# Forum Home Renovation Solar Electrical Systems  Solar PV driving regular Hot Water System

## pellicle

Hi  
Now that 1) the rebate is gone and 2) my off peak has gone up hugely I'm just wondering if anyone has done any calculations on using a Photo Voltaic solar system to power just your regular electric hot water system?  
I realise that its only going to generate electricity during portions of the day, and nothing on overcast or rainy days. However I'm wondering about using it to drive my HWS.  
I could then draw upon my existing Off Peak for 'topup' on low Solar Energy days.

----------


## Uncle Bob

I reckon if you want to just heat water a solarhart type collector would be more efficient.

----------


## cyclic

> Hi  
> Now that 1) the rebate is gone and 2) my off peak has gone up hugely I'm just wondering if anyone has done any calculations on using a Photo Voltaic solar system to power just your regular electric hot water system?  
> I realise that its only going to generate electricity during portions of the day, and nothing on overcast or rainy days. However I'm wondering about using it to drive my HWS.  
> I could then draw upon my existing Off Peak for 'topup' on low Solar Energy days.

  The 44 cent rebate does not end before close of business July 9, so you can still get your application into Energex through a Solar supplier before then. 
Once the form is into Energex,you then have 12 months in which to get your Solar installed.

----------


## Bloss

Numbers will simply not add up. Best to convert to solar HWS by adding a conversion kit of your electric is not too old (ie: < than 5 years) or else get a fully new solar HWS - see here for example: SHW-evacuated tube solar hot water.

----------


## pellicle

> Numbers will simply not add up. Best to convert to solar HWS by adding a conversion kit of your electric is not too old (ie: < than 5 years) or else get a fully new solar HWS - see here for example: SHW-evacuated tube solar hot water.

  which is of course logical if I'd thought of it. I'm not sure if our system is young enough. Will see. 
Actually I'd been looking at the evacuated tubes for another purpose! 
Thanks

----------


## Smurf

Technically it can certainly be done, but isn't economic compared to the alternative options. 
That said, someone clever with computers and electronics could theoretically design a system to use the regular HWS, supplied with variable voltage to control load, as a means of adjusting household load in order to use all solar power generated during the day and export none to the grid. This would be profitable in places where the feed in rate is well below the rate charged for off peak, or even zero.

----------

