[NCLUG] Re: "Green" power

[John L. Bass]

S. Luke Jones wrote:
> On Sep 13, 2008, at 12:29 PM, danbob wrote:
>> Just as a point of order, Sean, the average utility grid losses as heat
>> in the USA are 9.5 percent, between the power plant and your electric
>> meter. So "almost 100% efficient" is not correct, and that 9.5% is
>> heating the great outdoors.
>> DAN FINK
>
>
> Do you know how much of that is due to "heating up the wires" at night 
> for lack of anything else to do with the power?
This FUD at best, when getting more people to shift loads in time 
resolves the problems you are suggesting. Time-of-Use (TOU) billing 
provides incentives to fix this problem, and save every consumer at the 
same time. I've been on TOU for a couple years specifically to help be 
part of the solution to this long term problem. With PVREA off-peak 
power costs about $0.043/KWHr and nearly $0.13/KWHr on peak. For static 
loads like a 24x7 server this works out pretty close to the $0.085 
normal rate.

Time shifting major loads, like water heating is relatively easy ... an 
Intermatic EH40 timer simply shuts the water heater off during peak 
periods. Morning showers leave the water heater cool for a few hours, 
and it turns back on at 9AM to heat the water displaced by 6:30AM 
showers. I use a heat pump to cool/heat the house, which is also 
disabled during peak hours, that doesn't really have that big effect on 
the temp inside the house even when very cold outside. Those two 
changes, dramatically shifted our families power use into off-peak 
hours. We augment that with doing laundry and dishes off peak as well, 
and making other choices like baking during off peak.

What's left, is CFL lighting, four 30W servers for CWX.net and my 
business, and insignificant other uses. The time shifting saves quite a 
few dollars each year, and helps balance the grid demands. I will 
probably install solar PV to offset the remaining small peak loading.

> As I remember, many utilities offer power at negative cost for large 
> industries that can commit to using a lot of power at night.
references please, that document that assertion for generation and use 
in this area?
> This seems counterintuitive, but is the result of generation in large 
> plants like Rawhide that take two weeks to spin up or down, but use in 
> small appliances like air conditioners, clothes driers, and ... 
> energy-star computers that people put to sleep when they're not in use.
Again, references please, that document that assertion for generation in 
this area?

TOU time shifting resolves part of this problem. The other part is 
resolved by what is unsaid, and that is that most generation plants can 
scale production over a pretty wide range -- matching consumed 
coal/gas/oil to demand, and remain online. So it's not an all or nothing 
problem. Plants I'm familar with can be shutdown in a couple hours, and 
brought back online in about the same. I'm really interested seeing 
documentation about this 2 week number.

> Any discussion of electricity conservation is -- well, not 
> meaningless, but pretty shallow -- if it doesn't consider baseload 
> generation and time-of-day factors.
Does that help?

John