Are you optimising the consumption of your invaluable photovoltaic energy? It all starts with being aware of the peak solar times (when maximum PV energy is generated)… and saving it up for later!
Most solar in WA is installed on residential households so whether you’re a business owner or not, you might have PV panels at home and want to listen up!
PV systems generate most electricity around the middle of the day (10am-3pm) so we refer to these as peak PV periods.
But the current situation for most households (and some businesses) is that this peak-time PV is exported for almost nothing to the energy grid, where they get very little payback, instead of it being used for their own advantage – that is, to avoid the grid electricity costs they’d otherwise pay.
So what can you do if you’re generating all this solar during the day but not using the energy until later and being able to enjoy the PV $ savings? You come back home in the afternoon, start the air con to cool down the overheated house and are unable to use the already exported invaluable energy that you generated earlier.
This may not be necessary with the following technique, which is related to energy storage and insulation of the building. Here’s the principle.
The first point is the storage. We want the inside brick wall as a storage medium. This medium is able to store heat and cold for us and sustains the desirable environment in our rooms that is created by the AC or heater powered by PV while there’s plenty available during those peak times.
The second important point is not to lose the thermal conditions inside your building to the environment, which would mean that when you switch on the AC or heater later in the day, it needs to fight the conditions already in the building (while having less PV to power this process than earlier on). This can be done by sufficient insulation (e.g. 120-160 mm Rockwool) on the roof and double insulated windows and doors.
By using the high PV energy during peak times to run the air con / heater during the day and cool down the building (summer) or heat it up (winter), stored in the inside walls, you can provide the required energy buffer. The energy will remain thanks to sufficient insulation during the rest of the day and the storing medium, and can be exchanged with your body temperature in the afternoon.
The amount of energy to keep the house in the same stage is a lot smaller. With this technique, you may be able to drop your energy consumption during the evening because you’ve put in the “effort” earlier in the day when the PV was most available to support those heating and cooling systems!
(By the way, this all assumes that you’re on the normal 7c REBS feed-in tariff… If you’re on the high value solar FIT and making heaps of money selling your excess PV to the grid, go ahead – export away!)