Single room (Garage) electricity costs

pcgtron

Hi all. 

I've got a bit of a conundrum and wondered if you fine folks on this board can help. 
My wife runs a small business, and uses the garage occasionally to make the things she sells. She would like to know if it's possible to see how much energy she is using in the garage whilst working from there. 
Well do have a separate small consumer electricity unit in the garage, with 2 circuits, lights and power. 
I know we can fit tapos on the plugs and monitor energy use that way, but does anyone know of a device that would monitor all the energy used in the garage, lights and power? Is this even possible?

Thanks 

gefnew

You could use some of these connected to garage supply.
energy monitor: Search Result | eBay

Astria

Putting a ct clip around the supply that goes into the garage should measure all electrical current.

markin

Swap the lights for led and don't worry about it again, A tapo on the ext lead would seem the cheapest way.

QrizB

All the options mentioned so far are ok if your interest is simple curiosity

If your wife wants to account for energy use as a business expense you'll need a MID-compliant measurement device, like a proper sub-meter.

pcgtron

QrizB said:

All the options mentioned so far are ok if your interest is simple curiosity

If your wife wants to account for energy use as a business expense you'll need a MID-compliant measurement device, like a proper sub-meter.

It's not really about expensing the electric, but wanting to know how much she's using so as to price her products correctly in the marketplace. Lots of small business owners don't price correctly, and end up selling things with the profit margin being too small and hence not really earning any money from it. She wants to accurately work out the energy used so she can price correctly. 
I'd love to DIY this, so a Ct clip and an energy Monitor taking from the Ct clip would work? Lights are older florescent tubes, but I'm sure I could easily work out how much they pull perhaps hour 

[Deleted User]

pcgtron said:

QrizB said:

All the options mentioned so far are ok if your interest is simple curiosity

If your wife wants to account for energy use as a business expense you'll need a MID-compliant measurement device, like a proper sub-meter.

It's not really about expensing the electric, but wanting to know how much she's using so as to price her products correctly in the marketplace. Lots of small business owners don't price correctly, and end up selling things with the profit margin being too small and hence not really earning any money from it. She wants to accurately work out the energy used so she can price correctly. 
I'd love to DIY this, so a Ct clip and an energy Monitor taking from the Ct clip would work? Lights are older florescent tubes, but I'm sure I could easily work out how much they pull perhaps hour 

A CT around the live conductor into the garage consumer unit should work.

Astria

pcgtron said:

I'd love to DIY this, so a Ct clip and an energy Monitor taking from the Ct clip would work? Lights are older florescent tubes, but I'm sure I could easily work out how much they pull perhaps hour 

Yup, if you take it from the cable that comes into the garage everything will be accounted for, lighting, sockets, fixed appliances, etc.

Something like this would work but is probably overkill, it's just something I've used as I wanted multi ct-clip for different circuits: https://shop.openenergymonitor.com/energy-monitoring/

chris_n

A CT based device without a voltage reference can be horrendously inaccurate. If you have fluorescent lights, switch mode power supplies etc they will be miles out. I have an Owl system in a property I own in UK and it will tell me 350W is being used when in reality it is about 60W. If I switch a 400W heater on when the owl is saying 350W the consumption would rise to somewhere around 460W (switch mode PSUs create harmonics which are damped by the inductive load). You could add a proper meter (like they use for solar) into the supply to the garage CU cheaply, the meters are about £25.

FreeBear

gefnew said:

You could use some of these connected to garage supply.
energy monitor: Search Result | eBay

Be careful with a lot of those listings - Many are for In Home Displays that need pairing with a smart meter. Not a task you can do yourself, and they will only display data for the whole house.

The Owl devices will give an indication of the electricity consumption, but it won't be a true reading in KWh as the gadget doesn't monitor the mains voltage. That said, close enough to get an idea so that the cost can be factored in to the price of the final product.

[Deleted User]

wittynamegoeshere said:

You probably won't be able to electrically split out the sockets and lighting, as both are likely to be on different circuits from the consumer unit and both will likely be shared with other rooms.

This seems unlikely when the OP said they had a separate consumer unit for the garage, with one circuit for lighting and one for power..