needing ideas to calculated energy spend per shift

[Former Member]

Hi, i have a problem, im trying to make an transaction that gonna calculate the energy spent per shift, in production line i have an infinite counter that is always increasing.

in the beggining i made an transaction that calculation the energy spent per line and day (http://img9.imageshack.us/img9/6659/transenergy.jpg) and with this SQL :

select trunc(a."DateTime") "DateTime", max(a."Energy") as LINE_ENERGY, "Line_Number"

from z_opc_tags a

where a."Line_Number" = '10111]'

and trunc(a."DateTime") >= trunc(to_date('22.08.2009', 'dd.mm.YYYY') ) and trunc(a."DateTime") <= trunc(to_date('28.08.2009 23:59:59', 'dd.mm.YYYY hh24:mi:ss'))

group by trunc(a."DateTime"), "Line_Number"

order by trunc(a."DateTime") asc

could someone give me little tip to begin....i know that i have to catch the value of shift1,shift2 and shift3 and because the counter is infinite i have to make calculate like...shift1 = shift1......shift2 = shift2 - shift1.. and shift3 = shift3 - shift2 - shift1....i think

regards

Mário

[agentry_src · Accepted solution]

Hi Mio,

I have done some energy KPIs based upon data somewhat similar to what you show. I did mine using calculated tags on a historian rather than in a database. If you have access to a data historian, I think that it might be a better way to go. You would also be able to use actual machine run times to calculate the amount of energy used. It is an indirect measurement that would not be as good as direct meter readings for each machine or production area, but still will allow comparisons between shifts.

Good luck,

Mike

[Former Member]

Some excellent ideas so far. I agree that a historian is the best for this type of data. In addtion. You really should be more interested in power factor, not just kWHr per day. Our sister company does a lot in this area (energy monitoring and management) and what most people overlook when looking at energy costs is that they neglect power factor and simply look at kWhr.

[Former Member]

In most parts of the world, energy prices are not constant throughout the day. To truly get an accurate picture of energy costs or spending, you need to capture or access the historical prices (based on your company's purchasing contract(s) or co-generation costs), and merge these with the consumption history to calculate interval-based pricing.

[Former Member]

Mio,

As Mike suggested it s better to go with historian because it involves huge data as you said in your post.Any way for your current scenario are you trying to calculate energy spent/shift in a day right? So if it is the case you can query your database by shift date range i.e. shift start date and shift end date,call this in transaction and store calculated amount in a xml. Schedule this transaction at the end of the each shift using the scheduler.Call another transaction to get the calculated data on dashboard.

Hope this helps you.

-Suresh