Am I Crazy? Seems like a Lot more Off Grid System being Built by Grid Users Lately

[Ampster]

surplus inverters got liquidated on ebay?

Even though the scammer only built half of the trailers he claimed, there were still a lot of them built and auctions still go one to liquidate that inventory. One of my neighbors just parked one in his driveway which I assume was from a recent auction.

 

[MurphyGuy]

Not familiar with the "DC Solar Scam", but at $5k, not sure why someone would choose the Sunny Island over the Schneider XW that is at least $1.5k less. But if you got them for $1100 ... yeah i'd do that !!

The SMA Sunny Islands are a FAR FAR better inverter than Schneider, or any other inverter for that matter.. Don't get me wrong, inverters like the Schneider, Outback Radian's, Sol Ark, etc, are all good quality inverters, but none hold a candle to the SMA Sunny Islands..

Your comment about the Schneider being $1500 less is comical because its worse than you know. SMA Sunny Island are 120 volt inverters.. Yup.. for $5000, you get a 6000 watt inverter that only puts out 120 volts. You need TWO of them to make a 120/240 system.. so its not just another $1500 more, its another $6500 more.. and you end up with a 120/240 system capable of 12kW.

They are the most expensive inverter on the market.... but that extra expense is matched by the higher quality. You will find all kinds of debates about which of the Outback, Schneider, Sol Ark units are better than each other, but you rarely see SMA Sunny Islands mentioned, and the reason for that is because there isn't a debate about it any more than a debate about a Ferrari being better than a Chevy Camaro.

My point is, if you're going to depend on your off-grid system for your comfort and safety, the SMA's are worth the extra cost. and you can still find them in the $3k price range on Ebay.

 

[MrM1]

I would not put Sol-Ark in the same class as Outback and Schneider. But I hear what you are saying.

 

[MT off grid]

I built my lil off grid system to assist my grid powered house 4 years ago. At the time People asked me was I was "Crazy", "You Need a Sanity Check", "Why would you build an off grid system for your house if you are grid connected AND your cost per kWh was about $0.11" . I was told I would Never see an ROI.
- Why don't you go grid tie, they said.
- You are just wasting money, they said.

Well I knew I would not see an ROI, and that was never my point. I was building it:
1. For a "what if" scenario. What if the power goes out, or a hurricane sweeps thru, or worse
2. And I enjoy it as a hobby. I dont, golf, boat, etc.
3. And I did not want to fool with permission to connect to the grid

Now it seems that more and more people are building off grid / grid assist systems for there homes. Not grid tied, just battery based off grid that either have automatic transfer switches (like a UPS) or will actually assist the gird in providing loads to the home, thus lower grid power consumption. And when the power goes out, the home still has power (sometimes full power, sometimes a limited / select circuits of power.

Is it just me, or with the advent of larger and larger AIO systems, more and more people are doing this?

I was in the middle of my system until I found out that to pass inspection i need everything to be UL listed, spent several weeks calling inspectors all over the country (U.S) to make sure my local inspectors are correct and apparently NEC 710 stand-alone systems require all equipment he UL listed which increases my investment another 10-12,000 bucks more

 

[LB3]

You guys must pay even more for your electricity than we do here in California (~$0.45 peak, $0.20 off-peak) !

I didn’t realize California power rates were so high. I’m paying $0.11 with no peak hours.

Have you run the numbers on building a big battery and charging it during off peak hours and feeding it back during peak hours? With that kind of spread you might be looking at a significant ROI.

 

[MrM1]

I was in the middle of my system until I found out that to pass inspection i need everything to be UL listed, spent several weeks calling inspectors all over the country (U.S) to make sure my local inspectors are correct and apparently NEC 710 stand-alone systems require all equipment he UL listed which increases my investment another 10-12,000 bucks more

Yeah I bought everything UL listed at the time. Batteries were also LA. Now my LFP diy bank probably would not pass NEC 2020 (but I think we are still on 2014 or 17), but with some wiring mods the rest of the system would.

 

[fafrd]

I didn’t realize California power rates were so high. I’m paying $0.11 with no peak hours.

Have you run the numbers on building a big battery and charging it during off peak hours and feeding it back during peak hours? With that kind of spread you might be looking at a significant ROI.

Already done.

I’m actually just charging up a battery during the day using a small new DC-coupled array which I then use to offset consumption during peak hours of 4-9pm using a pair of 1kW GTIL inverters…

Even with a DIY 14kWh LiFePO battery that ‘only’ cost me $1500 all-in, breakeven will take most of a decade (though that should drop to 5-7 years once we purchase a planned-for EV…).

So battery costs mean there really isn’t much of any ROI to speak of, but the new battery system also provides backup capability, so that’s a value-add, and it will translate to even lower driving costs once we have an EV (I’m able to produce more kWh than I can consume without the EV).

 

[mciaio]

At .27/kwh and the utility companies taking away net metering, it's a no brainer. Plus equipment is hella cheap now.

 

[fafrd]

At .27/kwh and the utility companies taking away net metering, it's a no brainer. Plus equipment is hella cheap now.

I should have at least another 10 years to go before they strip me of my ability to export for full credit, but yeah, the only solar system that will make sense after the new successor tariff being proposed comes into force will be battery-based with a big enough battery to get through the night and an oversized array that can fill that battery up most of the year (all seasons but depth of winter in December and January).

Hopefully when that time comes for me, batteries will be much cheaper than they are today…

 

[Ampster]

Have you run the numbers on building a big battery and charging it during off peak hours and feeding it back during peak hours?

When you say, "feeding it back" do you mean supporting loads or do you mean backfeeding the grid? Either way the numbers are good in California with peak rates two and a half times greater than off peak rates. It is much easier to offset loads than to sell to the grid at peak rates.

 

[MT off grid]

Yeah I bought everything UL listed at the time. Batteries were also LA. Now my LFP diy bank probably would not pass NEC 2020 (but I think we are still on 2014 or 17), but with some wiring mods the rest of the system would.

2017 where I am but sure puts a mess in my plans

 

[eabyrd]

Is it just me, or with the advent of larger and larger AIO systems, more and more people are doing this?

that’s what I did, so no I don’t think it’s just you. I mirror your rationale too. It was never about ROI it was about not having to pull out the genset in most cases, learning and tinkering, and shaving a few bucks off the power bill was a windfall.

 

[LB3]

When you say, "feeding it back" do you mean supporting loads or do you mean backfeeding the grid? Either way the numbers are good in California with peak rates two and a half times greater than off peak rates. It is much easier to offset loads than to sell to the grid at peak rates.

I was just shocked to see such a high peak rates and wondering about more than just payback times but actually turning a system into a profit center.

I don’t know the laws in California and whether providers just provide credits or if they actually write checks to those feeding the grid.

If it can’t be done on a wholesale What’s the spread on the wholesale spot price in California and could grid tied batteries make a profile like Tesla’s system in Australia is purportedly doing?

Already done.

I’m actually just charging up a battery during the day using a small new DC-coupled array which I then use to offset consumption during peak hours of 4-9pm using a pair of 1kW GTIL inverters…

Even with a DIY 14kWh LiFePO battery that ‘only’ cost me $1500 all-in, breakeven will take most of a decade (though that should drop to 5-7 years once we purchase a planned-for EV…).

So battery costs mean there really isn’t much of any ROI to speak of, but the new battery system also provides backup capability, so that’s a value-add, and it will translate to even lower driving costs once we have an EV (I’m able to produce more kWh than I can consume without the EV).

I was thinking more along the lines of just a battery with no solar and just taking grid power to charge a battery during the off peak hours and selling it back a few hours later at a profit.

 

[fafrd]

I was just shocked to see such a high peak rates and wondering about more than just payback times but actually turning a system into a profit center.

I don’t know the laws in California and whether providers just provide credits or if they actually write checks to those feeding the grid.

If it can’t be done on a wholesale What’s the spread on the wholesale spot price in California and could grid tied batteries make a profile like Tesla’s system in Australia is purportedly doing?

I was thing more along a of just a battery with no solar and just taking grid power to charge a battery during the off peak hours and selling it back a few hours later at a profit.

Once you factor in round-trip efficiency losses as well as the $/cycle of the battery usage, it generally comes out to break-even (at beset).

Once batteries cost 10% of what they do today, the math would work out differently.

 

[wattmatters]

like Tesla’s system in Australia is purportedly doing?

Just to clarify, to what are you referring?

Tesla's "big battery" aka the Hornsdale Power Reserve (HPR), or do you mean their home batteries and virtual power plant program?

If the latter, then homeowners in that program, and homeowner batteries in Australia in general, do not make money from grid arbitrage. It provides a small additional income stream but it just makes home battery economics go from atrocious to just awful. There are a small handful who play the wholesale market but the reality is it's just not a money making proposition. Mostly they do it as a hobby.

If however you mean the former (which is really a site operated by French company Neoen using batteries not from Tesla) then these grid scale batteries only make a portion of their income from from arbitrage. Mostly they are contracted to provide Frequency Control and Ancillary Services (FCAS), IOW grid stability services. FCAS income comes from the network authority and also the South Australian government pays for the battery to have energy in reserve for emergency use. Financially it started out very nicely for two reasons:

i. FCAS had traditionally been provided by fossil fuel stations, especially fast start gas, and they were making hay while the sun shined (or wasn't as the case may be). But the battery is able to respond to grid issues within milliseconds, rather than seconds to minutes for gas. As a result it has all but put the FCAS gas operators out of business as it can respond faster and do so at lower rates than the gas FCAS operators could. The benefit is that even though this makes quite a tidy income stream for the HPR, it saved the network operator and state govt quite a lot of money as well. The gas operators were the losers.

ii. Early in HPR's operation, South Australia experienced a bad wind storm and major transmission networks were damaged including an interconnect with a neighbouring state. This caused wide spread outages, but even so, the battery was able to help protect many services and help the state get back to some normality while the (quite lengthly) repairs were undertaken. They made very good money during this period. This was a bit of a windfall and such events could not be considered a regular part of forward annual income streams. It's there if needed and the SA govt pays for that insurance (IOW having capacity on reserve). This is the income they can bank on.

Since then other large batteries have sprung up, the Hornsdale Reserve has been expanded but income streams are not going to be as lucrative as the FCAS market is now spread across more "big batteries" as are the grid arbitrage opportunities, and the state also started to introduce more large synchronous condensers to further support grid stability as the SA grid heads towards 100% renewable supply.

For grid scale operation, the early movers can do pretty well for their initial year or two, but ultimately competition from other battery projects will see them revert to the mean.

 

[OffGridInTheCity]

We're in Southern Oregon and have 11c/kwh grid. My ROI on 13kw PV (+12kw emergency stockpile PV), 100kwh battery, and 240v@100a inverting as of this month is 28.0605yrs! Maybe prices will go up but its not about 'making money'.

its about seeing if we could be Offgrid In The City and other than 3 months in winter we are

 

[wattmatters]

I was thing more along a of just a battery with no solar and just taking grid power to charge a battery during the off peak hours and selling it back a few hours later at a profit.

In Australia if on a retail electricity plan then exported energy is credited at ~1/3rd to 1/4 the price of imported energy (varies depending where you are but that's about typical). Part of the reason for this large gap is explained below.

You could instead go on a wholesale price pass through plan, but it is still a difficult scenario.

Even in this case all the grid service charges (distribution, network, carbon, etc) are only applied to energy imported, and not applied to energy exported. So you have to pay all those costs for every kWh you import but you don't get them back when energy goes the other way. IOW your energy price arbitrage spread has to be large enough to overcome that service cost differential. It rarely is, and when it does it's for short periods and home batteries ultimately can't send out energy fast enough to make it worthwhile. All domestic systems have a cap on power they are permitted to export (e.g. 5kW per phase is pretty typical although it varies with location).

 

[curiouscarbon]

I built my lil off grid system to assist my grid powered house 4 years ago. At the time People asked me was I was "Crazy", "You Need a Sanity Check", "Why would you build an off grid system for your house if you are grid connected AND your cost per kWh was about $0.11" . I was told I would Never see an ROI.
- Why don't you go grid tie, they said.
- You are just wasting money, they said.

Well I knew I would not see an ROI, and that was never my point. I was building it:
1. For a "what if" scenario. What if the power goes out, or a hurricane sweeps thru, or worse
2. And I enjoy it as a hobby. I dont, golf, boat, etc.
3. And I did not want to fool with permission to connect to the grid

Now it seems that more and more people are building off grid / grid assist systems for there homes. Not grid tied, just battery based off grid that either have automatic transfer switches (like a UPS) or will actually assist the gird in providing loads to the home, thus lower grid power consumption. And when the power goes out, the home still has power (sometimes full power, sometimes a limited / select circuits of power.

Is it just me, or with the advent of larger and larger AIO systems, more and more people are doing this?

I think you're not crazy.

My DIY is basically just a "solar charged UPS". It just seems more flexible than grid tie in every way. Part of why I'm building solar is to be less encumbered by external silliness, so my "return on investment" is measured in the degree to which it satisfies that criteria.

Grid tie is unacceptable to me because of the shenanigans around net energy metering and annoyance with permitting. Strongly prefer to just use my own locally generated power.

Also I like knowing that my system basically cannot ever harm a linesperson upstream.

Everyone got different situation different goals etc, it's interesting to read about all sorts of situations and systems and approaches here.

 

[LB3]

Just to clarify, to what are you referring?

Tesla's "big battery" aka the Hornsdale Power Reserve (HPR), or do you mean their home batteries and virtual power plant program?

I meant the HPR but didn’t know it’s name. I was just wondering if there was room for systems like that in California but on a much smaller scale that a DIYer could build for $50k or $100k that could return a decent ROI over the life of the system. But it sounds like it can’t be done with retail connections and would already be done wholesale if the economics worked.

 

[Bossrox]

I built my lil off grid system to assist my grid powered house 4 years ago. At the time People asked me was I was "Crazy", "You Need a Sanity Check", "Why would you build an off grid system for your house if you are grid connected AND your cost per kWh was about $0.11" . I was told I would Never see an ROI.
- Why don't you go grid tie, they said.
- You are just wasting money, they said.

Well I knew I would not see an ROI, and that was never my point. I was building it:
1. For a "what if" scenario. What if the power goes out, or a hurricane sweeps thru, or worse
2. And I enjoy it as a hobby. I dont, golf, boat, etc.
3. And I did not want to fool with permission to connect to the grid

Now it seems that more and more people are building off grid / grid assist systems for there homes. Not grid tied, just battery based off grid that either have automatic transfer switches (like a UPS) or will actually assist the gird in providing loads to the home, thus lower grid power consumption. And when the power goes out, the home still has power (sometimes full power, sometimes a limited / select circuits of power.

Is it just me, or with the advent of larger and larger AIO systems, more and more people are doing this?

I'm with you exactly, doing the same here. Like a hot rodder sinking all his hard earned cash into a hobby with no real return except the satisfaction of getting it done. But I'm aiming for getting enough where I can call the power company & say bye bye, cut me loose. Will call you if I need ya. haha.