Will just posted an excellent video, check it out.

[DerpsyDoodler]

The only difference in ROI between using grid power to mine or building an off-grid power supply to mine is the cost of the energy. The return from the mining is the same in both cases, hence it nets out and you are only left with the energy cost differential.

You're thinking about this wrong. Reread my post #23 (i edited it) and 24.

 

[wattmatters]

If someone has or develops the know-how to build a PV system, and can do consulting in the field because of that, these result in earnings you can not necessarily get through other means unless you want to argue that any and all jobs/careers/positions/opportunities are available to everyone and anyone.

First up, I appreciate your point of view. I don't agree with it but that doesn't mean you're wrong and/or I'm right.

If someone gains the experience, skills, knowhow and relevant trade qualifications to go onto consult on building solar PV systems just because they built a home DIY system, then great.

What that tells me is they were equally likely to gain skills, knowhow and relevant trade qualifications in something else that may also have lead to income earning activity. One always has to consider the opportunity cost of (relevant) alternatives not taken.

It wasn't the fact it was a home solar PV system per se that was responsible but rather the inherent talents and motivation driving them to learn and apply knowledge.

The skills and experience of building a DIY solar PV system are not somehow more magical than say learning to weld, or fix motor cars, or build or restore furniture, or play music or program software, build websites, do plumbing, carpentry, grow fruit and vegetables, raise livestock, trade securities, coach people in a specific discipline, even create educational content, and so on for any of hundreds of other prosumer kinds of hobby that could also lead to earning income.

I did just that in my last career, took a professional approach to my hobby and made it a successful and primary source of income for a decade of my life.

 

[wattmatters]

You're thinking about this wrong. Reread my post #23 (i edited it).

I can only have read and responded to what you wrote at the time, not what you subsequently write.

This is what I consider to be the key element of your re-written post:

The bottom line is your investment is X. Your return is Y.

If you build out a solar power plant, your investment is X. Anything that you can do with that power to generate income (regardless) is in scope as ROI or Y.

To which I respond with:

Yes you have an investment and a return on that investment. So if we build say a bitcoin mining rig and a solar PV system to power it, we can calculate the ROI of that entire investment. I've no argument with this.

What I'm saying though is we could have built the exact same bitcoin mining rig but not build a solar PV system to power it but instead purchase energy from the grid to power it. We can also calculate the ROI on this entire investment.

In both scenarios the earnings from the bitcoin mining component of the project will be the same. So that nets out.

Meaning the only difference between the two projects will be the cost of the energy supply (capex + operational).

So if you are wanting to know what is the ROI of just the solar PV system, the it's the difference in ROI it provides compared with the ROI of the alternative option of doing the same thing with grid energy instead.

 

[Supervstech]

I can only have read and responded to what you wrote at the time, not what you subsequently write.

This is what I consider to be the key element of your re-written post:


To which I respond with:

Yes you have an investment and a return on that investment. So if we build say a bitcoin mining rig and a solar PV system to power it, we can calculate the ROI of that entire investment. I've no argument with this.

What I'm saying though is we could have built the exact same bitcoin mining rig but not build a solar PV system to power it but instead purchase energy from the grid to power it. We can also calculate the ROI on this entire investment.

In both scenarios the earnings from the bitcoin mining component of the project will be the same. So that nets out.

Meaning the only difference between the two projects will be the cost of the energy supply (capex + operational).

So if you are wanting to know what is the ROI of just the solar PV system, the it's the difference in ROI it provides compared with the ROI of the alternative option of doing the same thing with grid energy instead.

I am sort of following each point of view…

my thinking is… if you have PV investment, and unused power… then add Bitcoin mining, and EV, removing the ICEV…

Your previous electric bill is fixed average charting. The solar investment is a fixed amount, you are no longer spending dollars on fuel, so that adds to the ROI, and the Bitcoin money would be additional funds, so, that adds to the ROI…

YES, A BITCOIN system will consume wattage, as will the EV, but the power bill you had previously is what you are calculating the ROI on… assuming you were going to purchase a new car regardless, the car price wouldn’t factor in, but if not, then it would… the miner price certainly should be added to the ROI investment total…

no?

 

[Texas-Mark]

If your provider is selling at low fees like $0.13 per KWH I just cannot see a ROI no matter what.

I sort of agree with this. My rates are between $0.10 and $0.11 and between the initial cost, replacement parts, minor upgrades, it is looking like 25 years or more depending on what else breaks. But in my case, I did it more for the hobby aspect than trying to save a a few bucks.

As for the EV argument, I do believe it should be calculated in the ROI. However, only to the extent that the savings are over the grid costs. So if there is $250 saved on gas per month, but using the grid would only cost $50 per month, you can only apply that $50 to the ROI calculations, and not $250.

 

[robby]

Im OFF Grid so grid to me is moot.
I get an EV and charge it at home with my own solar power, I'm not paying for fuel anymore and that saving is "banked". Any "Car Payment" is irrelevant as you have that with any new vehicle (usually). Instead of pumping $250 a month into a Big Oil Co that's 250 saved to bank account and I would consider that payback from my solar. With a 200mile + EV and plug in charge at home, any external charging would be minimal if at all (long trips only). Average driver drives <50 miles a day commute +.

I just don't see this as a net savings but more as a needed environmental thing to do. I am fine with that as we do need to move off of fossil fuels. but when you start doing the math to prove its a money saving endevour I think your never going to be able to prove that.

$250 a month using an average fuel cost of $3.2 a gallon means you could have bought 78 gallons of fuel a month or 20 gallons a week. On a typical 35mpg vehicle that would be 700 miles of driving per week or 100 miles per day.
Sure many people drive a 100 miles a day but not 7 days a week and 365 days a year, if you did that you would hit 100K miles on a new vehicle in 3 years. If we used a Hybrid at 50mpg the savings on gas gets a lot better.

The point is that the Gas is a variable that you can control input and output, I buy what I need and use what I need! The PV system is a fixed expense input with a net distributed savings that can swing from Negative to Positive depending on how much of the power you actually use. I guess the whole Bitcoin thing is to offset unused power but does that actually make any kind of consistent money on that power?

 

[Substrate]

Almost lost me at making digital currency mining part of the ROI.

Instead, I'll just buy the "how to play blackjack" pamphlet in the lobby of McCarren airport and move to my island in the bahamas.

My concern is that I see a shift going on - what started out as trying to hold manufacturers to the bar by exposing sub-standard parts, engineering (like low-temp sensors) and techniques, that substandard is now ok - the justification being that they are so cheap to get and replace as an alternative to using quality parts with manufacturers that might actually be around in 10 years.

Using quality manufacturers and products should be the only thing you base ROI on.

He'll learn. When you buy junk what happens is two things:

1) You simply buy the same junk over again. ROI lessens.
2) You buy the GOOD stuff up front, which is less costly than the above. ROI improves.

Unfortunately, most of what I see here is "what's the cheapest xxxx", and the results of that either come later, or the disappointed user is never seen again in the forum..

 

[DerpsyDoodler]

Almost lost me at making digital currency mining part of the ROI.

Instead, I'll just buy the "how to play blackjack" pamphlet in the lobby of McCarren airport and move to my island in the bahamas.

My concern is that I see a shift going on - what started out as trying to hold manufacturers to the bar by exposing sub-standard parts, engineering (like low-temp sensors) and techniques, that substandard is now ok - the justification being that they are so cheap to get and replace as an alternative to using quality parts with manufacturers that might actually be around in 10 years.

Using quality manufacturers and products should be the only thing you base ROI on.

He'll learn. When you buy junk what happens is two things:

1) You simply buy the same junk over again. ROI lessens.
2) You buy the GOOD stuff up front, which is less costly than the above. ROI improves.

Unfortunately, most of what I see here is "what's the cheapest xxxx", and the results of that either come later, or the disappointed user is never seen again in the forum..

I was a "what's the cheapest?" in my youth. People learn.

Also, I'm not saying you should go and build a solar farm for the purpose of mining bitcoin. i am saying that if you did (presumably its because you've worked out the accounting and determined you can make a profit). Therefore your investment is in power, and your return is bitcoin.

Now, in Will's case. He just wants to heat up his shop. He'll use miners, convert the power to bitcoin and put the heat generated to a useful purpose. His sole goal is heat. Bitcoin is a bonus and why the heck shouldn't he include it as ROI? Not to would be financially irresponsible.

 

[rin67630]

Using quality manufacturers and products should be the only thing you base ROI on.

He'll learn. When you buy junk what happens is two things:

1) You simply buy the same junk over again. ROI lessens.
2) You buy the GOOD stuff up front, which is less costly than the above. ROI improves.

The very first aspect, before considering quality (buying) is to be aware of what you can expect from solar and begin planning correctly.
That is crucial with designing off grid solutions, which are intended to provide all year power for living.
That is especially important the further you are from the equator: expect a lot of dynamics and finding the balance between too less and too much require a lot of experience.
Of course if you need off grid solutions just for 3 weeks holidays in summer, you get a different mileage.

 

[wattmatters]

Not to would be financially irresponsible.

Irresponsible is a harsh word.

Speaking financially (IOW without consideration of other benefits like enjoyment, learning, environmental, independence etc) let's try to find something we agree on. That I hope is a good place to start.

Would you agree with me that it would be sub-optimal or perhaps even imprudent to invest in off-grid solar PV system if there was an alternative source of energy that was cheaper?

Surely the financially responsible thing to do is to ensure the off-grid solar PV system you are going to build is in fact the best financial option. Else you may end up with a lower ROI than you otherwise would have. Failing to assess the relative merits of the alternatives would not be financially responsible.

If the grid energy is cheap, then spending on solar PV may not make much financial sense. Which is why I pointed out earlier the example of negative wholesale grid prices. Getting paid to consume energy is a much better financial option than spending money to generate.

But in many cases the off-grid system will be a better financial option.

Hence the ROI of the solar PV part of the system is the marginal gain in ROI over the next best alternative source of energy.

I have two solar PV systems.

One was designed to save money and provide a positive ROI with an extra benefit of reducing our carbon emissions. It's doing so quite successfully as I posted earlier. Grid tied solar PV in Australia is for the most part a no brainer from an ROI perspective for anyone that owns their home, has suitable roof space and expects to be there for at least 5 more years. That's in part because grid tied solar PV systems are so cheap to install here.

I have another solar PV and battery system (DIY off-grid) but that was not designed to provide a positive ROI and it never will. It's purpose is to be a backup source of energy during grid outages and as a project for learning and mental health benefits. I also use it to supply energy to run my pool pump, so it will provide some return since that allows me to generate extra export income from my grid tied system but not enough for a payback within it's lifespan.

The alternatives for backup power were a grid tied battery system (but they are ridiculously expensive here and have a negative ROI), or a generator. I have the generator as well but gave a pass to a grid tied battery system. I've modelled in great detail the return a grid tied battery would provide our home and it's pretty lousy - it's the solar PV which does all the heavy financial lifting.

 

[robby]

Now, in Will's case. He just wants to heat up his shop. He'll use miners, convert the power to bitcoin and put the heat generated to a useful purpose. His sole goal is heat. Bitcoin is a bonus and why the heck shouldn't he include it as ROI? Not to would be financially irresponsible.

Heat is just a byproduct of inefficiency in the process.
Since mining today pays so little it would be better to just buy a dedicated heater and use the saved energy to charge up his EV even more.

 

[Substrate]

Ok, we're going to cut Will some slack. He means well. Hope he laughs at this ...

Time to introduce a little humor. Since this is a DIY forum, I don't believe Will should *start* with a pre-built Tesla, but something more appropriate like a diy EV conversion. From the LVEVA organization:

1970 FIAT 850 Sport Spider EV Conversion and Restoration Project

Al D’inzillo, one of the original founders of the Las Vegas Electric Vehicle Association, passed away during 2017. His family graciously donated Al’s 1970 FIAT 850 Sport Spider to the L…

lasvegaseva.org

Drive around in this, and maybe I'll reconsider the whole ROI issue.

 

[upnorthandpersonal]

Heat is just a byproduct of inefficiency in the process.
Since mining today pays so little it would be better to just buy a dedicated heater and use the saved energy to charge up his EV even more.

Unless you talk about a heat pump, the heat generated by a dedicated resistor heater and an ASIC /CPU/GPU processing stuff is identical per Watt input into the system. 100% of the energy is turned into heat in both cases.

 

[robby]

Unless you talk about a heat pump, the heat generated by a dedicated resistor heater and an ASIC /CPU/GPU processing stuff is identical per Watt input into the system. 100% of the energy is turned into heat in both cases.

So yes technically all the energy becomes heat but in reality that heat is not nearly as effective at heating a room as feeding that same amount of energy into a space heater or heat pump. Lord knows this could be a long debate, so whatever you want to believe I will go with.

 

[Supervstech]

So yes technically all the energy becomes heat but in reality that heat is not nearly as effective at heating a room as feeding that same amount of energy into a space heater or heat pump. Lord knows this could be a long debate, so whatever you want to believe I will go with.

Some types of space heaters use radiant emissive the to warm surfaces quicker than air exchange would, but the net heating of the room is the same.

 

[DerpsyDoodler]

Irresponsible is a harsh word.

Speaking financially (IOW without consideration of other benefits like enjoyment, learning, environmental, independence etc) let's try to find something we agree on. That I hope is a good place to start.

Would you agree with me that it would be sub-optimal or perhaps even imprudent to invest in off-grid solar PV system if there was an alternative source of energy that was cheaper?

Surely the financially responsible thing to do is to ensure the off-grid solar PV system you are going to build is in fact the best financial option. Else you may end up with a lower ROI than you otherwise would have. Failing to assess the relative merits of the alternatives would not be financially responsible.

If the grid energy is cheap, then spending on solar PV may not make much financial sense. Which is why I pointed out earlier the example of negative wholesale grid prices. Getting paid to consume energy is a much better financial option than spending money to generate.

But in many cases the off-grid system will be a better financial option.

Hence the ROI of the solar PV part of the system is the marginal gain in ROI over the next best alternative source of energy.

Let me start with saying i only read up to what's quoted here, cause tldr.

That said, I agree with a lot of what you said. Though some of the things you said make me think you haven't read my posts 23 and 24.

Furthermore, what's being discussed here is ROI and whether or not you would include bitcoin mined on pv (presuming it is profitable) as ROI on that pv. Obviously, if there were no profit there would be no return. Someone arguing with that in mind and without explicitly pointing it out is disingenuous at best.

This is a discussion of what constitutes ROI, not about which ROI is better. If you want to acknowledge that bitcoin mined on PV is ROI on that PV, then I am happy to move forward with discussing other things. Otherwise we can discontinue discussion now.

Take time to read my posts 23 and 24. And consider the following.

When you invest in PV it's a 1 time upfront cost (sure there's maintenance but lets simplify for the sake of discussion).

whether you produce/use 30kwh a day, less, or more, your sunk cost stays the same.

If I have excess production, feed it to miners, and produce bitcoin, i am converting that potential energy at no extra cost (short of investment in the mining hardware) to money.

What does ROI stand for?

At the end of the day, it's only about accounting. Why would I not include the monetary worth of bitcoin mined (which i didnt have but now do) as ticking down on the original cost of PV so that all that accounting eventually turns to a net positive? This is a no brainer barring some retarded tax loophole that probably shouldnt exist in its defined form.

 

[ereams65]

….When you invest in PV it's a 1 time upfront cost (sure there's maintenance but lets simplify for the sake of discussion…..

So here’s the thing I think is often overlooked; said maintenance costs, or from an accounting standpoint “depreciation”. While there’s no way to standardize your ongoing costs, I do think it would be better if we could at least generalize an amount. Too many people spend little time thinking and more time doing and wonder at the end of the day “I put in Solar, why hasn’t my bank account grown?”.
These systems require money basically on a continual basis. I live in Florida and get tons of “sun hours” and while that’s great for the exposure it’s also a killer, long range, on components. So while I know that every system is different, is there a % most use?

And to the suggestion to “buy quality”; I used to think along those lines in general however I’m learning in my old age that the advice from my youth isn’t always applicable today. Case in point…one of my hobbies is woodworking. Due to a “last minute convenience I opted to buy a cheap ROS from Harbor Freight. Spent $20 when the “quality tool” was over $60. That was 10 years ago and I’m noticing it’s getting a little warm so time to replace. I don’t believe the $60 model would have gotten me 30 years of use because that would be the break even. Sure it’s a crapshoot, but in today’s robotic manufacturing process, often the only difference between the “quality” vs the “budget” is the name alone.

 

[Texas-Mark]

And to the suggestion to “buy quality”; I used to think along those lines in general however I’m learning in my old age that the advice from my youth isn’t always applicable today.

I agree. I used to buy Craftsman tools when they actually had some quality and a lifetime guarantee. However, i found that most of them rarely got used. Now if I need a tool I may only use once in a while I just buy one at HF for 1/4 the price, and if it ever does break (hasn't happened yet) I can buy another one and still be ahead of the game. Low cost does not always mean low quality.

As for the solar related stuff, most of it most likely comes out of the same factories no matter whose name is stamped on it.

 

[wattmatters]

This is a discussion of what constitutes ROI, not about which ROI is better. If you want to acknowledge that bitcoin mined on PV is ROI on that PV, then I am happy to move forward with discussing other things

I already acknowledged in my earlier post that one can calculate an ROI on a complete investment project (e.g. PV system, mining rigs etc). And yes I read those posts you suggested I didn't. Indeed I paraphrased the key point you make.

Then you say this thread is not about whether using solar PV results in a better ROI than an alternative.

Who defined that restrictive discussion parameter?
Where does the thread title or OP say that?

A: Nowhere.

Part of this thread picked up on discussion of the financial merits of investing in DIY solar PV/battery system.

A basic premise of assessing how much a solar PV system improves an ROI outcome over the alternative solution(s) is the true financial value to be assigned to that PV system.

 

[Jack Rabbit Off Grid]

What are his favorite 440w panels?