A few weeks ago, on a different board, a poster explained the difference between ENPH micro inverters vs “traditional” inverters.
He was extolling why ENPH was a great investment.
Basically, inverters are the point at which DC electricity is inverted to AC. The AC is then input to a system that uses AC - most home appliances or “the Grid”.
Micro inverters change DC to AC at each panel, or perhaps a subset of panels. (Yes, there are pros for this arrangement - more granular control data for the solar panel array.)
Traditional inverters capture the DC from an whole array of panels.
My question: why did Musk/Tesla decide AGAINST micro inverters? At the time, it was suggested (IIRC) that Enphase owned “all” the valid patents, and Tesla/Musk didn’t want to pay for patent use.
But, is that the reason?
Electricity is stored in batteries as DC.
Micro inverters produce AC, which must be converted BACK to DC for battery storage (in Tesla’s Power Wall, or Megapack batteries).
Traditional inverters are in line AFTER the battery, inverting the DC current from the battery to AC for use in the home, or supply to “the Grid”.
I’m also feeling very bullish on renewables, specially solar. For me the most attractive part is that unlike most energy sources, solar is becoming widely distributed which negates the power of governments and industries to operate monopolies. In energy like in everything else, distributed is a lot safer than central planning. Just see how the Fed can screw up the works – capitalistic central planning no better than Soviet 5 year plans. With the advances in battery technology the intermittency problem of renewables is being overcome. I had solar panels on my boat 25 years ago but that was too early in the adoption cycle. A quarter century later I’m convinced that solar has “Crossed the Chasm” which is an important milestone for investors as it reduces the risk considerably.
Tesla Energy storage and arbitration requires BATTERY storage. Ie DC electricity. This is true for Tesla Power walls, and for all the other “home battery backup companies” and the other “grid scale battery storage/back up companies”.
Inverting at each solar panel to AC, requires another “inversion” back to DC for battery storage.
Tesla Energy Megapacks and arbitration is potentially a BIG revenue future source.
Right now, many states (apparently) REQUIRE solar panels to dump the captured energy to the grid.
A home owner CANNOT directly use the energy her system captured.
In the event of a blackout, rolling brown out, disaster power outage, etc, the solar panel OWNER is also without power.
This design requirement is supposedly due to “powerline worker safety”.
But, a switch IS available, that will automatically cut power supply from the panel array and battery back up, to the grid and thereby protect the workers, while maintaining power to the home owner.
IMO, the real reason is to prevent viable distributed energy, and “protect centralized energy providers” income streams.
Back to micro vs traditional inverters.
Micro inverters directly SUPPORT the “dump electricity to the Grid (Central energy providers)” plan.
Traditional inverters, in a system with battery-power wall storage, avoid the DC to AC to DC for battery storage, and supplies DC directly from the solar array to the battery. Traditional inverters therefore, directly support Distributed (home) battery systems.
The 2nd Law of Thermodynamics says that changing energy from one form to another causes loss of (usable) energy as entropy.
Does conversion between DC to AC cause a loss of usable energy?
And DC to AC to DC is a less efficient system?
Is a traditional inverter system more efficient for home battery storage than a micro inverter system?
And for the grid level battery storage systems?
For investment purposes, as solar panels on homes with battery-power-wall installations increase, will micro inverter use decrease?
I know 2 local, Texas small towns, that have 5 ha solar farms. I don’t see any mega battery storage units, with them.
For installations that merely supply electricty to the grid during active (daylight) solar energy collection, micro inverters might be more efficient?
But for installations that store electricity in batteries, traditional inverters are more efficient?