I post part of the reply here, as the comments box is too small and I really wanted to give a comprehensive reply (that also shows the limitations of what I know (or think I know)).
The reply is whole as was meant (previous comments will be added in reverse order below later).
I totally agree with your first paragraph. Totally. It does not make any sense to stop all damaging activity (at least not without a magic wand to simultaneously address several problems).
As to the attainability of renewables, I am not so sure. Again, I don’t work in the industry, don’t have the 100% overview on ALL that is happening, but what I can tell you is that a) costs are falling rapidly, b) efficiency is going up (to a certain limit, granted) and c) environmental impact varies from tech to tech, but is generally considered lower than that of fossil fuel industry, coal and nuclear power plants. I give examples and quotes in the next reply.
I don’t feel capable on commenting on the case you build for nuclear, as I did no research in that field. As I understood, we’re not near fusion yet and fission creates waste (that to me, again, in the long run, is not sustainable. Unless we haul it into space (unethical? boomerang?, space debris).
I fully agree that wind and PV have intermittency problems, however, as you partly point out, sun does not shine ON ALL SIDES of the planet at once. With a global network, ... well, with other sources added (wind can operate at night), we can go pretty high in terms of energy self (local)-reliability.
Thanks for explaining the “Long Beach oil” and the purity of it, energy needed to purify it. Makes it more clear now. Thanks!
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Costs
“Solar technology costs are falling rapidly. Chrystalline silicon PV module costs fell by 70 per cent 2008-January 2012 and are forecast to fall by another 30 per cent by 2015, without subsidies” (Assadourian et al., 2013: Loc 2067).
Energy demand estimates ... and meeting it with renewables
‘Estimates of energy required to meet the world’s continuously growing energy demand vary, and future energy use scenarios vary greatly in their outcomes. A medium scenario examined by European Union foresees doubling of current energy demand by 2050’ [“current” was 13.2 TW in 2011? and is 14 TW in 2012] (EC, 2006; Assadourian et al., 2013).
‘Instead of raising the number of nuclear power plants worldwide from 61 to 1200, based on the immense power that is radiated daily to Earth from the Sun (i.e., 5000 times the estimated requirements for 2050), if we could cover 1 % of the Earth’s land surface with solar panels operating at 10% efficiency, a rough estimate is photovoltaic power could generate around 25 TW’ (Peter, 2011).
Problem is, as Peter (2011) points out, the availability of minerals. For example, cadmium (Cd) for the CdTe solar cells, to meet this demand, one would require amount of Cd for a factor of a 100 exceeding the identified world reserves (Peter, 2011; 3). But, new ways and new cells are underway (for more, see Peter, 2011).
As to the environmental impact of Cadmium (from PV panels production) and other renewables, see Assadourian et al. (2013): they maintain (based on a number of sources) that renewables have lesser impact in total than fossil, though I would exclude biomass from it, as it appears to be the most unsustainable of the crowd.
And about meeting the energy demand in 2050, Assadourian et al. write: “Even with greatly limiting the areas for solar energy development /.../, the potential capacities are estimated at 340 terawatts (TW) for PV and 240 TW for CSP [concentrating solar power systems] – much more than projections for energy demand in 2050, even without any efficiency measures” (2013: Loc 2067).
Locally produced energy (which, granted, needs some more development and changes to the energy grids and distribution)
Another argument in favour of locally produced, renewable energy is (so I read) that of avoiding transmission and distribution costs. Renewable energy sources (e.g., wind, solar, small hydro, wave, and tidal energy), though having different impacts on the environment themselves (also in the book), “have the additional efficiency advantage of converting natural flows of mechanical energy or sunlight directly into electricity, unlike fossil fuel combustion and nuclear power, which require inherently inefficient thermal energy conversion processes.” (Assadourian et al., 2013: Loc 2053, link below).
From an abstract of a book titled Renewable revolution: low carbon energy by 2030 (Sawin & Moomaw, 2009):
Global energy scenarios offer wide-ranging estimates of how much energy renewable sources can contribute, and how quickly this can happen. Many scenarios show a gradual shift to renewables that still envisions a major role for fossil fuels for most of this century. This report examines the potential for renewable energy to provide needed energy services for all societies while lowering heattrapping emissions of greenhouse gases. It concludes that it is not only possible but also essential to effect a massive transformation of the global energy system from its current fossil fuel base between now and 2030 that continues for the rest of the century.
Carbon free?
Photovoltaic cells and panels have a CO2 release of one fifth of that of an average emission rate of conventional fossil fuel-generated electricity. This was calculated for DSCs, with a premise of an efficiency of 8 per cent and lifespan of 5 years, but the number grows even five times smaller for CdTe PV modules (Peter, 2011). Therefore, though not ‘carbon free’, the carbon of PV panels is small enough that a large scale implementation of PV can substantially provide for the world’s energy needs and at the same time addressing some of the problems of climate change (Elliston et al., 2013; Peter, 2011).
References
Assadourian, E., Prugh, T., Adamson, R., & Starke, L. (2013). State of the world 2013: is sustainability still possible?. Washington, DC [etc.]: Island Press.
(Assadourian et al., 2013: Loc 2053 : https://kindle.amazon.com/post/Sdj9B8pvQ-C70-q3GkZt0Q).
EC (2006). European Commission: World energy technology outlook 2050: WETO-H2. See
ftp://ftp.cordis.europa.eu/pub/fp7/energy/docs/weto-h2_en.pdf.
Elliston, B., Macgill, I., & Diesendorf, M. (2013). Least cost 100% renewable electricity scenarios in the Australian National Electricity Market. Energy Policy [In press]. DOI: 10.1016/j.enpol.2013.03.038.
Peter, L. M. (2011). Towards sustainable photovoltaics: the search for new materials. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 369 (1942), 1840-1856.
Sawin, J. L., & Moomaw, W. R. (2009). Renewable revolution: low carbon energy by 2030. Worldwatch Institute.) Link: http://www.cabdirect.org/abstracts/20103141191.html;jsessionid=623D63DEC4D6A3DFBDF201E7C4390340?freeview=true
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