Some of you may recall that I had my meter replaced with a "smart" meter, which led to my energy consumption more than doubling. Despite seeking answers, I never received a clear explanation for this issue. Ultimately, I was forced to replace my solar system, with a new one I carefully designed to suit my environment, accounting for constraints such as 6.6kW panels, a 5kW inverter, shading, and limited roof space... so now I'm pretty clued up on solar power.
I repurposed the original system into an off-grid 2kW setup (DIY 48v battery + MPPT + Inverter) dedicated to powering the garage (beer fridges) and pool.
The first major realization: the grid cannot accommodate any additional solar input. Whenever the grid voltage exceeds 250V, the inverter automatically deregulates (3rd image starting @ 08:45), so you either use it or lose it.
Here's a dashboard I developed... anyone done anything similar? I've also got a couple of voice warnings for the person who supposedly doesn't use any power, when they exceed 500W when solar radiation is above 400W/sqm. 
It's weird that you never found out why your smart meter wasn't reading correctly. I can understand it if the smart meter was reading consumption on one phase which was different to the one used for the solar system, but you would think that if they were all on the same phase that they would read correctly.
I was reading something on some AC units where they use a fair bit of energy for a short period of time and then backing off, versus slowing down and drawing less all the time. Apparently this gets registered as drawing more than the energy produced and gets billed accordingly. I wonder if the granularity of these measurements becomes an issue? It would probably be an issue too if you had a 3 phase AC unit and only a single phase inverter.
Select to expand quoteFormulaNova said..
It's weird that you never found out why your smart meter wasn't reading correctly. I can understand it if the smart meter was reading consumption on one phase which was different to the one used for the solar system, but you would think that if they were all on the same phase that they would read correctly.
I was reading something on some AC units where they use a fair bit of energy for a short period of time and then backing off, versus slowing down and drawing less all the time. Apparently this gets registered as drawing more than the energy produced and gets billed accordingly. I wonder if the granularity of these measurements becomes an issue? It would probably be an issue too if you had a 3 phase AC unit and only a single phase inverter.
The issue stemmed from the unavailability of the original meter, a lack of independent consumption monitoring, and a $360 expense for testing the new meter, which revealed an over-measurement of 0.2%, well within the margin of compliance.... so now on a $250 I pay the utility ~$0.50 more than I should. Removing the old system with micro-inverters revealed that at least 2 of the 10 weren't functioning.
Regarding your latter point, this relates to Power Factor. My entire house maintains an average of 0.93 with both the AC and bore pump operating, neither of which individually drops below 0.91.
I can comfortably manage with the energy generated, but the challenge lies with another person who struggles to understand the importance of limiting appliance use to one at a time. Even though I've set up a warning system that audibly alerts the entire house when too many appliances are running simultaneously, the problem continues. For instance, at the moment, she has the washing machine, oven, dishwasher, and her AC running (with the outside door left open) alongside the cooktop. Then she adds the kettle, causing the warning to go off: "1750 watts over consumption; please turn off some appliances."
Select to expand quoteFlySurfer said..
I can comfortably manage with the energy generated, but the challenge lies with another person who struggles to understand the importance of limiting appliance use to one at a time. Even though I've set up a warning system that audibly alerts the entire house when too many appliances are running simultaneously, the problem continues. For instance, at the moment, she has the washing machine, oven, dishwasher, and her AC running (with the outside door left open) alongside the cooktop. Then she adds the kettle, causing the warning to go off: "1750 watts over consumption; please turn off some appliances."
Mehh, as long as an electric bar heater is not running at the same time under the AC then you are fine.
It sounds like your wife is cooking and cleaning, so things aren't too bad. You need to consider the monetary cost if you had to do all these things yourself.
I think the notion of reducing your energy bills is a bit of a never ending chase. I haven't even bothered thinking about it and happily send off a few hundred dollars to the providers whenever they want it.
Select to expand quoteFormulaNova said..
It sounds like your wife is cooking and cleaning, so things aren't too bad. You need to consider the monetary cost if you had to do all these things yourself.
I think the notion of reducing your energy bills is a bit of a never ending chase. I haven't even bothered thinking about it and happily send off a few hundred dollars to the providers whenever they want it.
She's cooking and cleaning for herself. I've already had my breakfast, washed my dishes by hand, and done my own laundry, but not all simultaneously.
The point I'm making is that we can operate comfortably with a night time base load of just 350W, or 1150W with 2 AC units running, if the household were more mindful of the number of appliances in use. For example, at this moment, everything is off except for an AC unit, and the inverter has downregulated to 4kW, with most of the generated energy going to waste. She could have taken this opportunity to run the dishwasher or clothes washer, which would have saved me $0.70... LOL.
