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Or, how quickly will we exhaust the geothermal sites, the dam-able rivers, and the rare minerals that go into batteries and solar panels? With present technolo

Or, how quickly will we exhaust the geothermal sites, the dam-able rivers, and the rare minerals that go into batteries and solar panels? With present technology geothermal is going to be a niche source. Hydroelectric generation is not, but most of its potential in developed countries is already tapped. When I speak of large scale renewable growth I mean utility-scale photovoltaics and wind. Neither solar panels nor batteries for stationary energy storage require rare minerals. Lithium ion batteries that maximize energy density, like those in cars and portable electronic devices, usually contain the comparatively rare element cobalt, but this is not required if lower energy density is acceptable. Batteries that stay in one place don't need maximum energy density and can eliminate cobalt. Lithium itself is not rare; lithium iron phosphate is a perfectly fine battery chemistry for stationary applications and requires no rare minerals. My estimates of labor intensity for renewables do not include storage or overproduction (to diminish reliance on storage). The numbers I've provided are for incremental nearer-term goals achievable without storage, like "displace the 28% of American electricity that comes from coal with renewables." Storage is immature and I'd be piling speculation on top of speculation if I tried to estimate how much storage and/or overproduction a zero-fossil energy system needs, and how much labor that will require. Note that a zero-fossil energy system built on nuclear foundations will need to deal with these questions too eventually; the difference between peak and average demand for electricity means that nuclear reactors too would need to be overbuilt or coupled with storage to take the place of fossil peakers. I think that nuclear power is quite safe enough, certainly safer than continued fossil combustion. I don't have any grudge against nuclear apart from the high costs and unpredictable schedules that have attended attempts to build new units. 15 years ago I thought it was obvious that building even the cheapest solar farms was a more expensive way to generate electricity than building an average nuclear reactor. But the numbers changed, and I changed my mind along with them.

arduanika 8y ago
Very interesting, thanks. I too would like to see "utility-scale photovoltaics". So...what is the limiting factor in producing new solar panels? A raw material, or well-lit land near population centers, or political will, or what?
- philipkglass 8y ago
  World capacity for the production of new solar panels is significantly under-used right now. There are no raw material limits in the short-medium term[1]. The rate of expansion of solar production is limited more by demand than supply at the moment. Some countries have dense populations and poor availability of sunny land, like Belgium and the Netherlands. The US has better sun and lower population density. There is some resistance to retiring coal from people who make money from coal. But generally speaking solar has always had a favorable public image apart from the high costs -- and the high costs are now turning into moderate and even low costs. Since large cost reductions have been so very recent, it's just taking a while for everyone to catch up. Just this month Florida Power and Light surprisingly announced plans to build more solar power than any other regulated utility in the world, for example: https://www.greentechmedia.com/articles/read/florida-power-and-lights-30-million-panel-promise-mean-for-florida https://www.greentechmedia.com/articles/read/florida-power-a... Their first large-scale solar project was a 25 megawatt facility built in 2009. Last year and this year they're adding solar capacity of about 300 MW per year. With the "30 by 30" announcement they apparently want to accelerate that to beyond 1000 MW per year. [1] In the long term, manufacturers will have to stop using conductive silver pastes to make cell contacts and switch to more abundant base metals like copper, tin, nickel, or aluminum. Multiple companies have already used copper metallization instead of silver at an industrial scale so I'm reasonably confident that this eventually-necessary transition will not be too difficult.
  - speedplane 8y ago
    Have you considered real estate prices? I don't doubt any of the stats you cite, but it seems that one of the biggest impediments to solar is the huge amount of area it requires. The real estate costs of putting such plants nearby large population centers seems to be one of the major costs. Rooftop solar seems to be a good solution, but it's still not economical without generous government incentives. Anecdote: A colleague of mine is trying to get approval for solar panels on top of a property she owns in a high density area of New Jersey. After doing an in depth cost/benefit analysis, she found it was economical, but only because New Jersey has very large incentives. Roughly 2/3 of the project would be financed by the government either in grants or tax credits.

arduanika 8y ago

Very interesting, thanks. I too would like to see "utility-scale photovoltaics". So...what is the limiting factor in producing new solar panels? A raw material, or well-lit land near population centers, or political will, or what?

philipkglass 8y ago
World capacity for the production of new solar panels is significantly under-used right now. There are no raw material limits in the short-medium term[1]. The rate of expansion of solar production is limited more by demand than supply at the moment. Some countries have dense populations and poor availability of sunny land, like Belgium and the Netherlands. The US has better sun and lower population density. There is some resistance to retiring coal from people who make money from coal. But generally speaking solar has always had a favorable public image apart from the high costs -- and the high costs are now turning into moderate and even low costs. Since large cost reductions have been so very recent, it's just taking a while for everyone to catch up. Just this month Florida Power and Light surprisingly announced plans to build more solar power than any other regulated utility in the world, for example: https://www.greentechmedia.com/articles/read/florida-power-and-lights-30-million-panel-promise-mean-for-florida https://www.greentechmedia.com/articles/read/florida-power-a... Their first large-scale solar project was a 25 megawatt facility built in 2009. Last year and this year they're adding solar capacity of about 300 MW per year. With the "30 by 30" announcement they apparently want to accelerate that to beyond 1000 MW per year. [1] In the long term, manufacturers will have to stop using conductive silver pastes to make cell contacts and switch to more abundant base metals like copper, tin, nickel, or aluminum. Multiple companies have already used copper metallization instead of silver at an industrial scale so I'm reasonably confident that this eventually-necessary transition will not be too difficult.
- speedplane 8y ago
  Have you considered real estate prices? I don't doubt any of the stats you cite, but it seems that one of the biggest impediments to solar is the huge amount of area it requires. The real estate costs of putting such plants nearby large population centers seems to be one of the major costs. Rooftop solar seems to be a good solution, but it's still not economical without generous government incentives. Anecdote: A colleague of mine is trying to get approval for solar panels on top of a property she owns in a high density area of New Jersey. After doing an in depth cost/benefit analysis, she found it was economical, but only because New Jersey has very large incentives. Roughly 2/3 of the project would be financed by the government either in grants or tax credits.