Off Peak Vs Time of Use.

Caban
Super Nova
2 Replies 2526 Views

Some musings here for those interested in the economy of their systems.

 

In days of yore I had two analogue meters. One was Main power and the other one was Off Peak power. On the Off Peak I had the Solar HWS Booster and the Pool Pump supplied. This would save money as those loads would be active when that power was available, late at night and weekends.

 

When my system was updated with Solar Panels and a Battery (late 2013) there was a digital Time of Use meter fitted the old Off Peak meter remained, though the pool had stopped operating it still supplied the HSW Booster. I would only require the booster on less than 10 days a year so it was unused most of the time.

 

When I assessed my usage in order to find the best package I made a spreadsheet which would estimate to cost tailored to my own energy usage. Having a battery it became evident that the most significant figures were the daily charges and the Feed In Tariff.

 

The daily charge for the Off Peak had to be weighed against the slightly lower cost of the supplied power. If my memory serves me I was using about 6kWh per quarter it was costing me 12c a day. I was saving only 2c a kWh ver the TOU rate. My off peak usage would need to be huge to make that viable. I requested that the circuits on the Off Peak meter be shifted to the general meter. I switch the HWS Booster on only when required.

 

The point I am making is that too often we can get fixated on the charge per unit of power or the feed in tariff but neglect the daily charge. A simple spreadsheet can unlock the best path.

11 REPLIES 11
Caban
Super Nova
0 Replies 353 Views

@profdraper 

The battery I have is LTO (Lithium Titanate) which is much more stable than other Lithium Chemistries and not vulnerable to thermal runaway. It also has a greater longevity. The set I have are under warranty for 20 years, so will still be covered when Musk Walls need to be replaced.

Lester
Powerhouse
0 Replies 344 Views

"I’m pretty sure AGL or any energy company is going to pick up on this option 2 battery pattern quickly, then quickly shift the plan to something else that suits them better &  makes them more money.

 

no such thing as a free lunch & track record shows they absolutey cannot be trusted ..,"

 

This is why I like the concept of option 2 with a battery / inverter set up ready to just add some good panels.

Changing the rules as they (suppliers and retailers, along with govco policy) go is just not a good environment to make set decisions and investments by people to save themselves in the long term.