POLYA, Gideon. Dr Gideon Polya (Australian biochemist and climate activist) on technically achieving 100% renewable energy for Australia by 2020

Dr Gideon Polya (Australian biochemist and climate activist) on 100% renewable energy by 2020, cessation of GHG pollution, re-afforestation, biochar & bicarbonate to return to 300 ppm CO2 from current disastrous 400 ppm CO2 (2011): “1. The Beyond Zero Emissions (BZE) plan for 100% renewable stationary energy for Australia by 2020 (Zero Carbon Australia by 2020, ZCA 2020) involves 40% wind energy, 60% concentrated solar thermal (CST) with molten salts energy storage for 24/7 baseload power, biomass and hydroelectric backup (for days of no wind and low sunshine) and a HV DC and HC AC national power grid. The BZE scheme was costed at $370 billion over 10 years, with roughly half spent on CST, one quarter on wind and one quarter on the national electricity grid.

2. Seligman scheme. A scheme for 100% renewable energy for Australia has been set out by top electrical engineer Professor Peter Seligman (a major player in development of the bionic ear). Professor Seligman’s scheme involves wind, solar thermal, other energy sources, hydrological energy storage (in dams on the Nullabor Plain in Southern Australia), an HV AC and HV DC electricity transmission grid and a cost over 20 years of $253 billion.

3. Wind power. Ignoring cost-increasing energy storage and transmission grid costs and cost-decreasing economies of scale for a 2- to 10-fold size increase, here are 2 similar cost estimates for installation of wind power for 80% of Australia’s projected 325,000 GWh of annual electrical energy by 2020: (1) 90,000 MW capacity, 260,000 GWh/year, $200 billion/10 years (10-fold scale-up from GL Garrad Hassan) and (2) 96,000 MW, 260,000 GWh/year, $144 billion (2-fold scale up from BZE ).

4. Science-demanded reduction of atmospheric CO₂ from current 400 ppm to 300 ppm requires “negative GHG emissions” achieved by cessation of GHG pollution ASAP and CO₂ reduction though re-afforestation, renewable energy driven CO₂ trapping in alkaline solutions, and biochar (as much as 12 billion tonnes carbon as biochar can be fixed annually globally from renewable energy-driven anaerobic pyrolysis of existing agricultural and forestry cellulosic waste).

5. Re-afforestation (SE Australian native forests are World’s best forest carbon sinks; 14 M ha, 25.5 Gt CO₂, 460 Mt CO₂/yr avoided for next 100 years if retained. Sir Nicholas Stern: only $20 billion pa to halve annual global deforestation.

6. Livestock production inefficient, requires compensating carbon sinks – we are all in this together.

7. Biochar. Atmospheric CO2 can be reduced from the current 400 ppm CO2 back to a safe and sustainable 300 ppm CO2 by fixing CO2 as cellulose via solar-energy-driven photosynthesis (nCO₂ + nH₂O -> (CH₂O)_n + O₂ ) with subsequent anaerobic pyrolysis of cellulosic material (e.g. waste wood and straw) to yield carbon (C, charcoal) ((CH₂O)_n -> nC + n H₂O).which can then be added to soil or buried in holes in the ground (e.g. used coal mines). Thus p224, Progress in Thermochemical Biomass Conversion, volume 1, IAE Bioenergy, ed. A,V, Bridgewater (Blackwell Science) informs us that we could obtain 1.7 GtC/yr (straw from agriculture) + 4.2 GtC/yr (total grass upgrowth from grasslands upgrowth) + 6 GtC/yr (possible sustainable wood harvest) = 11.9 GtC/yr. From this one can see why biochar expert Professor Johannes Lehmann of Cornell University is correct calculating that it is realistically possible to fix 9.5bn tonnes of carbon per year as biochar, noting that global annual production of carbon from fossil fuels is about 9 bn tonnes.

Unfortunately, biochar is expensive to produce and thus for every $1 derived from coal burning, $2-$3 will have to be spent at today's prices by future generations converting the consequent CO₂ back to carbon (biochar) (based on US mid-West corn stalk-derived biochar; multiply this by by 4 for the cost in the UK) i.e. a major issue of intergenerational equity.

8. CO₂ trapping as carbonate (CO₃^-). Theoretically one can use solar energy or indeed other renewable energy to generate alkaline solutions (high OH^- concentration) from electrolysis of saline solutions (i.e. NaCl solutions e.g. sea water) and thence trap CO₂ thus: 2Na⁺ + CO₂ + 2OH^- -> CO₃^- + H₂O + 2 Na⁺ (solid Na₂CO₃ can be stored underground).

9. Accelerated Weathering of Limestone (AWL).The waste gas from burning coal or gas is passed through a sea water-limestone (CaCO₃) scrubber with the following reaction: CO₂ (gas) + CaCO₃ (solid) + H₂O <-> Ca²⁺ (aqueous) + 2 HCO^3- (aqueous) . The scrubbing solution is then piped to the sea. Carbon in the oceans as bicarbonate is 10 times that in all recoverable fossil fuel reserves and about 60 times that in the CO2 in the atmosphere. The carbon in carbonate minerals is about 4,000 times greater than the carbon in oil and coal fossil fuel reserves and the AWL process would in part reverse the deleterious acidification the oceans due to the massive CO2 pollution of the atmosphere” (Section H, Gideon Polya, “2011 climate change course”: https://sites.google.com/site/300orgsite/2011-climate-change-course ).