Solar contractors face many decisions when it comes to finding the best solar design. One important consideration is determining whether to use module-level power electronics (microinverters or DC optimizers). Once costly specialty products, module-level power electronics have made great strides in the last decade and are rapidly growing in popularity. And there’s good reason for…
The home wind Generator systems are designed for reliable power output for the next 30 years or so. With every price increase of the utility company power your investment gets better all the time. Utility costs are rising all over and will accelerate over the next few years. We expect the cost of electricity to rise and double over Obamas term in office due to cap and trade and increased regulation and market pressure.
Kits (3) Wind Turbine Products (91) - Wind Turbines (14) - Primus Wind Turbines (2) - SkyMAX Wind™ Turbines (1) - Wind Turbine Blades (16) - Wind Turbine Hubs & Hub Adapters (7) - Wind Turbine PMAs & PMGs (20) - Wind Turbine Tails (2) - Brake Switches (5) - Diversion Dump Load Resistors (8) - Wind Turbine Hardware (18) Hydro Products (6) - Freedom & Freedom II Hydroelectric PMGs (2) - Hydro Parts & Accessories (4) Solar Products (71) - Solar Panels (9) - Solar Panel Kits (3) - Solar Charge Controllers (35) - Solar Panel Mounting (23) Charge Controllers (79) - Wind Turbine Charge Controllers (1) - MidNite Classic MPPT Charge Controllers (13) - Solar Charge Controllers (35) - Wind & Solar Hybrid Charge Controllers (34) - SkyMAX Wind Hybrid Charge Controllers (1) Power Without Batteries (3) Power Inverters (134) - Micro Inverters (4) - Transfer Switches (1) - UL Certified DC to AC Power Inverters (12) - Grid Tie Feed Inverters (28) - Low Frequency Inverter Chargers (41) - Modified Sine Power Inverters (28) - Pure Sine Wave Inverters (24) - Inverter Cables (16) - 220 Volt 50 Hz Inverters (2) - Power Inverter Remotes (7) Cable & Electrical Components (130) - Disconnect Switches (4) - Steel Enclosures (3) - Cable, Terminals, & Connectors (69) - Fuses & Breakers (23) - Surge Protection (2) - 3 Phase Rectifiers (9) - Blocking Diodes (7) Renewable Energy Appliances (16) - Solar DC Powered Chest Freezers (7) - DC Ceiling Fans (1) - LED Lights (2) - Other (6) DC and AC Meters (23) - Amp Meters (12) - Volt Meters (9) - Watt Meters (2) DC Water Heater Elements (6) Pond Aeration (26) - Aeration Kits (10) - Air Pumps (7) - Hoses & Accessories (10) DC to DC Step Down Converters (7) Batteries (29) - Flooded Lead Acid Batteries (5) - Lithium Ion Batteries (2) - Sealed AGM Batteries (4) - Battery Accessories (11) - Battery Desulfators and Chargers (7)
“New Wind May Be Cheaper than Old, Reliable Coal” • Wind farms have cost less to build and operate than coal-fired power plants for some time. The trend of lower costs for renewables has crossed a threshold: it is sometimes cheaper to build a brand new wind facility than keep an old coal plant burning, according to Lazard Ltd. [Casper Star-Tribune Online]
In 2016, the city bought its way out of a contract providing energy derived from fossil fuels and arranged to get its power from a 97-unit windfarm in Adrian, Texas, about 500 miles away in the Texas Panhandle. Georgetown doesn’t own the farm, but its agreement allowed the owners to get the financing to build it. This spring, Georgetown is adding power from a 154-megawatt solar farm being built by NRG Energy in Fort Stockton, 340 miles to the west of the city.
In 2007, the world's first turbine to create commercial amounts of energy using tidal power was installed in the narrows of Strangford Lough in Ireland. The 1.2 MW underwater tidal electricity generator takes advantage of the fast tidal flow in the lough which can be up to 4m/s. Although the generator is powerful enough to power up to a thousand homes, the turbine has a minimal environmental impact, as it is almost entirely submerged, and the rotors turn slowly enough that they pose no danger to wildlife.
Above this rated speed, the wind loads on the rotor blades will be approaching the maximum strength of the electrical machine, and the generator will be producing its maximum or rated power output as the rated wind speed window will have been reached. If the wind speed continues to increase, the wind turbine generator would stop at its cut-out point to prevent mechanical and electrical damage, resulting in zero electrical generation. The application of a brake to stop the generator for damaging itself can be either a mechanical governor or electrical speed sensor.
“What Changes Will Maine’s New Government Bring to Your Life?” • Swept to sizable majorities in last week’s elections, Maine’s Democrats will be in full control of state government for the first time since 2010. They are likely to look for ways to address a number of pressing issues, one of which is climate change. [Kennebec Journal & Morning Sentinel]
Climate change concerns coupled with high oil prices and increasing government support are driving increasing rates of investment in the sustainable energy industries, according to a trend analysis from the United Nations Environment Programme. According to UNEP, global investment in sustainable energy in 2007 was higher than previous levels, with $148 billion of new money raised in 2007, an increase of 60% over 2006. Total financial transactions in sustainable energy, including acquisition activity, was $204 billion.
This discussion is mainly about factory-made grid-tie wind turbines. The off-grid crowd has an entirely different set of decisions and goals. The main ones are that for off-grid use economic viability in comparison with the electrical grid is not an issue, and a wind turbine can make up for the loss of sunlight (and PV electricity) in the winter months. For the DIY group there are several good turbine designs available; Hugh Piggott and the two Dans have written books that outline this step-by-step. Building your own turbine can be a great hobby, and some of the topics touched below apply (such as proper site selection), but this discussion is not about those. The decisions involved in making your own turbine, and the cost basis, have little overlap with a the process of having an installer put a factory-made turbine in your backyard.
A parabolic trough consists of a linear parabolic reflector that concentrates light onto a receiver positioned along the reflector's focal line. The receiver is a tube positioned along the focal points of the linear parabolic mirror and is filled with a working fluid. The reflector is made to follow the sun during daylight hours by tracking along a single axis. Parabolic trough systems provide the best land-use factor of any solar technology. The SEGS plants in California and Acciona's Nevada Solar One near Boulder City, Nevada are representatives of this technology.