Accurate monitoring of power consumption

[mrnaz]

Hi there,
I am looking for a very accurate and cheap metering solution so that I can measure the actual power used by a house. The arrangement is grid tied, so there is already a power meter upstream of the invterter, but I was hoping that there was a way to monitor the total power consumed by the house.

Ideally, I would like to get enough data to be able to calculate the bill that the house *would* have got, had the power come from the grid.

The initial idea I had was to simply install another power meter between the inverter and the house. However, I'm sure there are inverters out there can can give meter-quality data output, and if there are, I would perhaps connect a small PC up to it and get it to read the power load every second and keep that in a database, but I'm not sure if that's a good idea. Perhaps there are inverters can can actually measure kWh used, which would be more accurate than spot metering at any granularity.

The data needs to be able to be collected by a PC running Linux (I'll put a small Linux box such as a SheevaPlug or one of those new exciting Raspberry Pi boards) which I can physically collect data from. I may even connect it to a GSM module and have it email the data to me via GPRS, but that's something I can solve myself. The part I'm not yet familiar with is the data collection.

What are the best solutions available to accurately measure power consumption by a whole household, including totals and time of day measurements?

[Sunking]

Well your GTI should have that built into it already., or you can just buy a meter that the POCO uses, but they are expensive.

[Naptown]

Well your GTI should have that built into it already., or you can just buy a meter that the POCO uses, but they are expensive.

Check out Hialeah (sp) meter They have refurbished revenue grade meters for about $30.00 and pans for like $40.00

[mrnaz]

Well your GTI should have that built into it already., or you can just buy a meter that the POCO uses, but they are expensive.

Yea I did know that, however, are GTI's accurate enough to supply billing grade data?

[bobfromnj]

Hi there,
I am looking for a very accurate and cheap metering solution so that I can measure the actual power used by a house. The arrangement is grid tied, so there is already a power meter upstream of the invterter, but I was hoping that there was a way to monitor the total power consumed by the house.

Ideally, I would like to get enough data to be able to calculate the bill that the house *would* have got, had the power come from the grid.

The initial idea I had was to simply install another power meter between the inverter and the house. However, I'm sure there are inverters out there can can give meter-quality data output, and if there are, I would perhaps connect a small PC up to it and get it to read the power load every second and keep that in a database, but I'm not sure if that's a good idea. Perhaps there are inverters can can actually measure kWh used, which would be more accurate than spot metering at any granularity.

The data needs to be able to be collected by a PC running Linux (I'll put a small Linux box such as a SheevaPlug or one of those new exciting Raspberry Pi boards) which I can physically collect data from. I may even connect it to a GSM module and have it email the data to me via GPRS, but that's something I can solve myself. The part I'm not yet familiar with is the data collection.

What are the best solutions available to accurately measure power consumption by a whole household, including totals and time of day measurements?

Don't know if this is very accurate and it only works with Windows, or Mac, might be worth looking into. I might even look at it myself.

http://www.efergy.us/

[russ]

Yea I did know that, however, are GTI's accurate enough to supply billing grade data?

Unless they specifically state the class they are not - I would be surprised if they are.

Like Rich pointed out - a revenue grade meter is not costly - here I pay 20$ US for a new single phase meter.