41–50 of 61 posts
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Energy is not Watts per hour (Watts/hour), it's Watts times hours (Watt-hours). Sorry for pedantry, but the units are the topic of discussion here.
That's got me trying to visualise "mile-gallons", and failing because its dimensions would be "length^4".
I got my "hybrid" inverter today. My panel size is 330w x 16. So 5.2kWh. Grid tied system. 1 year. Average production 28 kWh on a good day with no grid power cuts. Well the new hybrid inverter from phocus is supposed to use the generation when grid outside is down internally at home and that opens up a lot of possibilities. Been thinking about using solar water heating to reduce electricity consumption but that is a…
I wonder if anyone has invented a "storage heat pump" for air conditioning purposes.
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California still imports a large amount of power from other states (primarily Arizona and Utah, with some hydro from Oregon). So we essentially outsourced a lot of our power production to other states.
Arizona, Nevada, and Utah have quite a bit of area for solar PV. It’s fine for California to import from there as long as they use their leverage to force a move away from coal now, and natural gas later. Clean hydro from the PNW is no different than PJM and NYISO grids importing clean nuclear and hydro from Ontario, Canada (which they do).
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Arizona, Nevada, and Utah have quite a bit of area for solar PV. It’s fine for California to import from there as long as they use their leverage to force a move away from coal now, and natural gas later. Clean hydro from the PNW is no different than PJM and NYISO grids importing clean nuclear and hydro from Ontario, Canada (which they do).
Drawing solar from states to the east would only make the duck curve worse though, right? Power production would taper off even earlier than the peak demand.
Transmission is crucial for flexibility in balancing generation and consumption, as well as optimizing storage utilization. You can also assume there will be times you’ll throw away (curtail) clean energy as it’s cheaper than it would’ve been to store and then deliver it, but you still need that capacity available at other times (seasonal variability).
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> 2,000 MW of energy storage capacity I think this is where the confusion starts: if someone talks about "energy storage capacity", my first association is the amount of energy that can be stored, not the rate at which that energy can be discharged from the storage (i.e. power).
It is a bit confusing, but it isn't wrong, there are just two capacities in question. We could call them power capacity and energy capacity. This system can deliver 2000MW for four hours, or 1000MW for eight hours, but can't deliver 4000MW for two hours, because that exceeds the power capacity.
The battery energy storage is 8GWh with a power capacity of 2GW. There is no such thing as a power storage capacity, because power is a rate. However, the storage may have a power capacity. pedantic, I know.
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> Gigawatts and gigawatt hours are just different magnitude units for the same quantities, like meters and millimeters. I liken it more to distance vs speed. Power, like speed, is a rate, in particular the instantaneous rate at which energy is transferred. Expressed using the same scheme we use for speed (distance per time : power per time), power is watt-hours per hour (or 0.0036 megajoules per hour). I'm guessing w…
This is what confuses many people, especially with solar and battery storage. "I've got 400 watts of solar feeding into my 400AH of batteries with a 3000w inverter" Most people will have no idea how much usable power they get and how much energy storage they need to meet their needs. (this example is mostly from an RV perspective)
Assuming 12V, that's about 400Ah*12V=4800Wh of storage. 4800Wh/400W = 12 hours to charge those, which seems reasonable for an RV. The thing that seems a bit oversized is the 3000W inverter.
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Did you mean GWh?
No, GW -- as in the pumped storage facilities can deliver 4 GW of power continuously. The amount of energy that can be stored in California's pumped storage projects is enormous, measured in hundreds, if not thousands, of GWh, but that's mostly irrelevant to this discussion.
Is it irrelevant? As another thread mentioned, how long you can provide that power for that for and how fast you can replenish capacity seems relevant for its usefulness buffering solar for after hours.
I'm pretty unread on the energy storage situation so your insight or any good resources are very welcome!
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This is what confuses many people, especially with solar and battery storage. "I've got 400 watts of solar feeding into my 400AH of batteries with a 3000w inverter" Most people will have no idea how much usable power they get and how much energy storage they need to meet their needs. (this example is mostly from an RV perspective)
Amp hours is particularly annoying IMO because you can't convert it to energy without knowing the voltage.
Earlier quoted context omitted.
Arizona, Nevada, and Utah have quite a bit of area for solar PV. It’s fine for California to import from there as long as they use their leverage to force a move away from coal now, and natural gas later. Clean hydro from the PNW is no different than PJM and NYISO grids importing clean nuclear and hydro from Ontario, Canada (which they do).
Drawing solar from states to the east would only make the duck curve worse though, right? Power production would taper off even earlier than the peak demand.
Earlier quoted context omitted.
Hmm, in that case your comparison should be from MW to GW, not GW to GWh, right?
I referred to megawatts and megawatt hours in my first two sentences. "Gigawatts and gigawatt hours" was indicating counterparts to MW and MWh. Though apparently that grammatical construction was not as clear as I initially believed.