Grid tie inverters

Having had a interest in alternative energy through the years, I periodically look up things that relate to them. While reading a review someone had wrote concerning a inexpensive solar panel charging kit, the reviewer had mentioned a grid tie inverter. Not being familiar with these I decided to Google and see what I could find out. Wikipedia has a good explanation of the units and how they work. Very basic is they allow taking a DC voltage from the alternative power source and convert it to AC and parallel it with the utility power. It automatically cuts power when the Utility power goes down to prevent injury to line workers.

However I also noticed this website here that has a small rather inexpensive one that simply plugs into a wall power outlet to feed power generated from a small wind turbine or Solar panels. Rather fascinating how far the field has come that you do not need big expensive equipment to run in tandem with the utility company.

It used to require having batteries to store the Solar power and a regular inverter to power loads wired to it. Devices to feed through to utility power were out of the range of the small user. Rather amazing how technology is progressing. Now that I know that such a thing exists it starts to give me ideas.

Make sure it has the means to automatically stop feeding the line if the grid power goes out. Those poor guys out there climbing the poles in sub-freezing, stormy conditions to restore service don't need to be warmed up that way.

Yes, they are supposed to cut power when the Utility goes out. Backfeeding would be very dangerous. Same problem you have with running a generator the difference is these devices work in tandem with the line power. Whereas with a generator you need to use a transfer switch.

Being able to reduce your electric cost by picking up some of the load from a micro source (solar, wind, hydro) may just make this stuff economical. In the past the cost for storage batteries and maintenance was the killer. Not to mention the hazards of battery charging.

Of course you would need to get permission from your utility before installing. Some electric companies would allow you to sell power to them.

Doing some more research on the wind turbines, they may be practical for a location like mine. Since I live near the top of a mountain (Arkansas calls bumps in the ground, mountains.) I do get some reasonable wind. Though I would need to get above the trees with a tower. I looked at the listing for the low rpm wind turbines and it may just work out.

I have emailed the company to get some more information on these devices. I would not need a big system with the use of grid tie, I would just need something to offset the cost of putting the equipment in. I notice on my electric companies website a page for net-metering. This is where they allow you to spin the meter backwards to in essence store power. While they will not pay you for the power it can be used to reduce the cost of any succeeding months usage up to a years worth (Jan-Dec). They only cover the Kwh used and not the standard taxes and monthly connection fee though that runs about $15/mo for me. I downloaded the application and it seems fairly straight forward. One thing I have going for me where I live is no building permit requirements.

It may be a interesting experiment to undertake.

I see there is a real good video about these small grid ties. It is a bit long but it does explain quite a bit about them.

Very interesting stuff. That device does look very simple to use. My only concern would be if it would properly stop sending power into a circuit after a circuit breaker flipped. One of the guys I work with got a solar panel to run his ham equipment off of. He said its especially handy for field days.

I have to wait to get to a faster connection to watch the video. The tower may be your biggest expense. Even on open ground you need a fairly high tower to get the most advantage of a turbine. No chance of using the wind here. I tucked in a little pocket down the slope on the north side of a hill, and a lot of the usable wind comes from the SW. Solar is my only real option, and that's a little iffy. I'm going to try for solar water heating first. It seems to be the cheapest way to break into solar energy, and the electric water heater is my second biggest load, just behind the pump. Then I'd like to try a solar air heater to heat the house directly. It wouldn't save all that much money, since I heat with wood, but it would save some of my personal energy and hopefully keep the house warm enough to keep the pipes from freezing so I could leave the house unattended in cold weather. Have to figure out how to add some thermal mass in the heat path to make it work, and it has to be passive so a power outage wouldn't result in frozen pipes. Water heating with radiators might end up being the way to go instead of heating air, but would be tougher to make passive. Have to do some experiments. Third in line would be generating electricity. It seems to be the most expensive. Just getting the well running on solar would give me a pretty good payback, since that's my biggest load, and would be less involved than tying to the grid, since I'd store the energy as water in a big tank at the top of the property instead of batteries, and there's a pretty good spot for panels near the well.

Having a good spot for a wind turbine sounds excellent, especially if it's good year round. Only thing better would be a stream big enough for a hydroelectric system. CA requires the electric company to buy any electricity generated at the same rate they sell it, which is effectively the same deal as you have. What could be the killer on all of this is building permits. the county requires one for almost anything, even changing an outlet. And they aren't cheap. You're fortunate in that respect. (Needless to say, there's a *lot* of non-permitted work done in this county. An unfortunate backlash of over regulation.)

One solar electric project I'd like to do (and it brings this thread on topic ) is a UPS for the computer, or I guess really it would just be solar powering the computer. /Sigh/ So many ideas, so little time and money.

Yeah it is always a case of getting the economics to work out on this stuff. I do note that the fellow in the video made a classic error on figuring power. During the segment when he was back feeding the meter he expected it to reduce by a Kw from feeding for 40 minutes. His math was off since to use a Kwh would be 1000 watts continuous for a hour. The 230 watts that the unit developed would take almost 4.5 hours to roll his meter back by 1 Kwh. Easy mistake to make.

Solar water heating is fairly easy to accomplish. The big problem is preventing freeze up in a cold climate. Thus having to use a heat transfer method with a loop running antifreeze and than to the water tank to heat. I ran black pipe to get hot water when i first moved where I lived now. It was effective with water too hot to use without mixing with cooler water. Solar home heating is also a thought if you have sufficient sun exposure to the south west.

Solar panels are beginning to get to the point where they are worth while. I note that the prices are really not bad. This company has some decent looking products that I also looked at.

Years ago I wired up this ladies home for Solar use. She had panels feeding a battery bank and then a 5000w inverter to her home wiring. Her Water was pumped by an old wind pump windmill of the type you use to see dotting the plains. It would fill a water tank and from that a 12V RV pump would pump to a pressure tank and also run on demand. Her water was heated with a instant hot propane heater. It worked fairly good for her since her house was built with a lot of glass to catch the sun and a large attached green house area for growing vegetables.

It was not the most reliable setup though and the prices of the equipment was too high. However since the nearest grid power was too far it was a reasonable alternative. A lot has happened since than back than to make this stuff more economical.

I think it was quite common for those old windmills to provide running water and charge batteries used for electricity before the power grid spread to all the rural areas.

Heres another video concerning these small grid ties.

Well after a few back and forth emails with the first company Hurricane Windpower I find myself unimpressed with their customer relations. The fellow I corresponded with would not give me any specifications beyond the website pages. He was also insistent on doing things by phone and not email. That raises flags with me. Luckily there are no shortage of companies doing this stuff. I noted that Amazon has a listing for a 1000w grid tie unit that the company selling them has a good spec page here.

ETA: Boy, after wading through a lot of stuff on wind turbines, I am back to the belief that they are not economical in most applications. There is not much power available from the wind. Unlike hydro that use the weight of falling water at 8.34lbs per gallon or .43psi per foot height, air does not have much mass. You have to be careful of many of the claims from the wind turbine companies. Most are very inflated and even impractical in scope.

Solar power is getting closer to reasonable economy though it is not quite there. The prices of panels have come down major in the last year so that might be the only way to pursue. I did see several DC well pumps that are now available for a solar application. Though the price is certainly high if you have grid power as competition.

It is hard to beat the firewood, bozo!

Yup! Wind power has potential, but, like real estate and some other endeavors, the three key factors are location, location, location. There aren't that many places with consistent winds of sufficient velocity to make it pay. And those places aren't really desirable places to live. The most successful residential applications that I've heard of are where wind turbines are used in conjunction with solar. During most of the year there's sufficient sun to power things, in the winter when the weather's foul and there's not much sun, it's stormy and the wind is there. But you end up with two systems large enough to power the site, so it's a pretty expensive setup.

I'm convinced that alternative energy sources are best used to directly power specific uses (heating water, space heating, pumping water, etc.) rather than generating electricity to use for those purposes. After setting up solar water heating, using wind to directly pump water if location permits, using wood and solar for direct space heating, etc., then your electrical needs are much smaller and you can set up a much smaller and less expensive electric generation system for your toasters, computers, lights, TVs, etc., that require electric power. And if you can decide to do without some of those (TV, for instance) the electrical needs will be even smaller.

Right now I don't think electric generation on a small scale can compete financially with the grid except in a few special circumstances. But I'm hoping it won't be long until it does, and that it's because solar panel and generator costs come down, not because the grid cost go up! Until then using alternate energy sources (like wood) to reduce electrical loads seems to be the way to go.

Happiness is a sharp chainsaw!

On that sharp chainsaw, I bought myself one of those inexpensive chainsaw electric sharpeners at Harbor Freight for $30. Although I have used a regular hand round file since I was a pup it is hard to beat something that is more consistent. It works pretty good.

On the TV's, with these new LCD units the watt draw is very low compared to the older CRT. I have thought of upgrading my 30"CRT HD that I have had for 8 years with a new LCD just for the energy savings. Especially as the price for a comparable 32 inch LCD is now under $300.

Certainly reducing your electric usage is key to getting close to self sufficiency. Oh well, as things wear out, I try to match energy reduction with the economy of it all. Unfortunately many things that save energy cost more than the savings you get. You have to do the math.

Yup! I was looking for a flat panel monitor to replace my trusty Sony 21" CRT just figuring I'd save a bunch. I finally did the math and figured it would take 4-6 years to pay back. As I'm not sure the Sony will last any longer than that, there's no real reason to replace this one until it dies. I have a second 21" CRT I like to have for certain tasks, but I just don't turn it on unless I'm using it (I used to leave it on whenever the computer is on, essentially 24/7). I save more doing this than I would replacing both off them with new flat panels. Doing the math with most of my appliances I've come to the same conclusion: wait until they *need* to be replaced, use them less if the power costs bother you. I've not fixed my broken down dryer, just hang the wash on a line, as my contribution to cutting power usage. Saves the cost of building a new one in addition to the power to run it.

I'm OK sharpening chains free hand, but a long time ago I got a Granburg File-'n-Joint (I think that's what it's called). It's a clamp on the bar file guide that really does a fine job. I've looked at some of the cheaper electric grinders (and they seem to be getting cheaper), but just haven't been able to talk myself into it. Maybe someday.

Found a rather interesting place that sells Solar panel kits. This is where you can buy the cells and solder /wire together your own panels for quite a bit less than ones already made. Rather fascinating concept for a DIY type person. They are located at Spheral solar and there is rather attractive prices.

I just may give it a shot when I get some free time to put into it. I have some spare UPS's (bad batteries) that could be used as power inverters so no cost to make AC. Just would have to get some batteries.