I wanted to look at how much the “clipping” behavior of power-limited solar microinverters affected my annual energy production. The TL;DR version is: at worst, only about 0.6% loss due to clipping. For more, read on. Continue reading
One of the common arguments against solar as an energy source is that it’s just too variable. You can never count on it when you need it. What if clouds roll in and out? 
This probably only interests you if you’re from Minnesota in the US and have Xcel as a utility provider. Continue reading
Today marks the 1000th day of operation for the 2.53kw solar array on our roof. Continue reading
Read any collection of energy tips, and you’ll get pretty much the same thing. Turn off lights behind you, unplug your cell phone charger, put your AV center on a power strip, etc. The problem with these ideas, IMHO, is that you have to remember to do them, everyone in your family has to do them, and you have to keep doing them indefinitely to keep getting any benefit. And face it, it’s hard to change behavior. Continue reading
Now that we’re through 2012, and all the utility bills are in, I took a look at how we did in 2012 vs. the previous year. These numbers probably aren’t that interesting on their own; no big changes or revelations. But some might be interested for comparison. Continue reading
I’ve been thinking about code review lately, and took a little time to look at the Linux kernel git tree to see how many commits are marked with “Reviewed-by” (indicates that the patch has been reviewed and found acceptable). The short answer is, not a whole lot – or at least not consistently, but improving. Continue reading
I got a refurbed Cisco X2000 [amzn] ADSL router / wireless access point for cheap from Adorama, hoping to combine 2 networking boxes, and reduce clutter and power a bit. It comes in at 3-4W, and has an efficiency Level V wall wart, so that part’s all good.
Edit: Everything else is bad! Don’t get this device. Really. It’s the buggiest piece of junk I’ve had the misfortune of trying to run on my network. I’ll leave the rest of this post here for posterity.
Ok, this is a pretty utilitarian post. I did finally get my 18W Server up and running; in fact, it’s serving this post! But I can’t really get to 18W unless the 2x 2T WD20EARS [amzn] drives I have in it for media storage spin down when not in use.
And I had a heck of a time making that work. hdparm -y would quickly spin them down, but using hdparm -S to set an idle timeout seemed to have no effect; I had been trying to use hdparm -S 241 to set a 30 minute spindown time, and I had no luck whatsoever. With the drives spinning, the server used more like 30W.
Mostly through trial and error, I found out that if you set a lower spindown timeout, i.e. hdparm -S 3, the drive will spin down in 10 minutes. Continue reading
My previous post was about our Mini-Split A/C unit, purchased to get us through the few weeks of >100F weather we had this summer in the Twin Cities. But the post also alluded to the ability of these units to heat. Now that it’s cooling off, let’s take a look at that.
What these units do is move heat. Amazingly, they can move it in either direction! In the summer, they move heat out of the house, obviously enough, just like any A/C. But in the colder months, they can move heat into the house as well. Even when it’s cold outisde, you ask? Yep! How is that possible? Continue reading