Reegle Launches A Map Of The Clean Energy World

The Renewable Energy & Energy Efficiency Partnership (REEEP) announced on April 27, 2009 that it now provides a global map to assist researchers with information on clean energy topics by country.

The “Reegle Maps” application provides a visual entry point to clean energy news and projects by countries and regions. The map allows searches by sectors under the major headings of:

• Climate Protection
• Cogeneration
• District Heating Systems
• Energy Efficiency
• Renewable Energy
• Rural Electrification,
  
• ...and many subheadings under these major headings.

“Reegle acts as a unique state-of-the-art search engine, targeting specific stakeholders including governments, project developers, businesses, financiers, NGOs, academia, international organizations and civil society.”

“Reegle’s information gateway provides information and data on all the various sub-sectors within sustainable energy at a global level including:

• Jurisdiction and laws
• News and announcements
• Political declarations and discussion papers
• Project activity and financial reports
• Statistical data
• Studies, manuals and reports
• Tenders, grants and bids”

The REEEP was launched at the Johannesburg, South Africa World Summit on Sustainable Development (WSSD) in 2002. The REEEP’s goal is to accelerate the global marketplace for energy efficiency and renewable energy. The partner organizations actively facilitate financing mechanisms for sustainable energy projects, and structure policy initiatives for clean energy markets.

The REEEP lists of partners, international organizations, MOU organizations, governments, and international processes offers an impressive overview of global attention to creating a new energy economy.

Climate Literacy Guide Available

The U.S. Global Change Research Program/U.S. Climate Change Science Program in March 2009 released the 17-page report, "Climate Literacy -- The Essential Principles of Climate Sciences," with the subheadings "A Climate-Oriented Approach for Learners of All Ages" and "A Guide for Individuals and Communities."




"The Essential Principles of Climate Science presents information that is deemed important for individuals and communities to know and understand about Earth climate, impacts of climate change, and approaches to adaptation or mitigation. Principles in the guide can serve as discussion starters or launching points for scientific inquiry. The guide aims to promote greater climate science literacy by providing this educational framework of principles and concepts. The guide can also serve educators who teach climate science as a way to meet content standards in their science curricula."

"Development of the guide began at a workshop sponsored by the National Oceanic and Atmospheric Administration (NOAA) and the American Association for the Advancement of Science (AAAS). Multiple science agencies, non-governmental organizations, and numerous individuals also contributed through extensive review and comment periods. Discussion at the National Science Foundation (NSF)- and NOAA-sponsored Atmospheric Sciences and Climate Literacy workshop contributed substantially to the refinement of the document."



Earth photographed by Astronaut Ron Evans, USA Apollo 17 Mission, December 7, 1972. In this image, now known as "The Blue Marble," Antarctica is at the top. Other prominent features include the eastern coastline of Africa, the Island of Madagascar, the Gulf of Aden, the Red Sea, and the Arabian Peninsula.

USA National Science Board Wants Your Input On A Sustainable Energy Future

NSB Task Force on Sustainable Energy Public Review and Comment Opportunity

The USA National Science Board released for public review and comments the 61-page draft report, Building a Sustainable Energy Future (NSB-09-35) and dated April 10, 2009.

The report contains a wealth of information on USA energy science, technology, economics and policy by way of tight summaries based on an extensive reference list.

The public invitation for review and comments says:

"The fundamental transformation of the current extractive U.S. fossil fuel energy economy to a sustainable energy economy is a critical grand challenge facing the Nation today."

"Transforming toward a sustainable energy economy requires national leadership and coordination, a new U.S. energy policy framework, and robust support for sustainable energy research, development, demonstration, deployment, and education (RD3E). In its report, the Board makes a number of recommendations to the U.S. Government and offers guidance to the National Science Foundation."

"Given the importance to promote national security through increasing U.S. energy independence, ensure environmental stewardship and reduce energy and carbon intensity, and generate continued economic growth through innovation in energy technologies and increases in green jobs, we hope that you will take this opportunity to express your views on the draft report."

"Submit comments by Friday, May 1, 2009, to Tami Tamashiro, Executive Secretary, Task Force on Sustainable Energy, at NSBenergy@nsf.gov. If you have any questions, contact Ms. Tamashiro at (703) 292-7000."

From the report:

U.S. Energy Supply (p. 9-10):

Today, 85 percent of the U.S. energy supply comes from the combustion of fossil fuels (e.g., oil, natural gas, and coal), and nuclear electric power provides 8 percent. Sustainable energy sources derived from water (hydroelectric), geothermal, wind, sun (solar), and biomass account for the remaining 7 percent of the U.S. energy supply. Dramatic advances and investment in the production, storage, and distribution of U.S. sustainable energy sources are needed to increase the level of sustainable energy supplies.

U.S. Energy Consumption (p. 10):

U.S. energy consumption varies by economic sector and by energy source. About one-third of energy delivered in the United States is consumed by the industrial sector, and one-half of that is consumed by three industries (bulk chemicals, petroleum refining, and paper products). The transportation sector accounts for the second highest share of total end-use consumption at 29 percent, followed by the residential sector at 21 percent and the commercial sector at 18 percent.

Across all sectors, petroleum is the highest energy source at around 40 percent, followed by natural gas (23 percent), coal (22 percent), nuclear electric power (8 percent), and renewable energy (7 percent). The transportation sector has historically consumed the most petroleum, with its petroleum consumption dramatically increasing over the past few decades. In 2007, petroleum accounted for 95 percent of the transportation sector’s energy consumption.

Recommendation 2: Boost R&D Investment (p. 16-17): Increase Federal investment in sustainable energy R&D

• Support a range of sustainable energy alternatives, their enabling infrastructure, and their effective demonstration and deployment. Funding should support investigation into a wide range of sustainable energy RD3E topics, including, but not limited to:

Advanced, sustainable nuclear power;

Alternative vehicles and transportation technologies;

Basic S&E research that feeds into applied energy technologies;

Behavioral sciences as it relates to energy consumption;

Carbon capture and sequestration;

Economic models and assessments related to sustainable energy;

Energy efficiency technologies at all levels of generation, transmission, distribution and consumption;

Energy storage;

Information and communications technologies that can help conserve energy and/or use it more efficiently, such as broadband cyberinfrastructure;

Renewable energy supply technologies (e.g., solar, wind, geothermal,
hydroelectric, biomass/biofuels, kinetic, tidal, wave, ocean thermal technologies);

Smart grid;

“Systems” approach to large-scale sustainability solutions, including full life-cycle analyses of energy systems (e.g., advanced fossil-fuel technologies andbiomass-derived fuels); and

Zero-energy buildings.


Recommendation 3: Facilitate Essential Policies (p. 17):

Consider stable policies that facilitate discovery, development, deployment, and
commercialization of sustainable energy technologies to reflect advances in basic and applied
research

• Understand the explicit and implicit subsidies of current energy sources that impede conversion to the use of sustainable energy sources, and actively work to establish research-based strategies that encourage greater market deployment of sustainable energy technologies.

Conclusion (p. 22):

This report marks a concerted effort by the Board to join with colleagues and stakeholders throughout the Federal, private, academic, and nonprofit sectors to address the challenges and opportunities for sustainable energy in the 21st century. The recommendations made herein to the U.S. Government strive to promote leadership of harmonized efforts in moving toward a sustainable energy economy. In addition, the Board offers guidance for NSF that aims to prioritize innovation in sustainable energy, by supporting sustainable energy RD3E that leads to the development and deployment of viable sustainable energy technologies. With resolve and invigorated initiative, the United States is positioned to successfully build and support a sustainable energy future.

Appendix A: History and Context of Sustainable Energy (p.25-44):

Provides interesting reading on the topics listed under Recommendation 2 above, the current state of USA energy supply and consumption, and a USA legislative timeline from President Truman's signing of the Atomic Energy Act (McMahon Act) in 1946 to President Obama's signing of the American Recovery and Reinvestment Act of 2009.

South Africa To Produce 10,000 Gigawatt-Hours of Wind & Solar Energy Using Feed-In Tariffs

South Africa's National Energy Regulator (NERSA) in late March 2009 introduced a system of Feed-in Tariffs (FITs) intended to produce 10 (ten) Terawatt-hours (TWh) = 10,000 (ten thousand) Gigawatt-hours (GWh) of electricity generated from wind, solar, small hydro, and landfill gas for the country by 2013.

"Feed-In Tariffs - Boosting Energy For Our Future" Report Front Cover, World Future Council, Hamburg, Germany, 2008.

Feed-In Tariffs For South Africa:

A March 31, 2009 Media Announcement briefs the NERSA Decision on Renewable Energy Feed-In Tariff (REFIT).

The 40-page report, South Africa Renewable Energy Feed-In Tariff (REFIT) - Regulatory Guidelines 26 March, 2009, states in its introduction:

"Grid connected renewable energy is currently the fastest growing sector in the global energy market. Installed global wind capacity at the start of 2008 is in the order of 90GW, with total world installed capacity having doubled since 2004. India, China, the United States, Spain and Germany together added over 20GW of wind power in 2007. China and India each are currently installing wind electricity in excess of 1GW per annum and both have targets of achieving over 10GW by 2015. The capacity of grid connected solar PV has also quadrupled from an installed capacity of 2GW in 2004 to approaching 8GW at the end of 2007. Commercial-scale solar thermal power plants are also under construction in countries such as the US and Spain. Targets for the promotion of renewable energy now exist in more than 58 countries, of which 13 are developing countries."

'The renewable energy industry is now a major economic player, with the industry employing over 2.5 million people worldwide. Renewable energy companies have grown significantly in size in recent years, with the market capitalisation of publicly traded renewables companies doubling from $50 billion to $100 billion in just two years (2005-7)."

"South Africa has a high level of renewable energy potential and presently has in place targets of 10,000 GWh of renewable energy by 2013. To contribute towards this target and towards socio-economic and environmentally sustainable growth, and kick start and stimulate the renewable energy industry in South Africa, there is a need to establish an appropriate market mechanism."

"Feed-in Tariffs (FIT) are, in essence, guaranteed prices for electricity supply rather than conventional consumer tariffs. The basic economic principle underpinning the FITs is the establishment of a tariff (price) that covers the cost of generation plus a "reasonable profit" to induce developers to invest. This is quite similar to the concept of cost recovery used in utility rate regulation based on the costs of capital."

"Under this approach it becomes economically appropriate to award different tariffs for different technologies. The price for the electricity produced should be set at a level and for a period that provides a reasonable return on investment for a specific technology. The tariff should also be certain and long term enough to allow for project financing to be raised by the project."

"Feed-in tariffs to promote renewable energy have now been adopted in over 36 countries around the world, including Spain and Germany and a number of states in the US, and also including developing nations such as Turkey, Thailand, Sri Lanka, Nicaragua, Indonesia, Ecuador, China, Brazil, Argentina and most recently Kenya."

"The establishment of the Renewable Energy Feed-In Tariff (REFIT) in South Africa will provide an excellent opportunity for South Africa to increase the deployment of renewable energy in the country and contribute towards the sustained growth of the sector in the country, the region and internationally."






"Feed-In Tariffs - Boosting Energy For Our Future" Report Back Cover, World Future Council, Hamburg, Germany, 2008.

Climate Masters Program Comes To New Mexico In May 2009

The New Mexico Environment Department is offering the Climate Masters program at the Santa Fe Community College, Santa Fe, NM beginning May 26 and ending July 28, 2009.

The Climate Masters program is a free series of classes focused on climate change, what you can do to reduce greenhouse gases emissions in your daily life, and strategies for motivating others to do the same. In exchange for the 30 hours of course training, you will be asked to donate 30 hours of volunteer options in your communities.

For resources information, see "Resources for Climate Masters" at the University of Oregon's Climate Leadership Initiative, and the "Climate Master Handbook -- A Guide to Shrinking Your Climate Footprint and Motivating Others to do the Same".

Tesla Unveils Model S Electric Sedan

Tesla Motors, Inc. of San Carlos, California on March 26, 2009 announced that it is taking orders for an all-electric family sedan that carries up to seven people and travels up to 300 miles per electric charge.


















Tesla Model S Electric Sedan at the SpaceX rocket factory, Hawthorne, California, March 26, 2009. See "Up To Speed" in the Los Angeles Times for an associated article and more photos.

The Tesla Model S carries an onboard charger that can recharge the battery packs in as little as 45 minutes. The battery pack also is designed to be changed out in less time than it takes to fill a fuel tank on a similar gasoline-powered vehicle. As battery-pack swap and charging stations become more widespread in the new energy economy, drivers can expect to travel as far and as fast in electric vehicles as they can in gasoline-powered vehicles.


















Tesla Model S Prototype

The standard Tesla Model S goes from zero to sixty miles per hour in under six seconds and will have an electronically limited top speed of 130 miles per hour. The Model S will not require routine oil changes, and has fewer moving and breakable parts than cars powered with internal combustion engines. The Model S operating cost is about five dollars for each 230 miles traveled.

The anticipated base price of the Tesla Model S is $49,900 after a federal tax credit of $7,500. The company has not released options pricing. Three battery pack choices will offer a range of 160, 230 or 300 miles per charge. This pricing is consistent with Tesla's long-term plans to produce highway-capable electric vehicles at increasingly lower prices as the EV technology develops. Tesla's efforts are focused on accelerating the electric car revolution, according to Tesla Chairman and Chief Executive Elon Musk. Tesla was selected in January 2009 to make batteries and chargers for Daimler's Smart EV.


Daimler Smart ForTwo Electric Vehicles























The Tesla Roadster

Tesla is the only production automaker already selling highway-capable electric vehicles (EVs) in North America or Europe. With 0-60 mph in 3.9 seconds, the Tesla Roadster outperforms almost all sports cars in its class yet is six times as energy efficient as similar gasoline-powered cars and delivers 244 miles per charge. The Roadster, Tesla's first model, has a base price of $101,500. Tesla has delivered Roadsters to about 300 customers, and has nearly 1,000 additional customers on its wait list.

Hybrid CSTP/Natural Gas Power Plant Under Construction In Florida

The following information supplements the post of December 7, 2008 on a co-located solar/natural gas-fired power plant in Indiantown, Florida.

Co-locating industrial-scale solar power plants with existing fossil-fuel fired power plants can be an economical solution to power transmission and other problems. Co-location allows clean energy to be phased in as fossil-fuel energy is phased out, with the fossil-fuel energy plant becoming a backup, then eventually becoming unnecessary as solar heat storage technology improves.

Solar radiation is available onsite, whereas fossil fuels must be continually mined and transported to the old-technology plant. Co-locating solar power on the existing plant site takes advantage of transmission infrastructure already in place, avoiding costs of building extensive new transmission lines. Solar power plants avoid many of the water-use and land- and water-pollution problems of old-technology power plants. Thus, opportunities for land and water systems restoration after abandoning fossil-fuel power plants will increase substantially.

Lauren Engineers & Constructors and Florida Power & Light Company Building Martin Next Generation Solar Energy Center in Indiantown, Florida.

Lauren Engineers & Constructors is working with NextEra Energy Resources, a Florida Power & Light Company (FPL) Group Company on a new 75-megawatt (MW) concentrating solar thermal power (CSTP or CSP) facility.

The CSTP part of the facility will employ parabolic trough mirror technology and include approximately 180,000 parabolic mirrors on 500 acres of land. Solar power output is expected to be 155,000 megawatt-hours (MWhr) annually.

Artist's Conception of the FPL Martin Concentrating Solar Thermal/Natural Gas-Fired Power Plant, Indiantown, Florida.

Lauren Engineers & Constructors also worked with ACCIONA to build the Nevada Solar One Power Plant, a 64 MW parabolic mirror facility located in Boulder City, Nevada. This plant went online in June, 2007.








Nevada Solar One Concentrating Solar Thermal Power (CSTP) Plant, Boulder City, Nevada. This facility uses parabolic mirror technology and 182,000 curved mirrors, occupies 400 acres of land, and generates 64 megawatts (MW) of power. The plant began operating in June, 2007. Photograph: CNET News, March 12, 2007.


















Detail views of Nevada Solar One CSTP Plant showing parabolic mirror arrangement. The parabolic mirrors are aligned on north-south axes, and rotate from east to west throughout the day to track the sun. The mirrors focus sunlight on an oil-filled pipe that carries the heated oil to a heat exchanger. The heat exchanger creates steam that powers an electricity-generating turbine. Photographs: Acciona U.S. Projects.

USA Installs 1,265 Megawatts (MW) Of Solar Power In 2008

New Solar Energy Industries Association (SEIA) Report Details Solar Power Growth In The USA.

Xcel/SunEdison solar photovoltaic heliostats, 8.24 Megawatt (MW) Solar Photovoltaic (PV) Powerplant, San Luis Valley near Mosca, Colorado. This powerplant was activated in December 2007. View is eastward towards Sangre de Cristo Mountains.
Photograph by L.A. Brown, March 18, 2009.

The Solar Energy Industries Association (SEIA) released its 12-page summary report, 2008 U.S. Solar Industry Year in Review.

The report states 1,265 megawatts (MW) of solar power of all varieties were installed in the USA in 2008. These include 342 MW of solar photovoltaic (PV) installations, 139 MWTh (megawatts thermal equivalent) of solar water heating, 762 MWTh of pool heating, and an estimated 21 MW of solar space heating and cooling.

Surface detail of Xcel/SunEdison solar PV heliostat, Mosca, Colorado, showing reflective metal triangular ridges that focus solar radiation on solar PV receptors. Photograph by L.A. Brown, March 18, 2009.

California was the leader among state grid-tied PV installations with 178.6 MW, New Jersey followed with 22.5 MW installed, Colorado was next at 21.6 MW, Nevada installed 13.9 MW and Hawaii with 11.3 MW. For solar water heating systems, Hawaii led states, installing 37 percent of the total U.S. systems in 2008, followed by Florida at 20 percent, California with 7 percent and both Colorado and Arizona with 5 percent. The Mid-Atlantic States, an important emerging region for solar, installed 7 percent of solar water heating systems.

Close-up of solar PV receptors and reflective metal triangular ridges, Xcel/SunEdison heliostat, Mosca, Colorado. Note dirt on panel surfaces and dents in metal reflectors caused by hail. Photograph by L.A. Brown, March 18, 2009.

The SEIA report indicates solar PV manufacturing capacity in the USA increased by 65 percent in 2008. this created many new jobs in California, Michigan, Ohio, Oregon and Tennessee. Total solar power production capacity in those five states now stands at approximately 685 megawatts (MW).


















Solar panels, Xcel/SunEdison 8.24 MW Solar Photovoltaic Power Plant, Mosca, Colorado. These panels are supported by north-south aligned axles that rotate the panels from east to west throughout the day to track the sun. View is northeastward in the afternoon towards the Sangre de Cristo Mountains that form the eastern border of the San Luis Valley. Photograph by L.A. Brown, March 18, 2009.

The SEIA report notes that no new concentrating solar power (CSP) plants came online in the USA in 2008. However, CSP projects in the planning or construction stages currently total more than six gigawatts (GW; 6 GW = 6,000 megawatts). Among these are projects planned for California's Mojave Desert, Arizona and Florida.

Tracking The Sun

Solar Panels On Rooftops, Ohta, Japan, Focus Solar, 2008

Solar Photovoltaic Power Costs In USA Drop 30 Percent Over Past Decade

The Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory in California released a new report, “Tracking the Sun,” that documents the installed costs of solar photovoltaic (PV) power in the USA from 1998-2007.

The February 27, 2009 revision of the 42-page document indicates a positive outlook for the future of customer economics of solar PV. Primary indicators include an oversupply of solar PV modules in the near future together with lifting the cap on the Federal Investment Tax Credit (ITC) for residential PV will reduce costs for residential installations. Large commercial solar PV promises to be the dominant growth market because of economies of scale, but both large and small solar PV systems stand to make major gains in reduced costs per unit of energy generated.

The report examines 37,000 grid-connected solar PV systems installed in 12 USA states from 1998-2007. Among these, average costs before financial incentives or tax credits declined from $10.50 per watt in 1998 to $7.6 per watt in 2007 – roughly a 35 percent cost reduction over ten years.

Non-module costs such as inverters, mounting hardware, labor, permitting and fees, shipping, overhead, taxes and profit were responsible for the bulk of cost reductions.

Systems less than 5 kilowatts in size exhibited the largest cost reductions; however, data are lacking for larger solar PV systems with output greater than 100 kilowatts.

Average costs for all systems flattened and remained almost unchanged from 2005-2007.

Installed costs of solar PV show economies of scale. Systems less than 2 kilowatts averaged about $9.00 per watt in 2006-2007, and systems greater than 750 kilowatts averaged about $6.80 per watt during the same period.

State and utility cash incentives for solar PV installations declined from 2002 through 2007.

The increase in the Federal ITC in 2006 tended to stimulate commercial-scale solar PV from 2007-2009; however, residential solar PV should gain cost advantages in 2009 with changes in the Federal residential ITC.

In its introduction, the report says: “Despite the significant year-on-year growth, however, the share of global and U.S. electricity supply met with PV remains small, and annual PV additions are currently modest in the context of the overall electric system.”

Nonetheless, the growth of solar PV is encouraging. The data on its declining costs with time offer a promise of even more accelerated growth in the next few years.

A February 25, 2009 brief at WorldChanging expands upon the following:

Business Green reported on February 23, 2009 that the price of solar PV panels could fall by as much as 40 percent by the end of this year. Other analysts have been predicting this price drop that is based on huge increases in polysilicon supplies leading to a drop in production costs.

New Energy Finance also predicts a fall in solar PV module prices because of recent global investments in increasing silicon production.

China-based solar PV panel manufacturer Suntech Power Holdings estimates that demand from the USA could reach 700 megawatts (MW) during 2009 as a result of President Obama’s new stimulus package.

Climate Progress suggests if the dramatic price drop for solar PV panels materializes, solar PV will become "...one of the largest job-creating industries of the century, projected to grow from $20 billion two years ago to a $74 billion industry by 2017."

Solar Electric Power And Renewable Energy Futures For Colorado

SES Stirling Energy Systems Solar One Power Plant in the Mojave Desert near Barstow, CA will develop 500 megawatts (MW) of electricity generating capacity with an expansion option to 850 MW. The plant will use 20,000 to 34,000 solar Dish/Stirling concentrators like the ones shown here.

A recent report on the renewable energy future of Colorado assesses the state’s potential to meet its own renewable energy standards (RESs) while also producing renewable energy for export to other markets.

The report is entitled, “Connecting Colorado’s Renewable Resources to the Markets -- Report of the Colorado Senate Bill 07-091 Renewable Resource Generation Development Areas Task Force Revised Edition July 2008”

The 64-page document treats wind, solar, hydroelectric, and geothermal power generation, and biomass, ethanol, and biodiesel fuels. The report sets these energies in the context of policy, economics, power transmission, land-use, and related elements. Importantly, the Task Force assesses electricity generation costs for different carbon dioxide (CO2) emissions penalty scenarios.

For wind and solar power, the Task Force identified “Generation Development Areas” or GDAs indicating power generation potential from specific regions of the state.

For wind power, the GDAs lie on the High Plains east of the Rocky Mountain Front and within which the Task Force found a potential for ninety-six (96) gigawatts (GW) of wind power generation. I will treat the implications of wind power development for Colorado and other regions in a future post.

For solar power, the Task Force defined two GDAs in the southern part of the state together having a potential to generate as much as thirteen hundred (1,300) gigawatts (GW) of electricity.

One "Central Solar Power" GDA is the San Luis Valley of south-central Colorado. The other, larger GDA includes a region extending from the eastern base of the Sangre de Cristo Mountains well into the High Plains of southeastern Colorado along the Colorado-New Mexico border.

The Task Force acknowledges the impracticality of the 1,300-GW scale of generation, saying that all the land in the GDAs would need to be covered with solar generation equipment. Further, the 1,300-GW output would be more than one hundred (100) times the current peak energy demand for the state.

The Task Force makes no specific recommendation for the level of solar power generation, but says about two (2) percent of the total land area of the two GDAs would allow production of about twenty-six (26) gigawatts (GW) of electrical generation capacity.

The Task Force then describes three utility-scale solar technologies currently available and operating elsewhere in the USA and the world. These technologies are grouped under the heading of Concentrating Solar Thermal Power (CTSP), frequently referred to in other reports and the media as Concentrating or Concentrated Solar Power (CSP).

The three technologies are Parabolic Trough Systems, Dish/Stirling Systems, and Solar Tower Systems. In each of these systems, large mirrors focus reflected solar radiation onto receivers that transform the intense heat into energy.

Parabolic Trough Systems focus solar radiation onto oil-filled pipes, and the heated oil is used to boil water, creating steam to drive electricity-generating turbines.



Sandia National Laboratories Researcher Rich Diver poses with a Parabolic Trough solar power concentrator, Albuquerque, NM, May 15, 2007. The parabolic mirrors focus sunlight on the oil filled pipe running above his head. The oil then flows though a heat exchanger to generate steam to power a turbine to generate electricity.

As illustrated by SES Stirling Energy Systems, Dish/Stirling Systems use large, mirrored, lens-shaped dishes to focus solar radiation on a Stirling engine mounted at the focal point of the lens. The heated fluid in the Stirling engine expands, creating pressure to drive pistons or turbines for electrical power generation.



The SES Stirling Energy Systems SunCatcher is a 25-kilowatt (kW) Solar Power System consisting of a 38-foot diameter dish structure that supports 82 curved glass mirrors. The system is also called a heliostat because it tracks the movement of the sun throughout the day. The device labeled "Power Conversion Unit (PCU)" is the Stirling engine and its housing.

Solar Tower Systems use a mirror array to concentrate and focus solar heat on a tower containing molten salt. The heated salt is used to produce steam to drive electricity-generating turbines.



Solar Tower System at Sandia National Laboratories National Solar Thermal Test Facility, Albuquerque, NM. In this 2006 view the nine-acre test facility at Sandia consists of a 200-foot-high solar tower, 212 computer-controlled mirrors called heliostats, and a separate five-story control tower. The heliostats focus sunlight on the tower to generate heat that produces steam to drive electricity-generating turbines.

Each of these three industrial-sale systems has different land-use and water-use requirements plus heat storage potential across a broad range of existing and evolving technologies. Despite many references to steam, the Task Force does not assess water use for different industrial-scale solar power systems in the July 2008 revision of its report.

In fact, Parabolic Trough and Solar Tower Systems can either consume significant quantities of water through evaporation as steam, or they can minimize water consumption using closed-loop and other dry-cooling systems. Dish/Stirling Systems operate at high temperatures, and require essentially no water other than what is needed to wash the mirrors from time to time.

The U.S. Department of Energy, Sandia National Laboratories (SNL) in 2006 published comparative water uses for coal, coal IGCC (Integrated Gasification Combined-Cycle), other fossil fuels, biomass, nuclear, geothermal steam, solar trough, solar tower, natural gas, and hydroelectric power. This report for the USA Congress is entitled “Energy Demands on Water Resources,” and the water demand tables are on pages 17 and 38.

I will devote a future post to land- and water-use requirements for specific renewable energy technologies. I will also devote a separate post to rapidly developing opportunities and technologies for storing solar and other forms of renewable energy.

In concluding the section on solar power generation potential for Colorado, the Task Force discusses solar photovoltaic systems (Solar PV), distributed solar photovoltaics (DG), and current and necessary future policy for Colorado regarding solar power development.