I got lazy last year and didn't post an update. I also made some changes, to my setup which complicates how to compute the values; which made me put it off again and again. But since, I'm moving on to the next project in the next few months, I should probably wrap this one up with a 3rd and most likely final update.
So as usual, here's links to the previous posts:
Summary:
| Parameter | Value |
|---|---|
| Running Days | 1506 |
| Total Production | 34.87MWH |
| Total Exported | 5.087MWH |
| Total Used | 29.783MWH (34.87 - 5.087) |
| Peso Value (Total Used) | P327,613 (29,783 * 11) |
| Peso Value Credit (Exported) | P25,435 (5087 * 5) |
| Total Return on Investment | P353,048 (327,613 + 25,435) |
Extracting some of the information from the images I attached, my system has been running for a little over 4 years. I generated roughly 34MWH of electricity over that period, of which 29MWH I directly consumed and 5MWH was exported to Meralco for credits. Those credits were then consumed on months when I consumed more than I exported. The last electric bill that I paid to Meralco was in November of 2023; since then, all zero bills.
To compute the Peso values, I'm still using very conservative values. P11/kwh for what I consume, where the typical now is probably at around P14-P15/kwh. For the export, I use P5/kwh generation charge. Looking back at the bills I posted from 2 years ago and now, generation charges range from P6.7/kwh to P8.3/kwh. So with that, I exported about P25K worth of electricity to Meralco, P13K of which is still to be consumed.
With that, it is fairly straightforward. I invested P270K, and in the past 4 years I managed to gain back about P353K. But that's not the full story. 2 years ago, I spent another P15K to process the net metering. And since then, I also purchased another 5kwh capacity battery to expand my capacity to 15Kwh. As well as a few panels on micro-inverters, just because I want to get data on sub-optimal panel positioning and shading. This is where it gets a bit more complicated, because most of these I got for practically free or discounted. But not putting a price on it is not going to be very realistic for other people. So, I'd put a proper amount of about P60K for those upgrades even though that's not what I paid for it.
| Expense | Amount |
|---|---|
| Initial Investment | P270K |
| Net Metering | P15K |
| Upgrades | P60K |
| Total | P345K |
In conclusion, I've more or less broken-even after 4 years and any generation at this point onward is free electricity. The common concern most people bring-up is "maintenance cost". Again, in the past 4 years, I haven't done any sort of maintenance or cleaning of the panels. Battery degradation, for sure is happening now that I am moving to the 1k-2k cycles range. But it is not at a point where it is noticeable. Charge/discharge cycles can still hit the 15Kwh mark.
What's Next?
As I mentioned at the start of the post, I am moving to the next project; literally. Current house is starting to feel a little small, so I got a slightly bigger property and we'll be renovating in the coming months. Of course, part of the renovation is putting up a larger array on it and applying some lessons learned from this one.
So what happens to this one? I won't be removing the solar setup on it and have it rented out. It will transition from saving me money to making me money as I will be collecting the payments for electric.