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.

2 thoughts on “Running the numbers on Minnesota’s solar mandate

  1. Its better to give it a shot and see the changes rather than sit and discuss over the pros and cons, once the switch is made you can actually understand the benefits better.

    • Well, I wasn’t discussing pros & cons, just saying what the rate of installation will have to be to meet the target. Of course it is better to discuss pros & cons before making large commitments, but that has in fact already been done. I do think this will be a net positive for MN, and for the world.

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