We just talked about solar installations with a local company's representative, and it looks like a great deal EXCEPT that the solar can't take over when the power goes out - supposedly because of safety concerns. If a repairman is working on a pole, we were told, a surge could come out of our installation and electrocute him. However, we already have a stand-by generator powered by LP gas which has a transfer switch so that when the power is out and the generator kicks in, it prevents the electricity from that device from entering the system beyond our home. I'm wondering why that can't work with solar energy and whether others have had the same experience with the same limitations.
Solar Set-Ups - Can You Use Them When The Power Goes Out?
I have heard this too but I havent researched it much. Here is what I assume is happening.
Voltage from your solar panels out your inverter has to be at a higher voltage than the grid because it has to force out what it is not using. However, a generator is just powering your house at the same voltage or lower than the grid so it never goes out. I dont think the inverter would send it out not to mention that your inverter shuts down when it doesnt detect electricity from the grid. I agree this is stupid because you should have a setting on the inverter to stop xfer to the grid or at least have a breaker that severs the connection to the grid until it gets electricity back.
I would contact your solar company and ask them why a cut off is not available. I have an Automatic Xfer Switch on my stand alone system that detects when the voltage gets below a certain point and cuts my electricity back to the house electric when my batteries get too low. This is not a grid tie so it wouldnt work in your case but the technology exists.
Since it works with my generator I can't see why it couldn't work with the solar panels either. The rep told me it wasn't possible, though, and since he knew that was one of the main reasons I was interested in his product you'd think he would have come clean if there were a work-around.
The workaround I have heard of is having certain things powered ONLY by solar, like a freezer. A regular freezer would be a juice-sucker, but one of those Sundancer freezers would not need that much. Although they are expensive to buy, you would be able to keep your frozen stuff frozen even if your power went out. I have been thinking of doing this myself.
For other supplemental power in case of outages, there are rechargeable and crank lanterns and radios, etc. My problem is that a power outage would mean no heat, since the furnace needs electric to operate.
The only other option is to be totally off-grid.
I believe the generator doesnt create voltage higher than the grid like your solar panels do. Also, I believe the power from the solar panels goes directly into your inverter that regulates traffic and your generator does not. This is all speculation.
Dh was saying that the representative mentioned that there are some states that allow solar to function when the commercial power source goes out; NJ does not, apparently. I must have missed that. Or maybe he misunderstood.
We have three freezers, so that's a major concern. But we heat mostly with wood; oil is just a backup. We can stay warm and my stovetop is LP, so we can cook. The only thing we can't do is flush the toilets.
Wow, three freezers! You must have some good stock in there. I have been wanting to increase the use of my freezer but keep getting sucked into canning. Just bought another four boxes of jars yesterday. Getting ready!
I prefer the taste of frozen food and also canning just seems like so much more work! Isn't the nutritional value higher in frozen foods, too? But the problem with it is, of course, that you need electricity to maintain your bounty.
We have deer, chickens, geese, and lamb and pork that we buy with friends in there, too.
I like leafy veggies frozen, but the others like snap beans and cauliflowers and peppers I like to pickle. That's just a boiling water bath, so the processing time is way shorter than normal veggie canning. Pickled cauliflower, for instance, still has crunch. I also like to preserve fruit and make jams for the winter. The canned peaches in spiced honey I made last summer were a balm for my soul this winter, let me tell you. I also like to preserve fruits with flavored liqueurs and spirits, which doesn't work with freezing. This year I hope I will be freezing a lot of snow peas and snap peas, but I also intend to pickle 50 lbs of snap beans. So each has its uses. The one thing I would really like to try is canning soup, but that requires a pressure canner. I am still hesitating on that. I freeze it now, but it would be nice to just grab a jar, open, and dump it in the pot all ready to go for lunch.
Aha, so you're just using a hot water canner? Those preserves and peaches do sound wonderful!
With frozen stuff, I just have to plan ahead a bit. If I take it out a couple of hours before lunch, it's defrosted enough so that I can get it liquid and hot over a low flame in time to eat at a decent hour.
paracelsus - I freeze soup in glass jars. When I want some, I pop the jar in the microwave on 50% power until it's ready.
greenhouse gal and honeybee, I seem to be unable to plan ahead when it comes to food. I have tried freezing soup, and it ends up just sitting in the freezer for a long, long time.
I freeze soup in square plastic containers, and it slides right out. I do use plastic but try not to use the microwave.
I'm quite sure that you can have a "switch" on the solar system so that it doesn't feed power into the grid when the power is down. Whether that is allowed in New Jersey is a different issue. I would be very tempted to make sure that I could adjust my system so that it supplied me with power when the main system was down. If other states allow it, I'm sure they have stipulations on how the system is installed/configured to avoid potential dangers. That information would save having to figure out how to do it yourself.
It's beginning to sound as though it's definitely possible; now to find out whether it's just that particular company that doesn't provide setups like that or if it's a state regulation that one can't.
I have been looking into solar options and went to an introductory session put on by some fellows who install solar arrays. They said you would have to have battery storage for your solar power if you wanted to be sure to have it when the power goes out. However, they did not recommend this, as the batteries are rather expensive, need maintenance and the most likely times for us to have a power outage in our neck of the woods is in the wintertime when solar power production would be low anyway. Also, it is critical not to have power flowing into the grid from people's solar systems when there is a break in the line because of the potential for the electrical workers to get electrocuted by live wires.They suggested a propane generator for the power outages if you really want to have your electricity. I'd really like to 'go solar' since I have full sun all day long on my property, but the price is pretty steep even with rebates and incentives. The price has come down, but it could take 10 to 15 years to break even on a loan for a 4 kW system.
We were told the same thing about dangers to electrical workers, but since that's not a problem with our propane-fueled generator, I wonder why the same shut-off switch can't be used with solar. I do know that the batteries are expensive, but people who live off the grid use them and manage.
greenhouse_gal - Call the local utility and see who handles the solar. That person should know all the state and national regulations about solar and connecting to the grid.
You will have to have storage batteries. The number and size will be based on how long you want the power to run, what the load is, and what kind of reliablilty. So more hours, higher load, and better reliablility implies bigger and more expensivbe system. There are transfer systems out there and cost is based on size and what kind of features you want. I would also suggest that you talk with one of the storage battery manufacturers. They should be able to size the battery system for you.
I am not sure if there is a statewide regulation regarding this or not, but none of the people I know who have solar and who are also on the grid have been allowed to use solar as a backup when the grid is down. So even if I were to be able to manage it in terms of equipment, it might not be legal here.
I have a legal liability because of what I do for a living. So I can't give you hook up advise but I can tell you that there are regulations of some kind. Either a local engineering firm specilizing in alternative energy, or the local utility can tell you what they are or where to go find out what they are.
From what I'm seeing on the web, NJ has an active clean energy program and with it some rules/regulatutions on it's implementation. They also allow connection to the grid. They also have interconnect & net metering laws in place. Below is the URL for the NJ CLena Energy net metering and interconnect program. http://www.njcleanenergy.com/renewable-energy/programs/net-metering-and-interconnection
Here is the url for utility contacts. Please call them and ask questions. They will have an idea of what you can and can't do with connection and disconnection of the solar to the grid and also as a back-up system. Also should be able to tell you in general what quipment that they require. http://www.njcleanenergy.com/renewable-energy/programs/net-metering-and-interconnection/interconnection-forms
Thanks so much, Susan! Right now the incentive programs are drying up so we may be putting this off a bit. When we got a quote from a prospective installer, he first checked with our electrical supplier and let us know what was possible and what standards would apply. But he told us, as friends had been told, that solar energy couldn't be used as a backup when the grid was down. That was my question for this board - was this due to regulations or was there really an insurmountable problem with safety for linemen, and why wasn't this a problem with our LP gas generator, which also runs our whole house when the grid goes down.
I saw where some of the programs are drying up. I'm exceedingly skeptical about the not being allowed to be used as backup unless he's not selling you a cutoff or transfer switch. I still stick with the advice about talking with the utility rep directly. Good luck on whatever you decide to do.
dsireusa.org is a web page with a list of Solar incentive programs and regulations for the US. I've posted below the url that specifically applies to NJ. I don't know if there is anything information new to you but thought it might be helpful. http://www.dsireusa.org/incentives/index.cfm?getRE=1?re=undefined&ee=1&spv=0&st=0&srp=1&state=NJ
I also talked with a retired utility engineering freind who lives on the east coast. He sent me photos of a PV solar installation by a local utility in NJ. The installations are on what looks to be street side power/telephone poles.
There are a lot of those small solar units on utility poles in NJ. They started installing them further north but they're coming down here now, as well.
The photos I saw show what looks like regular sized solar panels. One per pole. The company name on one of them is Petra Solar. I just looked at their site and they have a photo of a utility installation that looks similar to the photos I have.
Yes, those are the ones I'm seeing, or something similar.
Okay. I'm part way through a solar class and reread the original question.
Here's what I think the issues are. The generator puts out AC power. The transfer switch with the generator disconnects the power from the grid. Most people have a manual disconnect and not an auto disconnect. With a PV system that actually feeds power to the grid you have to have a unit that senses if there is power on the line, disconnects the PV feed when there is not grid power present, and can sync (put PV array power in phase with what the grid phase is) to the grid power when grid is powered. Therefore unless the generator disconnect switch already syncs and auto disconnects from the grid then it will not fill the requirements for an actively connected PV system.
Most PV systems are 24 or 48 vdc. The DC is inverted into 120vac by an inverter.
BTW - Class instructor said to look for used batteries at places like golf courses or warehouses.
Since I have a whole-house generator, I already have a transfer switch which protects the grid during outages. So I don't understand why that wouldn't work for a solar setup. That was my question.
I've been following this discussion intermittently from the onset. I understand your original question, but I have yet to fathom why the system you have is a problem for the authorities... theoretical or in practice.
I'm sure the utility companies don't like the idea of us providing any of our own power, just as I'm sure they have been led kicking and screaming to accept it where they "must". I am also sure there might be possible hazards in connecting self-accumulated power to the grid, but not in the scary sense those are be made out to be.
There is a problem in finding a knowledgeable solar contractor who can tell the chaff from the grain, but they DO exist.
Darius, right now the incentives have dried up even further so we haven't pursued the issue. Since we have an automatic transfer switch on our generator, there must be such a thing for a solar setup, but no one seems able to confirm that. If we do decide to go ahead with it we had planned to talk to a couple of other companies and see what their take on it is, but we have another project that we're trying to get completed first.
GG - Could be the transfer switch would not be rated high enough to handle both currents or it doesn't meet the requirements for protection by the NEC code. There are specific NEC code requirements for both PV and generators. Do you have a manual or automatic transfer switch? Does the transfer switch have a sync switch on it?
BTW - Something to keep in mind if you get to the point of putting something in. The solar instructor live off grid and buys used batteries from golf clubs with golfcarts and places with forklifts.
No, I'm saying that IF we got a solar set-up it should be possible for IT to have its own automatic transfer switch with the ability to handle the current it generates. My propane generator DOES have an AUTOMATIC transfer switch and whatever else is required to keep the electricity it generates from entering the grid.