Solar Systems for homes

Number one question is how much power you will use. The essential question is really - Do you have air conditioning or an electric oven?
If not, it's easy and not too expensive. If you do, it slams the price up as you'll need more panels and, the expensive bit, more batteries.

Here's a trick - Add up the wattage of everything in the house, assume panels will produce half of their claimed output, then multiply by 0.8 to cope with losses in your inverter.
When you've done that, work out how many hours you need the lot to run for without sunlight. That's how many batteries you need, but you actually need more than that because you can't fully discharge batteries without damaging them.

That will give you an idea of if the supplier is ripping you off or not.

Another thing is go all LED lighting - Compared with old fashioned incandescent bulbs, you'll save an absolute fortune in panel and battery costs.  A 100w panel will run one 60W bulb - or a lot of LED lamps.
If you use 12v lighting, that takes out the inverter losses at least as far as lighting goes.

We're building in Las Terrenas, and will also have an "off-grid" solar solution. We will be connected to Luz y Fuerza, but will not sell power back and don't expect to use any!

We used EVR Solar. The owner, Frank, is back in Germany right now, but his electrician, Ulf (speaks German and Spanish), is in town and can help you out. I'll PM you his contact info.

Denise

ddmcghee wrote:

We're building in Las Terrenas, and will also have an "off-grid" solar solution.

https://evr-solar.com/

Interesting. Do you have anything like AC or ovens that use a lot of power, how many watts peak do you use, and do you have a rough spec of your system?

How many panels of what wattage and what do you have for batteries?

We have 24 panels and 300 KWH battery capacity. That's the extent of my knowledge of the system! My husband, Dave (RockyM), was the one in the weeds on this one.

Part of the reason we're keeping our connection to LyF is in case we do need a little extra boost if multiple AC units are running when we have guests. We only use AC at night, so little else should be on at the same time.

How much did that little baby cost?

Thanks for the information.  It will give us a good start.  Yes multiple A/C units buy only used with guests.  Larger home and built in 2017 so all LED already.   Definitely want adequate capacity and would rather oversize the system.  I understand the cost issue, but security off grid has a price for me so I'm willing to absorb the expense if it's done correctly.  I will reach out them and see what they have to say.

Thank you for your help.
--Scot

What is becoming popular these days is a dual system -
if your local luz is reliable

Have public power and use it to charge the batteries.
Yes, still having panels and a generator.

I just did this - as did some of my friends.

The batteries are constantly 'full'...if the street power goes off- the panels charge or we use the generator if nighttime

I am constantly on street power.... uses hardly any to 'float' the batteries.

I like it-- headache free

WillieWeb wrote:

Have public power and use it to charge the batteries.
Yes, still having panels and a generator.

I also looked at this. We have problems after thunderstorms or when trees (they grow crazy fast here) take down a power line. That can be once or twice a month in rainy season .. and dry season.
For people that just want a backup in the case of a power cut, these are really easy to install and far cheaper than a big solar system, but not off grid.

Certainly, depends on your local situation..... mine is reliable

Never off for mare than a few hours + I put in my own transformer

But even when off-- you just are back to solar..... still works

I want to emphasize the comfort of knowing your batteries are ALWAYS FULL.

No worries about sun tomorrow.... or using too much power at night.
Having a wine fridge.... extra freezer

I look at it expanding my battery bank.... more bang for the buck !!

With Luz y Fuerza, we pay more than the rest of the island! 14.50/kwh

The payoff with solar is much faster!

@Fred - I don't know the exact cost, but it was a fraction of what we were quoted in the US for a much smaller supplemental system.

Another thing I'm looking at is a limited system that will run AC all day. That means enough solar but limited battery, thus smaller dents in my bank account.
My big household bill is electricity (and that gets silly high when I run AC all day), but a full solar system with battery takes over 10 years to pay for itself, and that assumes no maintainance.

Fred wrote:

Another thing I'm looking at is a limited system that will run AC all day. That means enough solar but limited battery, thus smaller dents in my bank account.
My big household bill is electricity (and that gets silly high when I run AC all day), but a full solar system with battery takes over 10 years to pay for itself, and that assumes no maintainance.

You run the AC all day??

Full payback might take that long, but since you have to have some type of backup power here, and solar costs nothing on an ongoing basis (which protects you from rising energy costs), and it's greener!

Not all day as my bank manager would moan at me if I did.
However, it's ruddy hot here (about the same as your hot days) so it would be exceptionally nice to have it on.

I'm all for green as I would like my kids to grow up safe from the damage we're doing to the world, but I have to temper that with personal economics.
I'm all LED lighting, but only low power whatever electronics, and only use the car when walking would be a problem. My next vehicle will be an EV, probably with solar tech if I can get a deal I've been looking at off the ground.
On the bright side from my daughter's point of view, sea level rise predictions (even at best case) puts her school underwater within 2- years. She doesn't seem to have worked out she will be long left by that time - unless it's a revenge thing

Fred wrote:

Not all day as my bank manager would moan at me if I did.
However, it's ruddy hot here (about the same as your hot days) so it would be exceptionally nice to have it on.

Where is here? I assumed that since you were posting in the DR forum that you lived here. Are you familiar with the costs of things here? That would impact your comments on payback periods.

ddmcghee wrote:

Fred wrote:

Not all day as my bank manager would moan at me if I did.
However, it's ruddy hot here (about the same as your hot days) so it would be exceptionally nice to have it on.

Where is here? I assumed that since you were posting in the DR forum that you lived here. Are you familiar with the costs of things here? That would impact your comments on payback periods.

Not in DR but roughly the same climate conditions and considering the same issues, including the green thing.
I used Big Mac index to get a handle on how costs are likely to vary.