our case I figured that about half of that use would be after dark until daybreak the next day.
Considering that when investing in a solar system I definitely wanted to make sure that we'd have no more brownouts and virtually no more Noreco bills, so we wanted to include battery storage to get us through the evenings/nights.
To achieve that goal we decided on putting 16 panels on our roof, 6 facing south, 6 facing north and 4 facing east, 605 watts each, so 9.68 Kw in total. Combined with an 8 kw inverter and 2 batteries, 51.2V, 300 Ah each so 30.72 kwh in total.
This setup will hopefully ensure that we can survive even 3 consecutive days with lousy weather without needing Noreco.
Our system was installed early this month, so our actual experience so far has covered only a very sunny period. On these mostly sunny days our batteries get fully charged by 10 or 11 am in the morning. In other words, during sunny weather we have plenty (potential) excess electricity production. I can (tested) run all 4 aircons in the house (5.5 hp) during sunny hours without pulling any power from the batteries.
Obviously things will be less rosy during rainy periods, but I am pretty confident that even during these periods our Noreco bill will remain minimal.

Financially, we invested around 600k Php in our system. My expectations are that the system will pay for itself in about 4.5 years (I calculated with a 5% yearly increase in the Noreco rate). So even with the expectation that the batteries will need replacement after 12 years and the inverter after 15 years, then we'll still end up with a really good return over the expected life of the installation that will exceed 20% p.a. on an IRR basis (internal rate of return).

 

Some pictures to go with the thread:





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Further to my considerations:
To avoid misunderstandings, yes we did install batteries, but we do have a hybrid system, so not off-grid. That means we can use electricity from Noreco when needed.
We did not apply for net-metering yet, so we're not pushing excess electricity back to the grid. That may change but sofar my attempts to get clarity about the costs involved with that application were largely unsuccessful.
I did find out that the application process has recently been shortened a great deal based on instructions from the DOE (Department of Energy), Noreco now has only 10 working days to process the application, and the city has only 3 working days for the permit. Obviously things will take longer if your application doesn't fulfill the requirements.
Furthermore I found that yes you only get credits, not money, in return for the electricity delivered back to the grid and they only give you their "generation rate" which is only about half of what they charge you. That system works for households with an installation without batteries because they'd use up the credits after nightfall.
For us, with ample batteries in place, not actually getting paid would make net-metering a nono obviously, except there's been another change to the net-metering rules that says you can compensate the excess from the house with solar with the electricity bill for another separate building that you also own.
My calculations indicate we could expect to produce around 30k Php worth of excess electricity per year, so as long as the cost of getting approved is not excessive we could pocket that as a little extra return.
I'll keep you posted about any progress regarding the net-metering.

 

Very informative Dutchie. Our usage is about the same as yours so we're giving it serious consideration. Did you use a single contractor for supply and installation, if so who please? TIA

 

I sent you a private message