We do not have to guess too wildly what the cost of energy is going to be in the future.
My prediction is that spiralling energy costs will have gas as a long term loser in the cost stakes as the market increasingly opts for solar photo voltaic cells (solar PV) as electrical equipment becomes cheaper to buy and more efficient, running on free PV energy during the day, or at night with solar battery cells, and with its low maintenance costs compared to gas. As consumption of gas declines, the price of gas per unit will increase.
My prediction is that spiralling energy costs will have gas as a long term loser in the cost stakes as the market increasingly opts for solar photo voltaic cells (solar PV) as electrical equipment becomes cheaper to buy and more efficient, running on free PV energy during the day, or at night with solar battery cells, and with its low maintenance costs compared to gas. As consumption of gas declines, the price of gas per unit will increase.
When asked is Solar still the winner in the cheapest to run hot water stakes ? The winner is... (drum roll)... Heatpump/Solar PV ... A collective sigh and everyone looks confused...’what’s that?’ and ‘how can that be?’ The reason is that the electric element booster of the standard solar is more expensive to run (less efficient) than the heat pump process running on solar PV electricity.
Let me explain the process... your split system airconditioner and fridge collect (or lose) heat via a gaseous exchange process during change of phase (Google it). This heat can heat water very efficiently and for free if supplied by a PV array. ‘So could the booster of the solar,’ you say. Well yes, it could, but as it uses up to 10 times more energy, you’ll need more collectors... or chances are that you will want to turn on another appliance in your house at the same time, which would mean you buy your electricity back off the grid at the normal rate, defeating the advantage.
By using your ‘excess’ electricity by trickling it into a heatpump during daylight hours via a timer, hot water is free. This obviously works better where people are not home during the day i.e working families, but with the emergence of battery banks, the future looks bright for electricity.
There are downsides to heat pump technology:
Heat pumps can run off normal main electricity too but for the purpose of my cost saving illustration, totally free hot water would come from a PV/heatpump combo.
Let me explain the process... your split system airconditioner and fridge collect (or lose) heat via a gaseous exchange process during change of phase (Google it). This heat can heat water very efficiently and for free if supplied by a PV array. ‘So could the booster of the solar,’ you say. Well yes, it could, but as it uses up to 10 times more energy, you’ll need more collectors... or chances are that you will want to turn on another appliance in your house at the same time, which would mean you buy your electricity back off the grid at the normal rate, defeating the advantage.
By using your ‘excess’ electricity by trickling it into a heatpump during daylight hours via a timer, hot water is free. This obviously works better where people are not home during the day i.e working families, but with the emergence of battery banks, the future looks bright for electricity.
There are downsides to heat pump technology:
- They’re large in size and
- noisy 48Db (think split system compressor noise)
Heat pumps can run off normal main electricity too but for the purpose of my cost saving illustration, totally free hot water would come from a PV/heatpump combo.
Cost?
Heat pump including electrics around the $4500 inc gst less REC’s subsidy from the government (bonus for their efficiency) of around $800 (varies) plus plus PV array (say $4000 inc) versus solar from scratch of around $5800 inc gst (with ongoing electrical supply costs and the same cost with each replacement potentially every 10 years).
