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
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
A Hot Summer
2012 was a hot one. We’ve had at least 31 days over 90F, something which hasn’t happened since 1988, and July 2012 was the second warmest July on record in the Twin Cities. This is a departure from the norm; for example the average number of 90F days is 13 – we almost tripled it this year. Continue reading
Well, I guess the novelty wears off just a bit – the two-year anniversary of our solar anniversary came and went on June 29 w/o much fanfare or notice! Continue reading
PVWatts is a website run by the National Renewable Energy Lab (NREL) which can be used to estimate how much energy a given solar array might produce, based on historical mesurements of insolation. If you ever have a site analysis done, the installer will probably use it to estimate your potential for annual production, and you might wonder how close the the mark it’ll be. Now that I’ve had solar PV for almost 2 years, it’s interesting to look at how close the estimates were for my situation. Continue reading
I wrote about Opower almost 2 years ago, a company which is working to reduce energy use by simply making people more aware of what they use in comparison with others. At the time of that post, they seemed mostly focused on working directly with utilities, and sending out reports to customers showing them how their energy use compared to similar homes in their area. The idea seems to be that if you are at all conservation & efficiency minded, seeing where you are in relation to others may actually encourage you to do even better. They track the results, and apparently, it works. However, that method works only if the utility is on board to provide the data. Continue reading