As was stated on a previous page and in this age of global warming and wide spread environmental pollution, maybe one of the stupidest things we do is transport coal from western states to eastern power plants. Unit trains consume vast quantities of diesel fuel transporting millions of tons of coal to eastern plants only to have the plants waste 75% of the energy in the coal. Surely, somewhere, there is a better way. This page's focus is on photovoltaic technologies but major advancements also have been made in Concentrated Solar Power (CSP) systems. Large solar systems may prove to be inefficient generators of electricity based on a number of issues. For an alternative view, you are invited to read my case for nucler power on this page

A new world record was recently set (12/2006) by the Boeing Spectrolab company for photovoltaic energy conversion. Conversion efficiency is now at 40.7% with "hints of additional gains" to come. Analysts have commented that this latest breakthrough should bring the cost of PV generated energy in line with the average retail cost of coal generated energy. If true, this may be the beginning of a land rush to solar generated electrical energy. A big argument has been that solar systems don't generate power when the sun doesn't shine. This isn't exactly true as this article from Sandia Labs points out .

Small wind and PV systems typically generate electrical energy in the form of Direct Current (DC) and thus they require an inverter to convert the DC to commercial Alternating Current (AC). The IEEE organization, in the late 1990's, in concert with major researchers, proceeded to develop a series of electrical standards for the interconnection of all "Distributed Generation (DG) with the U.S. power grid. The IEEE organization first developed the IEEE 1547 standard to define interconnection requirements of 10 MVA and smaller systems. This standard placed unnecessary costs and complexities on small systems in the range of 10 Kw's. To address this problem, the IEEE then developed IEEE 929 which works in concert with the UL1541 testing standard (Note that REA's do not appear to be part of the IEEE 929 working group). Inverters supplied with the smaller home PV systems are now required to be IEEE 929/UL1541 compliant.

Keep in mind that Colorado REA's are largely unregulated and tend to be political island empires. They claim to be a democratic organization but in my experience they are not. They try to look like the scientific minded good guys but again, in my experience, they have little grasp of the overall energy picture. In this area, Tri-State is their main supplier and as far as I know the famous "All Requirements Contract" is still in force. Because I see no change in who supplies power for DMEA, the next section deals almost exclusively with Tri-State.

To me, the picture to the right is scary in deed. Tristate has made very heavy commitments to the use of coal. Reality suggests that natural gas should be the near term fuel of choice because of price and because it produces approximately only 1/2 the CO₂ of coal combustion. The use of natural gas in a combined cycle configuration boosts conversion efficiency to a 50+% value. It looks to me like Tri-State is largely stuck with old technology coal that has a conversion efficiency of approximately 33%. If you go to my evils of coal page, you can see the potential for regulations and laws that will heavily penalize the use of coal as an energy source. So is solar the answer. I sure don't think so. The availability factor for solar installations is a miserable 25%. In other words, they produce electrical output only 25% of the time on average. A major additional hidden cost of solar is some type of large capacity energy storage system. When the sun doesn't shine, electrical power still needs to be delivered to the connected loads.

Please continue to next page - - Coal -- Solar -- Wind

• CPV Growing Fast
• New 723-3 CRR Document
• Freeing The Grid
• Inverter List
• Performance Test Summaries
• Amer. Solar Energy
• Solar Industry Assn.
• N.W. Solar
• Springerville Output
• PV World Record
• Per Capita CO₂ Map
• Per Capita CO₂ List
• Intertia Storage
• Hydro Power Equation
• PV Inverters Explained
• Inverter Islanding Solved
• IEEE 929 & UL 1741 Explained
• Solar Energy Storage
• Incentives Database
• DMEA Net Metering
• Tri-State Resource Plan
• Colorado Country Life Coop