Menke Projects

Ever noticed all those little blinking blue lights all over your house after the sun goes down?  They are on the microwave, electric stove, network routers, mini-split, indoor-outdoor weather station, washing machine, and If I include the power draw of the ceiling fan in the bedroom, these little "vampire drains" add up to almost 400 watts every hour, although it does depend on what speed the ceiling fan is set on. So, the purpose of this blog is to collect everything I can find concerning whether or not an Enphase M215 Micro-inverter can be connected to a large 24 volt battery, and the 240 VAC grid so it would feed several hundred watts into my household grid all night long. From the data sheet the input voltage range can be from 16 to 48V, but the MPPT voltage range (voltage range that the switching supply will convert the solar panel voltage to a signal that can be useable for the AC output voltage stage) is limited from 27V to 39V. So if you want to use this wi

This morning (Friday, August 16, 2019) I noticed I was missing a young Bull Calf, perhaps 600 #, and when I checked the fence there was a section mostly down.  After cobbling a quick repair using rusty field fencing, I saw a bull calf with the neighbor's herd, but then decided he was not mine.  Making a tour of the fields, I found this, and immediately called dear wife to help with the situation: At this point, we decided to call the Vet in Dale, and I left that chore to Donna while I drove into Lockhart to buy more range cubes for the cows, and to make quick grocery run.  (Using the electric Leaf)  Upon returning home, I saw the calf standing in the field, but unable to move.  Looked like this, minus the water bucket.  (This was a real surprise,because I thought he was a "goner" ) : Notice the right foreleg.  Swollen to almost double normal size, and the calf will only take a few steps.  Calling the Vet again to report the theoretical "improvement",

Several of us have been discussing methods of charging our electric cars if the power grid quit working.  Our PV systems using Enphase Microinverters will not work if they are not supplied with 240 vac.  With a Net-Metering agreement with our electric provider, we can get paid at a wholesale rate for excess production, but with an Off-Grid PV installation, any excess power simply goes to waste.  With that in mind, perhaps a small Off-Grid PV system with enough output to charge a car using the 115 vac cable that comes with most EVs.  Dozens of email have been exchanged, and I'll post them here to document the "journey". Old style is the M215 Microinverter, with or without the Integrated Ground (IG).  These are being sold for less than $40, and seem to be brand new.  (I got some for $36, delivered.)  Look for used solar panels with 245 watt rating.  Very cheap, and work well with the M215. They cannot be shipped UPS, and must come via Motor Freight, or you can find th