Solar Power Push

[Mike J]

We had planned on putting in a 5 to 7 KW off grid system in 2023 but the expenses from the typhoon last year will delay that for at least a  year.  I have crunched the numbers and for us the payback looks like it would be between 4 and 5 years.   Currently planning on having battery backup for brownouts and night use.  The price of electricity here is high and the cost of labor to install a system is relatively low.  This, combined with the reduction in cost of solar panels, means the ROI (return on investment) is much shorter here than in many other countries.  I did a quick google and it suggest the ROI on solar panels in the USA for example is 10 years as opposed to the 4 to 5 ROI here.  

[Possum]

If one believes battery prices will fall significantly one could install a hybrid system and install the batteries later. Still get the benefit of net metering while you wait. I save about 4000+/month from net metering alone.

[jimeve]

Batteries of the future. 

 

[hk blues]

On 1/1/2023 at 2:03 PM, Greglm said:

Even on cloudy days the system produces some power. Dec. 24 was cloudy but still made 10KWH total consumption was 17.4. 5KWH was fed back for credit. At night power is 100% Meralco.

With net metering any excess is fed back to Meralco for credit. Any shortage is fed from Meralco.

I have a cheap diesel generator for backup for the occasional outage, it's used rarely. Less than 50 hours over 2 years. Much cheaper than batteries.

Thanks.

To be honest, the guy (German) who spoke to us pretty much lost our interest because he was not at all clued up on the FIT so we were left scratching our heads trying to decide if and how the system was going to pay for itself given we'd need to use 'outside ' power at night and on some cloudy/rainy says with no clue if the net metering would counteract this enough.

All that said, we are not mean with the power usage and still come in at 3k give or take a month so hard to fully justify the capital expenditure until such time as the batteries become affordable then I'd reconsider.

[Possum]

Minister if Finance here says she has calculated 4 year pay back. We have 4 AC units 3 of which run heavy during spring and summer day time. But the electric bill runs about 1800/month and we feed back quite a bit too as they days are longer. Actually if we didn't run AC at all and only ran appliances during the day the bill would be less than 500 even in winter and they would pay us at the end of the year. But the idea was to live comfortably for little money. We like our creature comforts in old age.

[Mike J]

15 hours ago, hk blues said:

All that said, we are not mean with the power usage and still come in at 3k give or take a month so hard to fully justify the capital expenditure until such time as the batteries become affordable then I'd reconsider.

The return that pays for the solar system is not so much what returns to the grid, it is what you harvest for your internal needs.   A relatively inexpensive system would not have batteries and would provide your power during the day.  When voltage from the inverter drops below a certain point electrical supply automatically switches back to the grid.   Consider the buying decision based on what you save as opposed to what would go back to the grid.  Also you are only going to get about 50% "rate" from the utility as what you pay for service.   So for example if you are paying 10 peso per KWH, your credit for energy returned to the grid will be about 5 peso per KWH.  As @Greglm posted, install now and you can always wait for the price of batteries to fall.  Truth is they may not get much cheaper as the price of lithium has increased as demand increases.  You can see from the chart below how the price for batteries was dropping rapidly but is now close to flat.  I actually expect it to rise unless some of the new battery tech reduces that demand.  The chart stops at 2018 so it may have already began to rise?    And you can see how the price for lithium risen exponentially. 

 

[jimeve]

2 hours ago, Mike J said:

The return that pays for the solar system is not so much what returns to the grid, it is what you harvest for your internal needs.   A relatively inexpensive system would not have batteries and would provide your power during the day.  When voltage from the inverter drops below a certain point electrical supply automatically switches back to the grid.   Consider the buying decision based on what you save as opposed to what would go back to the grid.  Also you are only going to get about 50% "rate" from the utility as what you pay for service.   So for example if you are paying 10 peso per KWH, your credit for energy returned to the grid will be about 5 peso per KWH.  As @Greglm posted, install now and you can always wait for the price of batteries to fall.  Truth is they may not get much cheaper as the price of lithium has increased as demand increases.  You can see from the chart below how the price for batteries was dropping rapidly but is now close to flat.  I actually expect it to rise unless some of the new battery tech reduces that demand.  The chart stops at 2018 so it may have already began to rise?    And you can see how the price for lithium risen exponentially. 

 

Have you looked at "LIfePO4" batteries, they last 4 x more than Lithium batteries.

 

Edited January 3, 2023 by jimeve
Link would not work.

[Possum]

2 hours ago, Mike J said:

The return that pays for the solar system is not so much what returns to the grid, it is what you harvest for your internal needs.   A relatively inexpensive system would not have batteries and would provide your power during the day.  When voltage from the inverter drops below a certain point electrical supply automatically switches back to the grid. 

This is very true. The amount fed back to the grid is like charging your batteries while you run everything in the house for free. The power grid is your battery.

The 50% reduction in what the utilities pay for your power is a scam created long ago all over the world by the "public" utilities. At this moment the 2.2KW I am feeding into the grid for 6 pesos is being sold to my neighbors for 12 peso per KW by Meralco. If I got paid the same as I am charged my bill would be 0 or close to it most months.

[hk blues]

6 hours ago, Mike J said:

The return that pays for the solar system is not so much what returns to the grid, it is what you harvest for your internal needs.   A relatively inexpensive system would not have batteries and would provide your power during the day.  When voltage from the inverter drops below a certain point electrical supply automatically switches back to the grid.   Consider the buying decision based on what you save as opposed to what would go back to the grid.  Also you are only going to get about 50% "rate" from the utility as what you pay for service.   So for example if you are paying 10 peso per KWH, your credit for energy returned to the grid will be about 5 peso per KWH.  As @Greglm posted, install now and you can always wait for the price of batteries to fall.  Truth is they may not get much cheaper as the price of lithium has increased as demand increases.  You can see from the chart below how the price for batteries was dropping rapidly but is now close to flat.  I actually expect it to rise unless some of the new battery tech reduces that demand.  The chart stops at 2018 so it may have already began to rise?    And you can see how the price for lithium risen exponentially. 

 

And yet again I'm left scratching my head at the Math!

At a monthly bill of 3k I'd bet the majority of that comes at night when the 2 x A/Cs kick in and the TVs and lights go on etc - we don't use/need them during the day so at the very best we'd save 1k a month (the daytime usage) so assuming a capital outlay of 100K we'd take 8+ years to make our money back - pretty much as I calculated 5 years back.  I've taken a broadbrush approach but it won't be a million miles out.

My conclusion is that unless my daytime usage was much higher we'd not recover our outlay in anything like 3 years. Of course, I could then decide to use the A/Cs all day but it's not something we need and I'd also lose out on the FIT.  

Unless I'm missing something.

 

[fillipino_wannabe]

10 hours ago, hk blues said:

And yet again I'm left scratching my head at the Math!

At a monthly bill of 3k I'd bet the majority of that comes at night when the 2 x A/Cs kick in and the TVs and lights go on etc - we don't use/need them during the day so at the very best we'd save 1k a month (the daytime usage) so assuming a capital outlay of 100K we'd take 8+ years to make our money back - pretty much as I calculated 5 years back.  I've taken a broadbrush approach but it won't be a million miles out.

My conclusion is that unless my daytime usage was much higher we'd not recover our outlay in anything like 3 years. Of course, I could then decide to use the A/Cs all day but it's not something we need and I'd also lose out on the FIT.  

Unless I'm missing something.

 

If you buy a 3kWh grid tie system for 150k pesos it would produce about 350 Kwhs per month, if you sold all the electric to the electric company for 6 pesos per kWh they'd give you a credit for 2100 pesos so you'd pay 900 pesos out of your 3000 peso bill.

2100 peso saving per month would be a 6 year ROI but that's assuming you use all of your electric during the night, more likely it would be 3-4 years as you'd be using some directly yourself during the day rather than getting the 6 peso credit.

Edited January 3, 2023 by fillipino_wannabe