Hot and Solar Review

No blog update for a week.  It has been so hot we have scarcely left the house preferring quietly sit in an air conditioned room.  Yesterday the mercury reached 40+C and today is only slightly cooler.  Apparently this is the hottest November in Perth since records started being kept! 

Not wanting to work outside I've been patiently waiting for a few purchases to arrive from Aliexpress.  Today the bike mobile phone holder arrived.

It came disassembled and without instructions.  Fortunately assembly wasn't too difficult.  It's all metal construction and appears to be well made.

The only issue was the new mobile phone protective case.  The case makes the phone too thick to snuggly fit in the bike holder.  My concern was that the phone might bounce out of the holder.

The back of the phone case has an aluminium plate with a folding metal bracket which allows the phone to be propped at a 30deg viewing angle.  The other aluminium plate slides and covers the phone's rear camera lens.

It looked like the larger of the two plates was secured in each corner with a Torq screw.

That assumption proved to be incorrect.  They were fake screws made of the same "rubbery" material that the case is made from.  Using a razor knife I separated the plate from the case discovering it was glued on.

The case was then thin enough to fit into the bike phone holder

It's too hot to go for a bike ride and test the new holder.

Solar Review

Approximately every two years I complete a review of the cost of our home electricity for the previous two year period.  I'm specifically looking at two areas.  First;  is it possible to reduce our consumption?  Second; is a home battery a financially viable option?

The house has the maximum sized solar array and inverter permitted by State Regulations.  That is; a 6.6kW array and a 5kW inverter.

During daylight we usually generate more electricity than we consume selling the surplus back to the grid electricity provider.  We purchase electricity from the network during darkness.  The cost of purchasing electricity is 400% more per kW that they pay us for our surplus that we send back to the grid.

During the last two years our daily cost for electricity has been $2.15.  Of that $1.04 is the supply charge which is the daily cost of being connected to the network.

I have calculated we would require a 10kW battery to be independent of the the grid.  I estimate the cost of the battery and installation at $15,000.  The battery has a life of 10 years.

My calculations reveal if we installed a battery and remained connected to the grid then it would take 37 years to recover the cost of installing the battery.

Disconnecting from the grid would result in it taking 19 years to recover the cost of the battery.

Obviously installing a battery under the current network supply costs isn't a financial option.

The battery only becomes financially viable if our daily cost was to exceed $4.11.  Deducting the daily supply charge leaves $3.07.  Therefore, we would need to triple our current average daily consumption to make installation of a battery a viable option.  Alternatively, the cost of installing a 10kW battery would need to reduce to $7850. 

Meanwhile, Jan received the latest water bill.  The amount exceeded $200.  However we only consumed $22 of water.  The remainder was the supply charge and the cost of sewage disposal.  The public is being constantly told water is scarce and to conserve it.  Yet we pay more to dispose the sewage!  Surely we should be told to use the toilet less frequently?  Actually the sewage charge is based on the council rates for the property rather than the number of people in the property or the amount of time the toilet is flushed.  Which just goes to prove people in authority believe the more affluent you are, the more effluent you produce!