5 ms·

Far more cost-effective would have been to skip the battery and just put a cheap chinese pure-sine-wave grid-tie inverter to bridge between the wall outlet and

Far more cost-effective would have been to skip the battery and just put a cheap chinese pure-sine-wave grid-tie inverter to bridge between the wall outlet and the panel. It's simple- it has a 110V line cord and plugs into the outlet, sending current the opposite way of normal. Do a search on your favorite e-commerce site for "grid tie inverter" and you'll see what I mean. These cheap inverters have most of the same safeties as the UL 1703 certified variety, and as long as you don't exceed current ratings (not likely with a little 200W panel) you're able to apply the power to your electric bill, without futzing with a lead-acid battery.

nikodunk 9y ago
Wow that's really great input. I'm going to check this out and write a follow-up! This would allow me to credit the power directly to my fridge bill, as opposed to just using it for lighting and devices!
- toomuchtodo 9y ago
  Do not do this. You could kill a utility worker, and it's against the law for safety reasons. Edit: Net metering/grid tie guidelines require inverters that will shutdown upon loss of utility power. Also, a disconnect switch must be on the exterior of the building/facility, clearly identified, and on record with the utility. Bonus points if you Google "lock out tag out".
cmac2992 9y ago
Does that work with a regular meter? My internet sluething says some people have been charged for the electricity the produce because they don't have a "compatible" meter.
- ldiracdelta 9y ago
  If you hook up a ton of these and actually generate _more_ than you consume at any time, you will actually _pay_ the power company for the power you push back into the grid. You have to get a special meter that can measure the direction of the flow. I have bought two residential roof-mounted solar systems and this is what they told me. If you never generate more than you use, maybe you're ok.
- zAy0LfpBZLC8mAC 9y ago
  If you have a traditional electromechanical meter, that should normally be able to run backwards, with electronic meters, it depends.
sushid 9y ago
So does this mean that you can offset your electricity cost because your solar panel just sends the electricity it generated back into the grid (and credits you for it)? How could I verify that it's working? It looks like you might also have to sign some sort of a contract with PG&E. Is this true? https://www.pge.com/includes/docs/pdfs/b2b/wholesaleelectricsuppliersolicitation/Feedin_Tariffs_FAQs https://www.pge.com/includes/docs/pdfs/b2b/wholesaleelectric....
marvin 9y ago
Couldn't you risk shocking some poor electrician that thought the power was turned off? Maybe the inverter has some sort of safety system that I don't know about; I'm no expert on this.
pilom 9y ago
Please do not do this. For one, it's illegal. All grid-tied solar systems require either a transfer switch or to automatically disconnect when the grid loses power. This is so that you don't electrocute an electrician working on lines he or she thinks are dead. Second, most non-"net" meters don't read negative currents. So if you are generating more than you're using, they'll keep spinning forward and you'll get charged for more than you actually used. Third, the fines if you're caught are pretty high because of the safety issues.
- mchannon 9y ago
  So many here say "it's illegal" without pointing to a single law. There is no such law to point to. No municipality anywhere outlaws plugging in CE-approved appliances into your home's outlets. Even if half of them did, this would still be worthy of bringing up for the other half. Even if it was illegal, wouldn't make such laws just or logical. Florida, after all, made off-grid living illegal. http://www.collective-evolution.com/2014/03/09/florida-makes-off-grid-living-illegal-mandates-all-homes-must-be-connected-to-an-electricity-grid/ http://www.collective-evolution.com/2014/03/09/florida-makes... Now what this approach _is_ is probably against the policies of your local electric utility, but they're incentivized to disallow anything that goes against their business interests, and can argue might somehow not be safe. Take for example HECO, Hawaii's electric utility, economically devastated by grid-tied PV. http://khon2.com/2014/03/19/state-investigates-illegal-photovoltaic-systems/ http://khon2.com/2014/03/19/state-investigates-illegal-photo... The way a grid-tie inverter works is like trying to jump on a merry go round that's already moving. In the happy path, the inverter keeps the PV power detached until it's ready to find its moment and sync it up to the grid. As soon as that grid signal goes away, the inverter is no longer capable of finding the signal to continue injecting current. The PV panel doesn't cause an explosion if it suddenly goes from 0% output to 100% output to 0%, so it's not exactly a big deal for a grid-tie inverter to perform this matching- it's in fact central to its functionality. Whether the grid goes down, your breaker trips, or you unplug the 110v line cord yourself, these things all function the same- safe for anybody foolish or unfortunate enough to directly contact the inverter's output lines with their bare hands. These things don't hurt electricians, whether they have 5 safety interlocks (fundamental to any grid-tie design) or 2-3 additional ones sometimes proscribed by certain electrical codes. "non-'net' meters" are getting to be few and far between, and utilities don't like older models because they require manual meter readers to go door-to-door. Naturally, you should be aware of what your specific electric situation is before getting into by trying one of these things out, but this is a weak argument against DIY grid-tie (much better arguments against exist). An amazing number of people don't understand how electric meters work. If your grid-connected panel puts out 200W (call it 2 amps) and your apartment is pulling 3 amps total, the electric meter will spin at a rate proportional to 1 amp. It doesn't require any intelligence or fancy technology. If your apartment is pulling 1 amp net, the electric meter will not spin any faster than 1 amp, no matter how old it is. The only difference between new and old meters is whether a surplus of 1 amp is read as -1 amp or 0 amps. On the off chance you're dumb enough to hook more unregistered PV capacity onto your property than your monthly use merits, utilities may assess fines or lockouts, but none will charge you for the excess generated as if it was consumed. Most are required by law to pay you for it (though an insultingly low rate). Am also a bit alarmed by how many downvotes I got for the words "cheap chinese", as if that was a red flag for safety. Inverters of every kind, from respected brands in respectable configurations, have gotten _really_ cheap (the same model I installed 10 years ago now costs 1/10 what it cost 10 years ago). They're also almost invariably now made in China. The fact is, even if your inverter is an incendiary device waiting to happen, you have a large number of built-in safety devices: a circuit breaker and hopefully enough common sense to keep the inverter away from flammable objects, and not to bury the inverter in a ratpile of shredded newspaper and gunpowder. I'd consider the cheap inverters far more likely to simply konk out far before their time than cause any kind of safety hazard. Circuit breakers save lives. As a worthy counterexample, a faulty inverter (though probably a faulty inverter installation, considering the fire spread) caused this house fire: http://www.telegraph.co.uk/news/earth/energy/solarpower/12092562/Solar-panel-malfunction-sparks-blaze-in-family-home.html http://www.telegraph.co.uk/news/earth/energy/solarpower/1209...
reaperducer 9y ago
The two big reasons not to do this are his own words: "cheap" and "chinese."
- quickthrower 9y ago
  Yep it going to be a fire risk.
s73ver 9y ago
"These cheap inverters have most of the same safeties as the UL 1703 certified variety" I've seen inside enough cheap chinese power equipment to know that is most likely not true.
adrianmonk 9y ago
If you're going to break the law, isn't it easier to just tamper with the electric meter or run an extension cord to your next door neighbor's outlet?
- 35bge57dtjku 9y ago
  Not if you want to avoid stealing.
  - dragonwriter 9y ago
    Using means not permitted by the law and your contract with the service provider to (attempt to, at any rate) reduce your utility bill would seem to be stealing.
    - 35bge57dtjku 9y ago
      No, it would be breaking an agreement or somesuch. If you're generating your own power you're not taking anything from anyone else, so it's not stealing.

nikodunk 9y ago

Wow that's really great input. I'm going to check this out and write a follow-up! This would allow me to credit the power directly to my fridge bill, as opposed to just using it for lighting and devices!

toomuchtodo 9y ago
Do not do this. You could kill a utility worker, and it's against the law for safety reasons. Edit: Net metering/grid tie guidelines require inverters that will shutdown upon loss of utility power. Also, a disconnect switch must be on the exterior of the building/facility, clearly identified, and on record with the utility. Bonus points if you Google "lock out tag out".

cmac2992 9y ago

Does that work with a regular meter? My internet sluething says some people have been charged for the electricity the produce because they don't have a "compatible" meter.

ldiracdelta 9y ago
If you hook up a ton of these and actually generate _more_ than you consume at any time, you will actually _pay_ the power company for the power you push back into the grid. You have to get a special meter that can measure the direction of the flow. I have bought two residential roof-mounted solar systems and this is what they told me. If you never generate more than you use, maybe you're ok.
zAy0LfpBZLC8mAC 9y ago
If you have a traditional electromechanical meter, that should normally be able to run backwards, with electronic meters, it depends.

sushid 9y ago

So does this mean that you can offset your electricity cost because your solar panel just sends the electricity it generated back into the grid (and credits you for it)? How could I verify that it's working? It looks like you might also have to sign some sort of a contract with PG&E. Is this true? https://www.pge.com/includes/docs/pdfs/b2b/wholesaleelectricsuppliersolicitation/Feedin_Tariffs_FAQs https://www.pge.com/includes/docs/pdfs/b2b/wholesaleelectric....

marvin 9y ago

Couldn't you risk shocking some poor electrician that thought the power was turned off? Maybe the inverter has some sort of safety system that I don't know about; I'm no expert on this.

pilom 9y ago

Please do not do this. For one, it's illegal. All grid-tied solar systems require either a transfer switch or to automatically disconnect when the grid loses power. This is so that you don't electrocute an electrician working on lines he or she thinks are dead. Second, most non-"net" meters don't read negative currents. So if you are generating more than you're using, they'll keep spinning forward and you'll get charged for more than you actually used. Third, the fines if you're caught are pretty high because of the safety issues.

mchannon 9y ago
So many here say "it's illegal" without pointing to a single law. There is no such law to point to. No municipality anywhere outlaws plugging in CE-approved appliances into your home's outlets. Even if half of them did, this would still be worthy of bringing up for the other half. Even if it was illegal, wouldn't make such laws just or logical. Florida, after all, made off-grid living illegal. http://www.collective-evolution.com/2014/03/09/florida-makes-off-grid-living-illegal-mandates-all-homes-must-be-connected-to-an-electricity-grid/ http://www.collective-evolution.com/2014/03/09/florida-makes... Now what this approach _is_ is probably against the policies of your local electric utility, but they're incentivized to disallow anything that goes against their business interests, and can argue might somehow not be safe. Take for example HECO, Hawaii's electric utility, economically devastated by grid-tied PV. http://khon2.com/2014/03/19/state-investigates-illegal-photovoltaic-systems/ http://khon2.com/2014/03/19/state-investigates-illegal-photo... The way a grid-tie inverter works is like trying to jump on a merry go round that's already moving. In the happy path, the inverter keeps the PV power detached until it's ready to find its moment and sync it up to the grid. As soon as that grid signal goes away, the inverter is no longer capable of finding the signal to continue injecting current. The PV panel doesn't cause an explosion if it suddenly goes from 0% output to 100% output to 0%, so it's not exactly a big deal for a grid-tie inverter to perform this matching- it's in fact central to its functionality. Whether the grid goes down, your breaker trips, or you unplug the 110v line cord yourself, these things all function the same- safe for anybody foolish or unfortunate enough to directly contact the inverter's output lines with their bare hands. These things don't hurt electricians, whether they have 5 safety interlocks (fundamental to any grid-tie design) or 2-3 additional ones sometimes proscribed by certain electrical codes. "non-'net' meters" are getting to be few and far between, and utilities don't like older models because they require manual meter readers to go door-to-door. Naturally, you should be aware of what your specific electric situation is before getting into by trying one of these things out, but this is a weak argument against DIY grid-tie (much better arguments against exist). An amazing number of people don't understand how electric meters work. If your grid-connected panel puts out 200W (call it 2 amps) and your apartment is pulling 3 amps total, the electric meter will spin at a rate proportional to 1 amp. It doesn't require any intelligence or fancy technology. If your apartment is pulling 1 amp net, the electric meter will not spin any faster than 1 amp, no matter how old it is. The only difference between new and old meters is whether a surplus of 1 amp is read as -1 amp or 0 amps. On the off chance you're dumb enough to hook more unregistered PV capacity onto your property than your monthly use merits, utilities may assess fines or lockouts, but none will charge you for the excess generated as if it was consumed. Most are required by law to pay you for it (though an insultingly low rate). Am also a bit alarmed by how many downvotes I got for the words "cheap chinese", as if that was a red flag for safety. Inverters of every kind, from respected brands in respectable configurations, have gotten _really_ cheap (the same model I installed 10 years ago now costs 1/10 what it cost 10 years ago). They're also almost invariably now made in China. The fact is, even if your inverter is an incendiary device waiting to happen, you have a large number of built-in safety devices: a circuit breaker and hopefully enough common sense to keep the inverter away from flammable objects, and not to bury the inverter in a ratpile of shredded newspaper and gunpowder. I'd consider the cheap inverters far more likely to simply konk out far before their time than cause any kind of safety hazard. Circuit breakers save lives. As a worthy counterexample, a faulty inverter (though probably a faulty inverter installation, considering the fire spread) caused this house fire: http://www.telegraph.co.uk/news/earth/energy/solarpower/12092562/Solar-panel-malfunction-sparks-blaze-in-family-home.html http://www.telegraph.co.uk/news/earth/energy/solarpower/1209...

reaperducer 9y ago

The two big reasons not to do this are his own words: "cheap" and "chinese."

quickthrower 9y ago
Yep it going to be a fire risk.

s73ver 9y ago

"These cheap inverters have most of the same safeties as the UL 1703 certified variety" I've seen inside enough cheap chinese power equipment to know that is most likely not true.

adrianmonk 9y ago

If you're going to break the law, isn't it easier to just tamper with the electric meter or run an extension cord to your next door neighbor's outlet?

35bge57dtjku 9y ago
Not if you want to avoid stealing.
- dragonwriter 9y ago
  Using means not permitted by the law and your contract with the service provider to (attempt to, at any rate) reduce your utility bill would seem to be stealing.
  - 35bge57dtjku 9y ago
    No, it would be breaking an agreement or somesuch. If you're generating your own power you're not taking anything from anyone else, so it's not stealing.