Monday, June 14, 2010

Solar Gardens Build Community Wealth - Transmission Lines Cost Jobs

San Luis Valley Transmission Line Could Cost Colorado 25,000 Jobs over 10 Years
By Joy Hughes, Solar Gardens Institute

     One of the arguments given for expanding transmission lines and industrial solar in the San Luis Valley is the creation of jobs.  We’ve proposed a distributed energy alternative -- rooftop solar and solar gardens, and solar self-sufficiency in the San Luis Valley.  In March 2010, the Colorado Solar Energy Industry Association (COSEIA) released a study showing that 1,000 Megawatts of distributed solar energy would create over 33,000 person-years of employment over ten years.  Says COSEIA:

     DG solar supports local business growth and allows every Coloradan to directly contribute to the New Energy Economy by producing their own clean electricity.  DG solar  also helps utilities reduce costs of purchasing expensive peak power electricity and updating grid infrastructure--  all cost savings that ultimately benefit ratepayers.


     By comparison, an inside source tells me that the 8.2 Megawatt SunEdison plant in Mosca was completed by 70 people in 6 months, and only takes one person to maintain.  This comes out to 45 person-years over 10 years, or about 5,500 jobs per 1,000 Megawatts. 

      This back-of-the-envelope calculation shows that by drawing resources away from rooftop solar, the massive industrial solar development spurred by building the SoCo transmission line over La Veta Pass would actually cost Colorado over 25,000 renewable energy jobs!  The San Luis Valley can build 200 megawatts of distributed solar for self-sufficiency and export, and still come out ahead in terms of jobs.

Solar Gardens Keep Money in the Local Economy

     I had a chance to visit the first community solar facility in America – the Ellensburg Solar Community in Washington State.  Each person who owns a share gets a credit on their electric bill.  Imagine that – a power company that pays you, rather than the other way around!

     That’s the great thing about solar gardens – subscribers have to be local.  So money that would otherwise leave the valley in electric costs will stay, cycle around, and have a multiplier effect.  We call this community wealth.

The Best Place for Solar in Colorado?  XCEL’s Own Study Says – Pueblo!

     The San Luis Valley gets more total sun hours than elsewhere in Colorado… but that doesn’t tell the whole story.  The time of day the sunshine arrives is important as well, using a measure called Effective Load Carrying Capacity, or ELCC.  When this is factored in, Pueblo wins!  To use XCEL’s own words:

     An examination of hourly weather conditions in both 2004 and 2005 indicate a significantly higher correlation of peak system load hours with clear skies in Pueblo than with clear skies in Alamosa.  That is, the chances of afternoon, monsoon conditions in Alamosa during Public Service peak load conditions appear to be greater than such conditions occurring in Pueblo. Thus, even though the annual energy capacity factor from a solar facility located in Alamosa is higher than the same plant located in Pueblo; generation from the Pueblo plant is better correlated to Public Service's peak loads.

XCEL Study Favors “Geographic Diversity” – Spread the Solar Around!

     XCEL told Colorado they couldn’t purchase enough solar energy because a lawsuit has blocked a transmission line into the San Luis Valley.  Yet their own study points out what we’ve been saying all along – it helps to share with your neighbors.

    Geographic diversity of solar plants appears to reduce the cost of integrating solar generation  on the Public Service system.  This conclusion should be viewed as preliminary since this  study examined only a limited set of scenarios.  However, this finding is consistent with results from prior wind integration studies: greater spatial diversity of generation leads to reduced variability in total production, which reduces integration costs. 
     Accurately quantifying the effect of geographic diversity on solar integration costs will be  difficult and was not a major area of focus in this study.  The Company does believe however that the reduction in integration cost with increased diversity makes intuitive sense and thus the general findings of this study in this regard are valid.

Dispatchability, Base Load, and Concentrated Solar Power

     Concentrated Solar Power (CSP), uses mirrors to focus light on a collector and create heat.  This heat can be stored and used on demand (dispatchability) and if stored for long enough could even replace coal plants (base load).  The largest systems planned would cover thousands of acres, though no plant has ever been built on this scale, anywhere in the world. 

     Even with the storage afforded by CSP, geographic diversity is still important.  In the San Luis Valley, winter fog can hang around for days on end while the front range is sunny, longer than such plants can store power

     The need for the energy storage afforded by CSP is put forward as a reason for building transmission lines into the San Luis Valley.  Yet if we had good energy storage in the valley, it would reduce rather than increase the need for new transmission to supply our farmers, who could then irrigate at night using solar power.

     Huge engineering hurdles remain – dealing with caustic materials at very high temperatures, coming up with the ideal heat transport medium, and scaling up to a much larger size.  Any technology in its adolescence is likely to have growing pains.  As with the Comanche coal plant, there is a risk of technical problems that could increase costs and cause delays.  By contrast, the PV solar panel is a proven, mature, and very reliable technology that is rapidly dropping in cost through economies of scale, and is favored by low temperatures in the San Luis Valley.

     CSP on a grand scale would have enormous impacts.  Huge fields of mirrors, power towers lit like a piece of the sun, and cooling towers similar to nuclear plants would certainly have a visual impact. Mirages can magnify the glow.  They would be noisy and take up land, water, and wildlife habitat.  Not something for an area or world-class scenic beauty!

      If we are serious about replacing coal with CSP, and we are going to be replacing those coal plants with gas anyway, then the best thing to do is to locate CSP or hybrid CSP-natural gas plants at the sites of the old coal plants.  These sites are already impacted, and have transmission and water rights already in place.

Energy Storage - Smarter than the Grid

      Which would be more valuable to a power user?  Generation and storage far away, or on site, for backup power?  The cost of solar panels and batteries are dropping. The cost of grid electricity is rising.  It will start to make more sense to not even bother with the grid, just as today it makes less and less sense to keep a land telephone line.

     Last year a company called Ceramatec (owned by Coors) announced a breakthrough in battery technology, and was listed as one of the top ten new technologies by Popular Mechanics.  This uses an established technology – the Sodium/Sulfur battery – but at a much lower operating temperature, making it much more cost effective.  If this or one of several other technologies being pursued pans out, it could store solar energy for each home without the need for power lines, power plants, or power companies.

     Energy Storage is becoming a hot topic!

     Smart Grid News - Pay attention to energy storage:

     Renewable Energy World - Community Based Energy Storage (We call it "battery gardens")

1 comment:

  1. Nice article on the importance of energy storage.I am looking to begin a project on Energy Storage in India. Hope I can achieve this soon.


    Sourabh Agarwal