- #1
essenmein
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- 294
- TL;DR Summary
- To me, intermittent sources of energy don't make sense in any large portion of grid power.
Maybe I’m missing something, and this thread is to at least try to drill down into this to help me understand what that something might be…
Basically I do not understand the almost cult like fascination with intermittent renewable energy for utility scale electricity production. My current opinion on this is that it is entirely a waste of critical time and resources as I can’t see how it makes any sense to pursue this as a long term energy solution.
While I understand that market forces, subsidies etc drive a lot of decisions, often in counter intuitive ways, I’d like to step back from that and look at the what to me are basics or fundamentals of the problem we need to solve, delivering reliable electricity.
To keep the numbers simple, your goal is to deliver 1kW continuously 24hrs a day (I know actual grid load changes over a day) eg California average daily grid load changes from 20GW to 26GW (2014 numbers, https://www.nrdc.org/experts/sierra-martinez/new-and-improved-electric-grid-california). How would you do it?
Then you are an isolated system, ie you cannot rely on someone else to generate for you while you have no power, IMO it’s easy to hand wave away the storage problem (and importantly its associated cost), but this problem comes back once you get sufficient proportion of intermittent sources.
This link is source for overnight capital number (pg 7) https://www.eia.gov/analysis/studies/powerplants/capitalcost/pdf/capcost_assumption.pdf
Note I am assuming overnight capital is per name plate rating, and does NOT consider capacity factor.
Example 1) Delivering this 1kW with nat gas, let's pick something cool sounding Advance Natural Gas Combined Cycle:
Overnight capital =$1100/kw
Fixed O&M $10/kw-yr (Going to ignore variable O&M since it’s such a small number $2/MWh)
So let's assume you want some redundancy, so you build two 1kw turbines total cost:
$2200 capex, $20/kw-yr O&M
Conclusion: Cheap but makes CO2, basically 100% reliable power.
Example 2) Advanced nuclear:
Overnight capital 6000/kW (although I’ve seen projections as low as 4k/kw for SMR)
Fixed O&M $100/kw-yr
Since nuke plants have very high capacity factors and only really shut down for maint/refuel let's place an Advanced Combustion Turbine next to it as backup during this downtime (+700 capex):
Capex total $4700-$6700, $105/kw-yr O&M
Conclusion: Cost effective, no CO2, basically 100% reliable power.
Now for the fun…
Example 3) Solar PV.
This is where the comparisons need more math. Let’s say you live in a nice sunny place (ie ideal for solar PV), you get 8hrs of good sun a day. So in that 8hrs you must generate your days’ worth of power. So your total required capacity is 24kWhrs/8hrs = 3kW. So you need to install at least 3kW solar PV.
Required capex = $7800, O&M = $70/kw-yr
But that’s not the killer.
You also need to store 16kWhrs.
In that eia link, they list BES (battery electric storage) at $2800/kw, with $40 O&M. I’m going to assume that is $2800 per kw/hr of capacity (please correct if wrong, li ion battery cost is about $200/kwhr, then you need the power electronics, 2800/kwhr feels expensive).
Another example: Tesla 100MWhr battery cost about $90 million, this puts it about $1.1 per W/hr, or $1100/kwhr
Capex for storage = $22000-44800, O&M = $640/kw-yr
Total to deliver 1kW 24hrs a day is:
Capex = $30000-52600
O&M = 710/kw-yr
Conclusion: Outrageously expensive, and with only 16kWhr of storage and 3kW of panel you have no way to handle a cloudy day.
Example 4) Mixed wind and solar:
50/50 mix average generation wind solar, now this is where actual conditions have huge impact and I making some big assumptions.
Lets say this mixing of renewables allows you knock your storage requirements in half. I have no idea if this is reasonable or not!
So you install 1.5kW of solar (total 12kWhrs generated) and 2kW wind at 30% capacity factor (14.4kWhrs)
Total capex = 1.5*2600=$3900(solar), 2*1900=$3800 (wind) total = $7700
8Kwhrs storage = $8800-22400
Total = $17000-30100
Conclusion: Still very expensive, and with only 8kWhr of storage you have no power on a windless night.So given that just to generate your required 24kWhrs per day, solar is already 1.5-2x capex vs adv nuclear just for generating capacity why are we doing this? It makes no sense to me.
Then to sell solar and wind as being cost effective due to capex per kw name plate rating is at best an oversight, at worst basically fraud.
Labeling plants that deliver consistent power 24hrs a day as “inflexible” and therefore bad is obnoxious, our power needs are steady and “inflexible”, these inflexible sources should be preferred, and the intermittent sources shunned unless they include the cost of 24hr power delivery, not including storage just punts the problem to someone else.
Grid scale battery electric storage for renewable to me is utterly insane, to support California grid for 1 hr with Li ion (Tesla) you need 200 of those "worlds biggest battery", that only gets you one hour of hold up for one state in the US, how much lithium is there on this planet? Power plants that can deliver the required power with NO storage should be the goal.
My current position is that looking at it with the above in mind the only sensible thing is 100% nuclear, give the rivers back, take down the wind farms, take down the solar arrays. Why dam a river when you can fit 300MW capacity in the basement of an average building?
What am I missing?
Basically I do not understand the almost cult like fascination with intermittent renewable energy for utility scale electricity production. My current opinion on this is that it is entirely a waste of critical time and resources as I can’t see how it makes any sense to pursue this as a long term energy solution.
While I understand that market forces, subsidies etc drive a lot of decisions, often in counter intuitive ways, I’d like to step back from that and look at the what to me are basics or fundamentals of the problem we need to solve, delivering reliable electricity.
To keep the numbers simple, your goal is to deliver 1kW continuously 24hrs a day (I know actual grid load changes over a day) eg California average daily grid load changes from 20GW to 26GW (2014 numbers, https://www.nrdc.org/experts/sierra-martinez/new-and-improved-electric-grid-california). How would you do it?
Then you are an isolated system, ie you cannot rely on someone else to generate for you while you have no power, IMO it’s easy to hand wave away the storage problem (and importantly its associated cost), but this problem comes back once you get sufficient proportion of intermittent sources.
This link is source for overnight capital number (pg 7) https://www.eia.gov/analysis/studies/powerplants/capitalcost/pdf/capcost_assumption.pdf
Note I am assuming overnight capital is per name plate rating, and does NOT consider capacity factor.
Example 1) Delivering this 1kW with nat gas, let's pick something cool sounding Advance Natural Gas Combined Cycle:
Overnight capital =$1100/kw
Fixed O&M $10/kw-yr (Going to ignore variable O&M since it’s such a small number $2/MWh)
So let's assume you want some redundancy, so you build two 1kw turbines total cost:
$2200 capex, $20/kw-yr O&M
Conclusion: Cheap but makes CO2, basically 100% reliable power.
Example 2) Advanced nuclear:
Overnight capital 6000/kW (although I’ve seen projections as low as 4k/kw for SMR)
Fixed O&M $100/kw-yr
Since nuke plants have very high capacity factors and only really shut down for maint/refuel let's place an Advanced Combustion Turbine next to it as backup during this downtime (+700 capex):
Capex total $4700-$6700, $105/kw-yr O&M
Conclusion: Cost effective, no CO2, basically 100% reliable power.
Now for the fun…
Example 3) Solar PV.
This is where the comparisons need more math. Let’s say you live in a nice sunny place (ie ideal for solar PV), you get 8hrs of good sun a day. So in that 8hrs you must generate your days’ worth of power. So your total required capacity is 24kWhrs/8hrs = 3kW. So you need to install at least 3kW solar PV.
Required capex = $7800, O&M = $70/kw-yr
But that’s not the killer.
You also need to store 16kWhrs.
In that eia link, they list BES (battery electric storage) at $2800/kw, with $40 O&M. I’m going to assume that is $2800 per kw/hr of capacity (please correct if wrong, li ion battery cost is about $200/kwhr, then you need the power electronics, 2800/kwhr feels expensive).
Another example: Tesla 100MWhr battery cost about $90 million, this puts it about $1.1 per W/hr, or $1100/kwhr
Capex for storage = $22000-44800, O&M = $640/kw-yr
Total to deliver 1kW 24hrs a day is:
Capex = $30000-52600
O&M = 710/kw-yr
Conclusion: Outrageously expensive, and with only 16kWhr of storage and 3kW of panel you have no way to handle a cloudy day.
Example 4) Mixed wind and solar:
50/50 mix average generation wind solar, now this is where actual conditions have huge impact and I making some big assumptions.
Lets say this mixing of renewables allows you knock your storage requirements in half. I have no idea if this is reasonable or not!
So you install 1.5kW of solar (total 12kWhrs generated) and 2kW wind at 30% capacity factor (14.4kWhrs)
Total capex = 1.5*2600=$3900(solar), 2*1900=$3800 (wind) total = $7700
8Kwhrs storage = $8800-22400
Total = $17000-30100
Conclusion: Still very expensive, and with only 8kWhr of storage you have no power on a windless night.So given that just to generate your required 24kWhrs per day, solar is already 1.5-2x capex vs adv nuclear just for generating capacity why are we doing this? It makes no sense to me.
Then to sell solar and wind as being cost effective due to capex per kw name plate rating is at best an oversight, at worst basically fraud.
Labeling plants that deliver consistent power 24hrs a day as “inflexible” and therefore bad is obnoxious, our power needs are steady and “inflexible”, these inflexible sources should be preferred, and the intermittent sources shunned unless they include the cost of 24hr power delivery, not including storage just punts the problem to someone else.
Grid scale battery electric storage for renewable to me is utterly insane, to support California grid for 1 hr with Li ion (Tesla) you need 200 of those "worlds biggest battery", that only gets you one hour of hold up for one state in the US, how much lithium is there on this planet? Power plants that can deliver the required power with NO storage should be the goal.
My current position is that looking at it with the above in mind the only sensible thing is 100% nuclear, give the rivers back, take down the wind farms, take down the solar arrays. Why dam a river when you can fit 300MW capacity in the basement of an average building?
What am I missing?
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