Posted on 05/07/2024 4:15:48 AM PDT by MtnClimber
It’s (D)ifferent when they do it.
IMHO, the main drawback from them getting a good ROI is that they don't need power as much as I do. Basically, their heavy energy use is with staying warm in the winter...which they use natural gas for. Their power bills are relatively small and, therefore, not much return can be gained by experimenting with turbines and inverters and possibly battery storage.
Here in the south the main energy battle we need to win is fighting the heat in the summer -- which means winning a power battle not a natural gas battle -- which means homemade power can give us a good ROI. (Now that we have an EV and drive it a lot, that's the main battle we have to win with our solar, especially after I made the A/C run more efficiently by using a variable speed heat pump and also a water heater that produces free cold air I duct into the HVAC return to help the HVAC keep us cool.)
It was Sen. Alan Cranston who shut down square miles of California, as wilderness, to save the views.
Now the view is preserved beneath those solar panels.
I would think long term Geothermal and a passive solar house would make the most sense in the south.
A house with three foot overhangs. 10-12’ ceilings. A geothermal heat pump to take advantage of the fact that the ground temp is 55 degrees.
Then super insulate with an air to air heat exchanger.
Some of those old adobe houses built in the desert of AZ stay cool even when it is 110 degrees. Just like some of those 700 year old stone houses in Sicily stay cool in the summer. Of course, the walls are 3’ thick.
True that. Key words being "long term". IMHO there's a long time to get the ROI -- too much time for things to break down.
Contrarily, if my system keeps working as it has been the past 3 years (really basing it on data from the past year and a half since I added onto it in the fall of 2022), with the expected decline in throughput based on the warranties of each component, and with a reasonable 3% inflation rate on the energy prices I'm mostly avoiding, then I'm looking at a payback timepoint of about 9 years from now (2033), which is 11 years after the upgrade. That means 9 years from now I'll have saved a total in energy costs equal to how much I still owe on the HELOC loan I took out to buy and install the equipment. But my solar panels will still have 14 more years (25 year warranty, guaranteed to still be producing 70% as much power in the final year) and my batteries will still have 8 more years (19 year / 50%). And because it was cheap enough to put into a low interest loan, what we're really talking about is I had little up-front cost (meaning, that money and all the money I save each month by not having sky high power, natural gas, and gasoline expenses is money that stays in our Roth IRAs growing tax free all this time until I eventually have to take some of it out to pay off the HELOC).
I just don't think I could have done that with the much larger cost of geothermal.
I think geothermal only works out IF you have your own excavator or backhoe. Meaning, you can do all the excavation yourself.
The other method is if you are already drilling a well for domestic water down 200’ into the ground. Then you run a loop in that 6” diameter hole in the ground.
When you decided on your solar array did you ever consider one of those free standing units that tracks the sun throughout the day?
I understand they are the most efficient available.
I assume they are also more expensive to install and maintain.
As it stands today, the only mechanical components in my entire solar system are the fans in my inverters. Of course, outside the solar system itself is the larger energy project that includes not just going solar, but the variable speed heat pump, hybrid water heater, and EV car. From that standpoint I'm depending on warranties to cover multiple mechanical parts.
Back to cooling and geothermal vs my system. A valuable part of my system is the hybrid water heater (built in heat pump) produces a byproduct of cold air. During the warm half of the year I duct that air into a new air receiver in the floor of the closet that my water heater is in. The end result is that every day, for the 2 to 3 hours the water heater runs, I have free cold air allowing my home's variable speed heat pump to stay in low power mode. And because the water heater runs at only 380W (as opposed to 4kW like a normal electric water heater), the total power load of my house is almost always within the 18kW capacity of my inverters to provide constant AC power from homemade DC power (either from solar panels or batteries).
In other words, the solar equipment works fine autonomously. The water heater is also good autonomously. And the variable speed heat pump works fine. But all of them together work better than the sum of their parts. I just don't see how I could use geothermal for dual purpose (to help warm the water tank while it helps cools the house) like I can use the hybrid water heater for dual purpose (cooling the home while it heats the water tank).
And, similar to geothermal but coming from the opposite direction, I utilize the heat in my attic. The air intake on my water heater is coming from an air duct from the attic above it. Basically, the water heater's heat pump doesn't have to work really hard to find heat in the air it takes in if the air is usually pretty warm (like attics usually are in Alabama). So God blesses us with free sun, thus I use it for power. And I have free heat in the attic (usually), thus I use it to optimize the water heater. And the water heater gives me free cold air, thus I use it to help cool the house 7 months out of the year (during the cold months I duct the cold air away from the living quarters).
Altogether it means my power bills average $80/month for an all-electric 2,300 sq ft home, including charging the EV to drive it 1,300 miles per month (local miles charged at home, not counting if we take it on a trip).
That sounds like a great system. Did you design it?
What do you do for work?
I have heard that solar panels have come down in price quite a bit recently.
I have considered building my own free standing static array. I have an open south facing field. My wife HATES the idea though. Especially since it would face our bedroom window. I also would do all the trenching to run the conduit to my house/garage(about 200’). Then hire my local electrician to hook it up. We have net metering here in NH locked in at $.06/KWH.
IMHO, ignore net metering in your overall design. That means both in a cost/benefit analysis (pretend your benefit is entirely on lowering your grid pull costs) and also in picking your inverters (choose inverters that allow you to optionally turn off the grid sell feature, sometimes it's called having a "no output" or "zero report" feature). That way if your state changes the regulations you're not left hating your system. Go solar only if your ROI is based only on saving your power bill (or if you want comfort in being less dependent on the overly regulated energy market). Then if you decide that selling power is good for you, it'll be like gravy on top.
That's what I did. Alabama doesn't do net metering. I avoided the "solar fee" by not selling power to the grid for a while. After doing the upgrade in Phase II and having it for a year, seeing how much power I pulled and how much excess power I would have sold to the grid, I determined that the tiny sell rate per kWh my utility gives us for selling power is a hair above the extra fees that come with it. Thus I've been selling power for half a year. If the fees change or the regulations change, I'll cancel my contract, change a few inverter settings, quit selling power to the grid, and go back to being a normal power consumer like everybody else except that I buy a lot less power from the grid.
Do a real analysis on your power consumption habits and how much you can do to save power in your home without solar. Extra insulation, sealing cracks, etc. I did that.
Then use this tool to see the average daily peak solar hours in your area and how that changes per month. I found that tool to be spot on for my area. Look at each of your past 12 months of power statements, how much power you pulled from the grid that month, and divide it by the 30 to get it per day, then divide it by the peak solar hours per day that month. This will give you on average, how many kW of solar you need to on average meet your needs that month. On sunny days you'll take in more power, on rainy days you'll take in less. Also, try to estimate how much of your power consumption is at night (battery storage) and much of your power consumption is bursty with many appliances running simultaneously (inverter capacity to meet the load). See how much it'd cost for those, subtract from that 30% for the solar tax credit (10% more if made in the U.S.), but know that the tax credit is non-refundable but does carry forward. So if you're willing to pay that much minus the credit and count it as a good ROI, then proceed.
In Phase I don't buy that much solar/inverter/and battery capacity up front. Buy enough to play with it for a year, test it to make sure it works as well as you think, track it month by month to see how much it changes in the seasons and if those changes conform to your power changes in the seasons. Be sure to have it installed in a way that can be added onto later if you like it. (i.e. inverters can work in parallel, thus in Phase I my inverter choice was one that I could later add a 2nd inverter in Phase II knowing they'd work in concert.) And, my personal preference, pick an inverter that tracks a lot of telemetry that you can export and study. The Sol-Ark inverters record in 5-minute candles how much power it has to put on each leg of your electrical panel to meet your homes needs at that moment. And how much solar is coming in. How much excess solar is stored to the battery bank. How much power is pulled from the battery bank. And how much power is pulled from the grid.
After running solar in Phase I for a year I did a deep dive in the numbers. It worked as good as expected. I was able to see which parts to upgrade and by how much in Phase II (I anticipated doubling battery stack and tripling solar panels, but the numbers showed me it'd be better to double solar and triple battery). This dive in the numbers after having solar in your area is where the real power is in figuring out how much you need of what to get the best ROI. You're looking for the sweet spot between taking advantage of the Economies of Scale, without trying to fight the Law of Diminishing Returns.
“Extra insulation, sealing cracks, etc. I did that.”
Ditto, but the house is 52 years old. There is only so much you can do. Also, added a Harman pellet stove insert to help use less heating oil in the winter.
It is 77 sunny today. Then back in the 50’s for the next five days with rain. The pellet stove will be burning again.
I'm in a similar situation. Though my house is not quite 30 years old, the next steps to improving the house would be replacing the windows with double or triple paned windows, and removing the sheetrock so I install real insulation in the walls instead of having just "builder grade" insulation. Those improvements simply are not feasible.
Tell me about pellets. Are they readily available? Is it the kind of energy market that's overly regulated and, thus, has limited supply, or is it easy to find from anyone with spare wood (i.e. saw mill's byproduct)? That seems very efficient if it's as easy to obtain as I just made it out to be.
Pellets are a by product from sawmills and planer mills. Similar to shavings used for animal bedding.
However, a pellet mill is a fairly substantial investment. Plus you have to bag them. Then put them 50 of the 40 pound bags on a pallet.
Here in southern NH they are popular because in the rural areas natural gas is not available. I heat my house with forced hot water boiler furnace. It burns #2 heating oil. Which is almost identical to diesel. The only other option is propane for heat in rural areas. Along with electric(too expensive) and cord wood. Traditional wood stoves or outdoor wood furnaces.
Bagged pellets are sold at Home Depot. Lowes, Tractor Supply, independent farm and Ag stores and the pellet stove retailers. You can buy them a bag at a time $5.99-8.99 or by the pallet(50 40# bags = 1 ton). Companies will deliver them to your house. They are shrink wrapped. So they are made to sit outside and be “weather proof”. As long as the shrink wrap does not get damaged.
I typically buy them by the pick up truck load. I have a spot in my garage I can fit about 24 bags.
I own a Harman pellet stove insert. Harman IMHO is the best quality pellet stove made in North America. There are also some good European brands too. Harman are made in PA.
I have the Harman Accentra 52i. It is an enamaled finish brown color. It sits in the masonry fireplace in my family room. This is not an inexpensive appliance. It is like buying another furnace. You also have to remove the damper and block off the chimney with stainless steel. Then run a flexible stainless steel flue pipe up to the top of your chimney. Altogether, it was over $7K.
It has reduced our heating oil use. I do not know exactly how much. It also allows us to keep the main room/floor of our home much warmer than I would just running the oil burner furnace.
The main negatives are it is loud when it is running. It has a combustion fan and two circulation fans. The combustion fan blows the air up the chimney. The circulation fan takes the air from the room and blows it through chambers above the burn pot. Warming the room air and blowing it back into the room. Ideally, you want to bring in outside air for combustion. That is much more difficult to do with a masonry fireplace.
The other negative as opposed to a regular wood stove is that you need electricity to run it. So, in the advent of a power outage it is hooked up to a circuit powered by my gasoline generator.
Lastly, mine is now nine heating seasons old. I need to replace the circulation fan. It still works but it is getting pretty loud. Like when it turns on, we have to increase the volume on the TV from 15 to 20. It is only 5’ from my wifes end of the couch.
All that being said, I am glad I have it. Plus, I guess I am also being GREEN because I typically burn pellets made right here in New England. Not that EVIL CO2 ERF killing petroleum .
If you decide to use a small hydrologic generator get with someone the understands hydraulic flows, like a plumber or pipe fitter. For a few beers he’ll gladly help you out.
It also seems like you're set up to not depend 100% on just one heating source. If pellets get hard to come by you have the heating oil (diesel). If oil gets hard to come by you have your pellets that might be enough to get by. Does that sound right?
I don't have that kind of diversified dependency on my house, but I do in my travel. If the left makes power hard to come by, then we can drive the gas pickup for long trips. If the left makes gasoline hard to come by, then we can drive the EV. (Of course with solar, if the left makes both power and gas hard to come by, then we can drive the EV at least for local driving.)
So, IF heating oil gets cheaper, I turn up the thermostat.
The pellet stove also has a thermostat. So you set it and it turns itself on and off. Just like a furnace.
The first two years I had the pellet stove, pellets would get scarce in the winter. You had to buy ahead in the fall all you needed for the season. Now, the best time to buy it now. Call around and see IF anyone has any left over they are willing to DUMP instead of sitting in their warehouse until October. Many more retailers sell them now.
Pellet stoves do have some moving parts. They do have a board. Which I had to replace once because I didn't have it plugged into a good surge protector. A lightning strike hit near the house and blew the fuse on it. It never worked right after that so I had to replace the board.
The fans are not hard to replace. You just have to pull the thing out of the fireplace. I need my sons help for that. It is on a track with wheels but weighs 450 pounds. I built a wooden platform to slide it out on. My fireplace is on a brick hearth about 10” above the floor. My family room is one large room across the back of my house. My kitchen, dining room and family are all together. The pellet insert is at one end. I use a computer fan to blow the air into the center hallway. Then it goes upstairs by natural convection.
Another benefit is there is no creosote. I clean the flue pipe once a year in October. I have my son help me pull it out of the firebox and clean behind it. There is also a fines box under the auger you have to clean out. It is where the sawdust and broken pellets end up that fall out of the auger. The auger also has a motor to turn it. So, there are actually four motors in my insert.
With my home solar, my maintenance consists of twice per year getting on a ladder with a water hose and a long handle brush to clean them.
My hybrid water heater has a small air filter I have to clean every now and then (I typically do it monthly during allergy seasons in the spring and fall). That's no different than cleaning the lint screen of a clothes dryer.
The main "maintenance" I do is always studying the data export from my inverters, comparing the past week or so's power movements to the same week the prior year, etc. Seeing how much the cost of gasoline is and how much it would have cost to drive my old pickup at 15 mpg instead of the EV, or how much it would have cost a fairly new gas crossover getting maybe 25 mpg if we had gotten one of those instead of the EV crossover.
I then sometimes tweak the inverter settings, most notably the setting on when the inverters power a separate electrical panel that's powered only when my home solar batteries are charged at least X%. I have one of the EV's two chargers on that intermittent electrical panel.
The idea is that if my wife and I come home in the EV with it charged more than enough for the next day, we plug it on the intermittent charger (charge the EV more from it's current state only if there's free power in batteries beyond what the home needs to go through the night without pulling from the grid). Or if we come home needing a charge whether or not the power is free, we plug the EV to the constantly powered charger.
So if we charge the EV up to 80% (the recommended top for local driving) on a sunny day and get 220 to 250 miles range with that, and drive it about 50 miles per day, that's multiple days per row we can have little to no free power (rainy days) before we decide to charge the EV with the constantly powered outlet (which means pulling from the grid if there's not enough free power). That happens sometimes. Or maybe there are days we drive it more (i.e. charging it to 100% for the next day to go on a trip means using the constantly powered cable). But for the most part, we use the charging cable tied to the free power electrical panel. That technique of charging the EV mainly on the free power cable does an amazing job of giving us mostly free miles, which comes out to about 1,300 miles per month (home charged miles, not counting trip miles).
The other reason to consider buying this particular model of pellet stove is that there is a 30% tax credit on it again.
There was not when I purchased mine. Not only is the 30% credit on the actual stove buy on the SS pipe and installation too. So, it could be $2K off the total $7K price.
Again, these things make a lot more sense up here in rural New England where our choices to heat our homes are limited to oil, propane, coal, cord wood and electricity. If natural gas is available it does not make as much sense.
FYI, my 52 year old house originally had electric radiant heat in the ceilings. This is because it was built during the oil embargo of the early 1970s. When electricity was actually cheaper than oil. The house has blue board attached to the ceiling joists. Then 18 gauge wires attached to the blue board. Then about 1/4” of skim coat plaster was applied over that.
The house had a thermostat in every room when we bought it. However, the previous owner had installed a forced hot water boiler furnace in the 1980s. With baseboard hygromic radiators. I removed the thermostats and reused the eight 20 amp circuits for other purposes like ceiling fans in the bedrooms. Some we just disconnected in the main panel and labeled where they went. In case we wanted to use them again in the future. There is 12/2 Romex going to each box.
Does the 30% tax credit artificially raise the price you pay up front? I see that with the EV tax credit and the solar tax credit. It basically didn’t help me with my purchases. In fact, I’m still waiting for my solar tax credit to come in from my year 2022 upgrades. (The tax credit is non-refundable, but does carry forward. So the two tax filings I’ve done since then didn’t have me at a high enough tax liability to get the entire tax credit — I got only as much tax credit as my tax liability. The remaining from the 1st year was passed to the 2nd year, then more to when I file taxes a year from now.)
I don’t think so. The price of the Harman pellet insert really has not changed much in the last 9 years from when I bought mine.
The only thing that I had read on the hearth.com forum is that lead time jumped when the tax rebate went into effect again.
LOL, ran into that last year, had to replace it, now it is quieter but still certainly not silent. I'm trying to buy a big enough battery and inverter to shut it down during an outage, needs to run about a half hour. The inverter I bought and battery doesn't stay constant on, so I think the battery is still too small.
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