A Hybrid system that can switch between using power from Solar panels and the Grid

[Mike90250]

..... $5000 for lifepo4 cells, $.......
The life of the system is more than 20 years, yet you can recoupe your invest in less than 6 years. Make a loyt of sense to me , rather than denial of the reality.

How many 20% - 85% cycles for lifepo4 ? about 2,000 ?
365 x 5 years 1,825 days/cycles.
365 x 20y = 7,300 days/cycles - which I find very hard to believe. What battery mfg is giving that number ?

$5000 for lifepo4 cells At what watt-hour size ? 2000ah at 12V or at 48V ?

I do understand the LFP cells are over 95% efficient, but I don't see the watt-hours or expected lifetime of the system spelled out. Panels I can see 20+ years, but the inverter, I think the better guess is 10 years, same with charge controller.
I_want_to_believe5.jpg

[russ]

Tasman - You do love to blow smoke don't you!

[tasman]

Let me see if I'm following this: they have a generator, plus grid-tied solar panels, plus batteries. During the day the solar power feeds AC to the grid, and the batteries are charged during the daytime using AC from the grid. At night the inverter runs off the batteries, or you switch to the generator when the grid goes down.

This seems terribly complicated to me, and I'm not clear what the benefit is. You don't say where this system is located, so I suppose if grid power is super-expensive it might make sense. But if grid power is that expensive and you've got batteries and a generator and solar panels, why not just go off-grid?

No you're not following it right. They charge their batteries during the day from the panels, as well as feed into the gird. At night they use the lifepo4 batteries for power. The generator is for when there is lots of cloudy days and no wind, or for their 3 phase workshop. When the generator is running, they are charging the batteries, 2000ah of lifepo4 and 7kw of solar is adequate for what they need, to pay back and make a profit from their system.

Don't know what you lot are using, but if haven't exoerienced good lifepo4 storage systems and the massive adivatages oif them, then you don't have a clue and using very primitive 19th century technology.

Let's say, down here, the avergage quarterly energy bill is about $400-500, that's $2000 a year, which is very conservative. A lifepo4 system of 2000ah and 7kw of solar, costs $6000 for panels and $5000 for lifepo4 cells, $1000 for a 6kw generator and required assecories. The life of the system is more than 20 years, yet you can recoupe your invest in less than 6 years. Make a loyt of sense to me , rather than denial of the reality.

[SunEagle]

1) batteries have a finite lifetime of 5-10 years, unless you destroy them earlier. They cost a few $$ too!

2) you are way overthinking this. Install PV. Charge batteries. Sell to grid. Use grid as prime power, inverter for only when grid is down. If grid is down too long and batteries go low, start the generator to charge them.

Do not try to daily cycle batteries selling to grid and using batteries at night, you will halve your PV harvest recharging batteries and the layers of inefficiency that involves. There is nothing cheaper than Grid power, then comes plain battery free Grid-Tie.

I don't know how to say it any clearer. Why do these people still feel they will be able to generate power cheaper using batteries than purchasing from their Utility?

They are either very naive or for some reason they just don't trust their POCO and think they can do it better.

[Mike90250]

1) batteries have a finite lifetime of 5-10 years, unless you destroy them earlier. They cost a few $$ too!

2) you are way overthinking this. Install PV. Charge batteries. Sell to grid. Use grid as prime power, inverter for only when grid is down. If grid is down too long and batteries go low, start the generator to charge them.

Do not try to daily cycle batteries selling to grid and using batteries at night, you will halve your PV harvest recharging batteries and the layers of inefficiency that involves. There is nothing cheaper than Grid power, then comes plain battery free Grid-Tie.

[Maitland Gill]

The Xantrex / Schneider XW series does most of that. It acts like a giant UPS for your house (well, it's transfer switches are good for 60Amps, your house is likely wired for 100A or more) It just needs batteries, and will charge them from the grid, when the grid goes down, the relay clicks and you are on inverter power for as long as the batteries last.

You can add PV panels & solar charge controller, or any other method you devise to keep the batteries charged.

Being able to produce our own electricity, allows us to reduce our power bill. The amount we save from this, can be used to expand our system. So the sooner we can start doing this, the faster we can become self-sufficient. Rather than wait until we can afford to install an Inverter to our Fusebox, what if we used a Grid-Assisted Uninterruptible power Supply (UPS), that can automatically switch to using power from a wall socket (The Grid). This is for when the Solar panels don't provide enough current and require an alternative power supply.

When you're ready to make changes to the Fusebox, the equipment that makes up a UPS can be used to supply power to the entire house. In Australia, the cost of replacing a switchboard is about $700. New circuits and having to rewire cables could bring this up to $5,000 [Home Improvement Pages - How much does it cost to replace a switchboard].

So I need to find a product (Inverter/Charger) that can:

1. Detect the amount of charge within a battery and switch over to an alternative power supply (The Grid through a wall socket) when the battery has been half depleted (Or drains to a level of you're choosing).

2. While the power from the house is being utilized (The grid), the device continues to power the product while also using Solar (When available) to recharge the batteries.

3. When the battery regains a percentage of it's charge, the device needs to switch back to using Solar as it's primary input source. This way, even if the Solar panels don't generate as much power as what's being consumed, the energy that had accumulated during the day, can still be used to run the appliance for a while.

4. The device will need to convert the DC to 240 Volts AC.

5. There needs to be a way in which an AS/NZS 3112 (Type I) can draw AC current from the output.

I know my demands are complex, but it seems so much more convenient than having to install a Grid-tier system to you're Fusebox.
For smaller applications (Bar fridge, Air-conditioner), the cost and reliability of such a system would help make Solar more accessible.

[SunEagle]

Not dumb or illegal, they are not contracted to have to use grid power, I've read it and it's about them supplying energy to the grid. They are getting an income from it, which according to them will pay off their system within the next couple of years, as they've had it for a couple of years now. Of course the power company may cut off their power, but according to the laws they have to provide a connection to anyone who pays their bills. Can't uinderstand why so many support the rich corporate world of using the law to their advantage to rip everyone off, but frown on those who use it to give the corporate world some of their own medicine.

Their batteries are lifepo4, should last decades considering they rarely get below 70%. We have very expensive electricity down here, so It's logical to use the generator on veggie oil which they source from local takeaways for their workshop requirements. They have very few times when they have no sun for more than a couple of days, so it's a long term guarantee of energy supply with excellent back ups and energy security.

They control their entire energy system through an old 256meg RAM x 10gig laptop running linux, the bloke designed and build the program himself, way out of my understanding but it works and controls lights and energy use around the home, very efficiently.

Why run a generator which requires lots of maintenance, wears out, emits lots of pollution and noise, or the grid where you have to pay for your energy when you already have it free. Doing the right thing is providing a secure reliable and cheap energy system for your families future, not supporting rip off profit making ideological elites and increasing their profit margins and bank balances at the expense of everyone elses life style. If people did the right thing, these rich morons would make just enough to have good lives, then reduce their profit margins and aid the huge amount of people struggling to survive in this rip of age of idelogical elitism.

This is the 21st century, not the 19th, just the same with everything, if you stick with past approaches, you end up with past outcomes.

Yes this is the 21st century. What I am saying is your estimation that is costs less to generate power with batteries then purchasing it from the greedy power company is wrong unless where you live the electric rates are more than $1/kWh.

So do the math and add up what it cost to purchase the solar panels, batteries, chargers, inverter, wires, fuses, etc. and then estimate the lifetime (about 7 to 9 years but not decades) kWh generation from those batteries. Divide that kWh generation value into what was spent and you will end up with a figure over $1/kWh.

Just about anywhere in the world you will be paying more to generate from batteries then buying from the Utility. Even with the cost of fuel being high, using a generator efficiently will end up costing less to generate a kWh then using batteries.

Also think about using that great software your friend designed that will help you efficiently use the power you purchase. That will save money without the need to purchase batteries.

[pleppik]

If you have a grid connect system, wouldn't it be easier to use a 240v battery charger during the day for your battery pack and at night, switch over to battery power via an inverter. Pretty cheap and it would overcome the hassle of spending more money. That way you get the return income from the grid and no bills.

I know someone who does that, they had an electrician connect a generator to the house for when they had grid power failures, which are often where they live. When they got their grid connect system, the same electrician came and wired their inverter to the generator power board, now they charge their batteries during the day from a power point and at night, switch to battery.

Seems to work really well for them, except they have had the power company arrive to check their grid system because of their lack of power use a couple of times and accepted that they only switched to the generator during grid power failures. The dumb power company electricians didn't have a clue about the wired inverter and thought it was part of the generator system. If you have a grid connect system, wouldn't it be easier to use a 240v battery charger during the day for your battery pack and at night, switch over to battery power via an inverter. Pretty cheap and it would overcome the hassle of spending more money. That way you get the return income from the grid and no bills.

I know someone who does that, they had an electrician connect a generator to the house for when they had grid power failures, which are often where they live. When they got their grid connect system, the same electrician came and wired their inverter to the generator power board, now they charge their batteries during the day from a power point and at night, switch to battery.

Let me see if I'm following this: they have a generator, plus grid-tied solar panels, plus batteries. During the day the solar power feeds AC to the grid, and the batteries are charged during the daytime using AC from the grid. At night the inverter runs off the batteries, or you switch to the generator when the grid goes down.

This seems terribly complicated to me, and I'm not clear what the benefit is. You don't say where this system is located, so I suppose if grid power is super-expensive it might make sense. But if grid power is that expensive and you've got batteries and a generator and solar panels, why not just go off-grid?

[tasman]

Not only are his friends looking for trouble, they are actually spending more money using batteries (the most costly) to supply their power instead of either that generator or the grid.

Maybe they will figure it out when they have to replace that battery bank.

Not dumb or illegal, they are not contracted to have to use grid power, I've read it and it's about them supplying energy to the grid. They are getting an income from it, which according to them will pay off their system within the next couple of years, as they've had it for a couple of years now. Of course the power company may cut off their power, but according to the laws they have to provide a connection to anyone who pays their bills. Can't uinderstand why so many support the rich corporate world of using the law to their advantage to rip everyone off, but frown on those who use it to give the corporate world some of their own medicine.

Their batteries are lifepo4, should last decades considering they rarely get below 70%. We have very expensive electricity down here, so It's logical to use the generator on veggie oil which they source from local takeaways for their workshop requirements. They have very few times when they have no sun for more than a couple of days, so it's a long term guarantee of energy supply with excellent back ups and energy security.

They control their entire energy system through an old 256meg RAM x 10gig laptop running linux, the bloke designed and build the program himself, way out of my understanding but it works and controls lights and energy use around the home, very efficiently.

Why run a generator which requires lots of maintenance, wears out, emits lots of pollution and noise, or the grid where you have to pay for your energy when you already have it free. Doing the right thing is providing a secure reliable and cheap energy system for your families future, not supporting rip off profit making ideological elites and increasing their profit margins and bank balances at the expense of everyone elses life style. If people did the right thing, these rich morons would make just enough to have good lives, then reduce their profit margins and aid the huge amount of people struggling to survive in this rip of age of idelogical elitism.

This is the 21st century, not the 19th, just the same with everything, if you stick with past approaches, you end up with past outcomes.

[SunEagle]

Really a bit stupid - if the power company ever figures out what is going on they have every right to pull the plug.

Do things right and don't cheat!

Your friends are the dumb ones.

Not only are his friends looking for trouble, they are actually spending more money using batteries (the most costly) to supply their power instead of either that generator or the grid.

Maybe they will figure it out when they have to replace that battery bank.

[russ]

Seems to work really well for them, except they have had the power company arrive to check their grid system because of their lack of power use a couple of times and accepted that they only switched to the generator during grid power failures. The dumb power company electricians didn't have a clue about the wired inverter and thought it was part of the generator system.

Really a bit stupid - if the power company ever figures out what is going on they have every right to pull the plug.

Do things right and don't cheat!

Your friends are the dumb ones.

[tasman]

If you have a grid connect system, wouldn't it be easier to use a 240v battery charger during the day for your battery pack and at night, switch over to battery power via an inverter. Pretty cheap and it would overcome the hassle of spending more money. That way you get the return income from the grid and no bills.

I know someone who does that, they had an electrician connect a generator to the house for when they had grid power failures, which are often where they live. When they got their grid connect system, the same electrician came and wired their inverter to the generator power board, now they charge their batteries during the day from a power point and at night, switch to battery.

Seems to work really well for them, except they have had the power company arrive to check their grid system because of their lack of power use a couple of times and accepted that they only switched to the generator during grid power failures. The dumb power company electricians didn't have a clue about the wired inverter and thought it was part of the generator system. If you have a grid connect system, wouldn't it be easier to use a 240v battery charger during the day for your battery pack and at night, switch over to battery power via an inverter. Pretty cheap and it would overcome the hassle of spending more money. That way you get the return income from the grid and no bills.

I know someone who does that, they had an electrician connect a generator to the house for when they had grid power failures, which are often where they live. When they got their grid connect system, the same electrician came and wired their inverter to the generator power board, now they charge their batteries during the day from a power point and at night, switch to battery.

Seems to work really well for them, except they have had the power company arrive to check their grid system because of their lack of power use a couple of times and accepted that they only switched to the generator during grid power failures. The dumb power company electricians didn't have a clue about the wired inverter and thought it was part of the generator system.

[Amy@altE]

I did not read the technical data but is there a way to disable the "charging" feature and just use the "transfer switch" component if you already had a good solar MPPT CC for your battery system?

The idea of a pure sine wave inverter with instant transfer between grid and battery is very appealing but with only 30A CC capacity you would be limited to the size of the battery system.

Agreed, which is why we don't sell a lot of them. They've got others without the charge controller built in, but this one has a lot of configurability that I like, it can set priority on using grid or battery. Just not connecting the solar to that connection and using an external one will accomplish that.

They've got the ST-1500-112 with Pure sine wave and 25A transfer switch for $615. http://samlexamerica.com/documents/p...414%20Lrez.pdf . It meets UL Standard UL-458 (pending listing), so it is designed for mobile use, not home.

[SunEagle]

$765. As you said, I like that it gives you the freedom to use a quality battery of your choice for a UPS. It is small, the solar charge controller is just PWM 12V 30A, but it's a cool product. We don't sell many of them at all, but if you are trying to build your own UPS, the price is about right. Charge controller $120 + inverter $500 + auto transfer switch $190 = $810.

I did not read the technical data but is there a way to disable the "charging" feature and just use the "transfer switch" component if you already had a good solar MPPT CC for your battery system?

The idea of a pure sine wave inverter with instant transfer between grid and battery is very appealing but with only 30A CC capacity you would be limited to the size of the battery system.

[Amy@altE]

Interesting item. Although it is just a big UPS system with external batteries that can be dedicated to a single or a couple of small electric loads.

I didn't see a cost but it might be worth while as a small backup system for a "critical load" if it is matched to a decent battery system. At least you could use good Deep Cycle batteries instead of the normal AGM batteries found inside most UPS boxes.

$765. As you said, I like that it gives you the freedom to use a quality battery of your choice for a UPS. It is small, the solar charge controller is just PWM 12V 30A, but it's a cool product. We don't sell many of them at all, but if you are trying to build your own UPS, the price is about right. Charge controller $120 + inverter $500 + auto transfer switch $190 = $810.