Saturday, May 19, 2012

World's Largest Concentrating PV System Goes Hot in Colorado!

Fans of utility-scale solar PV are likely aware of the world’s largest highly concentrating PV (HCPV) system that has been under construction in the heart of Colorado’s San Luis Valley. On May 10, Cogentrix Energy, LLC (a unit of Goldman Sachs) announced that it has achieved commercial operation at its 30MW HCPV project which will provide solar energy to Public Service Company of Colorado (PSCo) for compliance with the utility’s wholesale DG obligation under Colorado’s Renewable Energy Standard. The Amonix MegaModule® assemblies that form the heart of this system rely on Fresnel lenses to concentrate solar irradiation 500 suns onto triple junction solar cells originally developed by SpectroLab (a Boeing company) as part of the US space program. Looking like something out of the movie Transformers, the project consists of over 500 60kW (nominal) dual axis trackers on approximately 225 acres approximately 14 miles NW of the southern Colorado town of Alamosa (click here for a Google map). 

Truly an impressive facility, this project was bid into the 2009 All Source Solicitation conducted as part of PSCo’s 2007 Electric Resource Plan (Colorado PUC docket 07A-447E). Electricity from the plant, estimated at approximately 75,000 MWh for the first full year of operation, is provided to PSCo under a 20-year PPA. Financing for the approximately $145 million project was facilitated by a $90.6 million loan guarantee from the US Department of Energy proving that not all DOE-backed funding necessarily had to result in Solyndra-like failures (in fact, there is a fundamental difference between providing a loan guarantee for an energy development project such as this and a manufacturing facility such as Solyndra). The one downside, albeit a significant one, is that the Colorado PUC exempted this project along with another 30MW project in the San Luis Valley developed by Iberdrola Renewables from the 2% rate cap in Colorado's renewable standard. As I’ve pointed out previously, compliance with Colorado’s RES has been achieved, and even exceeded, but at a cost far greater than the 2% rate cap stipulated in the statute. 

Back in October 2011, I had the opportunity to tour the facility with Cogentrix VP Jef Freeman while it was still under construction. Below are a handful of the pictures I took at that time.

Approaching the plant from the southeast, it is difficult to get a true appreciation for the scale of the facility.

Looking closer, it isn't clear if this is a solar facility or a spaceport!

Loading the Amonix MegaModule panel assemblies onto the pedestals.

Look close and you might see the workers attaching the panel assembly to the pedestal from below.

To get a feel for the scale, check out the pickup truck in comparison to the trackers.  The Solectria inverter on each tracker can be seen in the foreground.
When not tracking the sun, or stored due to high winds, the panels will remain horizontal as shown here.

All photos Copyright Richard Mignogna, 2011.


  1. No sooner has everyone been touting the completion of this 30MW facility in the San Luis Valley than comes a report that Amonix is now laying off 76 employees (see the GreenTech Media post here: It seems that this one project is what has kept them afloat this long. In a way, that's really a shame. The technology needs to advance and more work needs to be done in that regard, although the entire cost of doing so does not all need to come from a single customer... or should I say group of ratepayers. Colorado could have done more if it had not allowed its two regulated utilities to break the bank on rebates for the small solar program.

    1. Hello Rick

      I saw a comment of yours on GTM regarding Net Metering. Do you think it would be possible to establish a minimum T&D grid fee for all customers (net-metered and non net-metered) and make that a fixed monthly charge. Then you'd add volumetric T&D charges on top of this fixed fee to cover T&D. Do you think the implementation of this sort of setup would be overly complicated? Do you think this adjustment in the rate structure is a good step towards having net-metered solar customers pay for their fair share of the grid?

    2. Alison,

      Thanks for your note, though it may be slightly off topic for this particular post. The short answer is that a combination of fixed and variable T&D charges represent one possible way of accounting for the net metering customer's use of the utility's facilities. The problem, ok... one problem, is transparency. In Colorado for instance, there is a T&D component in the flat service and facilities fee that all customers pay and there are various T&D charges embedded in a number of other rate riders added to a customer's bill. There is even a separate transmission cost adjustment (rate rider) on top of all of the above. On my last bill it amounted to eleven cents. In principle, it should be possible to do as you suggest and determine a minimum fixed fee to recover the capital expense and add to it a volumetric charge to recover O&M. But some net metering customers overbuild the system making them a net generator month after month and then argue that they should pay no volumetric charge at all. This too is wrong because they are using the utility T&D for all but about 6 hours a day. So, it becomes a huge problem of cost allocation just as it is for any widget manufacturer, perhaps worse. And, when so much of a bill is based on average rates for a customer class, someone is bound to argue that they are paying too much. That is where smart meters and time of use rates could help. But at some point this analysis can become too granular and be a waste of time considering the few dollars involved for an individual customer. Different rate structures and different regulatory schemes used in different jurisdictions all conspire against a single approach. But, there needs to be far better transparency as well as some acknowledgment that there is a cost and it isn't zero. So, in principle, yes it's possible. But that won't preclude the inevitable arguments about what costs should go into the determination of the respective charges.

  2. Thanks for the quick reply Rich. Sorry for the misplacement here but I couldn't find your email.

    I'm not concerned about the current customers who have overbuilt their systems. I'm concerned about future rate structures that provide better signals for people who build systems in the future. I think we all see that net-metering isn't a sustainable platform but at the same time it wouldn't be prudent to abandon the current NEM programs without carefully experimenting with new structures that don't shock the system. We're not going to find a solution on the first try and like you said, even the solutions we finally do find won't fit all situations. I'm only trying to figure out if the direction I'm thinking of is a practical direction.

    1. Allison,

      For as long as I've had this blog, I never realized there was no way to contact me directly. It also doesn't give me a contact for those who comment. I've now added an email link above.

      At any rate, I don't have that big a problem with net metering, per se. Xcel hasn't had a big problem thus far either, at least with the present level of penetration. I think it is ok to require that utilities offer net metering though I don't believe they should have to pay exorbitant rates to the generator. Don't most businesses buy at wholesale and sell at retail? Net metering proponents seem to want to turn that upside down. But, utilities are often their own worst enemy and tend not to engender much sympathy. Changes in technology seem to be moving us more and more in the direction of retail choice and self generation. Eventually, it appears that the regulated utility monopoly is going to go the way of the old telecom monopoly.

  3. This comment has been removed by the author.


Please feel free to comment. I welcome your thoughts. However, no anonymous comments. Professional discourse demands that you identify yourself.