Solar powered house in PR

What about solar  generators? I saw that home depot has one  with 1500 watts with  wind turbine adaptability. $999. no fumes or noise.  Wouldn't one or two of these cover the basics? Pr is entering the cooler months so airconditioning would not be as necessary.

I recall a fairly robust thread on the topic of solar power.  Really too much to get into here I think,

Three options are grid-tie; grid-tie with battery backup; and off-grid. 

The first is simplest and cheapest.  Basically panels wired to the house current.  When the sun shines, the meter runs backwards.  Sun goes down, meter runs forward.  Problem is that when the grid goes down, panels won't power the house.

Second option solves that problem by adding battery, but also adding costs.  Many options for batteries are available, with different lifespans.  One I just found that I think deserves a closer look is a saltwater cell battery.  Info here.

Third option requires more careful and judicious use of electricity.  Most suitable for those locations without access to a grid at all.

Cost of a system depends on which of the three options you choose and how much power you wish to generate.  Will you install yourself, or have it done?  There's a significant mark-up for companies to do this, but this is not a basic do-it-yerself sort of project either.  Failure to wire this with all the proper safety switches (such as transfer switches) can get linemen killed.

Regarding "solar generators" these are little more than a solar cell mounted atop a battery.  Good for charging a cell phone, but you can't run a refrigerator on one of them.

We have a 4kw off grid battery powered system.  We have had it  in place for 3.5 years now.  Our  house is well off the main road so we sought out alternatives when we were building our home and solar was the option we went with. Best investment ever!!

Batteries carry the bulk of the cost, there is barely any maintenance and our system came with a 10 year warranty on the panels and batteries.  Panels were rated to withstand 110mph winds and i know we had to have at least 130mph in our area with the storm if not more based on reports and they made it.


We used a company called Pura Energia (www.puraenergiapr.com) and I highly reccomend them as they gave us a thorough presentation in the beginning and have stood behind their work and gave me the basic steps to ensure we are always up and running.

I searched the PR forum for "solar" and went thru the 1st three of many pages without finding a thorough discussion so excuse me if I missed and this thread may be a rehash. But things are changing in that industry rapidly. But thanks Warner for the heads up and the info, and Larry same.

However in my search I did come across a few excellent posts by Mac and Gary and Adlin about what they were paying in PR per month for juice and for which things they were juicing. Surprised as were others who posted that the cost was not as coo-coo as is commonly mentioned in other arenas although this quirk was mentioned--seemingly cheaper in certain areas for no logical reason. But, basically 21c minimum wherever per kwh hr.

So there's that.

But that's when there's juice. I've been there enough when there were intermittent black outs, sometimes 6-7 hs and that isn't going to change once the grid is repaired.
Or worse if PR gets hit again.

So there's that.

Back of the envelope calculations, if you spent $10k for a whole house including a fair amt of a/c use on a battery solar system, it would take 4-6 years? to start getting juice for next to nothing? 

But wouldn't you'd be spending the same for juice from the grid anyway with no return?
Plus the $5k you'd pay for a good Generac silent gen for those no juice times?

Am I off on this?

I'm going to keep digging and post info that may be of interest.

I installed a 11Kw generator and I will be adding the solar panels and battery back up as soon as the company can install it. Several reasons for this decision, cost of electricity, reliability of the AEE service and cost and reliability of fuel for generator. Installing the solar system and batteries will cost around 17K for a system big enough to run my whole house. This will be expensive, but what price will you put to your peace of mind.
If one thing teach every one of us during this catastrophic event was that fuel is a big commodity and it's hard to find when the infrastructure collapse.  Also, to maintain a generator running for this long time it will be very expensive. Running 24/7 my propane system with use a 200# tank in 36-40 hours. At over $100/tank that's really pricey.
To those thinking about a generator, I will suggest going with propane fuel, you will be able to store a couple of hundreds pounds of fuel more easily than disel or gasoline. A propane tank will last a few years without having to do nothing to it. Plus, based on this event, it will be easier to obtain.

Doesn't the government still provide dollar rebates on solar installations? If my place were suitable for such a system, I would definitely look into it.

I was in Barbados a few months back and about half the homes there are powered by solar. Finland, Costa Rica, New Zealand, Netherlands and Norway are on track to be carbon neutral in a few years -- Costa Rica has already acheived that goal for about half the year. Notice that most of these countries are not known for their abundance of sunshine.

Solar is very doable in PR and if I were king, I'd put Musk, Branson and Rossello in a room together to come up with a plan to provide it for the entire island.

The local government have a rebate program, not too impressed with it since its basically first come first serve. If you file federal taxes you can claim the federal rebate, it's 30% of the total cost of your system. The problem in the island is that most people working in PR do not file federal taxes, so they cannot get the rebate.
As to why the island had not moved into renewable energy, simple, politics. Big energy contracts given for political favors and a capitalized energy system.
Hopefully now that the government have to fix a completely broken system and that the federal government is overseeing the process it will move towards renewable energy power.

dgdlaw wrote:

I searched the PR forum for "solar" and went thru the 1st three of many pages without finding a thorough discussion so excuse me if I missed and this thread may be a rehash. But things are changing in that industry rapidly.

I didn't mean to imply that you hadn't done your homework -- to the contrary, I was certain that you had!  But the search function isn't as intuitive as it needs to be, and thread titles often don't reflect where the thread ends up.  I too did a search for "solar power" and couldn't find the thread that I remember.  (Hmm, maybe a search for "PowerWall" would work).  SawMan, as I recall, has done a lot of investigation into solar, and I believe has solar cells on his house in the states.

Anyway, you are absolutely correct that the industry is changing rapidly, most especially with regard to storage.  Efficiency of solar cells has grown rapidly, but those efficiency gains may be tapering off.  Prices for cells also seem to have come down quite a bit. 

Big issue (if you go off-grid or backup) is type of storage.  Some use lead acid batteries, basic car batteries.  Advantages are easy availability and low cost.  Disadvantages are toxic off-gassing (must be ventilated!!!) and short life.  A battery bank of lead acid (this includes gels) could easily include a couple dozen batteries.

A second, and apparently popular approach among those with the cash to pay for the initial expense, is Lithium Ion batteries.  Popular model is the PowerWall from Tesla.  As I recall, a single unit, which is hundreds of batteries wired together in a single case, runs about $3000.  Depending on your energy needs, you may want two of these.  Advantages are non-toxic and modest size.  These are often wall-mounted.  Disadvantages are initial cost and the risk of fire.  Bad batteries can get very hot!

I posted a link above to a company that makes saltwater cell batteries.  If you follow the link, you will discover that this is a start-up company just emerging from bankruptcy.  Promising technology, but uncertain availability and cost.  Advantages though include no off-gassing and no fire risk.  You would however want a sizable battery stack.

Hereis a link to Aquion's blog that compares the battery options above.

One last thing you might want to consider.  Batteries die after they are "cycled" to their limit.  A "cycle" is a discharge and re-charge.  So when you ask how long a battery will last, this depends on how often you cycle them.  An off-grid system cycles daily.  An on-grid with backup cycles only when the grid is down.  Here'sa video from Aquion that discusses cycling and depth of discharge.

Oh, and a few links to solar cell manufacturers/distributors -- if you are thinking as I am of installing this yourself.

Solar Electric Supply -- Kyocera 4.5KW kit

Wholesale Solar

Plenty of good advise given here! So, not much to add.

Keep your homework going, it's the only way you'll justify expenses or recovery. It's extremely important 'you' work out 'your' needs to juice.

I'm slowly switching over my batteries to Li-ion's from Lead Acid. My testing so far leads 'me' to believe it's a better solution for 'my' needs.

Good thread, I want to learn more about this technology.  We plan to build a new house on the beach and solar will be part of the package. 

I have a friend who built his own solar battery storage system in Ohio using lead/acid batteries, he claims it works well, but didn't discuss the gassing issue.   

The costs of li ion battery storage will continue to come down.  When electric cars overtake gas, the costs will fall significantly as the industry scales up. 

Wind power may be possible, the prevailing wind on the island seems to be a steady easterly 10 -12 knots most of the time.  I bet a turbine would produce power about 70-80% of time.   Being on the beach, the wind is unobstructed so a tall tower is not needed.

Solar seems to be winning the battle on the cost effectiveness question, but the wind blows at night so that may be a factor in chosing a system.

A lot of good stuff already, I'll be busy checking out the links. I'll share if worthy but you guys are way ahead of me. Like to know how much LarryJ paid and if the ten year warranty covered the battery life or just malfunctioning.

Sitka wrote:

The costs of li ion battery storage will continue to come down.  When electric cars overtake gas, the costs will fall significantly as the industry scales up.

I wouldn't count on that happening in our lifetimes, absent EXTREME market distortions from government regulation.  First, the price of a barrel of oil is unlikely to rise above $100 anytime soon.  Hydraulic fracturing is much too profitable at that point.  Current known reserves, especially when shale oil is added in, are simply massive.  Only with government prohibition of hydraulic fracturing, even more severe taxes on gasoline (along the lines of Europe) and even heavier government subsidies of "green" energy, are electric cars likely to compete with the internal combustion engine.  Quite simply, the internal combustion engine provides high power at low cost, while electric engines do the opposite.  Add to that the sunk costs of a gasoline distribution network and the start-up costs of an electricity distribution network (recharging stations) and the length of time it takes to recharge, and I don't see electrics replacing the ICE.  May see more propane engines, but that's a different matter.  Anyway, basic physics and economics suggest that electric cars are unlikely to overtake gas in the near future.

Wind power may be possible, the prevailing wind on the island seems to be a steady easterly 10 -12 knots most of the time.  I bet a turbine would produce power about 70-80% of time.   Being on the beach, the wind is unobstructed so a tall tower is not needed.

Solar seems to be winning the battle on the cost effectiveness question, but the wind blows at night so that may be a factor in chosing a system.

Physics also suggests that wind power is a non-starter as well.  While you are correct that, at least in the coastal regions wind may be more steady than sun, the problem is one of force.  Wind (and water) turbines take kinetic energy and convert it into electrical.  The force of the fluid flowing over the turbine is what spins the generator.  Quite simply, wind has low kinetic energy, while something like water has much higher kinetic energy.  Simply think about the ability of those two fluids (wind and water) to move a turbine.  Water clearly has much more force.  Efficiency of wind turbines has peaked -- not because of technological limitations, but physical ones.

Now don't get me wrong -- wind turbines may make financial sense along the coastal regions, and as an element in residential (or commercial or public) electricity generation they can play a role.  But the idea that wind in combination with solar will somehow produce all or even most of our electricity is wishful thinking.  If you are looking for more reliable "green" energy, nuclear, hydro and geo-thermal all offer efficiencies that wind and solar can't touch. 

But as I posted elsewhere, the nature of a grid requires the utility company to respond quickly to changes in demand, and that rapid response is possible only with fossil fuel plants.

Here's a good article on the physics and economics of "green" energy.

And another on the nature of a grid and the limitations of supplying that grid with "green" energy.

Pretty smart dude there WarnerW! I agree whole heartily.

I agree with your wind assessment. Though it seems like it should work great, my yard tests show quite the opposite. I had a five blade 500w bird flying. Results surprised me.. My solar does better over-all.
My cousin and I are converting it use in his stream for hydro-power. That's where the power is.

Again, once up and running, yard testing will show dollar for dollar what works better. And, again, this is 'his' location. What works best for one, does not for all.

Quote "I have a friend who built his own solar battery storage system in Ohio using lead/acid batteries, he claims it works well, but didn't discuss the gassing issue. " 

Probably thinks everyone knows this.. Reality is no. It's the nature of the beast, so to say. The chemical reaction as to charge/dis-charge your LA batteries. Sulfating is yet another.
LA's have there quirks, but if proper maintained/stored/handled can last a very long time (past what is their rated duty cycle).

Li-ions I also don't see coming down in price only to the extent that the technology on them is not done. Yes, you can buy lower ah rated ones better (just meaning needing more) better than you could two years ago.
Technology is also showing that you can beat their duty cycle as well if used correctly. As you can see, I'm a fan.
I am slowly building my own Power-Wall.

WarnerW,  This site claims cost of lithium ion batteries have fallen 70% over the past 18 months.  I don't know if it is true.

https://www.greentechmedia.com/articles … gs.aFDF_bQ 

I suppose a solar system could be installed without batteries and use the grid at night.   Then at some point in the future, install batteries when it drops to lower cost.   But, I would prefer to just do it and be off the grid.

For a home solar system the cost estimates I have seen range from $25 - 35k.   Don't think they include a battery system at that price.

Sitka,

Li-ion battery prices may very well fall.  Wouldn't surprise me.  Dawg seems to be in that market, and would be best positioned to comment on Li-ion prices.  I just don't expect a surge in that market and a fall in battery prices because of electric cars.  Physics and economics argue against electric cars overtaking the internal combustion engine anytime soon.

I'm quite interested in these saltwater batteries.  I'm not looking to build for a couple of years, so I've got time to wait and see whether the company gets off the ground this time.  The characteristics of the saltwater battery are decidedly different, making for some interesting choices.  In short, batteries either release their stored energy quickly but incompletely, or slowly but more completely.  Lead-acid and Li-ion are in the first category.  As such, you get a lot of energy out of fewer batteries, but they "die" when they are reduced to 1/2 charge (this is known as "depth of discharge").  The saltwater batteries release their energy more slowly, but "die" after 90% discharge.  Seems that if your peak usage is high, you might go with lead-acid or Li-ion, but if your peak usage is low (and sustained), you might be better off with the saltwater. 

Don't really know how much power you want to produce Sitka.  $25-35K seems a bit high, even with batteries.  Wholesale Solar has a complete 4.32KW grid-tie with battery backup system for $16K.  I suspect that when it comes time for it, I'll build the house with transfer switch and appropriate sub-panels pre-installed.  Then I can track electricity usage over a period of several months, which will give me an idea of how much electricity I need to produce.  If I've designed the wiring properly in advance, the system should be "plug-n-play".  Buy it, mount it, and plug it in!

Sitka wrote:

WarnerW,  This site claims cost of lithium ion batteries have fallen 70% over the past 18 months.  I don't know if it is true.

https://www.greentechmedia.com/articles … gs.aFDF_bQ 

I suppose a solar system could be installed without batteries and use the grid at night.   Then at some point in the future, install batteries when it drops to lower cost.   But, I would prefer to just do it and be off the grid.

For a home solar system the cost estimates I have seen range from $25 - 35k.   Don't think they include a battery system at that price.

Sitka,

I got quoted $17-19K depending how many batteries I wanted. A solar array of 3.9Kw with an hibrid inverter and a battery bank of eithe 9.8kwh or 19.6kwh. All installed, grid tied and my 11Kw generator programes into the system. This will be an Outback technology equipment. Certified and approved by AEE.

Sitka wrote:

WarnerW,  This site claims cost of lithium ion batteries have fallen 70% over the past 18 months.  I don't know if it is true.

https://www.greentechmedia.com/articles … gs.aFDF_bQ 

I suppose a solar system could be installed without batteries and use the grid at night.   Then at some point in the future, install batteries when it drops to lower cost.   But, I would prefer to just do it and be off the grid.

For a home solar system the cost estimates I have seen range from $25 - 35k.   Don't think they include a battery system at that price.

As an aside to "off the grid" I remember a post a while back from a poster who lives in PR that mentioned even if you are off their grid, PREPA still bills you monthly charges or three regardless, not a lot, app $20 seems to come to mind.

dgdlaw wrote:

Sitka wrote:

WarnerW,  This site claims cost of lithium ion batteries have fallen 70% over the past 18 months.  I don't know if it is true.

https://www.greentechmedia.com/articles … gs.aFDF_bQ 

I suppose a solar system could be installed without batteries and use the grid at night.   Then at some point in the future, install batteries when it drops to lower cost.   But, I would prefer to just do it and be off the grid.

For a home solar system the cost estimates I have seen range from $25 - 35k.   Don't think they include a battery system at that price.

As an aside to "off the grid" I remember a post a while back from a poster who lives in PR that mentioned even if you are off their grid, PREPA still bills you monthly charges or three regardless, not a lot, app $20 seems to come to mind.

Only if you have a grid tied system. If you have no use of electricity they will still charge you a $3/month line fee. I know of folks that have disconnected completely from the grid and don't have to pay a dime to AEE.

That's to me is a smart system!

Solar to Grid Tie when times are good. Batteries when times are weird. And the generator when the SHTF.

olddawgsrule wrote:

That's to me is a smart system!

Solar to Grid Tie when times are good. Batteries when times are weird. And the generator when the SHTF.

That was my train of though with this system. Not only that but this way the life spand of your battery system is closer to 10yrs average.

Sitka wrote:

WarnerW,  This site claims cost of lithium ion batteries have fallen 70% over the past 18 months.  I don't know if it is true.

https://www.greentechmedia.com/articles … gs.aFDF_bQ

The best price I have so far, on a 18650 I would actually buy (which I will not because still too expensive) is $8.62 shipped. 100 pieces minimal.

I pricing 70% lower? Depends on how you run the numbers...

I have a source for good 18650's. It's a slow source but can't beat the price... FREE!

If I find something priced right, I will share. Well, after I buy my lot... LOL!

Our friends recently installed a large Generac the comes on automaticly in an outage.  Runs on propane.  I wonder how long  it will run on a 100 lb tank?  After the tank runs empty, getting a refill may be difficult in post Maria.

I think it cost about $4 or 5K. 

Also, if you don't need to run it for a long period of time, I think the fuel should be fine?  Not sure about that.

Your batteries LA's? If so you know of Pulse maintianing? You could beat that average..
You seem smart enough to build the circuit I can send you. Knocks the sulfate down while on storage mode..
Only issue with the circuit is you have to have a large enough storage bank. It's strong! Meant for large banks.

Sitka wrote:

Our friends recently installed a large Generac the comes on automaticly in an outage.  Runs on propane.  I wonder how long  it will run on a 100 lb tank?  After the tank runs empty, getting a refill may be difficult in post Maria.

I think it cost about $4 or 5K. 

Also, if you don't need to run it for a long period of time, I think the fuel should be fine?  Not sure about that.

Propane, gas or diesel? That is the question.. Sorry couldn't help myself there...

Which fuel is most available to you. What then is most convenient. 

How long will it run? Well, full value abut 12hrs.. !/2 value 24hrs..
BUT.. that is all according to what you use is!

First step is identifying what you need to have powered. Do an evaluation of your requirements.

Me I run 2 -4hrs a day to re-charge the freezers and frig. Oh ya re-fill water and shower.
How long now? 5-6 days...

Depends on you use and need.

Exactly,  in the present situation, it could be a challenge to refill any type of tank.   Gas does not store well for long periods of time, propane may be best choice for shelf life (don't know about diesel).  If you really wanted to have a supply to last a long time without refill, a 500lb propane tank could be installed.

I have 2  400# propane gas tanks for my 11kw generator. Based on specs, this should last between 48-60 hrs running constantly (24/7). I will agree with the comments here, it will be unnecessary to run it that way and it can be make to last longer. The determining factor of going propane was based of availability and shelf life. But even if the tanks were to last a week or two, it still be expensive to run it over a longer period of time in a situation like this. So having the solar system with battery back up is a good way to go.

I noticed propane was easier to find during the early stages after the hurricane than gas or disel. Our local propane company was delivering tanks right after the hurricane hits. That may not had been the situation in all areas. Plus with the two tanks we were covered for a longer time. We had friends that have gas generators that had to make the long lines waiting for fuel.

Knowing consumption is spot on. We first inquiried with companies in PR about this in 2012 as we were completing construction of our home and since we had no record of our normal consumption and had yet to purchase everything we planned on using it was difficult even getting someone to provide us a quote so we almost gave in to AAE's quote of 17K (for  materials  and labor only) just to bring standard power to the bottom of our driveway!! Pura Energia, came in at 24K for solar so we went with it. Most of the cost went towards batteries being shipped in from their provider in Spain. 10yr Warranty included batteries and panels (16 of each).  As you all have mentioned technology has significantly advanced since we got set up and now similar outputs can be achieved at a much lower cost. 4Kw has been fine for us and we have all the standard appliances along with 2 ACs and have neen fine.  We do have to monitor what we use at night...basically eliminate using anything that generates heat, but daytime use on a sunny day is unlimited.   

Love the articles tghat others have posted on this thread, has given me great input for when it comes time to upgrade...

LarryJohnsonPR wrote:

Knowing consumption is spot on. We first inquiried with companies in PR about this in 2012 as we were completing construction of our home and since we had no record of our normal consumption and had yet to purchase everything we planned on using it was difficult even getting someone to provide us a quote so we almost gave in to AAE's quote of 17K (for  materials  and labor only) just to bring standard power to the bottom of our driveway!! Pura Energia, came in at 24K for solar so we went with it. Most of the cost went towards batteries being shipped in from their provider in Spain. 10yr Warranty included batteries and panels (16 of each).  As you all have mentioned technology has significantly advanced since we got set up and now similar outputs can be achieved at a much lower cost. 4Kw has been fine for us and we have all the standard appliances along with 2 ACs and have neen fine.  We do have to monitor what we use at night...basically eliminate using anything that generates heat, but daytime use on a sunny day is unlimited.   

Love the articles tghat others have posted on this thread, has given me great input for when it comes time to upgrade...

The mistake a lot of people made is overestimate the system capabilities. You must change your usage habits in order to be proficient using solar energy. The usage of LED lighting and high energy appliances is a must. Monitoring your usage is important to maintain a good sustainable system.

Another smart cookie here; Adlin20!

I'm an experimenter/hobbyist at heart. I made up a circuit to run 110v LED bulb's from a drill battery and much more efficient than a inverter. Actually running 4 6w leds, I use half the wattage to run them. Pretty cool aye!
Well, it still is a 'bench test' and needs tweaking..

Right now I use these light bulb style led flashlights (6w) as my emergency lighting. Runs on my 18650 li-ion batteries (another reason I'm a fan).
Bulb flashlight

I only mention this as part of being efficient in your power use. Many ways of doing so and part of analyzing what you really require.

When we built our house, we did it thinking on going green. All lights are LED, higher efficiency appliances and plenty of natural light. Open concept for optimism the natural Caribbean breeze. House is plumb for solar water heater and roof downspouts are designed to eventually collect all rain water. Plus we have a man made canal we can take advantage as a water source. With the siolar and battery system we could be self sufficient 100% off grid.

Well... the present situation with power off for months with no clue when we will get power, I have decided to convert to solar off grid with battery. 

This will cost a bundle, but the thought of this occurring again in the future...no way.

Getting a cost estimate and will move forward with installation when we go back to the island.   

Let us know what you got, size and the cost when you get it Sitka.

I am installing a 3.9kw solar panel with a battery bank of 19.6Kwh, integrated with my 11KW generator. The cost of this system is$19K all installed with AEE permits hybrid system and satellite monitoring. That means , the solar system will provide 100% power to our house during the day. At night, we will be using the grid credit. When the electric company is off, the battery banks will kick in. If at any point, the battery bank goes below 50%, the generator will turn on and re charge the battery bank. I can set it up where the battery will be the first supplier, solar secondary and grid and generator as back ups.

Just came across this article on storage technology.  Looks like the same thing that Aquion is doing --- there's mention of a patent app but it seems that the basic design (saltwater battery) is the same.

Seems promising for large-scale storage and significant cycling.

https://mse.stanford.edu/news/researche … ind-energy

WarnerW wrote:

Just came across this article on storage technology.  Looks like the same thing that Aquion is doing --- there's mention of a patent app but it seems that the basic design (saltwater battery) is the same.

Seems promising for large-scale storage and significant cycling.

https://mse.stanford.edu/news/researche … ind-energy

Interesting but may be a while

Many of the posts are from 2017 and back. Any information/updates for those of us who are hoping to break ground and install an off grid solar system in 2019?

bmccarney72 wrote:

Many of the posts are from 2017 and back. Any information/updates for those of us who are hoping to break ground and install an off grid solar system in 2019?

Government is talking about a sun tax, to charge people with a tax if you produce your own electricity so as to help pay the debt of the electric company. No final word yet, but looks like it is coming.