A scale-able path to a sustainable world energy system by affordably replacing fossil fuels with solar energy
|
|
Energy Economics and Energy Production:
Current energy economics:
The politics of energy and climate change are complex with many opinions and much debate. However independent surveys always show that there is a majority consensus on the need to reduce CO2 emissions. This consensus has resulted in a surprisingly large amount of money ($250 B+/year) being spent worldwide on wind, solar and bio fuels (about half of this from government supported subsidies). The figure on the left above shows the 2014 world investment in new electricity generation equipment which shows that this $250 B amounts to about half the world's current $500 B annual investment in new electricity generation. Unfortunately as the second column in this diagram shows, due to the high cost and low capacity factor of wind and especially solar generation, this investment is only providing a small fraction of new average electricity generation capacity, 7 GW average (as opposed to its 40 GW nameplate capacity, which exaggerates wind and solar capacity). To reduce CO2 to 450 ppm by 2050 needs the equivalent of around 1 TW average new generation every year to replace fossil fuel primary energy of 1 TWy. see video
This shows the ineffectiveness of current policies supporting wind and solar in reducing CO2 emissions. Scaling the current policy of supporting wind and solar (assuming current rates of cost reduction with cumulative volume) to the approximately 1 TWa yearly new capacity required to eliminate CO2 emissions by 2050 would require at least 20X current yearly spending on wind and solar. This would be about $5 T/year, or over three times ALL current world $1.8 T annual investment in energy infrastructure shown in the figure on the right. This level of increased spending on energy is significant relative to total current world GDP of about $70T/y and would cause severe economic decline and a worldwide depression.
StratoSolar economics:
StratoSolar offers a solution that improves the effectiveness of current PV investment by providing 3X more generation for each dollar currently spent on utility scale in the desert and about 7X the overall current world average PV generation, which is reduced by cloudy, low capacity factor, northern locations and expensive rooftop installations. It accomplishes this by generating electricity with a combination of a low capital cost and a 3X higher capacity factor. Just as importantly it includes a low cost gravity energy storage solution for night-time generation and does not need backup generation to handle long duration random intermittency from clouds and weather. The rightmost column of the graph on the left shows the significant improvement in the amount of average generation if the current PV investment was spent on StratoSolar instead. This investment would need no government subsidy, saving government the over $100 B/y. subsidy cost for alternative energy. To generate these savings, the tradeoff is StratoSolar needs initial investment of a few millions.
Based on costs that match current (2017) PV panel plus system (BOS) costs of around $1.00/Wp for utility scale systems, StratoSolar could immediately provide cost competitive, cheap electricity (about $0.015/kWh to $0.03/kWh depending on financing costs) without subsidy, far less than half the lowest cost of current PV generated electricity and lower than electricity generated from gas or coal. Also, based on the historical 20% learning rate, as the installed cumulative PV generation Wp nameplate capacity ramped up over about a ten year period to about 4 TWp, the capital cost would reduce to less than $0.50/Wp and the resulting generated electricity cost would reduce to about $0.01/kWh. Then, investment in generation at between $0.5T and $1.0 T yearly out to 2050 would completely replace current fossil fuel energy with lower cost and CO2 free PV energy. This is far less than the world's current investment in energy infrastructure of about $1.8 T/y, which will need to double with economic growth by 2050.
This shows that moving to a CO2 emissions free future can be accomplished affordably and gradually, in a timeframe that keeps overall CO2 emissions close to the 450 ppm goal, all without disrupting the current energy infrastructure or risking economic growth. The key that makes this scenario realistic is that it is built on the solid foundation of a mature, high volume, PV manufacturing infrastructure and a PV technology roadmap that will lower cost with cumulative installed capacity. Realists like Vaclav Smil say that energy transitions take 80 to 100 years. Though it is not widely appreciated, current PV technology is already fifty years into its energy transition. StratoSolar is an incremental innovation that can enable PV to successfully scale and complete its energy transition by 2050.
Future energy production system scenarios:
Meeting the 450 ppm CO2 reduction goal by 2050 with a StratoSolar based combined electricity generation and gravity energy storage solution would result in a very different world energy system than that forecast by current EIA 2050 baseline projections. The links below point to three scenarios for 2050, each with the same final used energy consumption. The first scenario is a reference, largely fossil fuels based scenario based on the EIA baseline projection of current trends. The other two are possible StratoSolar based scenarios also detailed in the Sankey diagrams below. The StratoSolar based systems obtain all primary energy from non fossil fuel sources, mainly StratoSolar based solar energy. The Sankey diagrams provide an easy to grasp, quantitative visual view of the major energy producers and consumers and the flow of energy between them.
The StratoSolar fuel based scenario assumes that energy usage from fuels in the major economic sectors remains the same, but the fuel is now synthesized. This scenario requires 31 TWy of primary energy. The electricity based scenario assumes that cheap electricity would drive the sectors to consume energy from cheap electricity rather than expensive synthetic fuels. This scenario has the same amount of used energy but far less energy is rejected. This more efficient system only needs 19 TWy of primary energy. Broad adoption of heat pumps and electric cars would make this scenario realistic.
These scenarios illustrate that getting to a fossil fuel free energy system involves a lot more than just cheap electricity generation. The entire infrastructure will need to change and investments in this infrastructure will cost more than the investment in generation.
2050 EIA primary world energy baseline projection energy system scenario.
2050 StratoSolar fuel consumption based energy system scenario.
2050 StratoSolar electricity consumption based energy system scenario.
The politics of energy and climate change are complex with many opinions and much debate. However independent surveys always show that there is a majority consensus on the need to reduce CO2 emissions. This consensus has resulted in a surprisingly large amount of money ($250 B+/year) being spent worldwide on wind, solar and bio fuels (about half of this from government supported subsidies). The figure on the left above shows the 2014 world investment in new electricity generation equipment which shows that this $250 B amounts to about half the world's current $500 B annual investment in new electricity generation. Unfortunately as the second column in this diagram shows, due to the high cost and low capacity factor of wind and especially solar generation, this investment is only providing a small fraction of new average electricity generation capacity, 7 GW average (as opposed to its 40 GW nameplate capacity, which exaggerates wind and solar capacity). To reduce CO2 to 450 ppm by 2050 needs the equivalent of around 1 TW average new generation every year to replace fossil fuel primary energy of 1 TWy. see video
This shows the ineffectiveness of current policies supporting wind and solar in reducing CO2 emissions. Scaling the current policy of supporting wind and solar (assuming current rates of cost reduction with cumulative volume) to the approximately 1 TWa yearly new capacity required to eliminate CO2 emissions by 2050 would require at least 20X current yearly spending on wind and solar. This would be about $5 T/year, or over three times ALL current world $1.8 T annual investment in energy infrastructure shown in the figure on the right. This level of increased spending on energy is significant relative to total current world GDP of about $70T/y and would cause severe economic decline and a worldwide depression.
StratoSolar economics:
StratoSolar offers a solution that improves the effectiveness of current PV investment by providing 3X more generation for each dollar currently spent on utility scale in the desert and about 7X the overall current world average PV generation, which is reduced by cloudy, low capacity factor, northern locations and expensive rooftop installations. It accomplishes this by generating electricity with a combination of a low capital cost and a 3X higher capacity factor. Just as importantly it includes a low cost gravity energy storage solution for night-time generation and does not need backup generation to handle long duration random intermittency from clouds and weather. The rightmost column of the graph on the left shows the significant improvement in the amount of average generation if the current PV investment was spent on StratoSolar instead. This investment would need no government subsidy, saving government the over $100 B/y. subsidy cost for alternative energy. To generate these savings, the tradeoff is StratoSolar needs initial investment of a few millions.
Based on costs that match current (2017) PV panel plus system (BOS) costs of around $1.00/Wp for utility scale systems, StratoSolar could immediately provide cost competitive, cheap electricity (about $0.015/kWh to $0.03/kWh depending on financing costs) without subsidy, far less than half the lowest cost of current PV generated electricity and lower than electricity generated from gas or coal. Also, based on the historical 20% learning rate, as the installed cumulative PV generation Wp nameplate capacity ramped up over about a ten year period to about 4 TWp, the capital cost would reduce to less than $0.50/Wp and the resulting generated electricity cost would reduce to about $0.01/kWh. Then, investment in generation at between $0.5T and $1.0 T yearly out to 2050 would completely replace current fossil fuel energy with lower cost and CO2 free PV energy. This is far less than the world's current investment in energy infrastructure of about $1.8 T/y, which will need to double with economic growth by 2050.
This shows that moving to a CO2 emissions free future can be accomplished affordably and gradually, in a timeframe that keeps overall CO2 emissions close to the 450 ppm goal, all without disrupting the current energy infrastructure or risking economic growth. The key that makes this scenario realistic is that it is built on the solid foundation of a mature, high volume, PV manufacturing infrastructure and a PV technology roadmap that will lower cost with cumulative installed capacity. Realists like Vaclav Smil say that energy transitions take 80 to 100 years. Though it is not widely appreciated, current PV technology is already fifty years into its energy transition. StratoSolar is an incremental innovation that can enable PV to successfully scale and complete its energy transition by 2050.
Future energy production system scenarios:
Meeting the 450 ppm CO2 reduction goal by 2050 with a StratoSolar based combined electricity generation and gravity energy storage solution would result in a very different world energy system than that forecast by current EIA 2050 baseline projections. The links below point to three scenarios for 2050, each with the same final used energy consumption. The first scenario is a reference, largely fossil fuels based scenario based on the EIA baseline projection of current trends. The other two are possible StratoSolar based scenarios also detailed in the Sankey diagrams below. The StratoSolar based systems obtain all primary energy from non fossil fuel sources, mainly StratoSolar based solar energy. The Sankey diagrams provide an easy to grasp, quantitative visual view of the major energy producers and consumers and the flow of energy between them.
The StratoSolar fuel based scenario assumes that energy usage from fuels in the major economic sectors remains the same, but the fuel is now synthesized. This scenario requires 31 TWy of primary energy. The electricity based scenario assumes that cheap electricity would drive the sectors to consume energy from cheap electricity rather than expensive synthetic fuels. This scenario has the same amount of used energy but far less energy is rejected. This more efficient system only needs 19 TWy of primary energy. Broad adoption of heat pumps and electric cars would make this scenario realistic.
These scenarios illustrate that getting to a fossil fuel free energy system involves a lot more than just cheap electricity generation. The entire infrastructure will need to change and investments in this infrastructure will cost more than the investment in generation.
2050 EIA primary world energy baseline projection energy system scenario.
2050 StratoSolar fuel consumption based energy system scenario.
2050 StratoSolar electricity consumption based energy system scenario.
Elements of a complete sustainable energy system
Elements of future sustainable, carbon free, energy production systems:
This diagram shows the elements of a complete sustainable energy system that can evolve naturally from today's largely fossil fuel based system. A complete solution needs to provide daily storage for night-time electricity generation and synthesis of methane gas and liquid fuels for transportation and industry. These can also provide long term seasonal energy storage. The existing natural gas network has more than adequate storage for seasonal use. Most of the work on developing fuel synthesis technology is happening in Germany today. Synthetic fuel generation infrastructure would not need to achieve scale for at least a decade. StratoSolar electricity generation costs are already low enough to enable affordable synthetic fuels from hydrogen electrolysis and fuel synthesis plants. Scaling the technologies will take time but the low cost of StratoSolar electricity means that the economics of synthetic fuels competitive with fossil fuels is already established.
This first assumes a transition from coal to natural gas combined with alternative energy generation. This then leads to a transition to a completely sustainable alternative energy electricity generation system. The cumulative capacity growth of these first two stages leads to cheap electricity. This enables the affordable manufacture of synthetic fuels and the time allows development of the synthesis technologies. This process is gradual and involves little disruption of the current energy system. Currently there is little investment in hydrogen and fuel synthesis at large scale. This cannot and will not occur until PV generated electricity is cheap enough to enable the production of synthetic fuels that can compete economically with fossil fuels.
There are various options whose scale and/or presence in a future energy system will be dictated by the economics of the technologies as they are developed. The central technology for fuel synthesis is the manufacture of hydrogen from the electrolysis of water. This hydrogen can be stored and burned directly for seasonal electricity generation. It also serves as a feedstock for gas and liquid hydrocarbon fuel synthesis and ammonia synthesis.
This diagram shows the elements of a complete sustainable energy system that can evolve naturally from today's largely fossil fuel based system. A complete solution needs to provide daily storage for night-time electricity generation and synthesis of methane gas and liquid fuels for transportation and industry. These can also provide long term seasonal energy storage. The existing natural gas network has more than adequate storage for seasonal use. Most of the work on developing fuel synthesis technology is happening in Germany today. Synthetic fuel generation infrastructure would not need to achieve scale for at least a decade. StratoSolar electricity generation costs are already low enough to enable affordable synthetic fuels from hydrogen electrolysis and fuel synthesis plants. Scaling the technologies will take time but the low cost of StratoSolar electricity means that the economics of synthetic fuels competitive with fossil fuels is already established.
This first assumes a transition from coal to natural gas combined with alternative energy generation. This then leads to a transition to a completely sustainable alternative energy electricity generation system. The cumulative capacity growth of these first two stages leads to cheap electricity. This enables the affordable manufacture of synthetic fuels and the time allows development of the synthesis technologies. This process is gradual and involves little disruption of the current energy system. Currently there is little investment in hydrogen and fuel synthesis at large scale. This cannot and will not occur until PV generated electricity is cheap enough to enable the production of synthetic fuels that can compete economically with fossil fuels.
There are various options whose scale and/or presence in a future energy system will be dictated by the economics of the technologies as they are developed. The central technology for fuel synthesis is the manufacture of hydrogen from the electrolysis of water. This hydrogen can be stored and burned directly for seasonal electricity generation. It also serves as a feedstock for gas and liquid hydrocarbon fuel synthesis and ammonia synthesis.
Cost of future sustainable energy systems
Click for a larger image.
As the Sankey diagrams above show, there is more to an energy system than electricity generation. Fundamentally the problem with replacing fossil fuels is cost, but cost is rarely examined at this complete energy system level. The tables above show two cost estimates for the elements of the electricity based solution shown in the Sankey diagram above. The first case is StratoSolar and the second is a ground PV/wind solution. Both solutions are based on the same technologies. StratoSolar uses less PV generation capacity at a higher utilization. StratoSolar also does not require backup generation.
Given there are no variable operation and maintenance costs, capital costs dominate. Starting with the TWy column of average demand for each element (in the leftmost column), we use an estimate of capacity factor to get nameplate capacity. With this nameplate capacity and a $/W capital cost we calculate capital cost, $T. Spreading the cost over 30 years we get the yearly capital investment in Trillions of dollars. Fixed O&M is estimated at 2% of capital cost. Efficiency is energy out/energy in. These inputs let us calculate the individual $/kWh for each energy system element, based on 8% WACC and 20-year financing. The total $/kWh shows the total cost of energy based on the sum of the stages needed. E.g. the synthesis output column is the sum of generation and synthesis individual column elements. The $/kg shows the fuel cost based on 1kg of hydrogen which is close to one gallon of gasoline.
The $/W capital cost estimates for the various system elements are based on current goals and projections.
Generation:Today the average capital cost for PV generation exceeds $1.50/W. The 2030 projected cost is $0.50/W for ground PV and $0.27/W for StratoSolar. The StratoSolar $/W is better because of better operating conditions producing more power for the same PV panel. Ground PV panel rating is based on a solar input of 1kW/m2 and an operating temperature of 30C. StratoSolar is based on a solar input of 1.3kW/m2 and an operating temperature of -30C. In addition, StratoSolar has a capacity factor of 45% while ground PV is 20%. This is because ground PV has significant losses from atmospheric absorption and clouds while StratoSolar has very little losses from absorption and none from clouds.
Storage and synthesis: Capital costs for batteries or competing energy storage solutions are aiming for $1.00/W and twenty-year life. No storage technology can achieve these two numbers together today and no new storage technology has achieved any scale. Similarly, synthesis has goals for $1.00/W. H2 based electricity generation could be from gas turbines or fuel cells if that technology can become economically viable.
There are two overall systems shown in the tables, StratoSolar and a Ground PV/Wind. The $/W capital costs are estimates for 2030. The consumption column shows the yearly world energy bill based on the $/kWh these capital costs produce, which is a good sanity check. For comparison, the world currently spends about $6T/y on energy. Comparing the two cases, StratoSolar costs about $6.3T/y versus $15.7T/y for the ground PV/Wind solution. This cost advantage for StratoSolar is important because of the scale relative to GDP. StratoSolar's cost fits within the current spending on energy whereas the ground PV/Wind is 2.5 times current cost. 2.5 times current cost is not politically acceptable as it would totally disrupt all world economies.
The central message is that current wind and solar, even with optimistic assumptions are far from providing an economically acceptable solution. For those who really care about eliminating fossil fuels, investigating solutions that can make a case for success should seriously be considered. These tables show that for current wind and solar to become economically viable, their projected costs of generation have to reduce from the already aggressive $0.50/W projection to around a StratoSolar like level $0.12/W which is far more aggressive than the current learning rate for PV and implies a new, better much cheaper technology not yet invented.
Burying heads in the sand and ignoring the importance of economics will only guarantee fossil fuels will be burned until the end of the century. It's not an adversarial situation between ground PV and StratoSolar. StratoSolar is simply current PV technology deployed in a manner that solves the cost and intermittency problems of ground PV.
Given there are no variable operation and maintenance costs, capital costs dominate. Starting with the TWy column of average demand for each element (in the leftmost column), we use an estimate of capacity factor to get nameplate capacity. With this nameplate capacity and a $/W capital cost we calculate capital cost, $T. Spreading the cost over 30 years we get the yearly capital investment in Trillions of dollars. Fixed O&M is estimated at 2% of capital cost. Efficiency is energy out/energy in. These inputs let us calculate the individual $/kWh for each energy system element, based on 8% WACC and 20-year financing. The total $/kWh shows the total cost of energy based on the sum of the stages needed. E.g. the synthesis output column is the sum of generation and synthesis individual column elements. The $/kg shows the fuel cost based on 1kg of hydrogen which is close to one gallon of gasoline.
The $/W capital cost estimates for the various system elements are based on current goals and projections.
Generation:Today the average capital cost for PV generation exceeds $1.50/W. The 2030 projected cost is $0.50/W for ground PV and $0.27/W for StratoSolar. The StratoSolar $/W is better because of better operating conditions producing more power for the same PV panel. Ground PV panel rating is based on a solar input of 1kW/m2 and an operating temperature of 30C. StratoSolar is based on a solar input of 1.3kW/m2 and an operating temperature of -30C. In addition, StratoSolar has a capacity factor of 45% while ground PV is 20%. This is because ground PV has significant losses from atmospheric absorption and clouds while StratoSolar has very little losses from absorption and none from clouds.
Storage and synthesis: Capital costs for batteries or competing energy storage solutions are aiming for $1.00/W and twenty-year life. No storage technology can achieve these two numbers together today and no new storage technology has achieved any scale. Similarly, synthesis has goals for $1.00/W. H2 based electricity generation could be from gas turbines or fuel cells if that technology can become economically viable.
There are two overall systems shown in the tables, StratoSolar and a Ground PV/Wind. The $/W capital costs are estimates for 2030. The consumption column shows the yearly world energy bill based on the $/kWh these capital costs produce, which is a good sanity check. For comparison, the world currently spends about $6T/y on energy. Comparing the two cases, StratoSolar costs about $6.3T/y versus $15.7T/y for the ground PV/Wind solution. This cost advantage for StratoSolar is important because of the scale relative to GDP. StratoSolar's cost fits within the current spending on energy whereas the ground PV/Wind is 2.5 times current cost. 2.5 times current cost is not politically acceptable as it would totally disrupt all world economies.
The central message is that current wind and solar, even with optimistic assumptions are far from providing an economically acceptable solution. For those who really care about eliminating fossil fuels, investigating solutions that can make a case for success should seriously be considered. These tables show that for current wind and solar to become economically viable, their projected costs of generation have to reduce from the already aggressive $0.50/W projection to around a StratoSolar like level $0.12/W which is far more aggressive than the current learning rate for PV and implies a new, better much cheaper technology not yet invented.
Burying heads in the sand and ignoring the importance of economics will only guarantee fossil fuels will be burned until the end of the century. It's not an adversarial situation between ground PV and StratoSolar. StratoSolar is simply current PV technology deployed in a manner that solves the cost and intermittency problems of ground PV.