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trankillity t1_ivd3gll wrote

The problem with this is that the energy companies are doing everything they can to prevent solar being an attractive option. Most companies offer 4-6c/kWh for energy exported to the grid, while charging you 25-30c/kWh for energy imported from the grid.

So the best thing you can actually do with your energy is fully use it, but due to the constant sun in AU, that's nigh impossible - even with a small 5kW system.

If energy was brought back to a publicly owned service, I imagine they would very quickly build large battery banks to absorb the extra, and distribute it at night when it's not being generated as much. There are some companies that are working towards this system (known as a Virtual Power Plant - or VPP), but they are always heavily in favour of the company implementing them, not the customers.


RestlessAmbivert t1_ivdotc8 wrote

Are batteries more efficient in use and in terms of sustainably than physical storage systems, i.e., those that lift pillars/weighted sleds with excess power then convert it back to electricity when the weight is released during non-daylight hours?

Just curious if you knew offhand, hadn't looked into them in detail.


cowlinator t1_ive8pvd wrote

Pumped hydroelectricity storage is 87% efficient, but requires huge reservoirs. A brand new lithium ion battery is 88% efficient, but this goes down significantly over the battery lifespan. The efficiency of mechanical gravity storage systems varies widely but is usually under 80%


trankillity t1_ivdu7kc wrote

I don't know offhand sorry, but I imagine there's a LOT of energy lost in those systems due to the physics of mechanical energy transfer. That being said, I've heard there's some very efficient underground flywheel systems that have been implemented in the last few years.


Surur t1_iveo4u3 wrote

Yes, round trip is above 90% for batteries and around 80% for weights for example, and storing energy in batteries is a lot more energy dense than via gravity potential.


CamperStacker t1_ivepby6 wrote

Your numbers are childish.

Power has always only cost 4c/kwhour (8c after RET). The rest of the cost is transmission and distribution.

So no, your solar power isn’t worth 30c/kwhour - except at your house.

Allah there is no “extra”, solar didn’t reach 100%, so there has never been any ‘extra’ to store.


rutinerad t1_ivdzpep wrote

Virtual peepee sounds like a company for the future.


cowlinator t1_ive7v1f wrote

People are talking about using bi-directional EV chargers to store your house's power. I dont know if anybody is actually doing this yet tho


palitu t1_ivf61x0 wrote

There is a trial going on (probably more than one) search for v2g, vehicle to grid, trial


Shishakli t1_ivehbda wrote

>If energy was brought back to a publicly owned service

This is the best next step


Haquestions4 t1_ivf4j9y wrote

To be fair the company needs to maintain the grid, which is a big part of the bill.


trankillity t1_ivlnc28 wrote

The companies ALSO charge a daily access fee of around $1.20, which is where the vast majority of the cost associated with maintaining the grid would be accounted for.