Alternative Electricity Solutions
No theory here. In early 2000 I converted our home to grid-intertie electric using Trace Inverters, 16 Siemens solar panels and twelve L-16 six volt batteries. Probably could have used more solar panels but it worked satisfactorily.
Have reinstalled the gear we had with generators as main power source. Eight new L-16 batteries for storage. Did the conversion mid-Winter so it was "interesting" and mildly stressful. Thought would share some of the new info have learned.
Current system is not an intertie. I did the intertie in 2000 but we chose to eliminate the smart meter situation. We were running electric hotwater with 8kw generator but moved on to propane for hotwater, and a 2500w generator. We had been using electric clothes dryer, soon will be installing a propane dryer. Have done real well with interior clothesline on wet days and outdoor lines when sun shines.
Still using the Trace 4024 units, although no longer "stacked". Had some interface difficulty and the units are long obsolete, so have actually no need for the stacked 8kw load capability so we have one online and the other as backup. We also bought another stand-alone inverter. More on that later.
The inverters, system disconnect, and batteries are all located in our garage which was too valuable in Alaska to use as vehicle housing. The simple 6 breaker box which controlled electric service in the garage was converted to a full 125A service box and fed power from the inverter(s). A 6awg three lead conductor on a 60amp breaker now feeds the breaker box in the house. Meters are gone and feeds from meter disconnected and insulated. Both breaker boxes have main breakers to terminate power. Redundancy is always good when it comes to controlling live conductors. The main disconnect is a 300amp fused pull-out which immediately removes inverter, battery, and solar panel input from the system.
Not really going to discuss ampacity, wire sizing, or wiring basics and how-to details here. Homepower.com is a good resource for learning the basics, if you can do your own work based on code or regulation where you live.
Everything worked when put together, just like last time. Very blessed to have no false-starts with the wiring and power input. Basically used a 230v NEMA receptacle and 40' extension cord w/outdoor rated sheathing to deliver power from the generator to the inverter. The 4024 inverter(s) have built-in battery charger function, but are too old to do battery equalization. The Trace (later Xantrex, Schneider) inverters will intertie with generator to deliver a load in excess of the battery capacity in amperes. This worked great with our electric hot water heater, but wow the power required!
Propane is more user friendly for hotwater, unless you have a boiler fueled by woodstove. Everything is a compromise though. No free lunch in the energy arena when you have 3hrs real sun per day at height of Winter and temps below -20f at night...
The 8kw Generac electric start genset was retired to backup duty at about 800hrs of runtime. It has a spin-off oil filter and seems very well made. Bought it before really studied the whole AE power generation equation. Bought a Yamaha EF2000IS inverter genset and made a dual plug tie-in power cord to mate to the NEMA 230v power cord. Runs about 4hrs on one gallon and puts out 14amps or 1600 watts. The 4x larger Generac delivered about 3/4 hour runtime per gallon. With one inverter delivering 4kw max continuous, but really only delivering about 1200w most of the day, the Yamaha worked fine and saved a lot of fuel.
For really cold climate, nothing really delivers the power as well as a gasoline fueled generator. At -40F, nothing really wants to start. The Yamaha could be kept inside easily as it weighs only about 50lbs with one gal of fuel. Sometimes had to wheel the Generac inside to warm it enough to start and run easily. The generators were run under cover, but not in an insulated or heated shed. Intend to move them to a dedicated generator shed this year.
Generator is run when battery voltage drops to about 50% of full charge, or 24.2 volts. We run the genset manually, turning off the generator when the batter reaches float stage charging per the Trace LED display. Float occurs at about 85% of full charge. Trojan Batteries has a pretty good faq for battery maintenance and their batteries are good value.
Bought a 2nd Yamaha EF2000IS to run them in parallel. Has not been totally satisfactory but does work. Redundant backup. Converted a Honda 50amp inverter genset jumper set to NEMA 230 plug to use w/our extension. Works, but..
Found another genset at a pawnshop that became our daily workhorse. A Honda 2500w basic machine which puts out 20a continuously and runs 3+hrs per gallon. Had a decent condition 12awg grounded extension which I cut into two short pieces and made another dual 120 plug to NEMA 230 extension. This machine runs maybe 4hrs a day and is very fine.
The generator saga does not end there... Found a Honda 5500w basic set at another pawn shop, and an electric start Honda 5500 on craigs which needed a new generator head. Scavenged parts from the pawnshop set and now we have an electric start Honda in good condition. Invaluable was the learning to diagnose bad rotor stator and doing the parts replacement. For $300tot for both machines, it was a great project.
May still purchase a new Honda electric start genset. Unfortunately, their inverter models, even the electric start jobs, do NOT have the automatic choke of the basic models. Ideally, the 4500w machine delivers best economy at half load at about .6gal per hour and will do 4000w (iirc) at full load on about .8gal/hr. For our not too intensive electric needs, it would be perfect. Nobody stocks these in Alaska, though, because most buyers would go for the 5500 genset for about $300 extra bucks. So we're told...
We did buy another inverter, a basic no-frills Pure Sine Wave Cotek SK 3000 24v device that delivers 3000w continuous and surges to 6kw. Basic, almost bombproof machine, hopefully. have not installed it yet but did test it. With this we bought an IOTA 40kw 24v battery charger power supply as an outboard battery charger. The draw at max charge is just under the max of the Yamaha EF2000IS. The IOTA works with the Trace inverter charger and when run together with the 2500w Honda they deliver about 75amps of charge at 29.6 volts. When the Honda runs the Trace will send genset power plus whatever is needed from the battery to match powerdraw until draw from inverter exceeds 10kw surge or 4kw continuous. This gives us about 6200watts max usable power w/genset running. More if we are running the 5500w Honda or 8kw Generac.
The IOTA charger can be teamed with another charger and deliver 80amps. Can't say enough good things about these tough and capable machines. Intend to get another one and the paralleling module for times we might have to do an equalizing charge.
Our Trace inverter(s) will do autostart with the Honda electric genset. Few newer inverters really are made to do all the supplemental work with a generator as the original Trace designs. Magnum has one hybrid inverter that will allow additive current and autostart. Lots of info on all the possiblities on the Arizona Wind and Sun forums, and o the Homepower archives disc.
Gasoline storage? We ran some fuel that was at least 5yrs old w/o a problem or need to clean a carburetor. I did add some acetone, about 1oz to 5gals and also used SeaFoam and began treating any new fuel stored with StaBil. The marine formula StaBil looks to be the best value so now buy only that. There is also PRI-D and PRI-G for diesel and gasoline renovation. Might be great to have if you have some old fuel stashed away...
Probably most essential tools for diy power conversion and installation is a digital voltmeter, like a Fluke and a good set of cable cutters for making HD copper cables.
More to come if I think of other details that are important. Probably most critical is sizing your system to meet your needs. Have to look at start-up current requirements for machines with motors and compressors. Often takes 3x the current to actuate the motor to operating speed as it takes to maintain the rpms. LED or other energy saving lighting helps a lot. Where we live, no need for air conditioning and we use very efficient Toyotomi fuel oil heaters. Many things are just energy hogs like vacuum cleaners, dishwasher, Jenn-Air electric stove... Look at all your electric devices and their draw rates. Might get a Kill-A-Watt meter and monitor what you are using. Add up all your daily constantly in-use electric devices and tools and add maybe 25% more for extra capacity. Then buy your inverter and battery and charging gear accordingly...
Pretty wonderful to be self-sufficient to some degree on the electric. Really great to be able to put it all together and know the inner workings and be able to diagnose trouble sources and fix them. Really something every Survivalist ought be able to do.
Edited To Add: Oil for gensets. Since reading Chris Olson's posts on AZ Wind/Sun forum have been using Diesel rated motoroils in our air-cooled gensets. The Rotella 10-30 synthetic is the favorite. We use Rotella and Delo 5-40 year round in our diesel vehicles. Chris' posts on that forum are uniformly highly informative, objective, and written with an engineer's background and insight. He now has his own website: http://dairylandwindpower.us
The reason to use diesel rated oil is its superior ability to take the much greater pressures of diesel combustion and thereby deliver longer piston life in air-cooled motors. I change the oil about every 10 days to 2weeks as it strikes me to do so. This works about to about every 50 or 60hrs versus the every 100hrs Honda and Yamaha recommend. The Rotella 10-30 diesel oil has been priced at about $16/gal at WallyWorld so has been a good value. I try to keep about 8gals on hand. Also keep about 8 or 10 spare NGK spark plugs for each machine and mix-in some SeaFoam once a month or so just for VooDoo JuJu good luck...