How do I know if my meter’s electrical power supply is sufficient? Fun fact: the difference between both outcomes is a factor.1.73! And this is explained by the fact that a 400 V voltage also happens to be 1.73 greater than 230 V. We have used the same number here as well. (*) For quick calculations or for the sake of convenience, √3 is often replaced with the approximate value of 1.73. The formula used to determine the capacity for a three-phase connection of 230 V or 400 V is identical, i.e.: √3 x U x I. So, for instance, if you have a 25A dispenser in place, the maximum capacity is to be calculated as follows*:ģ x 400 + N(eutral wire): √3 x 400 V x 25 A = 17 300 VA The maximum capacity is thus: 230 V x 40 A = 9 200 volt-amperes (9 200 VA) or 9.2 kVA The majority of homes are supplied with 230 volts (V) single-phase with an intensity of 40 amperes (A). To calculate the maximum power that your meter can supply (expressed in volt-amperes), multiply the voltage (U) by the intensity (I) of the current that supplies your home. How do I calculate the maximum power that my electrical installation can supply? If you have special installations that consume a lot of energy, such as a sauna, pottery kiln or electric car, then that power might not be sufficient. As you never use all your electrical appliances at once, your basic installation should, in practice, more than suffice. In theory, this allows you to simultaneously supply devices with a maximum power of 9.2 kW or 9200 watts. Peck of Seward, Alaska and will be printed in the March 2009 issue of Scientific American.During normal energy use, the power supplied by your meter ( 9.2 kVA on average) should suffice.
Breeder reactors could match today's nuclear output for 30,000 years using only the NEA-estimated supplies.Įditor's Note: This question was submitted by G. Second, fuel-recycling fast-breeder reactors, which generate more fuel than they consume, would use less than 1 percent of the uranium needed for current LWRs. First, the extraction of uranium from seawater would make available 4.5 billion metric tons of uranium-a 60,000-year supply at present rates. Neither is economical now, but both could be in the future if the price of uranium increases substantially. Two technologies could greatly extend the uranium supply itself. Taking both steps would cut the uranium requirements of an LWR in half. And separating plutonium and uranium from spent LEU and using them to make fresh fuel could reduce requirements by another 30 percent. Using more enrichment work could reduce the uranium needs of LWRs by as much as 30 percent per metric ton of LEU. Further exploration and improvements in extraction technology are likely to at least double this estimate over time. About 10 metric tons of natural uranium go into producing a metric ton of LEU, which can then be used to generate about 400 million kilowatt-hours of electricity, so present-day reactors require about 70,000 metric tons of natural uranium a year.Īccording to the NEA, identified uranium resources total 5.5 million metric tons, and an additional 10.5 million metric tons remain undiscovered-a roughly 230-year supply at today's consumption rate in total. Most of the 2.8 trillion kilowatt-hours of electricity generated worldwide from nuclear power every year is produced in light-water reactors (LWRs) using low-enriched uranium (LEU) fuel. If the Nuclear Energy Agency (NEA) has accurately estimated the planet's economically accessible uranium resources, reactors could run more than 200 years at current rates of consumption. Steve Fetter, dean of the University of Maryland's School of Public Policy, supplies an answer:
How long will global uranium deposits fuel the world's nuclear reactors at present consumption rates?