0 Members and 1 Guest are viewing this topic. Read 5927 times.
I used to think this, too, but to my surprise discovered that DC transmission is much more efficient in terms of losses en route and cost of transmission towers and equipment—so much so that it can offset the extra cost of AC/DC and DC/AC conversion at each end. It is the system of choice for very long distance transmission because of this. It also vastly simplifies the connection between different grid systems as must occur to share loads (the AC can be synchronized easily to the local grid during the DC/AC conversion process. Imagine the process of trying to synchronize the AC of all the systems connected in a continent-wide grid system. (I don't want to think about it).Here's a great encapsulation of some of the considerations:https://en.wikipedia.org/wiki/Electric_power_transmission#High-voltage_direct_current
There are no DC transmission lines around here. Pretty hard to change voltage without a transformer, and that requires AC.
Most folks use a DSP based sinewave generator with a DAC to power amp. That is why they are crystal controlled for the master clock to divide down to 60Hz in the US. Any 16 bit DAC with an output filter will do better than something like an analog Wein bridge oscillator for stability and lower distortion 60Hz sinewave generation. The older Power Plants used that DSP/DAC technology to feed linear PA's for the balanced output. They had lower distortion, but lower output power than the newer units. Probably switched to PWM at some point in the newer units. Much more efficient than the 50% power conversion rate of the original PP's. My P300 dissipated 600 watts for 300 watts output. IIRC, the PPP is around 80% efficient at conversion.
I would recommend you stay away from Generac generators they don't have a good rep in off the grid.
Did you have a good read of the link? DC high voltage power transmission is more efficient than AC. The twist is that the converters needed at each AC/DC conversion are more expensive than transformers and so AC makes more sense for shorter runs.I think most of us know that changing voltages with a transformer requires AC, and that transformers don't work with DC. My point was that the efficiency of transmission of DC (in terms of transmission losses and construction costs) is so much higher than that of AC, contrary to my (and your) prior understanding, that the extra cost of the converters at each end of the transmission line is more than covered on long runs.This was a revelation to me when an electrical engineer, father of a friend of mine, who was involved in designing transmission systems was answering some of my queries about 40 years ago. Up until then I also thought AC was the only system used. I was asking about details on the long underwater link between Vancouver Island and the mainland, which carries most of the power for the entire island about 60km underwater. I was surprised that DC was used and also that it was so efficient. I can't remember the figures, but the losses were amazingly small.Here's a quote from the Wikipedia article on this page: https://en.wikipedia.org/wiki/Electric_power_transmission#High-voltage_direct_current"High-voltage direct current (HVDC) is used to transmit large amounts of power over long distances or for interconnections between asynchronous grids. When electrical energy is to be transmitted over very long distances, the power lost in AC transmission becomes appreciable and it is less expensive to use direct current instead of alternating current. For a very long transmission line, these lower losses (and reduced construction cost of a DC line) can offset the additional cost of the required converter stations at each end."also:"HVDC is also used for submarine cables because AC cannot be supplied over distances of more than about 30 kilometres (19 mi), due to the fact that the cables produce too much reactive power[citation needed]. In these cases special high-voltage cables for DC are used. Submarine HVDC systems are often used to connect the electricity grids of islands, for example, between Great Britain and continental Europe, between Great Britain and Ireland, between Tasmania and the Australian mainland, and between the North and South Islands of New Zealand. Submarine connections up to 600 kilometres (370 mi) in length are presently in use.[22]"
What about an entirely solar-power based home???
