wattmatters
Solar Wizard
I had a chat yesterday with the much better half and we have agreed to pursue a few specific options, which I am now going to research. The first two are:
1. Move our hot water storage tank energy from the overnight off-peak grid energy and onto our regular daytime tariff when our solar PV can supply most of the energy. Our solar PV can supply 70-80% of the HW energy demand, grid supplemental energy required for the balance. Currently our excess solar PV is exported to the grid, which offsets grid fossil fuel, but it also offsets grid daytime renewables.
So while this represents no difference in energy consumption, because the carbon emissions intensity of our daytime and night time grids are different, with night being almost all coal power while daytime grid has a much higher supply of renewables (and growing every day), this will have a net emissions reduction benefit. I estimate the benefit to be a reduction of 1.5-2 tonnes of CO2 emissions/year. I'm also working to do this in as a cost neutral way as possible.
2. Improve insulation at one end of the house. Our home is thermally pretty crap, and in many ways we can't do a lot about it due to its construction. This is our household electrical energy split:
If we can reduce aircon (heating and cooling) energy consumption by say 25%, then that will have a net emissions reduction benefit of about 3-4 tonnes CO2/year (accounting for average grid emissions intensity for times the heating and cooling are required).
Of the others, The pool pump is now powered off-grid via the repurposed DIY pre-loved solar PV system I installed. It replaced using the grid tied solar PV which frees up solar PV energy for the hot water system. Considering the emissions intensity of the grid at time of use, this reduced emissions by ~0.5 tonnes CO2/year. The pre-loved solar kit would have already repaid its embedded emissions (one of the benefits of re-using stuff instead of recycling it).
I have some other options to consider as well. One involves our vehicle.
1. Move our hot water storage tank energy from the overnight off-peak grid energy and onto our regular daytime tariff when our solar PV can supply most of the energy. Our solar PV can supply 70-80% of the HW energy demand, grid supplemental energy required for the balance. Currently our excess solar PV is exported to the grid, which offsets grid fossil fuel, but it also offsets grid daytime renewables.
So while this represents no difference in energy consumption, because the carbon emissions intensity of our daytime and night time grids are different, with night being almost all coal power while daytime grid has a much higher supply of renewables (and growing every day), this will have a net emissions reduction benefit. I estimate the benefit to be a reduction of 1.5-2 tonnes of CO2 emissions/year. I'm also working to do this in as a cost neutral way as possible.
2. Improve insulation at one end of the house. Our home is thermally pretty crap, and in many ways we can't do a lot about it due to its construction. This is our household electrical energy split:
If we can reduce aircon (heating and cooling) energy consumption by say 25%, then that will have a net emissions reduction benefit of about 3-4 tonnes CO2/year (accounting for average grid emissions intensity for times the heating and cooling are required).
Of the others, The pool pump is now powered off-grid via the repurposed DIY pre-loved solar PV system I installed. It replaced using the grid tied solar PV which frees up solar PV energy for the hot water system. Considering the emissions intensity of the grid at time of use, this reduced emissions by ~0.5 tonnes CO2/year. The pre-loved solar kit would have already repaid its embedded emissions (one of the benefits of re-using stuff instead of recycling it).
I have some other options to consider as well. One involves our vehicle.