Running the numbers on Minnesota’s solar mandate

At the end of the 2013 legislative session in Minnesota, legislators passed an omnibus energy bill which included, among other things, a requirement that investor-owned utilities in Minnesota (Read: Xcel Energy) must generate 1.5% of their electricity from solar by 2020.  There were a lot of other things in there as a result of the sausage law-making process for the solar mandate, including some that I’m not very fond of, but the bottom line of encouraging more solar development is a good thing in my book.  (Also, it was signed into law on my birthday!)

Solar Panels1.5% doesn’t sound like a whole lot, but what does it really mean in terms of physical solar PV deployments?  Numbers have been tossed around that this will require 450MW of new capacity in the next 7 years.

Assuming the 450MW number is correct, and picking 250W panels as a common panel size today, that’s 450,000,000 / 250 = 1,800,000 or 1.8 million panels installed by 2020.  That’s about 700 panels installed every day for 7 years.

If commodity sized (65x39cm) panels are used, that’s about 112 acres of panels (if they were laid out flat and edge to edge, which of course they aren’t) ;)  That’s roughly equivalent to 112 US football fields.

Is this possible?  Sure.  Austria installed 230MW in 2012 alone.  New Jersey installed 415MW in 2012.  And Minnesota gave itself 7 years to accomplish this goal.

Is 450MW the right number?  According to the NREL PVWatts calculator for Minneapolis, 450MW of optimally situated, fixed solar PV could be expected to generate 578,512 MWh of solar energy in the course of a year.

According to the EIA energy data browser, all utilities (including co-ops etc) in Minnesota generated 42,586,000 MWh in 2012.  578,512MWh is about 1.3% of that number.  Xcel is by far the largest generator, so if we take out the smaller co-ops etc, 450MW does seem like a reasonable ballpark number.

There are already large companies ready to jump at this.  Geronimo Energy has submitted a proposal to provide up to 100MW of capacity at up to 31 sites ranging from 2 to 10MW.  I honestly hope this isn’t the predominant mode of development.  We have an awful lot of flat roofs which would be well suited – for example, Ikea put 1MW on their Minnesota store last year.  100 acres or so isn’t all that much land, but I’d still rather see this go up on the built environment before we start using farmland & green space.

I’m excited to see how this works going forward.  Will my friends in the small-scale solar installation business stay busy?  Will SolarCity come to town?  Will companies like Geronimo make up the bulk of this with giant installations?  Will it reduce the need for new gas peaker plants?  Time will tell, but it’s an exciting time for solar in Minnesota, for sure.

Making it easy

belkin-conserve

(Image link goes to Amazon)

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

Uncompressing Cisco X2000 firmware images

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.


Continue reading

Spinning down a WD20EARS “Green” drive

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