How do you feel about offshore wind? It seems like a potent power source, each one can produce several MW of power. If we need 1TWh we need a few hundred thousand turbines.
I think the problem is that once you start analyzing the issue at scale the only solution that could be real today would be a widely distributed nuclear power generation system across the entire country. If we use a 1 GW reactor as the baseline, that means over a thousand power plants need to be built. While the distribution would not be uniform, for sake of easy numbers we can make this assumption and divide by 50 states. That means we need 20 new 1 GW class nuclear power plants per state. California might need 50, while Montana might be able to do with 5. Don't know, I did not model it to that level of detail.
The point is the scale of the requirement is absolutely massive. Almost unimaginable. And so, we have people in politics talking about no more internal combustion engines in 25 years and everyone conveniently ignores the physics that makes this absolutely impossible unless we start doing serious work immediately.
Solar sounds interesting on paper until you live the reality of solar. My 13 kW array is grossly inadequate for charging electric vehicles because the energy capacity I need has to be in excess of what we are using to run the home. We do a shit job of building efficient homes, so things like cooling your home in the heat of Southern California can easily run 5 kW for much of the day. The fantasy of a 13 kW array is that it is a 13 kW array. Well, it isn't. My peaks are around 8 kW on average. I reach 10 kW during a very narrow window of time in the year, the rest of the time this is what it looks like (actual data):
https://i.imgur.com/LTMNDO1.png
So, if you have two electric vehicles, an air conditioning system pulling 5 kW and other normal things in a normal home, well, this system is not adequate. I would have to probably install a 35 kW system to service all of it.
How many people are going go install 30+ kW systems on their homes to join the electric vehicle revolution? Even better: Most roofs simply don't have that much room. Add to this the fact that solar viability diminishes as you move north and you quickly realize solar isn't a magic-wand solution.
And, of course, now comes the problem of only having energy available while the sun is up. Which means you probably want a massive battery bank to store it and use it to charge your vehicles at night. AC to DC power conversion is in the order of 80% efficient. Charging, depending on technology, is about the same. So, you go from solar to charging and probably store about 65% of the energy you collect. Then you have to charge your vehicle at night. You have to convert it one more time. This means another 20% to 30% efficiency hit. In other words, the store-and-forward model is likely in the 50% range for energy (panel output to energy level in the car).
Physics is really heartless about this stuff. Most of the people (and politicians) pushing this stuff never bother to do any math, and, if they do, they conveniently ignore it.
To answer the obvious question: No, I am not going to upsize my system to 35 kW. That would be ridiculous and, in Los Angeles County, the building permit and regulatory issues you'd run into to put such a system on a home that more typically ends-up with a 7 kW system would be insane beyond description.
EDIT: One of the reasons for which my array peaks out at 8 kW is that the Los Angeles County Building and Permit department would not allow me to tilt the array to the optimal angle (about 34 degrees if I remember correctly). The array was built with the approved tilt angle of ten degrees. This is due to what I am going to call arcane regional planning rules and other issues. They also made me install --no bullshit-- 64000 lbs of concrete footings and design the array and structure for 200 mile per hour winds. The entire experience was beyond surreal and ridiculous. Want to talk about "clean" energy? Care to guess the CO2 contribution of making 64,000 lbs of concrete, which should include all the processes required to procure the raw materials, transport to the plant, make the concrete, mix it, load it into massive trucks, deliver and install it? I haven't done the math, but I would not be surprised if it exceeds the environmental benefit of having "clean energy" at home. Live and learn.
Whether you believe those studies or not is immaterial, though, because the economics of renewables are going to win in the end. Ten years ago you could have reasonable discussions about whether that was the case or not, but the trends did continue. The other day I saw a forecast of 0.04 USD/kWh for offshore wind within a few years.
I made some adjustments to my models and was able to get the cost of solar with batteries down. However, to be fair, I now need to factor in the actual solar generation efficiency (meaning, panel rating vs. what you actually get at the peak) as well as to account for the fact that the actual output power curve is roughly an inverted parabola. The energy produced by the system, then, would be the integral of the power curve over the period of solar production (roughly 7:00 AM until 5:00 PM).
One must then take into account that system efficiency (DC to AC conversion, battery charging, battery discharging) must consider a range of variables. For example, the Tesla Powerwall 2 is rated at something like 90% efficiency while only drawing 3.3 kW at what I would all laboratory-type environmental conditions: 25 degrees C. I am having trouble finding data on actual efficiency under real environmental conditions, hot and cold.
Beyond that, the efficiency of the cells (for any battery, not just Tesla's) degrades over time. In Tesla's case, they guarantee 70% over 10 years.
This means also modeling the replacement of millions of battery packs per year at or around the ten year lifespan range. Losing 30% of energy production would be a problem. So, you either overbuild or replace everything as soon as it drops below a certain threshold.
Over the 20 year deployment model I created, 5% of the battery packs would have to be replaced every year starting somewhere around 7 to 10 years after installation.
Then there's the lifespan and behavior of solar panels. I'll make the assumption that at the 20 year warranty expiration point, most solar panels will be at about 80% production. This assumes no other environmental factors are in play (dirt, scuffing of the glass, etc.). To finish the model one would have to include the negative temperature coefficient of panels: As the operating temperature increases, output decreases. A typical panel might have a coefficient of about -0.35% measured from a baseline of 25 degrees C. At 35 C, the panel produces 3.5% less energy. Panels can run very hot (60 C) because, well, the sun will heat them...they are not white reflectors. At 60 C the loss can be as high as 12%.
This, BTW, is why I installed three large (~6 ft diameter) fans under my solar array. I haven't done the math yet but I suspect they pay pay off in efficiency during the hottest periods of operation.
The model would have to allow for both failures and replacement due to degradation. I have friends with arrays consisting of around 15 panels who have already had to replace two or three panels after ten years. Once again, reality is far more stochastic than data sheet specifications.
Anyhow, the point is that the real-world model of solar energy systems is far from the simple idea of a solar array delivering power consistently and at peak performance.
I wonder how many of them have been updated to take into account constant wildfire smoke blotting out the sun in peak summer months.
It seems insane to me that we keep doubling-down on weather-dependent energy generation when everything we know about the weather is now in flux. Especially when we have a perfectly safe, scalable, and practically zero-carbon way to generate power sitting right next to us collecting dust.
Wait, what? Can you elaborate on why this was necessary? Thank you also for the useful data.
Once the plan checker got his mind set to these dimensions it was over. There was no way to convince him to apply any kind of logic to it. He quoted stuff like the 200 mile per our wind rating (also ridiculous) we had to certify the structure for. I even hired a nationwide civil engineering firm to try to apply pressure for a change. No. he would not allow us to proceed unless we went with his requirements.
It went beyond that, they issued insane fire rating requirements for the entire thing. My guess is that the project went $50K over budget because of these guys. Which means it will never pay for itself...ever. I would have done a million times better if I burned half the cash and put the rest on Bitcoin (which, at the time, would have felt like burning it).
So, it is a beautiful system but it was a complete waste of time and money. It made me wonder about the overall realities of solar in practice. If I knew then what I know now I would have never moved one finger to install solar.
BTW, I have neighbors with solar regrets for different reasons. One has to wonder.
A friend of mine is an architect. He told me the footings they had me pour would allow me to build a four story building on the same site.
As a libertarian/classical liberal this experience fed further confirmation of to my lack of interest for big government running everything. I can't even imagine the same level of surreal bullshit applied to, say, healthcare.