“Hurricane-Broken Air Power Base Has an Alternative to Rebuild for Resilience” • Rebuilding the hurricane-wrecked Tyndall Air Force Base in Florida will come with a massive price tag, but experts say it offers a chance to make the base more resilient to the effects of extreme weather. Hurricane Michael hit Tyndall as a Category 4 storm. [Infosurhoy]
Space-Based Solar Power Satellites seek to overcome the problems of storage and provide civilization-scale power that is clean, constant, and global. Japan and China have active national programs aimed at commercial scale Space-Based Solar Power (SBSP), and both nation's hope to orbit demonstrations in the 2030s. The China Academy of Space Technology (CAST) won the 2015 International SunSat Design Competition with this video of their Multi-Rotary Joint design. Proponents of SBSP claim that Space-Based Solar Power would be clean, constant, and global, and could scale to meet all planetary energy demand. A recent multi-agency industry proposal (echoing the 2008 Pentagon recommendation) won the SECDEF/SECSTATE/USAID Director D3 (Diplomacy, Development, Defense) Innovation Challenge  with the following pitch and vision video. Northrop Grumman is funding CALTECH with $17.5 million for an ultra lightweight design. Keith Henson posted a video of a "bootstrapping" approach.
The combination of wind and solar PV has the advantage that the two sources complement each other because the peak operating times for each system occur at different times of the day and year. The power generation of such solar hybrid power systems is therefore more constant and fluctuates less than each of the two component subsystems. Solar power is seasonal, particularly in northern/southern climates, away from the equator, suggesting a need for long term seasonal storage in a medium such as hydrogen or pumped hydroelectric. The Institute for Solar Energy Supply Technology of the University of Kassel pilot-tested a combined power plant linking solar, wind, biogas and hydrostorage to provide load-following power from renewable sources.
The New Zealand Parliamentary Commissioner for the Environment found that the solar PV would have little impact on the country's greenhouse gas emissions. The country already generates 80 percent of its electricity from renewable resources (primarily hydroelectricity and geothermal) and national electricity usage peaks on winter evenings whereas solar generation peaks on summer afternoons, meaning a large uptake of solar PV would end up displacing other renewable generators before fossil-fueled power plants.
In stand alone PV systems batteries are traditionally used to store excess electricity. With grid-connected photovoltaic power system, excess electricity can be sent to the electrical grid. Net metering and feed-in tariff programs give these systems a credit for the electricity they produce. This credit offsets electricity provided from the grid when the system cannot meet demand, effectively trading with the grid instead of storing excess electricity. Credits are normally rolled over from month to month and any remaining surplus settled annually. When wind and solar are a small fraction of the grid power, other generation techniques can adjust their output appropriately, but as these forms of variable power grow, additional balance on the grid is needed. As prices are rapidly declining, PV systems increasingly use rechargeable batteries to store a surplus to be later used at night. Batteries used for grid-storage stabilize the electrical grid by leveling out peak loads usually for several minutes, and in rare cases for hours. In the future, less expensive batteries could play an important role on the electrical grid, as they can charge during periods when generation exceeds demand and feed their stored energy into the grid when demand is higher than generation.
Markets for second-generation technologies are strong and growing, but only in a few countries. The challenge is to broaden the market base for continued growth worldwide. Strategic deployment in one country not only reduces technology costs for users there, but also for those in other countries, contributing to overall cost reductions and performance improvement.
Adam Schultz, a senior policy analyst for the Oregon Department of Energy, says he’s more encouraged than ever about the prospects for renewables. Because the Pacific Northwest features large-scale hydropower plants built as part of the New Deal, energy already tends to be less expensive there than the U.S. average. But solar and wind power have “gotten cheaper over the last couple years to the point that I can’t even tell you what the costs are because costs have been dropping so rapidly,” Schultz says. “We have enough sunshine,” he says (presumably referring to the eastern part of the state), “so it’s just a matter of time.”
Thirty years ago Bergey pioneered the radically-simple “Bergey design” that has proven to provide the best reliability, performance, service life, and value of all of the hundreds of competitive products that have come and gone in that time. With only three moving parts and no scheduled maintenance necessary, the Bergey 10 kW has compiled a service record that no other wind turbine can match. We back it up with the longest warranty in the industry.
The conversion of the rotational mechanical power generated by the rotor blades (known as the prime mover) into useful electrical power for use in domestic power and lighting applications or to charge batteries can be accomplished by any one of the following major types of rotational electrical machines commonly used in a wind power generating systems:
One issue that has often raised concerns is the use of cadmium (Cd), a toxic heavy metal that has the tendency to accumulate in ecological food chains. It is used as semiconductor component in CdTe solar cells and as buffer layer for certain CIGS cells in the form of CdS. The amount of cadmium used in thin-film PV modules is relatively small (5–10 g/m²) and with proper recycling and emission control techniques in place the cadmium emissions from module production can be almost zero. Current PV technologies lead to cadmium emissions of 0.3–0.9 microgram/kWh over the whole life-cycle. Most of these emissions arise through the use of coal power for the manufacturing of the modules, and coal and lignite combustion leads to much higher emissions of cadmium. Life-cycle cadmium emissions from coal is 3.1 microgram/kWh, lignite 6.2, and natural gas 0.2 microgram/kWh.
Since we mentioned maintenance: Consider that in a reasonably windy place a wind turbine can run 7000 hours or more per year. If it were a car, going at 50 km/h (30 mph), it would travel 350,000 km (or 200,000+ miles). That means you should plan for an annual inspection, and perform the needed maintenance (greasing for example), regardless of the recommendation of the manufacturer. It is just as important to inspect and maintain the tower annually. We know of a tower that collapsed because nuts worked themselves loose from their bolts over 2½ years time, no inspection nor maintenance were done during that time, ultimately leading to its undoing. Wind turbines and towers live in a very harsh environment. It is important to check for issues, such as loose bolts or tower guy wires that need re-tensioning, before they become a problem.
Renewable electricity production, from sources such as wind power and solar power, is sometimes criticized for being variable or intermittent, but is not true for concentrated solar, geothermal and biofuels, that have continuity. In any case, the International Energy Agency has stated that deployment of renewable technologies usually increases the diversity of electricity sources and, through local generation, contributes to the flexibility of the system and its resistance to central shocks.
As suppliers of inverters for turbines good, bad, and just plain ugly, we have pretty well seen it all when it comes to turbine failure. We can tell you unequivocally that you get what you pay for. Depending on your sense of adventure that can be good or bad; if you plan to go cheap, plan on (you) being the manufacturer’s R&D department and test center. Being a really good do-it-yourselfer with an understanding of wind turbines, alternators, and all things electric will come in very handy too. Just in case you do not believe us, you can read about it in this Green Power Talk thread. There are more threads with similar content on the forum, just browse around a little.