Anyone into solar power?

[MidwestPX 172]

I'm kicking around the idea of starting a small, emergency back-up solar power system in the home. Harbor Freight has a pretty decent 45w kit for $165 ($150 after coupon, free shipping but due to being big/heavy, $15 surcharge for freight). Seems folks are plugging them into 2-3 deep cycle batteries and getting good results. The panels themselves seem to hold up for 2-3 years too which is nice considering most of what HF sells is on the, ahem, less-than-durable side. At any rate, it looks like the most expensive part of this would be the inverters followed by the batteries. Anyone have any experience playing with solar power setups?

[Ray Ray 3,566]

Ty, Honda generators are really the best around. I understand you want to save money and it's a backup to the soar powered panels but look into them. Another good hi quality generator is Yamaha. Harbor freight has some really good deals on that stuff, but you know the old saying......

[tony357 386]

the downside to is the battery system, once the batts go dead over night per say, the panels will not be able to keep up.. worst case if power is out that long..depending on the batts used will depend on how often they need replacement 3-5 years..

[MidwestPX 172]

Ty, Honda generators are really the best around. I understand you want to save money and it's a backup to the soar powered panels but look into them. Another good hi quality generator is Yamaha. Harbor freight has some really good deals on that stuff, but you know the old saying......

I have and while they're small and relatively quiet, I want the first line to be solar since it's renewable.

 

the downside to is the battery system, once the batts go dead over night per say, the panels will not be able to keep up.. worst case if power is out that long..depending on the batts used will depend on how often they need replacement 3-5 years..

Yep, the deep cycle batteries I was looking at were warrantied for 5-7 years (Deka and Concorde). At that point, we'd likely be building a house with a hardwired solar setup anyhow.

[Malsua 1,422]

Just realize how little energy these panels will produce before you spend your money.

 

45W solar panels will probably get about 4-6 hours a day of direct sunlight charging.

 

100 amp/hour batteries x2

 

200 amp hours / 3 amp = 67 hours to fully charge.

 

67 / 5(hours of sunlight) = 13.4 days + 10% error.

 

Say, 2 weeks to charge the batteries to full.

 

Of course, you can speed this up by buying weaker batteries or more solar cells.

 

It also depends on what you want to do with this power. You're probably going to be better served just buying a 4000-6000 watt generator for $750-1000 that will run your fridge some lights and perhaps a well pump.

[MidwestPX 172]

My thought was to have a bank of 2-3 batteries charged at any given time and draw on them during emergencies and then, only when absolutely necessary. I can't splurge for a system to continuously run a full size fridge just yet

[Sigman 41]

I think you're much better off with a gas generator that can power a fridge, sump pumps, and some lights. Most likely you'll use it during a storm or hurricane when power goes off for periods of time. I'm thinking of getting a generator myself. We loose power occasionally with heavy storms.

[djg0770 481]

Ty,

Solar PV is not a very efficient means of making energy. Yet, the idea of making electricity for "nothing" is quite interesting. Honestly, I would avoid the HF systems though. 45 Watts is nothing. It's really an overgrown battery charger. Likely, it would be cheaper to purchase a battery maintainer and setup several 12 volt cells with an inverter and plug it into the grid, I bet your costs (even with charging the batts from the grid) would be less. The only positive is that the Solar would recharge when the grid goes down which begs the question, how often does the grid go down where you are?

 

If you're considering solar as a means of making energy, consider solar water heating. It's easily 10x more efficient per sq ft of panel than PV. It can be optimized (panels can be angled) to make the most energy in the winter when the sun is low in the sky which is likely when you will need the largest portion of the heating.

 

If you're really into green stuff, I suggest you look into Passive House construction. http://www.passivehouse.us/passiveHouse/PHIUSHome.html

 

Depending on your area, wind power may actually net you more electric generation than solar. Some vertical axis turbines now need only a 4mph wind in order to generate power.

[hd2000fxdl 422]

As others have said, a panel that small will just maintain the battery's and the amount of life and power and what you can run off of it in the case of an emergency isn't that great.

 

If you don't have many problems with loosing power, a basic generator would be your best option. don't forget most power outages happen when you need power to you pump to keep you basement from flooding, so having something even a small generator for that is a good idea. They also have battery backup pumps that are quit effective.

 

Now if you have more outages than you would like, and for longer periods of time than a whole house system is another option, not cheap even for manual transfer switches, auto transfer is a little more costly but I think if you that far in whats a couple extra bucks that one time your not home when on vacation.

 

As far as whole house solar, for the cost of what we currently play for electricity, it's not as cost effective even with incentives as it needs to be. Now in Hawaii where my cousin lives, it's very cost effective, but his electric is 3 times what I pay here.

 

Probably more than you wanted but, hey it's free.

 

Harry

[MidwestPX 172]

Power consistency isn't a huge issue here however, I like to be prepared for short term disturbances/outages. The principal reason why I don't want a generator as a first line of back-up power is due to its dependence on gas/diesel. I keep about 20 gallons on hand which would likely be consumed by my wife having to commute to work 50 miles round trip each day. As a physician, she can't skip work due to "little" things like power outages. I've been trading PMs with someone on another board and he's been using multiple HF solar panel kits in different locations with good results. The reviews of the kit have also been pretty good.

 

Eventually, my wife and I will be building an extremely energy efficient home in a more rural area and then we'll likely have an off-grid solar system installed. Until then, anything I do with solar power would be dabbling. Maybe I can swing both a small solar setup and a small genny...

 

Great input though!

[AnthonyG 36]

In the future when you go to your new place, you may wanna look into small wind turbines. They have really come a long way especially in private/home sector they can run on very little wind and produce good amounts of energy and prices have gone down. Running a hybrid system of solar/ wind is usually best bet if you have the cash. That way when there is no sun usually tthere is wind and vise versa.

[matt6669 71]

My personal opinion would be looking into a geo-thermal system. If you setup a good enough solar system with the geo-thermal system you could in fact power your entire house without the need to use any electric from the grid. Worse case scenario if the grid goes down even with a smaller solar system, the solar system could still power your heat pumps which would allow you to have constant heat or cooling in your house.

 

Whenever you go to look to start building your new house I would seriously think about talking to a geo-thermal specialist in the matter. My boss put one in his ski house in upstate ny and absolutely loves it.

 

As far as your current situation, I would just get a generator and be done with it. Solar power on a small scale isn't where it should be to be effective IMO.

[JackDaWack 2,895]

My personal opinion would be looking into a geo-thermal system. If you setup a good enough solar system with the geo-thermal system you could in fact power your entire house without the need to use any electric from the grid. Worse case scenario if the grid goes down even with a smaller solar system, the solar system could still power your heat pumps which would allow you to have constant heat or cooling in your house.

 

Whenever you go to look to start building your new house I would seriously think about talking to a geo-thermal specialist in the matter. My boss put one in his ski house in upstate ny and absolutely loves it.

 

As far as your current situation, I would just get a generator and be done with it. Solar power on a small scale isn't where it should be to be effective IMO.

I agree, unfortunately renewable energy is not worth the hassle and doesn't offer much on the small scale. To take advantage of renewable energy you need to put together a very efficient system, meaning you can support the house during the dark hours, and keep it running during the light hours while also charging the batteries. These systems use the batteries as a buffer and a power source. I would be aiming for at least 100watts per panel. You could buy some trickle chargers for some deep cycles and leave it at that. In the event you have a power outage the power will most likely be back on by the time the batteries would be charged again from a small solar power system.

 

I have been following solar power systems for a while now, and right now, unless you plan on dumping around 10k into a system its basically a waste of money. efficiency is the key to it all and right now efficiency=$$$

 

For about 10k you can purchase a 3,000watt systems that will easily run your home, conservatively. for 20k you could get a 5,000watt system. Most of them are warranted for 20 years too. plus batteries, its very expensive the point is to make up the difference in free energy. If your paying an electrical bill already then whats 1-2 bucks to keep the batteries charged a month..

[matt6669 71]

jack how big of a house could you completely power with a 3,000 watt system? or could you not power an entire house on that system?

[djg0770 481]

jack how big of a house could you completely power with a 3,000 watt system? or could you not power an entire house on that system?

 

P=VI or Power equals voltage times current. 3000 watts / 120 volts = 25 amps, or 12.5 amps at 240 volt. Not much power there for sure. Barely enough to run your computer, refrigerator and clothes washer at the same time. For entire home backup I would be looking at a 6kw system, knowing that I will likely not ever use it to its full potential, but knowing that I can.

[Maksim 1,504]

Did not know we have so many energy aficionados here.

[JackDaWack 2,895]

that's why i said conservatively, lol and went on to list a 5,000watt system. Just trying to give a relative cost per kw. Hell, a standard microwave will run about 1,000watts.

 

Remember, the purpose of solar energy is not to run completely on solar power, it's just way to expensive to set up a system for that. These systems are designed to take a large enough load off your grid consumption so you save money. When your making more energy then u use you can dump it into the grid and the power company will pay u for it, and when u need more then the system can support it will take it from the grid. Your looking at over 50k for a stand alone system since you would need a significant amount of power management and batteries to run the system during dark hours, and then charge them while in use during light hours. Take into account that everyday is not sunny, then u need even more power in reserve = even more batteries. If you want good batteries, there relative dangerous and very expensive. Add in the cost to replace the batteries every 10 years or sooner.

[JackDaWack 2,895]

P=VI or Power equals voltage times current. 3000 watts / 120 volts = 25 amps, or 12.5 amps at 240 volt. Not much power there for sure. Barely enough to run your computer, refrigerator and clothes washer at the same time. For entire home backup I would be looking at a 6kw system, knowing that I will likely not ever use it to its full potential, but knowing that I can.

 

That is only what the panels support, if you were to have a direct hook up. Since the power actually runs off the batteries and not the panels you can get much more power, but the batteries will deplete based on the difference of power in power out and # of batteries . Hence having them as a buffer. This allows you to run high power usage appliances for periods of the day like a microwave. They still need to be charged which means u need more power going into the system then out, so u would need a system that captures enough energy to charge the batteries while running the houses regular appliances, lights, tv, computer. If your not home for a decent amount of time, with everything off, a small system with a lot of batteries would work. If your home all the time, then a large system with not so many batteries may be better. so its about balancing the power in and power out vs stored energy. I dont think many people take into consideration that the batteries are probably the most important part of the whole system.

[JackDaWack 2,895]

jack how big of a house could you completely power with a 3,000 watt system? or could you not power an entire house on that system?

It is completely dependent on your houses power consumption. In my house there is no chance in hell that would be enough since some one is always home using power of some sort. However, if your not home during the day then it could power your house if you have enough batteries to support your power needs. During the day when your gone that should be plenty to recharge the batteries. At 12volts that's about 250amps of charging power which can be distributed to your (12v)batteries which can support about 20 batteries. at 130ah per battery you have roughly 2600ah in storage. which will run a 1500watts continuously for about 100 hours.

[hd2000fxdl 422]

One thing to keep in mined and I think I touched on it before but the cost effectiveness is what's really a very important consideration.

 

While very large systems can supply a whole house most systems don't really come close. You really have to weigh the cost of installation and maintenance and how long if ever you can get ahead of the money curve.

 

Going by memory and it's not what it used to be but here goes it: Not sure if today PV's are better but lets say you have 200 SF of panels 10'X20', this would produce on average about 3000 KWH per year. See what you use on average for a year and see what kind of dent you will be able to actually put into your electric bill savings. Now if you take an average of 15 cents per KWH you looking at a 450 dollar savings. Say it cost you only 5 grand to install the 200 SF system, it would take you over 11 years to break even on your investments.

 

Now to be green, have a battery backup for piece of mind great, but for actual cost savings in our area and the amount energy produced vs. our current cost per KWH I don't see it being the best option for me.

 

If I was building a new home and I would break it down to see multiple systems, GEO, Solar, and Wind and see what my options were but for cost savings most home owners would be better off adding a layer of insulation to there attic, and looking at more energy efficient systems to the outside of their home ie; insulated siding, upgrading windows and the biggest one, sealing the home so you limit the loss of your heating in the winter and cooling in the summer. Also items in your home, more efficient appliances and HVAC units also.

 

It;s not like you have to do all of this at once, but during your normal replacement of each item as they need replacement is what I see as the best options, oh and the cost of insulation and higher R value windows and siding can be an advantage come tax season when you file your taxes.

 

I know a little off the original topic, but they do all ties into one another.

 

Harry

[vjf915 456]

One thing you don't normally hear about solar panels.....they jack your taxes up even more because your house is worth more now. It's almost what you save in electricity goes towards taxes.

[NorthernYankee 94]

One thing you don't normally hear about solar panels.....they jack your taxes up even more because your house is worth more now. It's almost what you save in electricity goes towards taxes.

 

Actually that is not correct, Solar Power systems are exempted from Property taxes in NJ.

 

I have a 7.56KW system on my house which is 3,000 sqft and generate enough electricity to cover my usage each year. So I have no electricity bill each month and I generate approximately 9 SREC's per year which currently sell for $640. So I profit approximately 6k, this will allow me to pay off the system in about 4 years. Its a great investment for anyone thinking about it. I currently don't run a battery backup system off of it because its prohibitively expensive. But there are some fuel cell systems coming out down the road that should be a lot more affordable in the long run.

[hd2000fxdl 422]

Actually that is not correct, Solar Power systems are exempted from Property taxes in NJ.

 

I have a 7.56KW system on my house which is 3,000 sqft and generate enough electricity to cover my usage each year. So I have no electricity bill each month and I generate approximately 9 SREC's per year which currently sell for $640. So I profit approximately 6k, this will allow me to pay off the system in about 4 years. Its a great investment for anyone thinking about it. I currently don't run a battery backup system off of it because its prohibitively expensive. But there are some fuel cell systems coming out down the road that should be a lot more affordable in the long run.

 

Very nice, I didn't know the systems were getting that efficient, I may have to look into this more when I build a new home, but my current house I built 7 years ago and it faces the wrong was for even thinking about doing it now.

 

Harry

[NorthernYankee 94]

I lucked out my house faces due north so I was able to put all of my panels on the back roof.

 

Oh and in case anyone was curious about the property tax thing.

 

http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=NJ25F&re=1&ee=1

[JackDaWack 2,895]

Solar power has become much more efficient then it used to be, cheaper too. For the price of a 50watt panel 5 years ago u could probably get a 150watt today.

 

One thing i wanted to see improve were those solar strips, they came in laminated rolls. The product never seemed to hit the market but it was a great idea.

[NorthernYankee 94]

Yeah they are much more efficient that they used to be but still have a lot of room for improvement. Most panels are in the range of 6-15% efficiency with the best being about 20%, the newest have a theoretical efficiency of 35%. So this is an industry that has a great long term potential. I am hoping that in 30 years when my system is ready to be replaced I will be able to go from 32 panels to 8 or less.

[tony357 386]

I switched to deka batts this year at the shop, found these in their line up..

 

http://www.dekabatteries.com/default.aspx?pageid=443

[Wojo 98]

I've dabbled in the solar industry and have about 15 years of experience in all sorts of Energy Conservation Technologies.

 

Check out this solar project I spear-headed a few years ago - Wojo's Solar Roof Project

[tony357 386]

That is a sweet setup Wojo..

 

 

found these on youtube.on the lines of what you want to do.if you do this i would use tha gel or AGM batteries. no fumes and non spillable and will last 2-3 years longer than liquid batts skip past this knuckle head hooking directly to the panels.

 

[Wojo 98]

We repeated the process on three other buildings. We increased the battery size so we could also use them to assist with our 90+ minute emergency lighting circuits, electronic door locks and other life safety systems and kept them separate from the full emergency battery / gen system. On the weekends with the exception of high or very low temperatures, the panels powered the building. If the building is vacant, the meter would spin 'backwards'.

 

Consumer advice...stay away from the websites offering to tell you how to buy solar chips at a fraction of the money. They tell you to buy busted up panels and glue them together. For many reasons, don't fall into the trap of going cheap. If you are laying out coin, buy and cry once and go for the best stuff. Any small solar project without government incentives has a 15 year payback period. If you are doing it for survival, building a cabin off the grid, etc., then pay back period isn't a concern, reliability is.

 

You would also be surprised at how ignorant the building and fire departments are on solar...having to educate them was one of my biggest challenges during my projects.