diy solar

diy solar

What are the top 5 gotchas for going totally off grid

So I have thought about getting another Pi and playing around with HA. Can you integrate multiple things like my Solar and Pool? I wonder if it will communicate with my Pentair stuff?
There are a lot of integrations which are directly available from HA, plus the HA community store as well where people contribute a lot of integrations. There is a HACS integration for Pentair:

I just have mine on an Athom smart switch using ESPHome for integration with HA.

As for your Solar PV, depends on what system it is or monitoring you use. There are dozens of options within HA:
plus no doubt a lot people have already built and available within HACS.

My grid system is Fronius so I use the HA Fronius integration and my off-grid system I monitor with Solar Assistant which has an MQTT integration with HA.
 
The Fam is always asking what I want for Christmas so I guess it’s a Pi this year. Thanks
 
There’s no such thing as lack of “headroom”. Any full sized residential off grid system (such as the one the OP is enquiring about) will include a fuel powered generator. The only point of interest is the cost of fuel over the lifespan of the system vs the extra cost of the energy efficiency of whatever appliance/building extra you are considering.

A lot of the suggestions here are more suited to a very small building, or mobile application.

Fuel can power HVAC, but HVAC can't make up for cold/hot surfaces in a building (usually can only do it via changing the air temp, which can only shift the surface temps so much*). So it isn't a straight trade off between fuel and insulation. But I can see that it is for other appliance efficiencies :)

Although in Costa Rica the delta T is lower, so I reckon your primary surface temp issue is going to be sun on windows. Luckily the closer you are to the equator the more consistent the sun angle, so it's easier to design for effective shading.

*radiant HVAC (hydronic usually) can directly change the surface temps of the surfaces that it is embedded in. Radiant cooling is also possible: https://www.energy.gov/energysaver/radiant-cooling and https://radiantcooling.com/
 
Fuel can power HVAC, but HVAC can't make up for cold/hot surfaces in a building (usually can only do it via changing the air temp, which can only shift the surface temps so much*). So it isn't a straight trade off between fuel and insulation. But I can see that it is for other appliance efficiencies :)

Although in Costa Rica the delta T is lower, so I reckon your primary surface temp issue is going to be sun on windows. Luckily the closer you are to the equator the more consistent the sun angle, so it's easier to design for effective shading.

*radiant HVAC (hydronic usually) can directly change the surface temps of the surfaces that it is embedded in. Radiant cooling is also possible: https://www.energy.gov/energysaver/radiant-cooling and https://radiantcooling.com/
That’s the theory. Build a few dozen off-grid houses with varying levels of insulation and then get back to me on how well that translates to reality.

I’ve lived in a certified passivhaus building, and a tin shed (and a lot of levels in between). If you have constant air temp and humidity, the surfaces catch up. If you rely only on insulation, even in a passivhaus, the building temperature changes, and after enough consecutive days of extreme heat becomes very uncomfortable.

Best I’ve found for our climate (essentially a desert) is lightweight building with moderate levels of insulation, and the ability to rapidly turn over the air if required.

Every area will be different, that’s why you need to run the numbers for yourself to see if it’s worth spending extra.

Even your fancy pool pump, if it’s $1500 more than a standard pump, would you be better off installing extra PV instead?

Too many people blindly spend big dollars on hyper efficient appliances and building techniques, and end up disappointed.
 
Even your fancy pool pump, if it’s $1500 more than a standard pump, would you be better off installing extra PV instead?
"Fancy" VFD pumps draw 1/4 of the power of standard single speed pumps and don't create a big surge demand on start up requiring a big inverter surge power overhead.

That's a lot of inverter, PV and battery capacity you won't need to allow for on poor solar days. Depending on the pool size you might be talking about a 8-15 kWh/day difference in consumption. My VFD pool pump saved us 6 kWh/day and I don't think my off-grid inverter would have been capable of starting the old pump.

There are other appliances like that, e.g. our heat pump clothes dryer is more expensive than the cheaper resistive heat units but can run well on the off-grid while the older style unit would be a significant burden in terms of power draw and energy consumption.
 
I wouldn’t spend $1500 to save 6kwh/day.

This thread is blending small (less than 20kwh/day), and grid tied system requirements with fully off-grid requirements. They aren’t the same.
 
I wouldn’t spend $1500 to save 6kwh/day.

This thread is blending small (less than 20kwh/day), and grid tied system requirements with fully off-grid requirements. They aren’t the same.
I have one of those pumps and it’s saved us about $50 per month. So 5 months $250. So 6 yr break even. Certainly better ROI than solar but we are good with that. Now count in the flexibility of the pump as well as the GPM, and the decreased load requirements. I call that a good investment.
 
I have one of those pumps and it’s saved us about $50 per month. So 5 months $250. So 6 yr break even. Certainly better ROI than solar but we are good with that. Now count in the flexibility of the pump as well as the GPM, and the decreased load requirements. I call that a good investment.
How are you calculating the saving when you have an off-grid system as the OP is enquiring about?
 
Ok so let’s look at it this way to make up the load of a conventional pool pump which many run 24/7 during the season how much in dollars would he be forced to spend on more panels, increased inverter size and most importantly storage? Much more than the let’s say $1000 difference for the pump?
 
if you have money in the budget, go ahead and find devices that are more efficient.

this seems only important when the budget is constrained such that purchasing the higher efficiency device prevents the purchasing of a significant amount of other core components.

i have been operating a ~60L fridge completely off grid for almost 4 months now. it runs off of 12V DC and was not the cheapest thing, but also not insane price (ARB elements). running it from DC is much more efficient than having the extra idle power draw of a small inverter. i am very happy with it ?❄️it consumes between 90-320 Wh per day depending on weather. painting it white and adding an insulation panel on top reduced the consumption a lot and took only an hour or so of my labor.

each project has different goals and constraints ?️
 
Agreed everything is a trade off. I like your refrigerator idea. Ever look at an LP refrigerator? They run off DC and are super efficient. No auto defrost though
 
If you're thinking of going totally off grid, there are a few things you'll need to take into account. Here are the top 5 gotchas to be aware of:

1. Finding the right location. If you're not careful, you could end up in a place that's too remote, with no access to resources or help if you need it. Make sure you do your research and pick a spot that's right for you.

2. Building permits and zoning regulations. Before you start building your off-grid dream home, make sure you check out the local regulations. You don't want to get halfway through only to find out you're not allowed to finish!

3. Connecting to utilities. Even if you're off grid, you'll likely still need to connect to some utilities, like power and water. This can be tricky, so make sure you do your research and plan ahead.

4. Taxes and insurance. Going off grid doesn't mean you're exempt from taxes or insurance. You'll still need to plan for these expenses, so factor them into your budget.

5. Cost of living. When you're off grid, everything costs more - from food to fuel to supplies. Make sure you have a realistic budget and know what your cost of living will be before making the switch.
 
Agreed everything is a trade off. I like your refrigerator idea. Ever look at an LP refrigerator? They run off DC and are super efficient. No auto defrost though
unsure if this was addressed to me, apologies if not.

have not considered or evaluated that type of fridge as of yet.

that type requires two inputs, is that right? liquid petroleum and electricity.

for my situation, extremely long autonomy without maintenance of any kind is the highest priority. even with a large reserve tank, that type would require occasional refueling right?

kind regards ?️
 
What if I have to spend another $1500 on inverter capacity just so it can reliably start the pump?
Plus the 2 kW of extra solar PV required (plus some extra battery capacity).

Sounds like a win to me.
It’s becoming a circular conversation, no dedicated off-grid system that is designed from the start to power a typical house (20kwh/day) would have inverters that struggle to start any domestic pool pump.

I haven’t setup a single inverter off-grid system for years.

If the question is “how can i live as cheaply as possible”, then my answer is different.

The scenario i see most often (overwhelmingly) is “how do i take my current house and style of living and best make it work off-grid”. My answers are relevant to that scenario. My caravan systems implement many of the things being suggested here.

For a grid tie - especially if you can load shift, the design is significantly different again.
 
It’s becoming a circular conversation, no dedicated off-grid system that is designed from the start to power a typical house (20kwh/day) would have inverters that struggle to start any domestic pool pump.
I can see what you're saying. I guess if the assumption is there is unlimited space to install lots of PV capacity then knock yourself out.
 
It’s becoming a circular conversation, no dedicated off-grid system that is designed from the start to power a typical house (20kwh/day) would have inverters that struggle to start any domestic pool pump.

I haven’t setup a single inverter off-grid system for years.

If the question is “how can i live as cheaply as possible”, then my answer is different.

The scenario i see most often (overwhelmingly) is “how do i take my current house and style of living and best make it work off-grid”. My answers are relevant to that scenario. My caravan systems implement many of the things being suggested here.

For a grid tie - especially if you can load shift, the design is significantly different again.
I am that house and I have the system. 4409 sq ft modern home. On grid by choice 2 hrs a day but could be running the genset if I wanted. So I am off grid with grid backup. We run our entire home off solar no essential load panel. Also run a well, pool, geothermal, and have some livestock.
 
Hybrid water heater only use around 5-600w and condition the space they are in....ideal for a garage.
ICF for the house, super strong and great insulation. 50mm closed cell followed up with 100mm open cell spray foam insulation for the roof.
I am self building in Florida so we probably have the same requirements.
I'm another Florida self-build. Curious - are you going to be completely off-grid?

EDIT: just saw on another thread that you are indeed fully off-grid. What stage are you at, and have you had any County issues with being fully off-grid? Always looking for other FL off-gridders to connect with.
 
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I’m building a house from the ground up in Costa Rica which will be off grid with grid back up. I’m going to do a very high-quality system with basically all Victron maybe even Victron batteries as I am Victron dealer and get good pricing.

I have every choice in front of me for how the house is built and wired, voltages used, what appliances are chosen, light fixtures etc. I’m working on a load spreadsheet ans PDR I have some data from my current home there and some other similar homes. The home will be a luxury jungle villa at 1,500 ft elevation - very open to nature w/ very little HVAC needed but some storage spaces will be
dehumidified and we will put mini splits in the 4 bedrooms just in case someone has to knock down the humidity to sleep. I’m not asking for specific system design advice but rather general pitfalls.

What are the things that people don’t think about ahead of time that come up later or those things that “if I had it to do over again” .

For example there was recently a thread about a high efficiency front load washer that had inrush spikes back and forth due to the way the motor reverses. I would never have thought to consider this type of machine a special challenge for off grid.

Cook with induction or propane?
Passive rooftop water heater or several small instant heaters?
Pool pump choice/programming?
Lighting?
Smart home stuff?
Frig/freezer choices?
I have a similar situation as you...just a different location...100% off-grid, fairly remote, from the ground up.
I underestimated my peak loads.
I undersized my battery bank...mostly due to budget issues.
I used substandard, but "expert" recommended, parts.
I used hobby grade tools vs professional grade.

Now I am on my system 3rd upgrade, everything Victron. I love their impeccable quality and versatility for control. They do it all from end-to-end like no other. And no Victron batteries due to cost, I am expanding my battery bank with EG4-LifePower4 Lithium Battery | 48V 100AH | Server Rack Battery | UL 1973 Listed batteries.

I cook with primarily propane but we have a portable 2-burner electric cook top for back-up.
We use a single tankless propane water heater. I will be installing an electric one (with timer for daylight hours) right after the solar system upgrade as a pre-water heater so we won't use propane unless the electric water heater isn't working.
We don't have a pool...but a couple good dirt tanks with muddy water!
We don't do anything special for lighting, just standard SPDs, good panel grounding, and a 3 x 8' rods grounding system on the PVs and a separate ground system for the house.
The frig/freezer choices were just the best energy rated ones for a reasonable price that we could find. With the newer energy effcient models now available we weren't too worried about it. They are all pretty dang low draws/loads to begin with.

One thing I am extremely grateful for...we didn't do roof mounted PVs!!! I kept the roof integrity intact and the PVs on our ground 2 mounts are accessible as needed.
 
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