EM 500 Meter - Does my solar go directly to my house?

[Dan_p]

I am getting very frustrated. I cannot get a straight answer.

I have installed a 2kw solar system at my place and now have two EM 500 meters, one export and one import.

My question is, Is any of the solar power I have going directly into my house?

Or is it all going back to the grid and and what we are using is coming from the grid.

I have had different responses and info on the internet is rubbish. Here is a copy of the search I have tried in google.

http://www.google.com.au/search?q=e....,cf.osb&fp=e325bd1c2d99c923&biw=1366&bih=664

Seem to just get sales sites.

My answers so far have been:

A) Sales person: All solar power is used by the house as soon as it is produced.

B) Phase two electician who connected the meters: we use the power immediately, might not even use from the grid.

C) Electrician family member: Mostly the electricity goes back to the grid as the power coming form the panels is not constant enough to run things in the house.

A and B are similar answers. C makes the most sense. I need to know is the solar even wired to go to the house or does it just only go straight back to the grid.

I cant go on without the right answer. It should be a simple answer, right?

 

[Tigger]

Don't talk to me about solar power. We had it installed, for 14 months we saw little to no benefit to our bills. Our use didn't change. Your Q was one of several I had and could never get an answer to. Power supplier couldn't/wouldn't help with our problem. Ditto for electricity ombudsman. It's been over 12 months since we moved out, they are supposed to archive their data for 7 years but now I find they don't so have no way of getting our raw data to analyse. We're not the only ones with this problem either.

If you get an answer please let me know, I still think something was dodgy with wiring or meter or similar but I can't prove it. Why are you asking? Are your bills 'odd'?

 

[Dan_p]

Don't talk to me about solar power. We had it installed, for 14 months we saw little to no benefit to our bills. Our use didn't change. Your Q was one of several I had and could never get an answer to. Power supplier couldn't/wouldn't help with our problem. Ditto for electricity ombudsman. It's been over 12 months since we moved out, they are supposed to archive their data for 7 years but now I find they don't so have no way of getting our raw data to analyse. We're not the only ones with this problem either.

If you get an answer please let me know, I still think something was dodgy with wiring or meter or similar but I can't prove it. Why are you asking? Are your bills 'odd'?

We only got it hooked up yesterday and I am trying to understand the basic set-up.

I think (without any proof) that all of the electricity made by the solar panels goes back to the grid, regardless of whether we are using power at that time or not. Then all of the power we use is coming from the grid.

But I may be wrong. I am sure there is a simple answer but I havent been able to get one and it is frustrating me.

 

[HiEquity]

The simple answer is that every generator on the grid supplies every load on the grid. And the total generation and the total load on the grid are always balanced at any point in time, which is why the frequency stays at 50Hz.

You are part of an interconnected power system - it's impossible to distinguish which electrons go where. The only relevant questions are:

1) How much electrickery are your panels producing over the billing period? Read the export meter for this.
2) How much electrickery is your house using over the billing period? Read the import meter for this.

Depending on whether you are being net or gross metered, you can then work out your bill.

Think of it like water - if your house was both producing and using water, sometimes you would produce more than you use and sometimes less and there would be a lot of mixing between grid water and your own - does it really matter whether the water you produced is the water you use? It's all water at the end of the day...

 

[Dan_p]

The simple answer is that every generator on the grid supplies every load on the grid. And the total generation and the total load on the grid are always balanced at any point in time, which is why the frequency stays at 50Hz.

You are part of an interconnected power system - it's impossible to distinguish which electrons go where. The only relevant questions are:

1) How much electrickery are your panels producing over the billing period? Read the export meter for this.
2) How much electrickery is your house using over the billing period? Read the import meter for this.

Depending on whether you are being net or gross metered, you can then work out your bill.

Think of it like water - if your house was both producing and using water, sometimes you would produce more than you use and sometimes less and there would be a lot of mixing between grid water and your own - does it really matter whether the water you produced is the water you use? It's all water at the end of the day...

I guess it doesnt really matter, but I am curious now. Do you think the solar power runs down a cable back to the street ie through the export. It might not go all the way to the grid but what I am trying to distinguish is that does it leave my house first and then come back?

 

[HiEquity]

I guess it doesnt really matter, but I am curious now. Do you think the solar power runs down a cable back to the street ie through the export. It might not go all the way to the grid but what I am trying to distinguish is that does it leave my house first and then come back?

OK, a quick lesson in Electricity 101. Normally, let's say there is 10A of current coming down your street. Then lets say your solar panels produce 2A. This serves to actually reduce the current flow down your street to 10-2=8A. If your panels and your neighbours' panels produced 10A then the net flow would be 10-10=0A. There would be no current coming down your street but you would still be using 10A worth of current (and consequently power...).

This is meant to be one of the advantages of solar - the power losses in the cables in your street and elsewhere further back increase in proportion to the square of the current so the losses at 8A are 8^2/10^2=0.64x the losses at 10A. So the value of electricity produced at a load is higher than electricity produced at a power station. But we're only talking about the value of the losses here (not the electricity itself) and there are established mechanisms for recognising this value. It usually isn't as much as some might argue..

Hope this helps...

 

[Dan_p]

Hiequity, thanks for your response.

So in summary what comes off my solar panels goes to the street then I get it back straight away.

I am right in saying there is no cable going from my solar panels straight to my house, it goes to the street first.

Forgive me, I am incredibly thick

 

[HiEquity]

That's OK - let's go back to the hose analogy.

If there is 10 litres per min normally coming from the street and you start putting 2 litres per min into the hose at your end, then the flow just reduces to 8 litres per min. Your water gets mixed with the grid water and is physically indistinguishable from each other but the contribution of each and the resultant flow can still be measured and metered.

It doesn't go to the street and then come back, it just reduces the flow towards you. At times the flow will go back the other way and other times (at night) the flow is all towards you. The hose that connects you to your street to import power is the same hose you export through - it's only the net flow that matters. The water doesn't actually need to "go" anywhere.

Hope this helps...

 

[devank]

Isn't it how it is feed-in tariffs configured? Meaning 'Net' or 'Gross'. I connected when 2 or 3 years back and this is my vague understanding.

Because I have the 'gross' system all the solar generated electricity goes to the grid. All my house usage comes from the grid. My bill shows how much I use and the charges for it. Similarly how much I sold and the credit for it.

I believe 'net' means that the generated power is used by the house first. What ever left over is then sold to the grid.

 

[HiEquity]

Isn't it how it is feed-in tariffs configured? Meaning 'Net' or 'Gross'. I connected when 2 or 3 years back and this is my vague understanding.

Because I have the 'gross' system all the solar generated electricity goes to the grid. All my house usage comes from the grid. My bill shows how much I use and the charges for it. Similarly how much I sold and the credit for it.

I believe 'net' means that the generated power is used by the house first. What ever left over is then sold to the grid.

Hi devank

You are referring to the basis of how the billing is calculated (on total production from the panels or just the bit in excess of your own consumption). Both systems are in place in Australia so only the OP knows which one applies here.

I believe the OP's question relates to what is physically happening rather than how the bill (or credit) is calculated. This of course is not dependent on the metering method chosen.

 

[Dazz]

You are part of an interconnected power system - it's impossible to distinguish which electrons go where.

....but what about my Japanese made double layered solar panels that produce twice as much electrons as others (they only cost 1.9x as much to buy and install).

They also have little 'H' signs on them for identification.

How can I keep my little double electrons with the pure 'H's on them, without them getting all contaminated with the dirty little single electrons running up and down the street constantly. The little babies I produce are pure, and need to stay that way.

Help, I'm confused. Shouldn't I be charging a premium for my pure double electrons ?? The Synergy man wouldn't take me seriously. The Japanese manufacturer who sold it to me warned me about those Synergy men, apparently they are all cookoo.

 

[Dan_p]

That's OK - let's go back to the hose analogy.

If there is 10 litres per min normally coming from the street and you start putting 2 litres per min into the hose at your end, then the flow just reduces to 8 litres per min. Your water gets mixed with the grid water and is physically indistinguishable from each other but the contribution of each and the resultant flow can still be measured and metered.

It doesn't go to the street and then come back, it just reduces the flow towards you. At times the flow will go back the other way and other times (at night) the flow is all towards you. The hose that connects you to your street to import power is the same hose you export through - it's only the net flow that matters. The water doesn't actually need to "go" anywhere.

Hope this helps...

Right, so I am using my solar power first before it hits the grid.