New Gifft Hill weather station and other stuff

Coconuts · Post by **Coconuts** » Sat Apr 16, 2016 9:20 am

We'll be heading back tomorrow, after a very nice but busy two weeks at the villas. When I get back to work, a common question is "So, how was your vacation"? My answer is almost always: "We got a whole lot done!", which isn't what they expect to hear, but pretty much sums it up.

One project was to put up a weather station on the roof of Plumeria. It measures the air temperature, barometric pressure, wind speed and direction, rainfall, and humidity. Installation photo here:

: Installing the weather station

You can now monitor the weather on Gifft Hill, using the following link:
http://www.wunderground.com/personal-we ... =ICRUZBAY5
The air has been exceptionally clear for the last three days; we can easily see El Toro in Puerto Rico, 65 miles away, and Vieques is very clear along the horizon. Forecasts call for some heavy rain over the next few days, and it will be nice to know how much rain actually fell at the villas.

Among other projects at Plumeria was switching out the old, in-wall A/C units for whisper-quiet, very efficient split A/C units in each bedroom. Over at Coconuts, we power-washed the roofs and sanded all of the decks (2000 sq. ft.), and then applied two new coats of deck paint. I use the "we" liberally; we did have professional help, but there was still a a lot of deck furniture to move out and back.

: Newly painted deck at sunset

No visit would be complete without a supplies run to St. Thomas:

: Loaded

Six beach chairs were strapped onto the roof.

A highlight from our last trip was adding a ground-mounted array of 32 high-output solar panels:

: Setting the last panel in place

Together with the 27 roof-mounted panels that we installed last year, that brings us up to 59 panels - 18 kilowatts peak. This makes both villas carbon neutral as long as guests are reasonably prudent in their power use (essentially, don't turn everything on and leave it on, or leave the spas open). Despite the number of panels, most guests won't even notice that they are there; the ground mount is below a hedge of Bougainvillea, and the roof panels face away from the courtyards.

Eating at Joe's Rum Hut one day, I noted some people on the beach playing a game that I didn't recognize. My daughter rolled her eyes, and informed me that it was "Cornhole". That seemed like a nice new lawn or deck amenity, so I whipped up a set, with bags that match the target colors:

: Cornhole

I had a few more photos to post, but the way I do it (as attachments) is limited to five per post, so I will add a new post shortly.

All the best,

Kevin

mbw1024 · Post by **mbw1024** » Sat Apr 16, 2016 11:27 am

Love that sunset with no furniture in view. Great photo.
Look foward to being there in 5 weeks!

PaminMaine · Post by **PaminMaine** » Sat Apr 16, 2016 4:22 pm

Kevin,

This is the message on your link:
This PWS is not reporting
Last updated: 4/16/2016, 7:55:36 AM,
8 hours ago

Coconuts · Post by **Coconuts** » Sat Apr 16, 2016 4:55 pm

Pam: Yeah; I'm not sure what is going on. My personal link to the Rainwise site has been reporting fine all day, but the pick-up to Weather Underground stopped working at about the same time that I posted the link on VIOL. I also tried at that time to add a photo and other details, and got stuck in an endless "upgrade your account" cycle. That certainly makes for an embarrassing public launch of the weather station. I will need to connect with WU, probably on Monday, and see how we can get it back online. I'll update this thread when it is back up.

All the best,

Kevin

loria · Post by **loria** » Sat Apr 16, 2016 6:10 pm

you will LOVE the splits-- super quiet and very energy efficient.

RickG · Post by **RickG** » Sun Apr 17, 2016 3:14 pm

Sounds like you are accomplishing a lot. I love the split units too. Is all of your solar going to net metering, or do you have some batteries? We have panels and batteries on our boat.

Cheers, RickG

Coconuts · Post by **Coconuts** » Sun Apr 17, 2016 5:27 pm

Rick: We are using net metering for now, but are getting proposals on battery systems of each villa. From a reply in my other thread:

"The solar project is complete for now, and has more than met our expectations. I have some comments in my earlier post. The ground mount system used 315 watt LG panels, which is as high an efficiency as you can get now (20%). Solar City, via their acquisition of Silevo, is set to tick up efficiency to 22 - 23% starting next year. While we got in under the net metering cap, we are considering putting Sonnen (http://www.sonnen-batterie.com/en-us/start) battery storage systems at each villa. Sonnen battery storage systems are available now, and use lithium iron phosphate cells, with twice as many cycles (10K versus 5K) as the still a year away Tesla Powerwall."

On the split A/C theme, we installed Misubishi Slims at Coconuts in 2011, and really like them. Our next split event was to put two of Mitsubishi's cutting edge (2014 release) FH series. We use these for a bit in the heat of summer, but their main role is as heat pumps, for which they have really lowered our oil bill. Heat pumps (and air conditioners) do some thermodynamic magic in that you only spend 1 unit of power to move five or more. When we decided to switch to splits at Plumeria, we went with the same FH series; they will probably never be used to provide heat, but that are crazy efficient in A/C mode, with a SEER of 30.5!

All the best,

Kevin

RickG · Post by **RickG** » Mon Apr 18, 2016 4:43 pm

Good stuff, thanks for the details. The LiFePO4 are starting to take off. They still seem more expensive for our use, but the cycle life time is pretty amazing. If you go that way, will you go with a big inverter or do 24V/12V appliances? It seems like the inverter is the way to go unless you want to go off-grid.

Cheers, RickG

kklay · Post by **kklay** » Tue Apr 19, 2016 11:05 am

Kevin - enjoyed your update. We were so hoping to stay in one of your villas this Fall, but needed at least another couple to commit. . . . .maybe next time. Your views look amazing. My husband was very impressed with the grill! I'm really interested in your solar panels and I'm sure you are going to track overall savings from before and after - hopefully you can share with us!

GratefulDad · Post by **GratefulDad** » Tue Apr 19, 2016 11:40 pm

Kevin - I noticed you (and pretty much everyone else on STJ) use bleach, I suspect, as a cleaner and or mold inhibitor. I have found that white vinegar is an excellent cleaner and mold inhibitor. Combined with baking soda it removes stains and is much easier on grout, pipes, tile, glass, the person using it and the environment in general. Straight up, it drops the pH so low nothing could survive. I use 50% in a spray bottle and it works very well. 1 gal of white vinegar costs about $.89 here.

I hope you get that weather station up soon. I am interested in stuff like that.

Coconuts · Post by **Coconuts** » Wed Apr 20, 2016 1:02 pm

I am happy to report that I finally found the setting in my personal Rainwise account that somehow got reset, which prevented its data from being publicly available via Weather Underground. Here's the link again, and hopefully this time it will stay up permanently:
https://maps.wunderground.com/personal- ... =ICRUZBAY5

RickG: "If you go that way, will you go with a big inverter or do 24V/12V appliances? It seems like the inverter is the way to go unless you want to go off-grid".

Our panels all have very efficient micro-inverters, one for each panel. That prevents partial shading of one panel from pulling down the output of unshaded panels, and is fully compatible with the Sonnen LiPO4 battery system.

GD: Thanks for the tip. Suppressing mildew is important, and we will give white vinegar a try, but I won't be adding baking soda to it anytime soon... was that a prank?

kklay: I'm happy to share some details on solar performance. We installed whole-villa grid flow sensors, which we can monitor over the internet. We are essentially carbon neutral at this point, although that depends on how sunny the weather is, and how prudent our guests are. Yesterday and today have had a thin overcast and some clouds, but the guests are also doing very well, so still positive right now. The bare-bones power draw of each villa is about 400 Watts. The typical draw with guests using A/C and fans, but only when they are in that area, is a bit over 1 kW. Higher use levels would be up over 2 kW, and above 3 kW is "imprudent". We once had some guests who were up over 7 kW continuously. I called to say that we were concerned about a possible short in our electrical system, and asked if our electrician could stop by to make sure that everything was safe. The power draw dropped to reasonable values almost immediately, so no visit was required. Presumably, they closed the lid to the spa for the first time since they arrived...

Here is a snapshot of today's power use. On a clear sunny day, the green curve (power delivered to the grid) is a smooth top half of a sine wave, with only a few interruptions when a cloud sails past, or the spa pumps turn on. Today, as a look at the Spice Cam will show, is not one of those days. At night, the red shows net draw from the grid. Again, these guests are remarkably efficient, with a very low base draw, which more than makes up for a less than very sunny day. The spikes are the spa pump and heaters topping up the spa temperature.

: Solar grid flow today

Our most recent WAPA bills had a bill of $58 for Plumeria, and a savings of $113 at Coconuts. We are allowed to bank savings for up to a year, after which they expire. Our electrical bills used to average $800, but we had some wacky bills that topped $2100!! These would invariably be followed by very low bills, suggesting to me that no one actually read the meter on the previous month, and that they just made up numbers.

The price per kW-hr had crept up to $0.54 last year, but a conversion program from diesel fuel to propane has lowered it to about $0.34 per kW-hr. That is still triple most state-side electricity rates. All-in, we are probably out $75K, but this should reach breakeven in about four years, far faster than most places. I would be happy to answer any other questions about our solar gear.

All the best,

Kevin

GratefulDad · Post by **GratefulDad** » Wed Apr 20, 2016 5:48 pm

No prank sir. I am a chemist and the reaction by adding acetic acid (vinegar) and sodium bicarbonate (baking soda) produces carbonic acid which is very unstable. Further decomposition produces sodium acetate and CO2 which is why is foams up. Very good for deodorizing drains, garbage disposers, and cleaning. Put the baking soda in the drain or place to be cleaned and slowly add the vinegar, either straight up or diluted 50/50 with water. Good hack and your pipes, grout tiles ect will be clean and unharmed. Think about it, you can use vinegar on your salad and brush your teeth with baking soda. Can you invest bleach?

Glad to heat the weather station is up. I'll give it a try.

Are you going to any shows this summer?

StMax · Post by **StMax** » Fri Apr 22, 2016 12:19 am

Thanks for the weather station link......very nice.

RickG · Post by **RickG** » Fri Apr 22, 2016 2:01 pm

I see the weather station. Nice!

I see Randy at Reef Madness just committed for the Sonnen Batterie. I'm interested in how the LiFePO4 batteries work out.

Cheers, RickG

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