I find it’s best to use it to actually give context. Like prompted with a peice of information that the LLM doesn’t know how to look up (such as a link to the status or logs for an internal system), give it a tool to perform the lookup.
I’ve just done a legtimate 425 mile solar powered round trip which is the culmination of many things I will explain below. I can now effectively drive anywhere in a 225 mile radius and back for about $10 total cost and on 100% solar power.
I have a two complete solar systems on my house the first one was 10.98kW AC installed 4 years ago with the panels facing south. The second was just installed a few days ago and is a 9.9kW AC with the panels facing east/west. Combined the system will produce over 20MWh of power per year. Both systems are grid tied used EnPhase microinverters and are now combined together for monitoring in one site.
I have an EnPhase IQ EV Charger. This has a mode where it communicates with the solar system, understands how much power is being produced and consumed in the house and then adjusts the EV charger output to match the excess solar production.
I have an EV with the largest battery that is available. The Chevy Silverado EV truck has 24 battery modules with a total gross capacity of slightly over 200kWh. The efficiency on road trips at high speeds is about 2.1miles per kWh. I have verified this with a real world road trip of over 400 miles.
The cost of the solar is around 5 cents per kWh over the 25+ year lifespan of the system.
Another less commonly discussed option is community solar (also called offsite solar). It's especially attractive if the roof line of your house isn't ideal for solar panels or if you expect to be replacing your roof within the lifespan of your panels. (Or if you have a historic association like I do that makes almost every home project impossible.)
You still purchase and own the panels, but often a third party maintains them for you and they are installed as part of a large, offsite array. Since they're usually installed at ground level, they can also do more interesting things like follow the sun. The way it works is the power your panels produce is subtracted from your energy usage via an arrangement made with your utility provider.
Like any solar purchase, the cost of your panels can be financed over time and charged against your energy production. So the net effect is your power bill just goes down until the panels are paid for. At that point all the power you generate is deducted from your power bill. To me, it's most all the upside of owning panels on my roof.
The described version of community solar is nice. How it is usually implemented like in Maine ends up sucking.
The root cause is that they wanted community solar customers to be able to opt-in and opt-out any time. As such it isn’t really what you describe which is owning panels offsite, you are more or less doing a short term rental on them. As such you don’t get the full benefit from them but simply a 15% discount on the current residential rate.
I very much think that proper community solar would be a larger upfront investment just like panels on your roof are. With a small monthly cost to maintain the grounds and pay taxes on the real estate where the panels exist. All power generated would be metered for the specific panels you own using microinverters.
I don't understand the purpose of consumers owning individual solar panels in a large array. How is that better than a single entity owning the whole array, and what function does the consumer provide?
> I don't understand the purpose of consumers owning individual solar panels in a large array. How is that better than a single entity owning the whole array, and what function does the consumer provide?
I don't now if it's better, but it is different.
The benefit to the utility in this case is much lower capex - it's basically like the restaurant franchise model, but for power.
But like you imply, there's a tradeoff that can be made between capex and opex - in this case, the utility could own everything and consumers could pay for electricity on an ongoing basis. IMO, this model is superior due to reduced principal-agent problems.
Just to be clear you're talking about variable costs not total costs. Total costing include time value of money, amortization etc. (I'm no hater I also drive an EV).
> I have an EV with the largest battery that is available. The Chevy Silverado EV truck has 24 battery modules with a total gross capacity of slightly over 200kWh. The efficiency on road trips at high speeds is about 2.1miles per kWh. I have verified this with a real world road trip of over 400 miles.
This is interesting. While it has the most storage capacity, the range is not good for that much battery.
I don’t think the Silverado is optimized for driving range, but rather - can it do typical “truck” stuff. For example hauling and/or towing. For this workload, having more towing capacity in a slightly less aerodynamic package is probably a good trade off. You don’t get a truck for the efficiency, you get one so you can do stuff with it.
Still, having a 400 mile range also makes this more useful for the middle of the country where there are wide open spaces between towns for charging. Also, having a legitimate truck EV makes it more likely for traditional truck buyers to think of getting an EV.
I'm looking at doing similar stuff right now. I already have a house battery.
However, looking at getting an EV - were you able to get bidirectional charging going?
I saw a few places mentioning demos of it over the past 5 years, but I can't find any v2x charger/car configurations I can buy and use in the UK.
Before looking at any of this stuff, I didn't realise how large and cheap the battery in an EV is compared to house batteries. Now I'm struggling to justify getting an EV if I can't do at least V2H bidirectional charging.
Interesting thanks! It looks like most of the GM vehicles that v2x works with are... uh... not really something a European would consider an option (not even sure if some of them will fit on our roads). Ford UK makes no mention anywhere of anything to do with v2x though.
There's a few places that apparently offered it here, but when I've contacted them, they've all explained it was a tech demo, or trial, or some other PR type thing which means they didn't take it any further and regular humans can't buy it. I think there's some nuance or regulation around the UK power network which is stopping any progress with bidirectional charging here.
Over here though, if you don't have old electric heating, or an electric shower, 9.6kw is very much more than enough for the average household. I have a relatively high usage, and a 6kw inverter can power my house in a powercut, as long as I don't use the electric shower. The various retired people in my life tend to use 2 - 4kwh /day, the peak draw is the kettle which uses 3kw for a minute or so.
> Thier max output is only 9.6kW so it can’t do a whole home backup and the car can only run in backup mode when the grid is out.
9.6kW should be enough to backup your entire house, that's 87A... Lots of people only have a 100A supply in general. Depending on your setup you may have to limit what you use at one time but even in a large house that will be more than enough for AC, lights and electronic devices.
9.6kW is 40A at 240V, and a 240V 100A single-phase residential service is 24kW.
Still, 9.6kW should be more than enough to run a fridge, lights, receptacles, sump pump, a 2-3 ton A/C unit, and a furnace fan. It would be challenging to impossible to back up a home with electric (resistive) furnace and electric (resistive) water heater with only 9.6kW.
That’s peak production, without battery storage the fluctuation during the year will likely be too much to keep the “lights on”. Would be cool to have a smart home that prioritizes the electricity supply to different systems based on how much is available.
>This has a mode where it communicates with the solar system,
I just find this so cool. We have projects like SETI where the solar system tries to communicate with us. Here, you, just one person, have set up a machine talking with outer space and the solar system. Space is talking and we are listening. Amazing. Rock on space cowboy.
I assume you're on a pretty attractive net metering agreement? That's a huge system.
Unless you're consuming a significant portion of that, the payback rate is going to be pretty badly impacted by having such a large system for most people.
I consume about 17MWh a year between two EVs and a large heat pump for winter heating.
I will have overproduction now with the 2nd array. We do have net metering at about 80% of the cost on NEM 2.0. Our bill is split by transmission, generation, distribution and fees. We get 100% on transmission and generation and 25% on distribution.
$0.05 is the rate we pay in BC at night. I was still debating whether to add solar or not, I guess your post answers the question.
Until we can get to $0.01 there is no point in solar in BC at least.
From an efficiency standpoint, we should probably be building grid-scale solar in Alberta and pumped storage in BC. There's more sunshine on the east side of the Rockies.
As a resident of Alberta, I pay $0.205/kWh for energy and delivery, which I largely attribute to bad decisions made by our provincial government. Even still, my 10 kW rooftop solar install is barely financially viable at those rates.
With that said, it would help if the Canadian government didn't have enormous tariffs on solar panels. Canada levies taxes such that solar panels here cost nearly triple what they cost elsewhere.
The article is about installing solar panels on vehicles. Your truck has no solar panels installed on it. What is the relevance of your anecdote to this discussion?
Dropbox does have a terminal level which I think was IC4 when I was there.
On the other hand they have recently done a layoff round every 1-2 years and if you are not a growing employee with a higher salary you could be at risk.
It should be funded by a carbon tax… the root cause of the more rapid and intense climate change.
Gas and carbon emitting electricity sources should be a LOT more expensive than they are. That would then push more people to EVs and renewables even faster and if there is demand than economies of scale will be reached and the prices of EVs and renewables will fall even further.
Ah yes, people who are currently struggling with the prices of eggs and other necessities will run out and buy an EV tomorrow (absent infrastructure improvements of course) if only we increase their electricity bill too as a form of punitive social tax. Let's also not forget to twist whilst squeezing their testicles.
Compare: "How dare you start fining anybody who poops in the local water supply! Some poor villagers can't afford to dig their own latrines! You monster!"
You're presenting a false dilemma: We can have laws against inflicting harm on other people through pollution and do more to help the poor. Granting a special license to pollute is not a reasonable way to fix chronic poverty anyway.
Batteries cost a fortune, have all kinds of supporting hardware that has to be maintained, fire prone, and they depreciate. Who wants that on their books?
> Batteries cost a fortune, have all kinds of supporting hardware that has to be maintained, fire prone, and they depreciate. Who wants that on their books?
Natgas cost a fortune, have all kinds of supporting hardware that has to be maintained, fire prone, and they depreciate. Who wants that on their books?
All of that is more true for natgas than for batteries.
You seriously do not believe your argument. All those costs are aggregated. As opposed to a battery endpoint, which is not. Someone is going to have to bear the cost. Right now a proprietor has to foot the bill for tanks, pumps and fuel on a shakey financing model. Just hoping they can sell enough mountain dew, CBD, and cigarettes to keep their head above water.
California is also going negative quite often now. Instead of dropping prices and encouraging usage during those times they curtail. The utility model is completely broken.
As A CA resident living under the thumb of PGE I have to say that nothing shocks me any more.
The current PGE rates basically redline a whole portion of the state.
Gray Davis got run out of town on the back of Enron's nonsense. The fact that there is abject lack of fall out from the current pricing is, outrageous.
in most of US the cost of residential power is almost entirely in the delivery, not the generation. If folks knew how much they were being fleeced they'd lose their minds.
Or, California just needs to increase its battery storage capacity some more. (This week they announced storage systems now already have over 10,000 megawatts in capacity — "about 20% of the 52,000 megawatts the state says is needed to meet its climate goals.")
That will be a tough game to chase long term as batteries need to be removed and replaced regularly. Assuming the storage capacity needs continue to grow, CA would need to replace larger and larger stocks of batteries on the scale of 5-15 years depending on what kind of warranty the battery manufacturers are providing.
And for lithium batteries, maintaining an overcapacity drastically increases the lifetime by reducing the depth of the cycle. e.g., you get vastly more cycles at %50 DoD vs %80. This would increase the lifespan to be many decades
California isn't exactly known for water management practices, though sure there are storage systems that use kinetic potential as a battery. In theory that can be used at very large scales, if the water and elevation is available for use.
Is be really curious how the math works out with regards to how much water would be required for say 3 days of use in LA. That may even be an over estimate of storage needs given how few rainy days they get.
The California Environmental Quality Act (CEQA) makes it extremely difficult to build new pumped storage facilities. It's possible in principle but will take many years to get through the construction permits and inevitable lawsuits.
California is already planning a giant off-river reservoir that will be dependent on pumping to fill. If it could be set up to kick in instead of curtailment it could be a win win.
That is assuming all batteries are lithium-ion, but the state is going for a larger mix of storage tech.
As just one example, iron-air batteries:
> The CEC is supporting this project through its Long Duration Energy Storage (LDES) program, a fund dedicated to accelerating the implementation of non-lithium technologies offering 8+ hours of energy storage. Form Energy will use the grant funds to develop and operate the project, and PG&E will provide land and an interconnection point at the substation site.
For some reason grid storage reporting always seems to use a power metric instead of storage metric, which makes no sense to me. I've seen this in a half dozen stories, and found that even the government reports do this. I think it stems from someone reusing a column to represent both storage and power across generators and batteries.
> For some reason grid storage reporting always seems to use a power metric instead of storage metric
Grid scale batteries are used primarily for real time demand management, and therefore their most relevant property is how much immediate power they can output and for how long. If they were only described in terms of energy (i.e MWh) without separating the power and time components, then it wouldn't be clear how much immediate value they could provide to the grid.
It's analogous to how in an EV the max horsepower is determined in large part by the power output rating of the battery, but the range is related to the the energy capacity.
>their most relevant property is how much immediate power they can output and for how long.
You listed two properties there.
Only one of these two properties is present in a figure that is solitarily presented as "10,000 megawatts."
We can tell this because only one property is presented.
And because it is a very-clearly ambiguous and singularly-useless instance of a unit that sees frequently-erroneous use, we do not know if this singular figure relates to "how much" or if it relates to "how long."
It probably relates to one of them, I'd suppose.
However... we do know that it cannot relate to both things, as-presented. The singular property presented can't even be extrapolated to relate to both things.
> The singular property presented can't even be extrapolated to relate to both things.
Both things aren't equally important.
The energy capacity of the battery isn't provided for the same reason that coal plants don't specify the size of their coal piles or hydro plants don't specify the potential energy storage capacity of their reservoirs.
Power is the most relevant property to the real time operation of the grid, and the specification of power (and not energy). The grid operators need to know how much power a battery (or other generation source) can provide, and for how long. That tuple <power, duration> what any dispatchable energy source ultimately bids onto the real-time electricity markets.
The energy storage capacity of a battery is a function of what energy market it is designed to fit into.
For example, a battery that primarily functions in the frequency regulation market (modulation of supply and demand every few seconds) doesn't need a lot of storage capacity, but needs high power output. In contrast, a battery that shifts supply over the course of a single day might need more capacity (4 hours).
From the grid operator's perspective, the storage capacity is an implementation detail of the particular power source, or at least a secondary consideration.
> For example, a battery that primarily functions in the frequency regulation market (modulation of supply and demand every few seconds) doesn't need a lot of storage capacity, but needs high power output.
For ERCOT this is fixed as a hard requirement so there's no point in specifying the time-- it's all going to be the same. For example:
> Fast Frequency Response (FFR) – subset of RRS
> – Must be capable of sustaining its required response for at least 15 minutes
(if necessary)
> Sure do! They definitely need all both of those things!
When a generation provider bids supply onto the grid, it doesn't tell the operator what the maximum storage capacity of its equipment is, it tells the ISO how much power it can output for a given time frame (or alternatively how much energy it can deliver during a timeframe).
That is different that the total energy storage capacity of the battery itself, which is what I think you asked for.
The grid operator usually pays more attention to the former when it comes to day to day grid stabilization, and especially so for batteries, because batteries today don't do long term energy storage.
It's a measure that makes perfect sense for conventional electricity production: 10,000MW of aggregated coal generation can hypothetically produce 10,000MW more-or-less indefinitely, as long as it keeps being fed things like fuel, water, and maintanence.
But it doesn't make any sense at all, by itself, for energy storage: A net 10,000MW battery might be able to produce 10,000MW, but for how long can that output be sustained? Unlike a group of coal plants, it absolutely cannot do this indefinitely; at some point, that battery will become completely discharged.
It takes at least two figures to describe a working bucket of energy (whether that bucket is Lithium cells or pumped storage or whatever): The capacity (megawatt-hours is a fine figure here, and units like Joules also work), and the maximum input/output (and plain megawatts works fine for this part). Using only one figure doesn't really describe anything at all.
I don't know when or why we stopped doing this, but it's misinformative in a way that leads to a bad generalized understanding of the these concepts with the populace that is actually paying for all of this stuff.
Its fine as long as the amount of time it can provide rated output is longer than it time it takes to bring replacement generation capacity on line.
I don't care how long my UPS will actually last as long the holdover time is long enough to cover the time it takes to deal with all of the foreseeable problems in starting up the backup generator.
I don't think that grid-scale batteries are working with consumers on the grid in the same way that your home UPS is with you in your house.
Perhaps most-obviously: Consumers who are suddenly running on grid-scale batteries have no idea that this is a thing that is happening. There's no signal for them to shut their stuff off -- automated, or not.
It's a whole different paradigm than your UPS under your desk is: With your UPS, your system(s) receive a signal that things are running on local battery, and you've elected to configure things to use that signal to order an automated shutdown.
But, again: That doesn't happen with the grid-scale batteries under discussion -- at all. You're comparing apples to dildos here.
(Which is not to say that grid-scale batteries offer new opportunities for power cuts, because the opposite of that is true. It is instead just to say that unknowingly using grid-scale batteries is nothing like monitoring a local UPS is.)
> It's a whole different paradigm than your UPS under your desk is: With your UPS, your system(s) receive a signal that things are running on local battery, and you've elected to configure things to use that signal to order an automated shutdown.
The setup you described there wasn't the situation I was describing at all.
I was describing a situation where there is utility power, a UPS, and a standby generator. When the utility power goes out, the generator has to start, stabilize, and only then can the load be transferred off the battery.
The requirement is that the UPS meet this current power demand for longer than the generator start up and transfer time (the "holdover time" I was speaking about in the previous post.)
For things like frequency response the holdover time is a fixed requirement. ERCOT requires all energy storage resources be able to maintain output for 15 minutes.
I mean during the great texas power outage natural gas plants ran out of fuel because of supply issues that were not typically supply issues it would be more honest if every power plant also listed it's on hand 'fuel battery'. Now I'm sure they may do this with ERCOT, but it's not something typically reported.
Why, sure. It would be good to know how long a conventional generator can keep running when everything around it has gone wrong. For coal, for instance, that might be represented by the mass of the piles of coal that are normally on-hand -- or by the electricity (in MW-h, say) those piles of coal should be able to produce. Having this information close by would seem to be a good thing for an organization like ERCOT, so as to be factored into their emergency playbook.
But that's still a different case than a battery, wherein: Even if everything is going right, using energy from a battery must eventually cause it to become depleted.
It's never like a coal plant that (ideally) consumes fuel at one end, and spits out electricity at the other end as a continuous process. A battery, in this context, can be in a charging or a discharging state, but it can never be in both of those states at the same time -- using a battery is not at all a continuous process.
Best I can guess is batteries are rated by name plate power. And raw capacity is about 3-4 times that.
Wouldn't surprise me if there is a bunch of finkie dinkie technically driven accounting stuff around how fast and how deep a charge and discharge cycle they're willing to do vs price. Not to mention adding supply effects the price as well.
Your link claims that curtailment is largely due to congestion - "when power lines don’t have enough capacity to deliver available energy". Dropping prices will not help with that?
True. Nevertheless, if one believes in what many environmentalists and scientists say they believe, and one understands math, one must also support an immediate and massive expansion of nuclear power -- on their front lawns, if need be. The fact they do not is suspicious.
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