Subject: From: Date:

Re: [ECS] Load Control LEC1964.aol.com Mon, 13 Jul 1998 20:27:27 EDT

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Dan & Mike,
     Maybe this will help to understand the concepts of Load Control (Load
Management) as I know it.
     From the beginning, all electric utilities have strived to reduce their
operating costs and their capital expendatures. They knew that building new
power plants and expanding delivery facilities to meet ever increasing
"demands" especially peak demands was very costly. Their analysis showed when,
where, and how these demand loads presented themselves. Certain time periods
during the day, that vary seasonally, can be designated as high or "On Peak"
and a periods of low or "Off Peak" could also be identified. They also
understood that by offering customers a reduction in their overall energy
costs (a lower energy charge) they could encourage customers to shift their
energy loads to a different time, quantity or both. As a result, various
"rates" were created.
     Most utilities offer several "Rate Schedules" for residential as well as
business customers. For example, they may include: (1) Standard Residential.
(2) Residential time of use. "TOU". (3) Residential time of use with demand.
"TOU with demand". (4) and possibly a  residential standard rate with demand.
     The TOU is the easiest to explain. If your on the TOU rate your power
costs during the "Peak hours" say from 12 noon till 9 pm will cost you more
than the "Off Peak hours" which are defined as the remaining portion of the
day in most Rate Schedules. You could have more than two "periods" but this is
unlikely. The incentive to change from your existing standard rate or to stay
on a TOU rate would be the fact that the charge for the Standard residential
power use is higher than the TOU Off peak, but lower than the TOU On peak.
Theoretically, if your on TOU and used only power during the Off peak there
would be significant savings over a Standard Rate. On the other hand if you
used all of your power only during the On peak you bill would higher than the
Standard Rate. Clear as mud, right?
     A load control might refuse or limit use of certain high energy
appliances during On peak periods. This could include clothes dryers, water
heaters, cooking stoves, and of course air conditioning systems. This is not
something for everybody. It will obviously change your life style.
     The use of demand Rate Schedules adds an additional level of complexity
depending on how the utility structures those rates. Each utility has some
sort of document or booklet that describes their Rates Schedules. You have to
request it.
     Generally, the "Load Demand" is the averaged power used over the
"Interval". The interval is a finite time period. Say the interval is 30
minutes. Power use goes up and down during that particular interval and is
averaged and recorded as the "Load Demand" in your watthour meter. The
utilities Rate Schedule will define a Demand value, in kilowatts, that if
exceeded will escalate your energy charges which of course is the the
incentive for keeping your "Load Demand" low. Once again "Load Management"
would restrict certain types of electrical devices from operating during any
one interval.
      For myself, I have an interest in the telemetry and have several uses
for it. I am exploring the possibility of some form of load control. No
decision yet.
      If your still interested in the hardware additions and the ECS Events
for the telemetry, I will attempt to give you what ever it is you might want
in these areas. It will take some effort for me to figure out my math
hopefully you won't ask me to much in that area. Please be aware that opening
your breaker panel is very dangerous. If you have a friend you are VERYsure
can handle that work or if you can, no sweat. Otherwise, see if you can get
your utility to give you a contact off the meter or use the "Power Sentry".
      Hopefully, this has been of some help.

Larry C.

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