LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[hellosailor]

Juicebox sounds like a clever idea, allowing the customer to STORE solar power which they may be required to sell to the utility. But I think the utilities may be quick to argue that if a customer is using a system like this, to store power and then sell it at a different time and higher rate, they are in violation of the connection "contract" and law.


Think about it: The law requires the solar power be resold in certain ways. OK, but part of the premise is that it is SOLAR power, which of course is only made when the sun shines. During the day. And now the consumer is selling BATTERY POWER, their own home-made electricity which is not necessarily from solar sources, and certainly not being produced in the normal "now" fashion from solar panels when the sun shines.
Slam, door closes. Utilities are happy to get rid of pesky customers. Juicebox....will need some clever lawyers and lobbyists. Otherwise we could all ride our exercycles and require the utilities to buy that power also.(G)


Nice concept though. I'm not sure I'd call it "realized" until some MSRP's and other cost figures were available online though.

[DotDun]

Originally Posted by hellosailor

Juicebox sounds like a clever idea, allowing the customer to STORE solar power which they may be required to sell to the utility. But I think the utilities may be quick to argue that if a customer is using a system like this, to store power and then sell it at a different time and higher rate, they are in violation of the connection "contract" and law.


Think about it: The law requires the solar power be resold in certain ways. OK, but part of the premise is that it is SOLAR power, which of course is only made when the sun shines. During the day. And now the consumer is selling BATTERY POWER, their own home-made electricity which is not necessarily from solar sources, and certainly not being produced in the normal "now" fashion from solar panels when the sun shines.
Slam, door closes. Utilities are happy to get rid of pesky customers. Juicebox....will need some clever lawyers and lobbyists. Otherwise we could all ride our exercycles and require the utilities to buy that power also.(G)


Nice concept though. I'm not sure I'd call it "realized" until some MSRP's and other cost figures were available online though.

JuiceBox stores 8.6kwh of power which is ~$1.05 at the current top rate ($.125kwh) for power from the utility I'm connected to. Point: JuiceBox is pretty small.

My understanding of Net Metering, power produced and passed to the utility first offsets any power drawn from the utility. Only power produced over and above your usage does the utility actually 'buy'. IMO, to buy that excess at wholesale rates makes sense, it's only fair. In this scenario, Net Metering IS your battery.

[Colin A]

I doubt they would have much issue with it as more households add solar they will end up with an excess of capacity during the sunshine and low capacity at night as the current base power generators are slowly phased out. I gather this is already an issue in places like Arizona where solar adoption has been high they are having trouble running the generation properly to handle a base load will all the solar coming in ( do we fire up another peak generator or will it just idle inefficiently) storage batteries can help with this and at least buy some time when the grid dips before new generation comes on. Mind you this will require power storage that's set up to handle this. Juice box seems to handle it in an isolated fashion buy releasing some of the power when your household draw goes over a certain point.

[Hoopla]

Some power utilities around the world are already providing their customers with complete solar/AC inverter systems with battery storage just like this Juicebox to encourage them to enter into longer supply contracts.

[hellosailor]

Yes, except the JuiceBox web site expressly says this will allow customers to sell power at night, at the highest rates, rather than during the daytime when rates are lowest. So they are cleverly suggesting to customers that this thing will make more money for the customer.


Small market, small potatoes, but that makes it easy for utilities to "swat the fly" while the question is still small and before there are enough owners to do something foolish, like, petition their legislators or make objections.(G)


Sometimes the utilities just see something like that and get po'd at the concept of it, so they grab the big stick first.


I wish them luck, I just don't see a mass market or any real "deployment" there yet.

[Cottontop]

Originally Posted by hellosailor

Juicebox sounds like a clever idea, allowing the customer to STORE solar power which they may be required to sell to the utility. But I think the utilities may be quick to argue that if a customer is using a system like this, to store power and then sell it at a different time and higher rate, they are in violation of the connection "contract" and law.


Think about it: The law requires the solar power be resold in certain ways. OK, but part of the premise is that it is SOLAR power, which of course is only made when the sun shines. During the day. And now the consumer is selling BATTERY POWER, their own home-made electricity which is not necessarily from solar sources, and certainly not being produced in the normal "now" fashion from solar panels when the sun shines.
Slam, door closes. Utilities are happy to get rid of pesky customers. Juicebox....will need some clever lawyers and lobbyists. Otherwise we could all ride our exercycles and require the utilities to buy that power also.(G)


Nice concept though. I'm not sure I'd call it "realized" until some MSRP's and other cost figures were available online though.

Well, I'm only interested in it to the extent I can put it on a boat, which is why I mentioned it in this forum.

Somewhere on their website they mention a price of $9,900 for their 8.6kwh system, but it is not clear what is included in that price.

[Colin A]

As with other home systems this one runs at a higher voltage (50vdc in this case) so converters would be required. They also note it was designed to be tied to a Schneider inverter for charge control so that again would seem to be limiting. But the more of these out there the more the tech will come down in price. This is designed for a very controlled charge from a known source which is very different then what you find on most boats.

[hellosailor]

Putting it on a boat would be a waste unless the boat was a dock queen.


Whatcha gonna do with all that expensive and bulky AC interconnect and transfer equipment, if there's no mains power company tied into you?(G)


Not to mention, a convenient refrigerator-sized space, conveniently located so it doesn't tip over the boat.


I see a lot of this stuff as an answer in search of a problem.

[JAMcDonald]

I sail singlehanded, so the human factor is not always reliable. I'm building a 180A Calb main bank with HousePower BMS, contactor, HVC relays to cut off charging from alternator and solar. I'm using a off-1-2 Blue Sea battery switch to select between banks. I envision sailing offshore when for some reason a LVC event occurs and the contactor disconnects the main bank. I didn't hear the alarm warning of the event prior to losing main bank power. Suddenly no autopilot, big broach, etc. So I've been studying relays, contactors, etc wondering if I could automate switching between the two banks. Because of the voltage differences, a battery combiner is not the answer. Any thoughts would be appreciated.

[dannc]

Originally Posted by DotDun

...

My understanding of Net Metering, power produced and passed to the utility first offsets any power drawn from the utility. Only power produced over and above your usage does the utility actually 'buy'. IMO, to buy that excess at wholesale rates makes sense, it's only fair. In this scenario, Net Metering IS your battery.

The definition of Net Metering varies by state and/or power company.

I have not checked the recent laws so things may have changed, but in NC I could sell power to my power company but they would pay whole sale rates while I was buying at retail rates.

A few years ago I attended a PV class and the instructor said that it was simply not worth it for a homeowner in the state to try to sell surplus power back to the power company. If one designed and built their PV system to match their power needs, the cost and hassle of selling back to the power company was just not worth it. The instructor had built subdivisions full of PV installations and as the time limits expired on the power buying agreements, the home owners were no longer selling back to the power company.

Later,
Dan

[toddedger]

I'm in a about the same position, singlehanding with the same size bank. I can't imagine needing to automate battery switching. One should be aware of battery level before taking a nap. Keeping track of the battery level isn't any different then keeping track of your position.

[Colin A]

Originally Posted by dannc

The definition of Net Metering varies by state and/or power company.

I have not checked the recent laws so things may have changed, but in NC I could sell power to my power company but they would pay whole sale rates while I was buying at retail rates.

A few years ago I attended a PV class and the instructor said that it was simply not worth it for a homeowner in the state to try to sell surplus power back to the power company. If one designed and built their PV system to match their power needs, the cost and hassle of selling back to the power company was just not worth it. The instructor had built subdivisions full of PV installations and as the time limits expired on the power buying agreements, the home owners were no longer selling back to the power company.

Later,
Dan

Yeah it changes state by state. For a while in Mass you could also sell renewable energy credits to energy producers as well as selling power back to the energy company (kind of like Carbon swapping) This meant some people got really quick paybacks A neighbor near my brother got all the normal tax incentives to add solar then got another $2300 bucks a year in clean energy credits, his system was paid off in 3 years. This is unusual however.

[Hoopla]

Originally Posted by JAMcDonald

I sail singlehanded, so the human factor is not always reliable. I'm building a 180A Calb main bank with HousePower BMS, contactor, HVC relays to cut off charging from alternator and solar. I'm using a off-1-2 Blue Sea battery switch to select between banks. I envision sailing offshore when for some reason a LVC event occurs and the contactor disconnects the main bank. I didn't hear the alarm warning of the event prior to losing main bank power. Suddenly no autopilot, big broach, etc. So I've been studying relays, contactors, etc wondering if I could automate switching between the two banks. Because of the voltage differences, a battery combiner is not the answer. Any thoughts would be appreciated.

You have two options I think. The first is widely employed Genasun style setup and incorporates a dual charge and load bus involving 4 relays or 2 LVE and 2 HVE driven by the BMS so that the offending bank is isolated and the good bank remains connected. This may require one BMS per bank depending on the number of relay outputs/loads and whether your employing latching or non latching relays. The latter obviously are safer but draw more current.

The second option I haven't properly turned my mind too and may be spurious so please forgive me if it is but involves utilising special LFP LVE and HVE VSR's that are measuring pack voltages between the two banks such as those manufactured by Victron.

[JAMcDonald]

Originally Posted by toddedger

I'm in a about the same position, singlehanding with the same size bank. I can't imagine needing to automate battery switching. One should be aware of battery level before taking a nap. Keeping track of the battery level isn't any different then keeping track of your position.

I agree with you theoretically, but having spent 4 days in a Moore 24 on the 400 nm Long Pac, I unfortunately can easily imagine needing to automate battery switching. I've amended the thread to add an important fact: The reserve battery (mandated by offshore racing requirements) is an AGM, not a LiFePO4.

[JAMcDonald]

Originally Posted by JAMcDonald

I sail singlehanded, so the human factor is not always reliable. I'm building a 180A Calb main bank with HousePower BMS, contactor, HVC relays to cut off charging from alternator and solar. I'm using a off-1-2 Blue Sea battery switch to select between banks.

The reserve battery is an AGM, so voltages etc. are obviously different.

I can envision sailing offshore when for some reason a LVC event occurs and the contactor disconnects the main bank. I didn't hear the alarm warning of the event prior to losing main bank power. Suddenly no autopilot, big broach, etc. So I've been studying relays, contactors, etc wondering if I could automate switching between the two banks. Because of the voltage differences, a battery combiner is not the answer. Any thoughts would be appreciated.

Revised for clarity.