FYI: Energy related terminology and definitions
Fuel cells – A fuel cell is a device that converts chemical energy directly into electricity via a modified oxidation process. The process also produces heat, water and possibly carbon dioxide depending on the fuel used. The different varieties of fuel cells are distinguished by the electrolyte used, though the construction of the electrodes is also different in each case. However, in all types, there are separate reactions at the anode and the cathode, and charged ions move through the electrolyte, while electrons move round an external circuit. There are five types of fuel cells. They differ by the chemistry temperature they operate on, catalysts used and raw fuel input.
Geothermal Energy – Energy harnessed from stored thermal resources of the Earth. The most common application of geothermal technology is to use superheated water and steam from circulation pipes that extend into the ground for use in a turbine to generate electricity. Classic geothermal electricity generation plants exist in California and Iceland. Although not completely renewable by pure definition the thermal resources of the Earth are so enormous that at current scales, geothermal is often classed with renewable energy. Of course being non-fossil based also places geothermal in the clean energy space.
Hydrogen - The real opportunities and the paradigm shift of how we use and transport energy, of which hydrogen holds promise, are buried under a pile of media hype and mere myths that have thus far caused only a lot of public excitement. These unfounded expectations have resulted in subsequent disappointments so the whole industry of ‘hydrogen as energy source of the future’ goes through up and down cycles, driven by public perception as much as by technical breakthroughs, which are significant. Ardour Capital has been trying to dig through this pile of misconceptions to find the real opportunities in the hydrogen world and to help its clients survive the cyclical changes that are typical for an emerging industry. Here are some interesting facts about hydrogen. Hydrogen was ‘discovered’ by Sir William Grove in 1839, the same year he discovered the fuel cell. In the early 1900’s a hydrogen/methane mixture called “town gas” was used in the US for lighting and heating. Hydrogen is a commodity used extensively and safely in the chemical industry. In the United States, it is produced at a staggering rate of approx 4 billion SCF per day. Wide flammability range, difficult detection and low ignition energy means that hydrogen must be respected. On the flip side, its low viscosity, high diffusivity, high molecular velocity, and low energy density suggest that a hydrogen fire may be easier to prevent and/or contain than that of natural gas, LPG or gasoline. Hydrogen is available today. Intermediate cost hydrogen (<$0.75/kWh) is available in the form of welding cylinders, but generally requires sizeable demand in a concentrated geographic location. Low cost hydrogen (<$0.20/kWh) is potentially available in locations where there are existing pipelines or large reforming operations. One welding-size cylinder of hydrogen contains approximately as much energy as one gallon of propane.
Micro Turbines – Micro turbines are small gas turbines used to generate electricity. Basically about the size of a refrigerator, they typically have power outputs in the range of 25 to 300kW. In comparison, large power stations are entire buildings and have much higher power outputs of around 600MW to 1000MW. The small size of micro turbines is a major advantage that allows them to be situated right at the source of electricity demand. This eliminates energy losses that usually occur when transmitting electricity from power stations. Such transmission losses are quite significant and can easily amount to 7% of the power generated.
Solar – Solar power is a technology that converts radiant light energy to electricity. It is most closely associated with solar power. Photovoltaic cells are the basic building blocks of this energy technology. These cells are made of semiconductor materials such as silicon. The amount of electricity a photovoltaic cell produces depends on its size, its conversion efficiency, and the intensity of the light source. As you would imagine, sunlight is the most common source of the energy used by photovoltaic cells to produce an electric current. There are also myriad companies that produce supporting products to the major OEMs: power electronics, bi-polar plates, control and monitoring systems and software, etc.
Wind – Using the Earth’s wind resources is as old as human history in that sailing, milling and pumping water date well back in time. However by modern definition wind power refers to using energy stored in the kinetic motion of wind to turn a turbine to make electricity. Wind is a multi billion dollar business today and is poised to continue growing as political and financial incentives appear to keep it at the forefront of renewable energy installations. It is now not uncommon to see plans for single-tower wind turbines of 5 mega Watts (MW) for application in off-shore wind farms that can approach 400 MW. |
