That it falls short during cold winter days is telling me we could probably solve that by not building Australian houses like tents with no doors.
Proper building codes with proper insulation standards would probably reduce winter demand from residential homes by a huge chunk.
Yeah that’s kinda cool I guess but like…what about paying a bunch of money to keep obsolete coal plants open instead?
Now that’s the kind of logic the global capitalist oligarchy can get behind!
just a few hours of battery storage is still a huge amount of storage. Are plans being made to tie BEVs into this on a national scale? I figure that’s the most effective way to get closer to this goal
Check this out: https://raygen.com/projects/raygen-power-plant#resources
Batteries were a stopgap until we worked out something better. This plant gets 70% efficiency and more than enough energy storage by refrigerating a cold block, then using stored waste heat + the cold block to create a temperature differential, creating steam (in a closed loop, don’t need a big water supply) to spin a turbine that generates power when the sun goes down. Absolutely genius, already deployed and operating and yet nobody is talking about it.
What’s the advantage of that solution over existing solutions like heating molten salts?
Efficiency. You’re collecting 70% (potentially 80%) of the available energy. The best PV is below 30% and the best molten salts are 35% max.
I could not see where the 70% comes from, apart from the round trip efficiency of the heat capture. I dont know if that is what you are referring to. Do they have a input v output energy comparison somewhere?
I thought molten salt storage gets like 90% efficiency. What’s the advantage of storing energy by cooling blocks?
To run a heat engine you need a temperature difference in order to generate work. When your system generates heat as a byproduct you can amplify the amount of work by increasing the temperature difference. This is how the cold block “stores” energy.
What’s your source on 90% efficiency? Here it’s stated 35% max.
I’m just talking about storage. Molten salt energy storage is mentioned here: https://en.wikipedia.org/wiki/Thermal_energy_storage
I am listening to a The Solar Insiders Podcast, which is interviewing the CEO of RayGen (thanks for intoducing it to me, really cool).
the 70% is the efificency of the energy storage, which is similar to pumped hydro. ie, they put in 1MWh to the chiller, and will recover 0.7MWh from the organic rankin cycle turbine.
so, they get the 30% of the solar (or whatever it is), plus the recovery of the heat. They were saying that for 1 tower, they get 1MW of solar and 2MW of heat. but they never said how much of the 2MW of heat gets converted to electricity, or what the efficiency is, but it sounds like they need to consume electricity to use the ORC (ie for the chiller).
one other thing is that they ORCs can provide grid inertia which is a cool outcome too.
Hi mate, I think you misunderstood me.
It captures 30% of energy as PV and 60% as heat energy. The whole system itself is about 80% efficiency in terms of the energy captured from the sun, not the PV itself.
This makes it more effective than if you somehow had a molten salt and a normal PV plant in superposition on the same site.
i haven’t been able to find the actual insolation to electricity efficiency anywhere. Do you have a link that shows the incoming energy to output electricity?
i haven’t read about your link yet, but as for storage, the study states
82% of demand was directly powered by wind and solar without having to pass through storage or be curtailed
so the majority of the energy is used without being stored, and having the round trip losses.
… now back to reading ray-gen
True, but at that scale it doesn’t have to be battery storage.
Are plans being made to tie BEVs into this on a national scale?
Not much yet from the government itself, but it’s a known opportunity. Smarter grids and changes in utility and customer behaviour (demand response, i.e. shifting demand to when power is cheapest and most abundant) would help a lot, and vehicle and house batteries would contribute to that.
Although I’ll add that part of the point of the article is that even with zero storage you don’t need much fossil supply, and that just supplying a large amount of wind and solar can massively cut our electricity emissions. Whereas focusing on the challenges of the last 1-2% too much can get us bogged down in the longer term problems, when we can address the immediate issue today. That doesn’t mean that the longer term problems should be ignored, of course.
yeah, I think that is what i like about it. it show a ‘realistic’ renewables input, and looks at what you need from a storage and “other” to maintain the grid. then scores the renewable as a percentage.
I’ve heard a lot about how the grid can use my vehicle’s battery for storage and how this will be hugely beneficial for the grid. However, I’ve never heard anyone explain why I would want to participate.
The grid gets valuable energy storage, adds a bunch of wear to the battery I had to pay for, and I get…?
Demand management is much easier to make a case for and probably much simpler to implement. I get cheaper electricity on my EV charging circuit but the power company gets to turn it on and off. The grid gets demand management, I get cheaper power. I’ll still be charged the next day, I don’t care that my car was turned off for a couple of hours.
This simulation used 24GW/120GWh (five hours at average demand) and achieved 98.8% renewable supply at a cost of $95/MWh, including the cost of additional transmission, storage and curtailment.
so they used a large number for storage. However, there is 7GW/33GWh of existing, under construction or financed BESS projects, and according to the study, 10GW/40GWh of storage will allow for 94% renewables, which is pretty bloody good.
But yeah, it would be interesting to see BEV’s assisting.
The plan is in progress, from the private sector. I’m currently one of two private non trial household in the country currently who can actually do this at the moment. No one else will be able to for a few more years. But hopefully when new tech and new standards come out, it will be much more wide spread, there is definitely demand for it, especially with rising electricity prices
Can you share any details? Eg, what car, other bits and pieces, your impressions so far?
We have 2 compatible cars. A 2018 Nissan Leaf ZE1 e+ with 62kWh battery, and a 2014 Nissan Leaf ZE0 with 24kWh battery (both Japanese imports). These are total battery sizes, so the usable capacity is lower. The ZE1 seems to be about 50kWh usable, and the ZE0 about 16kWh.
The V2G charger we got is the Wallbox Quasar. It reached end of production in July 2022, and was first approved for use in South Australia in December 2022, 6 months after production ended. I had been contacting everyone I could find to get one, and I was very surprised when JetCharge got back to me a few months later asking if I still wanted one. It took a few weeks to sort out paperwork and logistics, and about a day to install. The unit was about $10,000 and the installation about $5,000 for a total of $15,000.
The Quasar does what it says on the box, but I now understand why Wallbox decided to end production in favour of a new (as yet unfinished) model. The Quasar 1 does not support V2H (at least not well). It has a minimum charge/discharge rate of 6A (1.4kW) so a separate house battery is needed to fill the gap if the house is using less than 1.4kW and you don’t want to import or export power to the grid.
It also doesn’t have the ability to run during a grid outage. We have a house battery with off-grid capabilities, but we can’t legally have the Quasar on the backup circuits because of its ability to overload the house battery. (The same reason the AC and stove are not on the backup circuits).
Both of these issues will likely be fixed on the Quasar 2. The Quasar 2 will be released first as a CCS only model (not compatible with the Leaf), and a CHAdeMO version might be released a year or 2 later, but Wallbox has not confirmed anything yet.So far I’m happy with the system. It’s definitely not for everyone, and needs constant attention to get any benefit from it.
We are currently getting wholesale electricity prices from Amber. Most days we roughly break even on cost, but occasionally the prices spike from 20c/kWh to over $10/kWh. This only happens once or twice a month, but we make more in those days than we pay for the entire month for electricity.
The house battery (10kWh) can export for up to 2 hours, and the car (50kWh) can theoretically export for 10 hours. In practice, the car won’t export below 20% (I’m assuming this is a limit in the car, not the Quasar), and it often isn’t charged above 80%. This still leaves 30kWh which can last for up to 6 hours at maximum export rate. This is more than enough to cover any possible price spikes, and run the house overnight. The price spikes rarely last more than an hour.Amber provides some automation for the house battery - importing when prices are low, and exporting when prices are high. They are looking into providing a similar type of automation for V2G. Having to manually set the V2G charger to export during high prices is a nuisance, and without the price push notifications from Amber, we would miss many opportunities to sell to the grid.
The Wallbox app is designed for all Wallbox chargers, and the V2G features seem to have been added as an afterthought. I have encountered several bugs so far, and several design decisions that I don’t agree with. Schedules can be set in the app for charging and discharging, but there are bugs with this too. I’m hoping that most of these issues will be fixed before V2G becomes mainstream.
We have a unique situation here. A house with 10kW of solar, a V2G compatible car that’s home most of the time, a house battery, and wholesale electricity prices. V2G works really well for us, and I regret nothing. Without these things however, V2G probably wouldn’t be worth the current upfront cost.
Thanks, that was a great read, and very informative.
Glad it’s working out for you!
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