14.4 KW solar, 40.96 kWh backup, 2 solark 15k inverters, off grid family home, doable or delusional?

[Zwy]

LPG (propane to the yanks) is a poor choice where I am in Australia- close to one of the most expensive ways there is to power a home...
LPG is currently $1.19 per litre, so a 40kg tank costs close to $100 a tank, and would last a house with a gas stove and hot water service about 2 to 3 weeks per tank...
View attachment 194563
A 500 gallon tank is 2300 litres, at $1.19Au a litre to refill here where I am, (in Brisbane it's cheaper), is just over $2700Au per tankload (plus delivery fee)- five of those tanks and you have paid for my LYP battery bank and have some left over...



View attachment 194566

Propane is a bargain here in the States, no doubt about it. It is byproduct due to processing natural gas which the States have an abundance of, even flaring off excess natural gas.

If everyone here switches to solar, then propane will end up once again at giveaway prices. 37 years ago I remember paying around $0.30/gallon.

 

[Hedges]

... even flaring off excess natural gas.

Because that is so much better in terms of global warming then letting people burn it for domestic heat or motor vehicles.

I suspect it has to do with oil leases, company wants to extract as many $$ as possible, no regard for wasting resources. If someone owned the resource, they might pump more slowly such that there was a market for the gas too.

If we can burn propane or NG in a generator to top off batteries during winter, also using the "waste" heat (CHP), we come out further ahead.

There are fuel cell CHP units, including high temperature reformer for NG, but don't know about cost effectiveness. Don't know if that would be possible with propane.

 

[Zwy]

Don't forget a 'gas' clothes dryer DOES have an electric motor. ;-)

Yes, but my electrical system for my house supplies free electricity.

Heat pump dryers take more electricity than gas.

The largest load in my house next to HVAC is the clothes dryer. I've looked for heat pump dryers in the larger size, never find any at a retailer around here or any heat pump dryer for that matter. It is always order one in.

Gas dryers are in abundance. I just checked and the Samsung 7.8 cu ft heat pump dryer I was interested in is now on sale with $700 off the price and is $1627 plus tax.

Gas dryer is around $700. The difference is $927 x 5% = $46.35

So I'd still have the $927 plus pocket an additional $20.35 in interest earned on the $927.

Compound that over 20 years of propane in the tank and I will have $2,459.61 extra.

However there is one thing that could change my mind. The High-Efficiency Electric Home Rebate Program will pay up to 50% of the cost up to $840 (income between 80 percent and 150 percent of Area Median Income) so that would be $813 rebate.

The heat pump dryer I'm looking at uses less than 1Kwh to dry clothes. It is a toss up, I could sell the extra propane tank (probably not) and it would fetch about $1500 in today's market.

 

[Quattrohead]

Propane is a very volatile material in terms of actuality and price, I would not want to rely on it long-term because people are turning against it because it's dirty and produces carbons. I buy my batteries, solar panels and inverters and I am done, I don't need to rely on anyone ever again.

 

[Zwy]

Propane is a very volatile material in terms of actuality and price, I would not want to rely on it long-term because people are turning against it because it's dirty and produces carbons. I buy my batteries, solar panels and inverters and I am done, I don't need to rely on anyone ever again.

It comes down to economics for me when it comes to some directions I've taken. I know propane will be available for a long time due to natural gas processing. This country will be using natural gas for a very long time, there is no way the world population can be fed without processing natural gas. I don't care what some might think, it isn't happening.

I hedge costs all the time, both in business and personal expenditures. I've installed solar as an example hedging against future energy costs once I'm retired. I hedge against fuel cost by buying fuel for business vehicles in bulk and at time when there is a dip in price. I hedge on propane costs the same, I need propane for the business heating needs and pre pay/summer fill in bulk. I own enough propane storage tanks that I can hedge a year in advance easily.

The clothes dryer is no different. On one hand you have proven reliability and long service life with gas. The operating expenses are ongoing but compared to an electric dryer whether on solar or not, the gas dryer is a bargain.

The heat pump dryer may not last as long, repairs could be expensive and it requires more cleaning compared to the gas. It does have the advantage of lower energy usage than electric, so it fits solar well. Actual energy costs compared to gas- no clear winner except in winter with low sun hours, gas holds the advantage.

Cost is slightly less with gas than heat pump with energy rebates/credits from the IRA. Heat pump holds the advantage of recycling the heat and is ventless, gas will require makeup air into the building envelope.

I'll let it stew but when it's December with clouds for 2 weeks, gas would be the winner.

 

[Quattrohead]

100% agree, it will change depending on where you are in the US and the world.

 

[Doggydogworld]

I suspect it has to do with oil leases, company wants to extract as many $$ as possible, no regard for wasting resources. If someone owned the resource, they might pump more slowly such that there was a market for the gas too.

It's a lack of pipes. You drop some wells in the middle of nowhere, both oil and gas come out. It's easy to pump the oil into a tank and have a truck empty it regularly, but if you don't have pipes in place you just flare the gas. The gov't frowns on this, but wants to keep the oil flowing so permits it up to a point.

Eventually if your field produces enough gas, and is near other fields and/or a nearby pipeline, it makes economic sense to lay pipe and collect all the gas.

I saw a spot the other day about a company putting bitcoin mines and server farms at remote oil fields. They get free(ish) gas to generate electricity and the oil company gets the gov't off their back.

 

[G00SE]

When I first embarked on learning how to power our offgrid homestead my intent was propane for the range, water heater, and dryer.
My intent has now changed to electric range, heat pump water heater as well as heat pump washer/dryer combo. (I’ll just hang dry 6 months a year if needed)

We still intend on propane, but as a fuel source for the generator and potentially have a backup gas wh to boot.
It’s apparent that depending on one’s current situation and/or desires are will strongly influence choices.
The ones in here demonstrating a lack of cost benefit to replace perfectly functional equipment, or the ones that don’t have a priority of off grid sustainability seem entirely on point in sticking with gas.
If one’s starting from scratch, I don’t much see the point anymore. My initial rationale was cost. But if one shops around there are amazing prices for solar gear

 

[ksmithaz1]

Yes, but my electrical system for my house supplies free electricity.

Heat pump dryers take more electricity than gas.

The largest load in my house next to HVAC is the clothes dryer. I've looked for heat pump dryers in the larger size, never find any at a retailer around here or any heat pump dryer for that matter. It is always order one in.

Gas dryers are in abundance. I just checked and the Samsung 7.8 cu ft heat pump dryer I was interested in is now on sale with $700 off the price and is $1627 plus tax.

Gas dryer is around $700. The difference is $927 x 5% = $46.35

So I'd still have the $927 plus pocket an additional $20.35 in interest earned on the $927.

Compound that over 20 years of propane in the tank and I will have $2,459.61 extra.

However there is one thing that could change my mind. The High-Efficiency Electric Home Rebate Program will pay up to 50% of the cost up to $840 (income between 80 percent and 150 percent of Area Median Income) so that would be $813 rebate.

The heat pump dryer I'm looking at uses less than 1Kwh to dry clothes. It is a toss up, I could sell the extra propane tank (probably not) and it would fetch about $1500 in today's market.

For the complexity I like the gas unit, dirt simple, heat source, blower/drum motor. For the safety I like electric. If installed properly gas should be perfectly safe, and modern gas devices don't have pilots, and have shutoffs and flame detection, but I'm old and have had a few bad experiences. Propane is a bit hotter (temp) than NG, and I prefer cooking by regulating temperature rather than heat volume. It's a subtle difference, and a gas oven will handle the dissipation to regulate the temperature, I just find gas surface units annoying.

A big advantage of propane/NG is the ability to run a demand HWH. If I had gas that is the one thing I would definitely spring for. The electric units draw way too much demand power. I might re-consider if I build my plant out more.

 

[SilverbackMP]

I would probably not opt to go "off-grid" with solar, in a place that had even 5 weeks of zero production.

Cough. Southwest-SoCal bubble. Cough

Propane, in Missouri was $1.69 per gallon in October (cheaper in spring and summer),

Can’t be much difference in Louisiana (which may be even cheaper).

Gas is not expensive when you have it in abundance and not too expensive when you don’t blow the pipelines running to your area/country (ok UK, “countries,” lol).

 

[Bop]

We have gas in abundance here in Australia, but refining and transport costs add up (especially when the government isn't majorly subsidising the oil and gas industry (coughs USA)
When LPG/propane costs $5.70US a gallon, tell me it is still 'cheap to run' and you would still be using it...

 

[SilverbackMP]

We have gas in abundance here in Australia, but refining and transport costs add up (especially when the government isn't majorly subsidising the oil and gas industry (coughs USA)
When LPG/propane costs $5.70US a gallon, tell me it is still 'cheap to run' and you would still be using it...

The ORIGINAL POSTER is in LOUISIANA. I guess we have an Australia bubble along with a Southwest-SoCal bubble. (Side comment: Probably would have helped if Australia hadn’t of shitcanned most of their oil and gas industry except for that coal for that lovely Chinese money (and that dude with the blown 73 Ford Falcon trying to crack his own)).

Point being, use what makes sense in your locality. Me running 100% ethanol in vehicles in Missouri wouldn’t make sense but would sure in the hell make sense to a Brazilian.

 

[Zwy]

For the complexity I like the gas unit, dirt simple, heat source, blower/drum motor. For the safety I like electric. If installed properly gas should be perfectly safe, and modern gas devices don't have pilots, and have shutoffs and flame detection, but I'm old and have had a few bad experiences. Propane is a bit hotter (temp) than NG, and I prefer cooking by regulating temperature rather than heat volume. It's a subtle difference, and a gas oven will handle the dissipation to regulate the temperature, I just find gas surface units annoying.

I've always had a gas stove and will always have one. Back when the power would go out, we could use the oven for heat and still cook and heat water.

With my solar system, I still have no desire to switch.

A big advantage of propane/NG is the ability to run a demand HWH. If I had gas that is the one thing I would definitely spring for. The electric units draw way too much demand power. I might re-consider if I build my plant out more.

I run a powervent propane water heater, that thing is pretty good on gas. The shop has a tankless and it gets used often, even run the heated water thru a pressure washer. It does require flushing every year or two. Before I would put one in the house I'd go with an electric ahead of the powervent propane water heater as a dump load. Eventual plan is gasification wood boiler for middle of winter with 1400 gal of thermal storage with another small thermal storage tank in the basement where I can use air to water heat pump or the wood boiler for heat storage when it is shoulder season: spring and fall. I can add a heat exchanger from the wood boiler for hot water too. That gives unlimited hot water.

I want the ability to heat the house 3 or 4 different ways. That gives me option, I might be gone a month in mid winter in the future or take off for a week on a short trip.

 

[SilverbackMP]

I've always had a gas stove and will always have one. Back when the power would go out, we could use the oven for heat and still cook and heat water.

With my solar system, I still have no desire to switch.


I run a powervent propane water heater, that thing is pretty good on gas. The shop has a tankless and it gets used often, even run the heated water thru a pressure washer. It does require flushing every year or two. Before I would put one in the house I'd go with an electric ahead of the powervent propane water heater as a dump load. Eventual plan is gasification wood boiler for middle of winter with 1400 gal of thermal storage with another small thermal storage tank in the basement where I can use air to water heat pump or the wood boiler for heat storage when it is shoulder season: spring and fall. I can add a heat exchanger from the wood boiler for hot water too. That gives unlimited hot water.

I want the ability to heat the house 3 or 4 different ways. That gives me option, I might be gone a month in mid winter in the future or take off for a week on a short trip.

Working on pretty much the same setup.

 

[Hedges]

Eventual plan is gasification wood boiler for middle of winter with 1400 gal of thermal storage with another small thermal storage tank in the basement where I can use air to water heat pump or the wood boiler for heat storage when it is shoulder season: spring and fall. I can add a heat exchanger from the wood boiler for hot water too. That gives unlimited hot water.

If you get/store thermal energy from a givenn source, e.g. boiler & storage tank, using that as thermal input to heat pump, no extra energy is obtained.

Heat pump needs excess quantity of lower grade heat.

You would get as much energy using stored hot water directly. Only thing heat pump does is boost temperature, could make radiators put out more. What it can do is cool off the tank faster if you need higher grade heat.

 

[ksmithaz1]

Interesting

 

[Zwy]

If you get/store thermal energy from a givenn source, e.g. boiler & storage tank, using that as thermal input to heat pump, no extra energy is obtained.

Not the way this works.

Heat pump needs excess quantity of lower grade heat.


You would get as much energy using stored hot water directly. Only thing heat pump does is boost temperature, could make radiators put out more. What it can do is cool off the tank faster if you need higher grade heat.

Plan is to add a buffer tank of lower temp that is not part of thermal storage. Eventual plan is radiant staple up and other low temp emitters, perfectly suited for a heat pump. I will also add a propane fired condensing boiler for when I might be gone and temps are well below 0°F. Arctic heat pumps can work that low but they do suffer efficiency losses. The heat pump is for excess solar mainly as a heating dump load.

The 1400 gallons of thermal storage is not for the heat pump. It is for accepting the heat from the gasification boiler. Gasification requires thermal storage in order to maintain high refractory chamber temps and capture the heat energy from the high fire. Thermal storage temp of 180°F is too high for a heat pump to add heat (unless a 2 stage heat pump is used), thus the need for the buffer tank where mixing can occur to have a lower water temp for low temp emitters. It isn't any different than using a thermostatic valve to control temps to low temp emitters. The advantage of using low temp emitters combined with thermal storage is the thermal storage can be used from 180°F down to 110°F instead of a high temp emitter which is run to a minimum near 140°F. This extends the time between batch burns.

Wood boiler and thermal storage will be in a separate building than the house. Hot water will be piped off the top of stratified thermal storage to the house where it will be mixed with colder water in the buffer tank. The water in the buffer tank is then circulated thru the low temp emitters. The advantage of hydronic heat is the buffer tank can be heated from several sources, it doesn't matter as long as it is heat energy.

 

[Banjoman]

Same here- the US is 'power mad' when it comes to many things- 'utes' with 4 times the horsepower of my 8 tonne tilt-tray truck (and fuel consumption to match), HUGE electrical demand (some US fridges use more than my entire 3 bedroom house with three people living in it- including a 'gadget mad' older guy (guess who that was lol) and a teenager who never learned what an off switch was...)
Our daily consumption was around 7-10kwh a day- in total... running off an 80A 240v mains supply and 6kw of gridtie solar, the electricity bill was usually- zero...
(in fact we often got a few bucks back from them...)
Seriously lol
(they direct deposited the 'bill' amount on the due day straight into our bank account if it was a 'negative bill')
View attachment 194507
Many offgrid houses here in Australia comfortably run multiple A/Cs, cook on electric and have a lifestyle that it is hard to tell you are actually running purely from solar...
Of course solar here seems to be a lot cheaper than the US as well which helps- people quoting multiple tens of thousands for systems is crazy high price wise (gridties here cost about $3500Au or about $2300US- thats fully installed, no more to pay,and will give you about 35kwh a day in generation, where a 10kw system (requires 3 phase on at the house) is about $6500Au ($4200US) again fully installed, no more to pay, and will generate about 52kwh a day...

My own offgrid system cost me under $2000Au for ex gridtie panels (secondhand, from an installer doing upgrades/repairs) 72x 250W panels totaling 18kw of panels, the most expensive thing was the battery bank ($11800Au) for 20kwh of LYP batteries (better than LFP for either high or low temp applications) 16x400Ah cells- the total system cost $17500Au in total for everything... ($11400US)- sufficent to run a workshop with a mill and metal lathe, welders, air compressors etc, and a 3 bedroom house with A/C- in total that 18kw of solar will be getting up to 90kwh a day...
And I plan to buy an EV this year to boot lol (looking at the BYD Atto3)
all offgrid...

If you don't mind asking what is an LYP battery? First Ive heard of this.

 

[Bop]

If you don't mind asking what is an LYP battery? First Ive heard of this.

LYP is a form of LFP specifically LiFeYPO4- basically Yyitrium is used as a doping agent in the battery- it is slightly more expensive than LFP, but has a usable temperature range of -45C up to 85C
This is the spec sheets for my battery pack here (20kwh nominal, 16x400Ah cells)

Unlike L/A or LFP, they can be charged down as low as -20C (-4F) with no throttling , down to -45C (-50F)with throttling (reducing the charge rate from a maximum of 3CA down to 1CA max (thats 1200A down to 400A on my cells), and the same with the upper end (which is where I like their performance, being in N/E Australia, we regularly get temps in excess of 40C(105F) for weeks on end) unlike LFP and L/A which need to start throttling above 40C, the LYP doesn't need to start throttling until its over 60C(140F), and stop charging at 85C(185F)... in which case, the battery temperature is the least of my worries lol
(people in Marble Bar still wouldn't have to throttle LYP- despite it hitting 52C there a few weeks ago- thats 125.6F!!!)

They have a slightly poorer charge density than LFP (slightly larger physically and slightly heavier for the same storage capacity, by about 10%) but for household use thats not an issue... and the ability to accept full charge rates up to 60C more than makes up for it...

Not exactly new- they have been on sale here in Australia since 2008, elsewhere since 2002...

 

[G00SE]

Is that what Winston cells are, or is that just a similar cell casing?