Power prices and Mercury's three year fixed plan

Forums › Off topic › Power prices and Mercury's three year fixed plan

1 | 2 | 3 | 4

1081 posts

Uber Geek

#483550 21-Jun-2011 11:09

To confuse things further, your unit price for Powershop is calculated on your ratio of day/night usage (if you have a suitable meter). Your unit price will be higher if you use power mostly during the day. I don't know what the actual formula is but I suspect it something like unit price = base price x (day usage + 0.5xnight usage)/(total usage).
Ie night rate is 1/2 day rate.
If it were possible to buy unlimited units for future use, you could manipulate your unit price one month.

timmmay

20587 posts

Uber Geek

Trusted

Lifetime subscriber

#483571 21-Jun-2011 11:53

StarBlazer: For Example, if you pay 10% more now, it needs to be at least 10% cheaper at the end of the three years and have increased steadily so that the 0% saving is at the mid point - which means you are betting on a 20% increase. If it reaches the 20% increase earlier than 3 years you have saved. If it doesn't, you didn't. When did they last increase their prices and by how much?

Here's a graph of price trends. I can't see it from work (flash issues) but from memory of looking at it last night power rose in the region of 20%.

Skolink: To confuse things further, your unit price for Powershop is calculated on your ratio of day/night usage (if you have a suitable meter). Your unit price will be higher if you use power mostly during the day. I don't know what the actual formula is but I suspect it something like unit price = base price x (day usage + 0.5xnight usage)/(total usage).
Ie night rate is 1/2 day rate.
If it were possible to buy unlimited units for future use, you could manipulate your unit price one month.

I only have one meter, an old one. To put in a new meter could be expensive, as i'd possible have to rewire to the hot water cylinder.

I wonder if a smart meter can do the job of more than one meter.

I use little power during the day, mostly some in the morning and evening for heating. It wouldn't be a problem to shift the time of some power use, such as the clothes drier and maybe turning the heat pump on earlier in the morning. The cost of wiring might outweigh the savings though.

richms

28191 posts

Uber Geek

Trusted

Lifetime subscriber

#483573 21-Jun-2011 11:59

timmmay:
I wonder if a smart meter can do the job of more than one meter.

I use little power during the day, mostly some in the morning and evening for heating. It wouldn't be a problem to shift the time of some power use, such as the clothes drier and maybe turning the heat pump on earlier in the morning. The cost of wiring might outweigh the savings though.

They do, after mine went in 2 months later genisis moved me to a day/night tariff as it worked out cheaper.

No idea how to get the day and night readings out of it, as all it tells me is the house and shed readings, which means pressing a button which is a pain vs the old having 2 meters that I used to have.

Richard rich.ms

timmmay

20587 posts

Uber Geek

Trusted

Lifetime subscriber

#483578 21-Jun-2011 12:06

Did you put the meter in Rich, or did the power company decide to upgrade you? Day/night would be easy, since there's no wiring changes. Putting in controlled hot water would be another saving, but that could be a wiring change.

dolsen

1476 posts

Uber Geek

Trusted

Lifetime subscriber

#483579 21-Jun-2011 12:06

timmmay:

I only have one meter, an old one. To put in a new meter could be expensive, as i'd possible have to rewire to the hot water cylinder.

I wonder if a smart meter can do the job of more than one meter.

I use little power during the day, mostly some in the morning and evening for heating. It wouldn't be a problem to shift the time of some power use, such as the clothes drier and maybe turning the heat pump on earlier in the morning. The cost of wiring might outweigh the savings though.

We changed to a day / night plan at our place. There was, I think, a $60 meter reconfiguration change.
This included removing the "ripple control" box, so, the hot water cylinder became uncontrolled.

timmmay

20587 posts

Uber Geek

Trusted

Lifetime subscriber

#483580 21-Jun-2011 12:10

dolsen:We changed to a day / night plan at our place. There was, I think, a $60 meter reconfiguration change.
This included removing the "ripple control" box, so, the hot water cylinder became uncontrolled.

Can you do that without requiring a new meter? The Meridian pricing pdf suggests it's done by a separate meter.

Having a night rate of 11pm to 7am would probably only reduce my power bill slightly. One load of washing at night, and the heat pump coming on at 6.30 instead of 7am.

richms

28191 posts

Uber Geek

Trusted

Lifetime subscriber

#483587 21-Jun-2011 12:29

timmmay: Did you put the meter in Rich, or did the power company decide to upgrade you? Day/night would be easy, since there's no wiring changes. Putting in controlled hot water would be another saving, but that could be a wiring change.

They did it because they were swapping out them all. The savings of day/night basically offset the added cost of accurate metering over the old spinning disc one.

Richard rich.ms

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

dolsen

1476 posts

Uber Geek

Trusted

Lifetime subscriber

#483589 21-Jun-2011 12:40

timmmay:
dolsen:We changed to a day / night plan at our place. There was, I think, a $60 meter reconfiguration change.
This included removing the "ripple control" box, so, the hot water cylinder became uncontrolled.

Can you do that without requiring a new meter? The Meridian pricing pdf suggests it's done by a separate meter.

Having a night rate of 11pm to 7am would probably only reduce my power bill slightly. One load of washing at night, and the heat pump coming on at 6.30 instead of 7am.

Depends what your current set up is and what the power company needs. At our old place, they still put in a new meter (a digital one but not a smart meter), and, I think they used the ripple control to switch which tariff the meter recorded. The new house already had a smart meter that was capable of recording the new tariff but I believe that on that plan they removed the controlled part of the load so we still needed to have someone come out and change the wiring. All included in the cost of the meter configuration change.

If you were in Christchurch, the genesis energy day night plan times are 9pm-7am, elsewhere it seems to be 11pm - 7am.

It's still worth it to us as we offload a lot of the power to off peak times where we can.

Skolink

1081 posts

Uber Geek

#483603 21-Jun-2011 13:00

timmmay: I only have one meter, an old one. To put in a new meter could be expensive, as i'd possible have to rewire to the hot water cylinder.

I wonder if a smart meter can do the job of more than one meter.

I use little power during the day, mostly some in the morning and evening for heating. It wouldn't be a problem to shift the time of some power use, such as the clothes drier and maybe turning the heat pump on earlier in the morning. The cost of wiring might outweigh the savings though.

When we were previosly with meridian, I calculated we would have saved about $20 over the entire 2009 year being on the 'anytime' (~22c/kWh) single rate compared to the 'day/night' (~13/27c/kWh) rate.
Now that we have solar hot water heating, and use far less power at night, the savings would have been greater.

Our electronic day/night (dual register) meter and seperate ripple controller we replaced by a single Arc Innovations 'smart' meter. It has the ripple control built in, and is configured to have 3 registers - day,night and weekend day. Unfortunetly it cannot measure the controlled load seperately, so to be on a plan like the Meridian 'Anytime Economy' I would need a second smart meter (as the neighbours have).

The smart meter was installed for free by Meridian who are the metering authority for Christchurch.

AFIK it is illegal to NOT have your hot water cyclinder wired through a ripple control relay, for the purposes of emergency load shedding. Maybe your lines comany has different rules, but I doubt it.

richms

28191 posts

Uber Geek

Trusted

Lifetime subscriber

#483613 21-Jun-2011 13:09

Skolink:
AFIK it is illegal to NOT have your hot water cyclinder wired through a ripple control relay, for the purposes of emergency load shedding. Maybe your lines comany has different rules, but I doubt it.

No, that is a choice of tarriff to have it controlled or not. Thats why they have different rates on anytime and anytime composite with genesis and the others have similar things.

You lose the hot water for a few hours a day in exchange for a slightly lower unit price. Made sense when it was 7 and 9 cents, but now its up to 21 and 23c the savings are just not there.

They charge a fee to have them reconfigure it, you cant just change the breaker that the water is on and tell them. Wonder how many people changed the breaker that their water was on during the "power crisis" and never changed it back again.

Richard rich.ms

Skolink

1081 posts

Uber Geek

#483622 21-Jun-2011 13:19

richms:
Skolink:
AFIK it is illegal to NOT have your hot water cyclinder wired through a ripple control relay, for the purposes of emergency load shedding. Maybe your lines comany has different rules, but I doubt it.

No, that is a choice of tarriff to have it controlled or not. Thats why they have different rates on anytime and anytime composite with genesis and the others have similar things.

Wrong. From the Orion website
"Most people install ripple receivers to take advantage of the cheaper pricing plans that are available, and, for electric water heating, it’s mandatory to install and maintain a ripple receiver."
http://www.oriongroup.co.nz/load-management/load-management-information.aspx

It may be that you choose to only have your hot water switched off for emergency load shedding, but you must have it connected to a ripple controller. There is more than one ripple control signal on the network, so you can have night, afternoon boost, all day non-peak, or anytime. There must be a minimum cyclinder size for the requirement to apply, but I haven't looked into what that may be.

richms

28191 posts

Uber Geek

Trusted

Lifetime subscriber

#483625 21-Jun-2011 13:22

Perhaps that's just down there, but in Auckland there is no problem having an install without one, never seen one installed in a business or apartment install either.

Richard rich.ms

timmmay

20587 posts

Uber Geek

Trusted

Lifetime subscriber

#483626 21-Jun-2011 13:24

I have an electrician coming over this week, I can always ask them if I have ripple control installed.

Going to night rates looks like a good option, but having to have another meter is just a pita. If my antique meter's ever replaced then maybe i'll switch.

richms

28191 posts

Uber Geek

Trusted

Lifetime subscriber

#483627 21-Jun-2011 13:26

Dont do anything that results in a meter change if you have an antique one, they underreport non linear loads like computers ;)

Richard rich.ms

timmmay

20587 posts

Uber Geek

Trusted

Lifetime subscriber

#483628 21-Jun-2011 13:27

richms: Dont do anything that results in a meter change if you have an antique one, they underreport non linear loads like computers ;)

Just computers, or things like LCD TVs as well? The main power uses in the house are hot water, heat pump, heaters, then somewhere way behind that computers.

1 | 2 | 3 | 4