M
Mark Thorson
- Jan 1, 1970
- 0
Now that the blackout has shaken the public's faith in
the electric power industry, we have an opportunity
to make much-needed large-scale changes in how
electricity is distributed.
The system we use now evolved from 19th-century
technology, with patches to adapt it to the rapid
growth which occurred in the 20th century. If we
were creating a new system today, we would never
choose 60 Hz AC. That's almost an ideal frequency
for causing heart fibrillation during an electric shock.
Much better would be the Air Force standard, which
is 115 VAC at 400 Hz. The main reason they chose
400 Hz is not safety, however, but to make transformers
smaller and more efficient. Weight is a major issue
for aircraft.
The Army uses 28 VDC. This is also safer, both because
of the lower voltage and absence of fibrillation hazard.
Edison originally promoted DC electricity in the late
19th century, but it lost out to the AC system because
the transformer technology of the time required AC.
Had the DC system been adopted, the electrical generating
plants would have to be located close to the consumers
of electricity.
We don't have that limitation. With solid-state electronic
switching power converters, we could use high-voltage DC
for distributing power. There would some losses in the switches,
but these are more than compensated by reduced losses in the
transmission lines.
Solar-power enthusiasts often convert their homes to 12 VDC.
That's for compatibility with cheap multicell lead-acid batteries
used to store power.
I propose that now is the time to adopt a new standard.
A DC standard would be best, to reduce the shock hazard.
The voltage should be the lowest practical voltage, both for
the improved safety and perhaps equally important for the
perception of improved safety in the mind of the public.
If you go much below 12V, the wires needed for high-power
appliances become rather thick. If you go much above
28 VDC, the shock hazard from touching exposed live wires
or terminals becomes too high.
the electric power industry, we have an opportunity
to make much-needed large-scale changes in how
electricity is distributed.
The system we use now evolved from 19th-century
technology, with patches to adapt it to the rapid
growth which occurred in the 20th century. If we
were creating a new system today, we would never
choose 60 Hz AC. That's almost an ideal frequency
for causing heart fibrillation during an electric shock.
Much better would be the Air Force standard, which
is 115 VAC at 400 Hz. The main reason they chose
400 Hz is not safety, however, but to make transformers
smaller and more efficient. Weight is a major issue
for aircraft.
The Army uses 28 VDC. This is also safer, both because
of the lower voltage and absence of fibrillation hazard.
Edison originally promoted DC electricity in the late
19th century, but it lost out to the AC system because
the transformer technology of the time required AC.
Had the DC system been adopted, the electrical generating
plants would have to be located close to the consumers
of electricity.
We don't have that limitation. With solid-state electronic
switching power converters, we could use high-voltage DC
for distributing power. There would some losses in the switches,
but these are more than compensated by reduced losses in the
transmission lines.
Solar-power enthusiasts often convert their homes to 12 VDC.
That's for compatibility with cheap multicell lead-acid batteries
used to store power.
I propose that now is the time to adopt a new standard.
A DC standard would be best, to reduce the shock hazard.
The voltage should be the lowest practical voltage, both for
the improved safety and perhaps equally important for the
perception of improved safety in the mind of the public.
If you go much below 12V, the wires needed for high-power
appliances become rather thick. If you go much above
28 VDC, the shock hazard from touching exposed live wires
or terminals becomes too high.