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> “If California is to have any hope of getting to 100% renewable energy on an August day in the future ... it will take 100 GW more energy produced by solar. H

> “If California is to have any hope of getting to 100% renewable energy on an August day in the future ... it will take 100 GW more energy produced by solar. Halting the progress of rooftop solar makes that goal impossible" I'm also confused by the scales here. How are they praising the use of 15,000 MW (15GW) and 8,000 MW (8 GW) in one sentence, in an article about 97% of California's energy being used, and saying they need 100 GW in the next sentence and being sad they can't put it on rooftops. In an article showing a photo of a solar cell field in a vast, desolate, arid region of central valley.

Retric 4y ago
In California August requires a lot more electricity due to AC than April. Seasonal demand differences can be huge, and why a lot of maintenance for nuclear reactors etc take place in the spring and fall.
- vmception 4y ago
  I'm catching on. Is there not enough space in central valley for this? is there too much loss transporting that electricity to population centers?
  - Retric 4y ago
    In theory moving electricity 1,000 miles can have minimal transmission losses. Unfortunately California’s grid lacks the infrastructure to support significant long distance transmission.
    - incomethax 4y ago
      Sort-of. Transmission for HTHV lines (745kV single circuit cost $2.5-4M/mile with ~1% line loss; 345kV single circuit will cost ~$1.5-2M/mile with 5% line loss). For 1MW solar capacity you typically need about 4 acres. 100GW of solar would require 400k acres of land - and come at a cost of about $3 billion for the panels, not to mention the price of land or entitlements. Add in cost of substations and transmission you’re realistically looking at a $10+ Billion project. Which while doable would not profitability compete with other grid solutions. If panels drop by another 30% and power densities improve the grid will naturally tend towards that direction.
      - outworlder 4y ago
        If I were a billionaire, I could spend 10 billion project with a massive reduction in fossil fuel emissions. Or I could spend over 4 times as much to buy a social media site. Decisions, decisions.
        vmception 4y ago
        One sounds like an expense, the other sounds like a transfer from one pocket to the other while allowing for shifting the public perception any way desired while retaining unparalleled access to capital.
      - zeroonetwothree 4y ago
        If only we weren't spending $105 billion high speed rail no one will use, we might have been able to scrounge up $10 billion for solar.
      - Retric 4y ago
        The US already has 121GW of solar installed the majority of that being large scale Grid solar. Which shows the transition is already happening at current prices. A major part of that equation is there is a lot of land in the US available for under 2,000$/acre, however spending more is a tradeoff to reduce the need for longer distance power transmission etc. PS: 10B for 100GW at 30% capacity factor for 20 years is 10,000,000,000$ / (100,000,000kW * 0.3 * 24h * 365 * 20) or 0.2c/kWh ignoring interest. So, I think you messed up your estimate somewhere if you think that’s uncompetitive.
    - VintageCool 4y ago
      California already has some big long-distance transmission lines. Path 65 (aka Pacific DC Intertie) is a 3.1 GW line connecting the hydroelectric dams of Washington and Oregon to Los Angeles. Path 27 (Intermountain DC) is a 2.4 GW line connecting LA to a big-ass coal plant in Utah that is being shifted to wind+solar+natgas+hydrogen. Path 66 is a set of AC lines that combine for 4.8 GW from Oregon to Southern California.
      - Retric 4y ago
        Yes, but not of the places you listed are where you would put solar to supply California. If anything they will likely be used to move excess solar power out of California. The map of solar production shows a compromise between building it in the most efficient place vs where demand and incentives is located. https://en.wikipedia.org/wiki/Solar_power_in_the_United_States#/media/File:U.S._utility-scale_fixed-tilt_solar_photovoltaic_electricity_generating_capacity_in_2017_(44840888834).png https://en.wikipedia.org/wiki/Solar_power_in_the_United_Stat...
  - jeffbee 4y ago
    Space is of no concern. You would not install solar in the Central Valley generally because it is the most productive irrigated farmland on the planet. You would however put it right on top of Edwards Air Force Base, which is large enough to supply the energy needs of the entire United States, if paved over completely with solar panels.
    - throwaway48375 4y ago
      There's plenty more empty space in the adjacent area.
imachine1980_ 4y ago
not all california energy is produce in california california fo example pays to nevada if don't remember wrong to, shut down their panels to make their output higher than it is for example, or like this articule say pay other state to buy their electric excess output meaning the technically could be true article: California invested heavily in solar power. Now there's so much that other states are sometimes paid to take it https://www.latimes.com/projects/la-fi-electricity-solar/ https://www.latimes.com/projects/la-fi-electricity-solar/
- ocbyc 4y ago
  Shame only one period in this entire reply.
everybodyknows 4y ago
Earlier rooftop solar discussion: https://news.ycombinator.com/item?id=30193521 https://news.ycombinator.com/item?id=30193521

Retric 4y ago

In California August requires a lot more electricity due to AC than April. Seasonal demand differences can be huge, and why a lot of maintenance for nuclear reactors etc take place in the spring and fall.

vmception 4y ago
I'm catching on. Is there not enough space in central valley for this? is there too much loss transporting that electricity to population centers?
- Retric 4y ago
  In theory moving electricity 1,000 miles can have minimal transmission losses. Unfortunately California’s grid lacks the infrastructure to support significant long distance transmission.
  - incomethax 4y ago
    Sort-of. Transmission for HTHV lines (745kV single circuit cost $2.5-4M/mile with ~1% line loss; 345kV single circuit will cost ~$1.5-2M/mile with 5% line loss). For 1MW solar capacity you typically need about 4 acres. 100GW of solar would require 400k acres of land - and come at a cost of about $3 billion for the panels, not to mention the price of land or entitlements. Add in cost of substations and transmission you’re realistically looking at a $10+ Billion project. Which while doable would not profitability compete with other grid solutions. If panels drop by another 30% and power densities improve the grid will naturally tend towards that direction.
    - outworlder 4y ago
      If I were a billionaire, I could spend 10 billion project with a massive reduction in fossil fuel emissions. Or I could spend over 4 times as much to buy a social media site. Decisions, decisions.
      - vmception 4y ago
        One sounds like an expense, the other sounds like a transfer from one pocket to the other while allowing for shifting the public perception any way desired while retaining unparalleled access to capital.
    - zeroonetwothree 4y ago
      If only we weren't spending $105 billion high speed rail no one will use, we might have been able to scrounge up $10 billion for solar.
    - Retric 4y ago
      The US already has 121GW of solar installed the majority of that being large scale Grid solar. Which shows the transition is already happening at current prices. A major part of that equation is there is a lot of land in the US available for under 2,000$/acre, however spending more is a tradeoff to reduce the need for longer distance power transmission etc. PS: 10B for 100GW at 30% capacity factor for 20 years is 10,000,000,000$ / (100,000,000kW * 0.3 * 24h * 365 * 20) or 0.2c/kWh ignoring interest. So, I think you messed up your estimate somewhere if you think that’s uncompetitive.
  - VintageCool 4y ago
    California already has some big long-distance transmission lines. Path 65 (aka Pacific DC Intertie) is a 3.1 GW line connecting the hydroelectric dams of Washington and Oregon to Los Angeles. Path 27 (Intermountain DC) is a 2.4 GW line connecting LA to a big-ass coal plant in Utah that is being shifted to wind+solar+natgas+hydrogen. Path 66 is a set of AC lines that combine for 4.8 GW from Oregon to Southern California.
    - Retric 4y ago
      Yes, but not of the places you listed are where you would put solar to supply California. If anything they will likely be used to move excess solar power out of California. The map of solar production shows a compromise between building it in the most efficient place vs where demand and incentives is located. https://en.wikipedia.org/wiki/Solar_power_in_the_United_States#/media/File:U.S._utility-scale_fixed-tilt_solar_photovoltaic_electricity_generating_capacity_in_2017_(44840888834).png https://en.wikipedia.org/wiki/Solar_power_in_the_United_Stat...
- jeffbee 4y ago
  Space is of no concern. You would not install solar in the Central Valley generally because it is the most productive irrigated farmland on the planet. You would however put it right on top of Edwards Air Force Base, which is large enough to supply the energy needs of the entire United States, if paved over completely with solar panels.
  - throwaway48375 4y ago
    There's plenty more empty space in the adjacent area.

imachine1980_ 4y ago

not all california energy is produce in california california fo example pays to nevada if don't remember wrong to, shut down their panels to make their output higher than it is for example, or like this articule say pay other state to buy their electric excess output meaning the technically could be true article: California invested heavily in solar power. Now there's so much that other states are sometimes paid to take it https://www.latimes.com/projects/la-fi-electricity-solar/ https://www.latimes.com/projects/la-fi-electricity-solar/

ocbyc 4y ago
Shame only one period in this entire reply.

everybodyknows 4y ago

Earlier rooftop solar discussion: https://news.ycombinator.com/item?id=30193521 https://news.ycombinator.com/item?id=30193521