December 16, 2010 - a tale of two solar projects

Let's celebrate a milestone: I've now been blogging here for over a year.

Florida solar?  Setting sun over the Everglades.

Two news articles about solar power from across the country caught my eye today.  Taken alone, each describes the success of a solar power project.  Read together, the differences between the two projects are thrown into relief.

First, South Carolina utility Santee Cooper is building that state's largest solar array.  Santee Cooper's $1.3 million Grand Strand Solar Station project is under development in Myrtle Beach.  The utility is installing 1,300 solar photovoltaic panels on the roof and surrounding grounds of a warehouse it owns there.  In total, the project is expected to produce a peak of 311 kW under optimal conditions.  Adding this 311 kW will increase South Carolina's solar PV power production by 50%.

Santee Cooper funded the project in part through a $475,000 grant from the South Carolina Energy Office, as well as about $500,000 from the utility's voluntary Green Power opt-in program.  (The utility's Green Power program allows customers to procure renewable energy, and tack the additional costs onto their existing monthly utility bill.  All utility revenues from the program must be rolled into renewable projects.)  The power will be sold into the grid, and is projected to be enough to power about 30 homes.

Second, in California, developer SolarReserve has received final approval from the California Energy Commission (CEC) for its Rice Solar Energy Project in Riverside County.  The 150 MW Rice project uses a concentrating molten-salt power tower technology developed by Pratt & Whitney Rocketdyne to create and store heat, allowing it to generate electricity on demand even when the sun is not shining.  (FPL is using a different form of concentrating solar in its 75 MW Martin Next Generation Solar Energy Center in Florida; there, FPL is using mirrors to concentrate light to heat water to be added to existing thermal steam generator piping.)  This is enough to power about 68,000 average homes in the area.  To help fund the project, SolarReserve has secured a 25-year PPA with Pacific Gas & Electric Co.  The California Public Utilities Commission approved that contract in September.  SolarReserve anticipates completing its permitting and breaking ground in 2011.

On first glance, these two projects share some commonalities.  Both rely on solar energy to produce electricity.  Both rely on a diverse set of funding sources, including grants, incentives, and contracts.

Yet the projects' differences are perhaps greater.  First and foremost, the Grand Strand Solar Station may be South Carolina's largest, but at 311 kW it is 482 times smaller than the Rice Solar Energy Project.  This is a radical difference in scale and project scope.

This comparison is even more stark when you consider that the Rice project isn't even California's largest solar development.  Currently, that title is held by the nine-unit, 354 MW Solar Energy Generating Systems project in Kramer Junction, California.  Operated and partially owned by NextEra, SEGS is the largest installation of solar plants of any kind in the world.  Even bigger projects are on the horizon: nearby in Riverside County, Solar Millenium and Chevron are planning the Blythe Solar Power Project, a 968 solar thermal plant.  By comparison, the scales of these projects make a 311 kW rooftop solar project seem minuscule.

Finally, the technologies are different: the smaller Grand Strand relies on solar PV, while the Rice project uses molten salt to produce steam.  The Rice project will also benefit from using salt as an energy storage medium, while as a PV project the Grand Strand must rely on less efficient and costlier tools like batteries and capacitors.

Solar power is well poised to play a key role in our energy future.  As technology improves and installed costs decline, developers of solar projects seem well-poised to profit.  Larger-scale utility projects can often provide better economies of scale than smaller projects.  However, smaller distributed projects like the Santee Cooper installation can also play a role in the energy mix.  The balance between the two types will be driven by policies, incentives, and ultimate value.