Guru
Joined: 09/08/2007
Location: AustraliaPosts: 4406
| Posted: 07:58pm 02 Jul 2017 |
Agree the economic future does not look bright, but personal circumstances can vary a great deal, age, career and marital status, children, mortgage, and so on.
Its not just the inevitable financial and social collapse, but the possibility of nuclear war is also rapidly increasing.
Anything we can do to become more self sufficient and less dependent on "the system" may help to isolate us somewhat.
I am living in suburban Melbourne and hope to become completely grid free over the next twelve months or less.
Doing it in stages, and am gathering data and learning as I go.
First stage currently working now, is to use solar to supplement rectified dc grid power to drive an inverter (without a battery). Its not a conventional grid tie system, it feeds nothing back. At the moment we are right at the winter solstice, but still am getting about 55% from solar even on totally miserably cloudy days.
That rises to about 80% at the summer solstice.
I have sufficient solar input to cover all my daily consumption over about a seven hour period even on the worst solar days. Night time grid consumption over seventeen hours is only about 45% of my total.
Stage two will involve a completely different system that uses a high voltage Lithium battery (100v nominal, from thirty Winston cells) which should see me totally off grid.
I will then have two different systems available, new system and the old system as reserve. So if something blows up or requires maintenance I can do it without going back to 100% grid power.
System three is planned for some time into the future, but the way to get very high system efficiency is to first use a higher voltage battery, and build an inverter that does not require the use of a large toroidal output transformer.
An output transformer greatly increases the zero load idling power, no matter how you go about it, and limits the maximum peak output power.
A much better way would be to directly PWM the battery voltage to create an ac voltage directly, that can be used without requiring a transformer. This will greatly increase the efficiency at very low output load and allow massive peak power demand with good voltage regulation.
There are definite safety issues with this, but a 100v battery is still practical if treated with the utmost respect.
A +100v battery and a -100v battery would not be any more dangerous than a single 100v battery, but supplies 200v between the battery rails.
If we PWM that with a half bridge switcher we can get up to 140 volts rms output directly, referenced to zero volt ground.
Two PWM outputs operating out of phase would provide two voltage regulated 120v outputs, or 240v between. Something like the US power distribution system.
The efficiency would be very high, especially at very low loads, and high dc voltage means low current everywhere in the system. That is what I eventually hope to have.
I also agree that Gold or Silver is a pretty safe store of value, has been throughout all of recorded history, and still is.
Cheers, Tony.