Off The Grid

So I'm seriously considering going off the grid, but I wanna do it sensibly, and not spend too much money.

I looked at this solar lease program my state's offering, but their contract involves equipment I think is over-priced, a fifteen year lease which would obligate me to pay them 200/mo, with the option to buy the system after the fifteen years for "fair market value," or pay thousands of dollars to have it removed, which I would be contractually obligated to do if I opt not to keep it. 'Seems like a ripoff to me. Plus I think it's connected to the grid, so you get credit for the energy you generate, but you're still connected, and therefore you're at someone's mercy. I'd be better off taking out a second mortgage to pay someone to install an off-grid system, yet I still think I could save a boat load of money by designing it and installing it myself.

Like my kitchen, which has taken a decade to plan and build myself, I expect this to be an ongoing process over several years, but I see it as a worthwhile investment.

I live on a hill with good solar exposure and wind, so I'm thinking of going solar with a solar water heater and photovoltaic panels, and a wind turbine.

I've got a background in engineering, so I'm pretty good at running the numbers once I know what they mean, and I put myself through college doing electrical work, so installation shouldn't be a big deal.

My idea is to start with a small system and make it bigger as I can afford it. I would still be connected to the grid, but gradually I would become less and less dependent on it until I could get enough equipment to get off it completely.

I'm not a big fan of batteries, but I can't think of any other way to store the energy to drive my lights and appliances, so I'm thinking about a transfer switch for my electrical panel, an inverter, and a battery bank, which can be hooked up to photovoltaic panels and wind turbines.

Anybody with any experience in this area willing to share their experiences, tips and advice? I've read plenty on the subject, so ideally what I'm looking for is someone with hands-on experience.

 

Check into NiFe batteries, Nickel/Iron.

They are the original type storage battery built by edison. They haven't been built on this continent in a long time, but you can still find old ones.

As to why I say this, to give you an idea, the ones I have were manufactured between 1940 and 1950. I have no clue what they did most of their life. I know that the last 10 years they have been sitting for some of the time outside unprotected, and part of that time in an unheated garage. When I got them, I cleaned them up (swept the tops) and added a bit of water to top them off and they work fine.

There are people who have been using this type of battery in off grid installations for decades without any more work then topping up the water in them. The electrolyte is just potash and water, so its not toxic or harmful such as the acid in lead acid batteries.

If you can't find a source for used ones, you will need to look at getting them imported from overseas, but it is an expensive option. If you want more info on that part of it, check out;

http://www.beutilityfree.com/conten...da726df4f0c0=36aecca790f23c96efe300fdd70761d8

As for the rest of your plan, make sure you eliminate as much power wastage as possible first. You should buy (if you dont have one now) a device like a Kill-a-watt product;
http://www.killawattplus.com/?gclid=COLykte-r5kCFSQhDQodzEHCIg

Feel free to pm me if you have questions.

Tom

 

I think you just solved my battery dilemma, my biggest obstacle, thanks!

Too bad they're so expensive (I'm sure that's why they're not that common), but in the long run the payoffs are major, particularly to the environment.

the rest of that site (www.beutilityfree.com) is pretty informative too.

 

I got a site to offer too: http://store.solar-electric.com/


x

 

They aren't common, because we (people) then to discard old in favor of new with little thought, add in the fact that companies prefer to sell a product that need to be replaced on a regular basis, rather then something that would outlast most people.

There is a commonly stated opinion that is totally misguided, in that because they batteries are so large compared to new ones, that they are not as good (take up too much room and weigh too much). Yes, in terms of size and weight and day to day use, they are not as good as lead/acid batteries, but the fact that they will likely last over 100 years of constant use (with proper maintenance).

As for buying new ones... if you have the money to do so, they are definately a good investment as you will not have to replace them in your lifetime (if the new ones last as long as the originals).

My advice however, would be to do your damndest to find old ones, as I said, the ones I have were built between 1940 and 1950, and are in almost perfect condition, they take and hold charge with no issues.

They do require different equipment then lead/acid batteries to use however. They tend to lose charge over time (compensate by having trickle charge going into them at all times. They cannot be damaged by over or undercharging, will not freeze.

If you cannot find any used ones, and cannot afford to buy new ones, there are people on the net that are building homemade versions of them, I suggest goggling it.

Tom

I'm attaching the original instruction booklet of Edison batteries. **the attachment didnt seem to work right, if you want it, pm me with your email address**

I also have a DIY guide to building some. I have never tried the DIY plans so make no claims about whether or not it will work as is stated, but will send it to you if you are interested.

 

Thanks for the other link too.

It's all about marketing, which is more perception than reality, and is geared toward dependency. The only way around it is to design and build a system yourself. I'll look for some used NiFe batteries.

The next thing I'm looking for is a transfer switch and an inverter. I would want to size these to accommodate the highest load I could expect to support in the future. I'm guessing I could pull it off with 40-50A, 2-pole, say 10KW max. That might be kinda pricey, so I may need to pare it down to something that'll run a few essential things like a water pump, a boiler, and some lights, which I could probably get by with 1000W or less.

Anybody know anything about automatic transfer switches? Ideally I'd wanna be able to continue to use the grid, pumping energy into it or out of it, with a battery backup for when the power goes out, but all the automatic transfer switches I've found are used for generators. I'm pretty sure I could hook up one of those things to a battery bank instead of a generator, I mean all it does is sense when the power's down, switch the source to the generator side, and send a signal to the generator to fire it up, right?

I can appreciate the importance of making what you've got as efficient as possible, and cutting down on consumption. The less energy you need, the less power generation and distribution equipment you need, which translates to major savings. It makes you much more energy conscious.

 

They are very expensive to buy.

You are better off setting your battery bank up, and having a charger from the grid as back up, with a few plugs coming off the grid for high powered stuff that would suck the batteries dry.

That way, the electrical company has nothing to do with your alternative system.

As you increase your generating and storage capacity, you can wean yourself off the grid totally.

 

True, but manual transfer switches are cheap.

You might have something there, I could re-wire the big stuff to the grid and transfer the lower drawing stuff to the batteries, maybe put in a separate electrical panel, and move the circuits over as the system can support it.

It occurs to me I may have it all wrong thinking about the transfer switch, maybe I should focus on a sort of hybrid system that would pump power back into the grid when the batteries are charged and I'm generating more power than I'm consuming. The trick then is to interrupt the power when grid is down so as not to electrocute the guys who come out and work on it, but they must have those for the setups that connect to the grid anyway, right? Anybody know about these things?

That's the idea. The electric company is a BIG consideration, it would be nice to get them out of the way.

 

That is called a grid-tie or synchronous inverter

http://en.wikipedia.org/wiki/Synchronous_inverter

The problem with this is that they aren't worth what you pay for them in terms of making any money back. Most of it depends on how your utility company is set up.

Here in ontario, we have net metering, but its a rip off and waste of time as far as I'm concerned. Years back we had a government controlled company that looked after the electrical grid, gernation etc. and they didn't do net metering at all. A lot of us fought to get it brought in. They did finally.. sorta...

They divided the company into three, a generation company, a distribution company and an equipment company. We still only get one bill, but it is considered different companies. Part of the bill pays for the power, part pays for the transportation (through the lines) of it. When you have a net metering set up, it is only the power itself that is considered. In other words, if you used 100kw of power from the grid, and produced 100kw of power to pump into the grid, you would still be paying a bill, because they only pay you for the power itself.

 

Cool, thanks. We have fixed costs associated with our grid, but for about 7% more in the price of the power itself, I'm able to get 100% of my power from renewable sources-hydro, wind, and solar (assuming it's not a scam and they're just charging those of us who wanna think we're being environmentally conscious more for our power).

You're right about grid tie inverters being expensive, they're about five times as expensive as regular inverters, but there's a trade off. If I use a grid tie inverter off my DC bus, I can connect my battery bank and my solar panels and wind turbines to the bus, and have the grid tie inverter connected to my panel and the service. Then I won't need a transfer switch, right?

Of course, if I put in a manual transfer switch, I don't have to worry about any of these issues, I can switch over to batteries when I want, or switch back to the grid when I'm using my oven or whatever. The issue then is if I'm connected to the grid, my batteries are fully charged, and I'm still generating power, that power will be wasted if the batteries can't accept it. Being constantly connected to the grid assures that any extra energy I generate gets credited to my bill, but that's only profitable if the extra amount I generate exceeds the fixed cost I'm paying to the power company.

 

What would be really cool would be an automatic transfer switch that runs off the batteries/inverter by default, and switches over to the grid when the charge gets low, or when the power demand exceeds what the inverter can handle.

 

There's got to be such a thing. I build and maintain remote communications sites and I have set ups to auto start generators at low voltage conditions. If I come across one or something that will do what you want I'll PM you.

I've been off grid for the last 20 years and I think key to living with alternative power is to limit your power requirements.

 

My thoughts exactly.

I'd cut the grid off and be totally independent of them.

Put your money into more solar panels.



x

 

It's possible that an automatic transfer switch used for generators could do such a thing. In that case your default power source would be from the batteries and the inverter. An inverter with a cutout for low batteries or overcurrent would switch the power source back to the grid, since it would sense that the output from the inverter was dead (this is backwards from the traditional configuration of hooking the grid to your default supply terminals).

Getting off the grid completely is the ultimate goal, but I'm already tied in, so it makes sense to leverage what I've got while I can, and ween my way off if I can do it without too much extra expense. I've been looking at my electric bill statement lately, monitoring my daily power consumption--it's gonna be a challenge.

Cutting your power requirement in half effectively cuts the equipment you need (and thus the cost) to power your home by a factor of two. I can probably only afford a 3000-3500 W system, and it'll be a few years. The biggest ticket items I've found when it comes to the power budget are the ones with heating elements like stoves, dryers, toasters. Do away with those and you're on your way to a load that's feasibly supportable by alternative means. Energy star appliances pay for themselves in no time.

 

http://www.xantrex.com/web/id/246/p/1/pt/18/product.asp

 

What's that thing cost?

I was thinking more like the $75 low voltage disconnect wired to a relay.

 

If you are connected to the grid, you need a proper synchronous inverter.

There is no leeway in that at all. You will electrocute someone at some point without one.

Which was why I suggested right from the start, avoiding the whole issue by not having the grid connected to an alternative power system.

 

True! I wasn't thinking about the whole back feed thing. I was thinking more in just turning the grid AC on to a battery charger when the batt voltage was low.

 

Thats the best way, in my opinion anyway. Keep an automatic charger on your bank and plugged in. When the power is up the batteries stay full even if your pv panels or wind system doesn't. When the power goes out, you know you start with full batteries.

And, you never have to worry about killing someone or that the company may complain about your setup.

 

I see, so if I understand you correctly the synchronous inverter serves as the link between the DC and AC buses. The DC bus connects the inverter to the batteries and solar panels, while the AC bus connects the inverter to the power distribution panel and the grid (I assume the connection to the grid is monitored, and if the power goes down the inverter has the smarts to shut down the A/C side to avoid back feed). Then the batteries can be charged by both the grid and the solar panels, but when they're charged, the power from the solar panels is fed back into the grid.

I agree this seems like the best option.

What I was proposing earlier shouldn't pose any hazard to the utility company, since the common terminals of the transfer switch would be connected to the distribution panel. The default position of the transfer switch would connect to the inverter/batteries, but when power cuts out it switches the power source from the inverter to the grid. Therefore a connection between the grid and the inverter isn't possible, so there wouldn't be any backfeed issues.