Solar panel results with data!

[debbie112]

@tenderloin The insurance Is from our longtime house insurance. I just added it to the policy. They only insure in case of damages and not due to solar manufacturer defects (like I think solaric offers).

It’s a grid tie inverter.

I wanted to get a good costower ratio while being on the upper end on power:size. I finally decided on Janko 535W panels. Reviews are good but not by much from other solar panels.

My main conclusions are:

• Don’t buy the premium premium solar panels that last 25 years. By the time you have your solar panels Out of warranty already (10-12-15) years, solar panel prices will have dropped significantly and that will provide you a better ROI.
• Battery technology also isn’t up to what I’d say are economical levels just yet so hybrid isnt my direction now, Currently better to use your power grid as your ‘battery’
• Do go for net metering if you have extra capacity. This requires a bit of data gathering and analysis imo.
• Go for mid range inverters that have a warranty of at least 5 years and have good monitoring technology. Mine is a Solis inverter, They’re China made and cheaper than the US Or Germany brands that boast 15-25 year warranty, I don’t need that long of a warranty. I want to be able to be lean enough to adapt to the latest tech.

 

[seekingpeace1]

@debbie112 Mga up to how many years ba magagamit yung solar panels? Like after a number of years ba eh bumababa yung power generation niya?

 

[bakersh3]

@seekingpeace1 Yes. Nagdedegrade ang output. Pero minimal lang. Magagamit sya for more than 20 or 30+ years. There are companies nga 25 years of warranty nung panel, pero very expensive pa rin sya as of now.

 

[seekingpeace1]

@bakersh3 Good to know. At least kampante ako kapag makaafford na ko nyan balang araw.

 

[nerissa1969]

@debbie112 Wow this is huge.

 

[blackbird72]

@debbie112 Will using batteries not completely eliminate dependency from Meralco (on 'normal' days)?

 

[godsgirl98]

@blackbird72 His system can only generate 30% of his power requirement. Adding a power bank will not give you 70% of that power requirement out of nowhere.

 

[mikey124]

@debbie112 I'd like to include that while the OP's computation appears very ideal with an ROI of 4 years, the computation does not include cost of maintenance, rate of degeneration, and lifetime of a solar panel which must be accounted for.

A solar panel is a form of tech and it gets more inefficient over time which would possibly lengthen its ROI, or worse, it could get destroyed even before the date of expected ROI. According to this article, average degeneration rate is 0.8% a year (noting that the results are from a review of literature and not from a scientific survey which might skew the results towards more efficient panels rather than inefficient ones, meaning 0.8% is an ideal estimate and it could rise past the 1% or 2% mark). A quick Google search also tells us that 25-30 years is an average industry standard for the life of a solar panel. Daylight inefficiency is also a major factor to key in as the Philippines is notoriously prone to storms and typhoons. Mere placement of panels on your homes also play a role.

Going back to the computation, daylight inefficiencies should be multiplied to total capacity. I say this because cloud coverage, among other things, will directly affect the overall kilowatt 'peak' (kWp) power of the panel, not the price after the fact.

If I may suggest an alternative savings computation:

Savings from Meralco, PHP = [(total capacity, kWp * daylight inefficiency, % * hours of peak performance, h) - total solar consumption, kWh] * PHP 5/kWh

You may also use this calculator to calculate what the total peak capacity will be after 4 years given: 17.5 kWp, 0.8% (or 0.08) degradation rate, 4 years; result: 17.444 kWp

To those curious about Meralco's Net Metering, here's a link.

My opinion:

I'm not sure if I get the point of solar panels as "investments" because in my eyes they appear to be liabilities more rather than assets. Assets provide cash-flow and increase in value over time. While they may be a source of cash flow in the short term (by means of Meralco buying your excess power after ROI), solar panels decrease (and cannot increase) in value over time, unlike "true" investments like paper assets and real estate (heck, even crypto) where cash flow, appreciation, and compounding interest can truly be realized (emphasis on "can"; returns are not guaranteed). There will come a point when you will have to throw the panels away. Additionally, they cannot be compared with returns on paper assets (as OP just did). As a matter of fact, they're apples and oranges. That's my two cents.

PS. I'm not against the whole idea of implementing solar panels for power. I'm an environmental advocate and I believe in clean energy. While solar panels were made for the better, I don't believe in the efficiency of the technology just yet. Currently, the net environmental impact of production far outweigh the benefits.

 

[debbie112]

@mikey124 Thank you for that valuable insight. Truly appreciate it,
I agree with you that your computation is more correct than mine and would provide a better estimate. Thanks.

Your investment standpoint is interesting. While I agree that ‘true’ investments are the ones that will increase your net value over time by way of appreciation or additional cashflow, I disagree that this can’t be counted as an Investment per se.

If you loosen up the terminology of what you want to consider as an investment to include ‘A current purchase/entity that will decrease costs of operation in the short/long term’ then we can consider at such. Both definitions have the desired effect of increasing net value (but the latter definition does so by means of operation expense reduction). Is it an asset then? Depends who you ask.

Case in point: Does switching your building lights from fluorescent to LED to save on power count as an investment? Since at the end of the month my net profit is increased, I consider that as an investment.

Btw, thanks for computing the efficiency decrease and the research of that standard 0.8%. It’s nice to add to my spreadsheet lol. Just like to add that that decrease honestly sounds great to me. I was expecting a larger decrease.

 

[karenlc2]

@debbie112 no need to loosen up on what is considered investment; his definition is wrong.

stating that

solar panels decrease (and cannot increase) in value over time

& therefore aren't investments is like stating that

a thing decrease (and cannot increase) in value over time

so it can't be considered as an investment is wrong. big telcos (TEL, GLO, CNVRG) & other manufacturing companies (URC, MONDE), & majority of businesses basically invests in machinery/technology because their assessment is that the IRR is higher than their target hurdle rate.

a thing is an investment if the NPV is positive, meaning the cash inflow will make up for the cash outflow over the life of the thing.

e: i would like to hear regular updates though (monthly? quarterly? whichever is convenient for you) re your solar coz there's this issue (idk if true) that its output degrades over time.

 

[karenlc2]

@mikey124 manufacturing, tech, & other companies regularly buy equipment that depreciates; they sell at a lower price or just throw away as scrap. TEL, GLO, CNVRG, URC, MONDE do that & wouldn't be around w/o buying equipment whose value decrease over time.

a thing is an investment if the NPV is positive, meaning the cash inflow will make up for the cash outflow over the life of the thing.

 

[lunamay]

@mikey124 I agree.

 

[heloise23]

@mikey124 Tip for solar panels - polishing compound

 

[believerofhim]

@mikey124 In my context this becomes an investment bec I have rental properties and would like to install solar and also rent it out (they pay me for providing electricity instead of meralco).

 

[tboymessiah]

@debbie112 I have 3 aircons, 1hp inverter, .5hp non inverter, 2hp inverter, 24cuft inverter ref, 3 pc working 8hrs because online classes, this month ang bill namin ay php2800. Aircon is open 8-4pm then 8pm-6am. Dati nung walang online class naglalaro yung bill nmain sa 1200-1800 php. Dati my battery kami for excess production, pero ngayon naka net metering na kami, madali lang naman magapply sa meralco, it took us 2 weeks siguro.,mura lang yung nagastos namin for net metering kasi kami pa lang sa area namin ang unang nagapply, mas mahal kapag may existing na na naka net meter sa area nyo.

 

[tboymessiah]

Also pre solar installation ang bill namin ay 6k.

 

[jesusfreak_2008]

@debbie112 thank you sir for the informative post! a couple of questions though since I'm also interested in a DIY set-up. Thanks!

1. Ilang solar panels for your set-up?
2. How much space did it cover (sqm)?
3. Can you provide links (or name) where you bought the panels and inverter?
4. Can you provide pics (if okay lang) of your set-up?

 

[debbie112]

@jesusfreak_2008

1. See comment below for answers to 1 & 2.
2. Lazada - Solis 5g Inverter. They’re actual website is https://solarprice.com.ph. The panels I got from Greewatt corporation. You can find them on Facebook.
3. I’ll do so later on.

 

[helloihaveaname]

@debbie112

• How are you selling power back to Meralco? I like the power generation but your power generation chart plateaus when we're usually at the office, so it's not useable unless stored for later use?
• Does your inverter include batteries?
• How much lot area did it cost you?
• Where is the general location of the installation? no need for exact address, I just need to compare general weather/climate

 

[debbie112]

@helloihaveaname

• I work from home so power is mostly utilized. Selling power back to meralco is by the net-metering mechanism I mentioned. Any excess you have, you sell to meralco then they credit you for 5.0php for each kWh you contribute to the grid. The way I like to think of it is, I use meralco as my ‘battery’ albeit at a huge ‘efficiency’ loss (5php / 9php). Net metering application usually go up to around 30-35k.
• inverters almost never come with batteries. You buy a different type of inverter for that and you buy the batteries separately. I do not have batteries
• uhhh don’t know really. You can look up 535W Jinko solar panels for its area and multiply it by 14 (the number of panels I have). I have a lot of spare roof to add solar panels on if I decide to do so.
• Paranaque