Energy for a Greenhouse-Constrained World
Main Conclusions - Roadmap
By 2030
Keep global warming under 1.5°C
This goal persists at all times and is thought to be must crucial in the first stage.
60% carbon-free electricity (starting at 24% in 2014)
This will consist of hydro, solar, wind, geothermal, tidal, and wave energy (in decreasing order).
The other 40% of electricity will be supplied by a combination of nuclear, natural gas, and biomass from waste only.
40% carbon-free non-electrical energy (starting at 14% in 2015)
Such conversion can occur by electrification, cogeneration, and hydrogen fuel cells.
Build national HVDC grids
Efficiency measures
Building renovation for insulation
Low- & zero-energy requirements for new buildings
By 2050
80% decarbonization of electricity
60% carbon-free energy
Balance intermittency - To account for seasonal fluctuations hydrogen-based energy, batteries, flywheels, and pumped hydro storage will be used.
By 2070
100% decarbonization of electricity
80% decarbonization of energy
There will be significant advances in battery technologies in this stage, decreasing financial and areal costs of energy storage.
By 2100
100% carbon-free energy
If fusion technology has been developed by this time, few decarbonized energy concerns will remain.
By 2120
Further energy efficiency measures
The strategies detailed in earlier stages continue to be carried out, as relevant, in later stages.
Part 1: Literature Review
100% Clean and Renewable Wind, Water, and Sunlight All-Sector Energy Roadmaps for 139 Countries of the World - Jacobson et al
Though this paper is not the practical guide to an energy transition that it claims to be, it does present vital analysis, schemes, and calculations for energy transition. As Clack et al pointed out for their 2015 study, there may still be inconsistencies between different sections, underestimates of cost, excessive rapidity of installation rates, and lack of consideration of grid complexity. These shortcomings prevent the paper’s scheme from being implemented in its exact presented form, but, as semi-theoretical investigation, this paper bears many insights.
It raises several crucial considerations that are often disregarded in discussion of energy transition. For example, the work:energy ratio is so much significantly higher for the WWS system that it reduces energy needs by 23%. Jacobson et al also bring to attention the absence of energy needs for mining, transporting, and processing of fuels when using renewables. Such factors are conveniently, or even inconveniently, disregarded by many calculating the cost and infrastructure installation rates for a transition to renewables.
Another significant consideration that is not prone to the above counter-arguments is that this scheme is the change needed to prevent a 1.5°C global temperature increase. The Paris Agreement has set the threshold of maintaining global warming below 2°C, and to exert best efforts to maintain it below 1.5°C, which 195 countries have agreed to. Thus the WWS energy transition is a pathway to this politically required standard.
The paper does not address or investigate the self-identified social and political factors that are “the main barriers” to the implementation of WWS (109). It doesn’t even list factors under consideration. And it states that “Nuclear and coal-CCS may also represent opportunity costs in terms of their direct energy costs and in terms of their time lag between planning and operation relative to WWS.” Nuclear power plants are already installed and in operation at significant capacities, so there need not be any time lag between planning and operation.
Further crucial considerations in discussion of energy transition are laid out in the calculations of air pollution mortality and morbidity rates, as well as their cost. There are also computational decisions in the research that make its estimates more generous, such as requiring all energy to be generated in a country, rather than including international trade that will reduce total generation requirements.
Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar – Clack et al
Clack et al conduct a detail-attentive analysis and evaluation of Jacobson et al’s study. Many of their criticisms are relevant concerns, such as inconsistencies between different sections, dependence on UTES, a reliance on the availability of electric aircrafts, underestimates of cost, excessively rapid installation rates, and lack of consideration of grid complexity. This evaluation, however, is of Jacboson et al’s 2015 paper. Their 2017 publication, considered above, eliminates many of these concerns, including the dependence on UTES and electric aircrafts. Though other concerns of a similar scale may have arisen in the 2017 version.
In terms of a non-researching reader’s takeaway, the paper is heavily critical, recognizing very few strengths of the WWS proposal. And it does not leave the space for significant influxes of societal and commercial support, which have historically led to entirely unprecedented growth rates. Many of our most widely used technologies – automobiles, fossil fuels, digital devices – spread at unprecedented rates and scales, defying expectations and estimations of the possible. So unprecedented growth rates should actually be expected, and are certainly possible. To address specifically the later parts of the Implausible Assumptions section, including figures 3 and 4, the installation rate required by the WWS model should also be compared to the growth rates of automobiles, fossil fuels, digital devices, etc. If the required growth rates were plotted alongside Moore’s law, for instance, they may seem altogether more reasonable.
Natural scientists must consider the messages they convey to policy-makers, non-experts, and colleagues of their field. Clack’s overarching view of energy policy, especially at present, is that a significant increase in renewable energy installations needs to take place (by assumption of the 80% paper he co-authored). If a policy-maker reads this paper in isolation, not reading the Jacobson et al or MacDonald et al research, they may dismiss the possibility of entirely renewable energy supply altogether. A statement is needed in this paper, of the time frame or additional circumstances Clack et al deem requisite for fully renewable energy production.
Moreover, it is insignificant to quibble whether it is possible to provide 100% or 63% of energy, compared to the urgency of promoting development in renewable energy fields at present. Requiring the complete proof of feasibility demanded by Clack et al unnecessarily delays progress (2). Implementation usually adapts to circumstances anyway, only a reasonably feasible plan is needed to begin. And the standard demanded is higher than the level of proof supplied in the MacDonald et al paper, which the authors evaluate as sufficiently evidenced.
Clack et al’s analysis claims that there are no energy storage systems available to cover the need presented in Jacobson et al’s paper. This is worth questioning, with significant recent innovations in this area. A brief calculation will investigate the feasibility of the residential energy storage:
Jacobson et al name a 52,200 GW installed capacity (and an 11,800 GW end-use load) for their 2050 WWS system (Table 2).
25.7% of this is residential (Table 1).
The world population is estimated to be 9.7 billion by 2050 (UN Department of Economic and Social Affairs). At a generous estimate, the 139 countries in the study represent only 90% of the population, so 8.7 billion.
This means that the 2050 WWS system requires a 1542 W/capita (349 W/capita for end-use figure) capacity.
The Tesla Powerwall 2 has a 5kW continuous capacity, so that requirement is easily fulfilled by existent technology.
It only has a 13.5 kWh storage capacity, though.
Taking Qatar as an example, since it has particularly high energy consumption:
Annual energy consumption per capita in Qatar was 15,309 kWh in 2014 (IEA Statistics). Jacobson et al’s paper assumes no increase in demand by 2050, due to efficiency reductions (Table 1).
This yields 1276 kWh consumption per capita in a month in Qatar. Or 284 kWh in a week.
The energy density of lithium ion batteries has been increasing by 5-7% annually (Evarts). Assuming a 6% increase rate, Li-ion batteries would only reach a 92.3 kWh capacity by 2050. However, within that timespan it is likely that the growth rate will increase and/or a new type of battery or energy storage technology will be developed, especially if there is significant commercial interest.
Disregarding temporarily the possibilities of trading energy with a neighboring region or employing other energy storage technologies, it seems that the residential energy storage in a Li-ion battery would be infeasible, though almost feasible, for the scheme proposed by Jacobson et al.
To consider another technology, pumped hydro storage capacity is 168 GW globally (DOE), this is only 1.4% of even the end-use WWS load, so not a far-reaching solution by any means. Its capacity can be expanded significantly in the next few decades, but even a five-fold increase is not sufficient for batteries and pumped hydro storage to fulfill all storage needs. Several further technologies are needed.
Future cost-competitive electricity systems and their impact on US CO2 emissions – MacDonald et al
This study appears methodologically sound, as far as can be ascertained from this five-page summary. This may be a result of their choices of presentation in this summary.
One criticism is that the HVDC grid proposed in this paper needs to also be made a smart grid, if the entire U.S.’s grid is being rebuilt. Functions such as bidirectional energy transfer, sensors, and remote-controlled separation of its segments will be needed for renewable energies. And it is not worth the material and economic investment of building an entire new grid if it is not smart.
This paper ignores the environmental effects and risks of any other energy source that could supply the last 20% of energy. This scheme requires effects such as air, water, and ground pollution or nuclear accident risk to exist. And the paper never mentions this fact.
Additionally, any research that investigates the future of energy supply needs to include a requirement for 100% renewable energy by a later date, perhaps 2060. The consideration of Jacobson et al’s paper, that a 100% transition by 2050 is needed to prevent a 1.5°C global temperature increase is crucial. As stated, this threshold is required of most countries by the Paris Agreement.
Additionally, this paper proposes a significant increase in energy demand in the U.S. While the proposed energy transition to 63% renewable energy has a significant positive environmental impact, the resulting system is far from sustainable. Full sustainability requires that no net impact is made to the environment, and even the production of PV panels makes this renewable energy unsustainable.
Analyzing energy technologies and policies using DOSCOE – Platt et al
As a template program that can presumably be used to calculate optimal energy combinations for other portfolios than a natural gas and hydropower baseload scheme, as well as other parameter-modifications, the software presented offers diverse implementations. Section 5 presents some of the potential implementations. It would also be insightful to incorporate the air pollution mortality and morbidity costs, global warming costs, or drinking water sanitation costs that correlate to non-renewable energy production, as further examples.
Using such an algorithm to guide scientific or policy decisions carries potential misguidance. In a program, the scientific and political assumptions of the computer scientists are written into the program. Thereby they are not necessarily intelligible to all its users, and they are certainly not presented as explicitly as in a research paper. This is clear in the present paper, as the authors do not discuss their choice to use natural gas and hydropower as a baseload, for example. As another example, DOSCOE does not allow for the modeling of excess energy use for manufacture of storable products, as MacKay presents. The authors are explaining how the code works, rather than discussing the choices that went into it, as the previous papers on energy schemes did. And, if DOSCOE were to become a legal parameter by which to evaluate energy portfolios, researchers and commercial agents would be forced to incorporate the program’s scientific, political, and economic assumptions into their evaluations.
Could energy-intensive industries be powered by carbon-free electricity? - MacKay
This analysis is clearly written and relatively easy to follow for a non-expert reader. It engages less so than any of the other authors’ papers in providing a practical guide to an energy transition. It contains insightful theoretical calculations for its time of publication, and MacKay does not claim any scope beyond this for the study. He phrases the description as: “This review quantifies the scale of infrastructure required in the UK.” It provides quasi-initial figures, computing from essential parameters, without considering a large variety of complications. Numbers are rounded for convenience and the primary parameter for evaluation is area, rather than including cost, resilience, and air quality too, as MacKay points out himself. In 2013, perhaps, such initial estimations were significantly valuable to gaining an understanding of the potential for renewables. And it is only as a result of such estimations that more detailed analyses have been written. Additionally, this paper is able to inform a larger population on the renewable energy transition than the other authors’ works.
MacKay does not investigate methods of implementation for these decarbonization schemes either. A computation of parameter-based possibility does not begin to examine the logistics of such change or whether it is possible in these domains.
Solar energy in the context of energy use, energy transportation and energy storage – MacKay
The style of this paper is similar to the previous one. It gives a quantitative, computational estimate to theoretically explore renewable energy alternatives.
In questioning the plausibility and social acceptance of covering 1%, or even 3%, of the UK’s land area in solar power fields, MacKay brings up the comparison that only 2.7% of the UK is covered in buildings and roads (13). However, this statistic is questionable, as A Land Cover Atlas of the UK from the University of Sheffield gives a statistic of 6% (Rae). Solar panels could strategically be installed in locations that are separate from populated areas, remotely located, or simply out of view. This could significantly decrease land use concerns.
The proposal of utilizing excess solar energy for the production of storable products is a noteworthy one. It has significant potential to diminish or even eliminate the intermittency issues of solar power. This may also be a pathway to implement a 100% renewable electricity scheme. If vast excesses of renewable energy capacities are installed, excessive in relation to electricity demand, electricity can be supplied by entirely renewable sources. Any excesses are used to produce hydrogen fuel, which can then be used to power other sectors of the energy market.
MacKay’s discussion and conclusion downplay the challenge of energy storage too, not sufficiently emphasizing this obstacle.
Part 2: Global Energy Goals for the Next 100 Years
Similar to the Paris Agreement, countries will make a commitment to keep their energy consumption at or below 7000 W/capita (World Bank List). Or they will keep their energy consumption per capita at its current levels, whichever is lower. This agreement bears an exception for countries below 7000 W/capita with sufficient need to increase the standard of living, indicated by a Human Development Index below 0.75 (United Nations). Any country that wants to use energy beyond 7000 W/capita must increase its Happy Planet Index at a directly correlated rate (Wackernagel).
2030
Keep global warming under 1.5°C
This goal persists at all times and is thought to be must crucial in the first stage. Carbon emissions will only decrease in subsequent stages. The factor of greenhouse gas time lag may require further attention to this goal in subsequent stages.
60% carbon-free electricity (AGEB, Asian Development Bank, U.S. EIA, World Data)
From 24% in 2014 (World Bank Breakdown)
This will consist of hydro, solar (PV & thermal), wind (onshore & offshore), geothermal, tidal, and wave energy (in decreasing order).
The other 40% of electricity will be supplied by a combination of nuclear, natural gas, and biomass from waste only.
Any new nuclear and natural gas facilities are required to be cogeneration plants. And 40% of all nuclear and natural gas plants must be cogeneration - by retrofitting, if required (Basha, Beccali).
40% carbon-free non-electrical energy
From 14% in 2015 (International Energy Agency)
(40% of the non-electrical energy used at present needs to be to 40% carbon-free by 2030, whether electrical by that time or not)
Such conversion can occur by electrification, cogeneration[1], hydrogen fuel cells, or direct use of renewables (e.g. solar thermal, direct mechanical energy from a wind turbine).
Transportation transitions via electrification and hydrogen fuel cells.
Heating transitions via solar thermal and cogeneration.
Turbine-driven industry processes transition via electrification, solar thermal, and direct mechanical energy from renewable sources.
(Lawrence Livermore National Laboratory)
Build national HVDC grids
This fast low-loss transmission allows for the concentration of solar power plants in deserts and wind farms in uninhabited regions and offshore.
Balance intermittency
Use nuclear, natural gas, hydro, and biomass production as baseload. Google Github Energy Strategies tool gives indication that a 39% nuclear-gas baseload and 61% solar-wind energy scheme is realizable in California (Robson). This is at 12.4 GW solar, 3.0 GW nuclear, 26.4 GW wind, 22.4 GW natural gas at $44.24 USD/MWh and 19.5 Mt CO2/yr. A significant amount of the natural gas in this exemplar can be replaced with hydro energy.
Efficiency measures
Building renovation for insulation
Low- & zero-energy requirements for new buildings
Passive heating, cooling, ventilation, lighting technologies
Renewable energy generation in/on buildings
Recycling & reuse to decrease production energy
Subsidization of recycled goods
Sharing economy platforms
2050
80% decarbonization of electricity
60% carbon-free energy
Balance intermittency
Renewables can be installed at a capacity greater than peak electricity demand. Excesses will be used to produce storable substances like hydrogen, ice, aluminum, and hot water. Such a capacity will not be realizable by 2050 due to economic and logistical constraints. This, however, is the long-term aim.
Energy storage
To account for seasonal fluctuations hydrogen-based energy (as mentioned above), batteries, flywheels, and pumped hydro storage will be used.
There will be significant improvements in the efficiency and cost of PV panels in this stage, decreasing financial, land, and raw resource costs for solar energy.
2070
100% decarbonization of electricity
80% decarbonization of energy
There will significant advances in battery technologies in this stage, decreasing financial and areal costs of energy storage.
2100
100% carbon-free energy
If fusion technology has been developed by this time, few decarbonized energy concerns will remain.
2120
Further energy efficiency measures
The strategies detailed in earlier stages continue to be carried out, as relevant, in later stages.
Part 3: Regional Strategies for Future Electricity Generation
Areal power density = power per unit land area = extent of resource x energy conversion efficiency x capacity factor x packing factor
Preliminary calculations, using theoretical data as well as data from currently operational renewable energy projects that sometimes lie in other countries, are presented. Locally informed calculations, from geographically specific measurements, need to be conducted before project planning. These figures give an initial scope of solar and wind potential.
Solar power in Nepal
Extent of resource
5 kWh per m2 per day (Poudyal)
16 MJ per m2 per day = 4.44 kWh per m2 per day (Pondyal)
Energy conversion efficiency (crystalline silicon)
15-20% (MIT)
16 (Han)
Capacity factor
10% in Germany, 20% in Arizona (class notes)
Packing factor (monocrystalline silicon)
0.6 – Hong Kong (Chow)
0.82 – New Delhi (Nawaz)
Areal power density
4.7 kWh per m2 per day x 0.16 x 0.15 x 0.7 = 0.079 kWh per m2 per day
= 3.29 W per m2
Extent of resource, capacity factor, and packing factor determined as midpoint between two data figures.
Energy conversion efficiency determined by the more specific of the two data points (year and PV cell type are specified).
Land use for 1 GW
3.04 x 108 m2 = 304 km2
Wind power in Nepal
Extent of resource
Average wind velocity: 3.5 m/s
Maximum wind velocity: 9.5 m/s
(DTU Wind)
Average wind velocity: 3.8 km/hr = 1.1 m/s
Mid-range wind velocity: 4.0 m/s
10 of 29 regions’ velocities round to or are above 4.0 m/s
Maximum wind velocity: 46.8 m/s
(Upreti)
Energy conversion efficiency
Maximum given by Betz limit, 0.59 (class notes)
0.45 will be used since ideal operation is not expected due to maintenance difficulties. Many areas of Nepal are remote and difficult to access by car.
Capacity factor
Ranges from 0.2 to 0.4 in the U.S. (U.S. EIA)
The midpoint, 0.3, will be used
Packing factor
3848 m2/turbine – sweep area
Need the length of 4 rotor diameters between each turbine (Ríos)
= 1400 m
So each turbine occupies a circular area of radius 700 m
πr2 = 1539380 m2/turbine
Ratio of turbine area to spacing
3848 m2/1539380 m2 = 0.0025
P = 0.5 ⍴Av3
Where ⍴ = air density
A = sweep area = πr2
v = wind velocity
(RWE)
Mean elevation
2565 m (CIA Factbook)
Air density
0.88 kg/m3
Sweep area
πr2 = π(35)2 = 3848 m2
For the 1.5 MW GE model
P = 0.5 (0.88 kg/m3) (3848 m2) (3.5 m/s)3 = 72593 W
The power is calculated based on the average wind speed. The extremely high wind speeds are not relevant, since turbines turn off at this point due to safety issues.
If only the regions of the country with higher wind speeds are chosen for installation, the power values can be higher than the calculated value.
If the wind turbine is able to turn 360°, the land area it takes up is equal to its sweep area, 3848 m2.
Areal power density
72593 W / 3848 m2 x 0.45 x 0.3 x 0.0025 = 0.0064 W/m2
Land use for 1 GW
1.56 x 1011 m2 = 156 000 km2
Hydro power is not suggested at a large scale for Nepal because of the uniqueness and fragility of its ecosystems. Nothing akin to the Himalayan highlands can be found elsewhere on Earth, with myriad unparalleled geological formations. Additionally, due to the high altitudes and resulting low oxygen, high radiation, and extreme weather conditions the ecosystems are exceptionally sensitive. Several international and Nepali corporations plan to build further hydro power stations in Nepal, but these are contested in the Nepali population.
Solar power in Saudi Arabia
Annual average daily Global Horizontal Irradiance: 5700 Wh/m2 to 6700 Wh/m2
Annual average daily Direct Normal Irradiance: 4400 Wh/m2 to over 7300 Wh/m2
(Zell)
“The western inland sites with average daily totals of over 6474 Wh/m2 (average yearly totals of 2400 kWh/m2/year) are superior to the eastern sites with average daily totals closer to 5510 Wh/m2 (average yearly totals of 2000 kW h/m2/year)” (Zell).
Areal power density
Fixed horizontal panel: 6.2 kWh per m2 per day x 0.16 x 0.2 x 0.8 = 0.159 kWh per m2 per day
= 6.63 W per m2
Tracking panel: 5.85 kWh per m2 per day x 0.16 x 0.2 x 0.8 = 0.150 kWh per m2 per day
= 6.25 W per m2
Extent of resource determined as midpoint between two data figures.
Capacity factor determined as similar to Arizona for this hot arid desert.
Packing factor determined as similar to New Delhi for this flat desert.
Energy conversion efficiency determined by the more specific of the two data points (year and PV cell type are specified).
The midpoint between the two data figures for DNI is incongruously lower than that of GHI. “Significantly larger DNI variability is expected because of the effects of high aerosol loading and clouds on the direct beam” (Zell).
Land use for 1 GW
Fixed horizontal panel
1.51 x 108 m2 = 151 km2
Tracking panel
1.60 x 108 m2 = 160 km2
Wind power in Saudi Arabia
Extent of resource
Average wind velocity: 3.5 m/s
(Rehman)
Average wind velocity: 3.3 m/s
Maximum wind velocity: 5.0 m/s
(Tagle)
Energy conversion efficiency
Maximum given by Betz limit, 0.59 (class notes)
0.45 will be used since ideal operation is not expected due to maintenance difficulties. Sandstorms are very common in Saudi Arabia, and complications are likely to arise from sand in the turbine mechanism.
Capacity factor
Ranges from 0.2 to 0.4 in the U.S. (U.S. EIA)
The midpoint, 0.3, will be used
Packing factor
Ratio of turbine area to spacing
3848 m2/1539380 m2 = 0.0025
P = 0.5 ⍴Av3
Where ⍴ = air density
A = sweep area = πr2
v = wind velocity
(RWE)
Mean elevation
665 m (CIA Factbook)
Air density
1.12 kg/m3
P = 0.5 (1.12 kg/m3) (3848 m2) (3.4)3 = 84695 W
The power is calculated based on the average wind speed. The extremely high wind speeds are not relevant, since turbines turn off at this point due to safety issues.
If only the regions of the country with higher wind speeds are chosen for installation, the power values can be higher than the calculated value.
Areal power density
84695 W / 3848 m2 x 0.45 x 0.3 x 0.0025 = 0.0098 W/m2
Land use for 1 GW
1.02 x 1011 m2 = 102 000 km2
In my proposed transition scheme, a non-renewable baseload is used until 2030. As mentioned, a combination of nuclear, natural gas, hydro, and biomass can supply this baseload. Google Github Energy Strategies tool gives indication that a 39% nuclear-gas baseload and 61% solar-wind energy scheme is realizable in California (Robson). This is at 12.4 GW solar, 3.0 GW nuclear, 26.4 GW wind, 22.4 GW natural gas at $44.24 USD/MWh and 19.5 Mt CO2/yr. A significant amount of the natural gas in this exemplar can be replaced with hydro energy.
Hydrogen can be produced from excess renewable energy during high-production, low-demand intervals. This can be stored and used in hydrogen fuel cells. To this end, renewable power complexes can be built at a scale beyond peak demand, and this intentional excess can be used for hydrogen.
Additionally, chemical batteries, flywheels, and pumped hydro storage can be installed to serve energy storage needs too.
Nepal
Energy consumption
492.2 W/capita (World Bank)
Population
29,384,297 (CIA Factbook)
Total energy consumption
15.2 MW
89.8% of electricity is currently being provided by hydroelectric plants
6.3% from fossil fuels
3.6% from non-hydro renewables
To provide 10.1% of energy through solar and wind, a 5:1 ratio is suggested. 8.42% solar and 1.68% wind, which gives 1.28 MW of solar and 0.26 MW of wind.
0.39 km2 for solar
This is only 0.00026% of Nepal’s total area. And only 0.00032% of its area is required to provide 10.1% of its energy. This means that only 0.0032% of Nepal’s land area is required to provide all of its energy. If an HVDC grid can be installed to transport energy from low- to high-density regions, the solar power infrastructure can be built, and intermittency issues can be addressed as outlined above, solar power could provide a significant amount of energy for Nepal. Since most of its energy is already supplied by a carbon-free method, there is no need to replace hydropower to address this criterion. However, if Nepal’s energy demands grow significantly in the near future, solar power represents a viable and reliable option.
40.56 km2 for wind
This is only 0.028% of its land area, so it is a very achievable amount. Due to the extreme difference in areal power density between solar and wind, it may still be preferable to install solar panels. These calculations suggest that every unit of land can provide far more energy using solar power, though it must be noted that the areal power density is not usually found to be so extremely disparate.
Saudi Arabia
Energy consumption
8472.2 W/capita (World Bank)
Population
28,571,770 (CIA Factbook)
Total energy consumption
2.42 x 105 MW
99.9% of electricity is currently being provided by fossil fuels
To provide all energy through solar and wind, a 5:1 ratio is suggested. 83.33% solar and 16.67% wind, which gives 2.02 x 105 MW of solar and 0.40 x 105 MW of wind.
30503 km2 for solar (fixed panel)
This is only 1.4% of the land area. And only 1.7% of the entire land area would be required to supply 100% of energy. Saudia Arabia’s population density is very low – less than 4 people/km2 in several regions (NASA SEDAC). Solar power plants could be installed in its unpopulated deserts, with an HVDC grid to supply urban areas with power. If the measures, outlined above, to deal with intermittency are sufficient, Saudia Arabia could, with enough time to install infrastructure, rely on solar power.
4,080,000 km2 for wind
This is more than the area of the country, so it’s entirely infeasible. There could, however, be a significant number of offshore installations in Saudi Arabia, as it’s a peninsula.
Works Cited
Part 1
Department of Energy. “Pumped Hydro Storage.” DOE Global Energy Storage Database, Feb. 2017, www.energystorageexchange.org/.
Evarts, Holly. “New Method Increases Energy Density in Lithium Batteries.” Columbia Engineering, The Fu Foundation School of Engineering & Applied Science, Oct. 2016, engineering.columbia.edu/press-releases/increase-energy-density-lithium-batteries.
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Part 2
AGEB. “Germany reaches 29.5 percent renewable power in 2016.” Jan. 2017. Energy Transition, energytransition.org/wp-content/uploads/2017/01/img2.png.
Asian Development Bank. “Nepal Energy Sector Assessment, Strategy, and Road Map.” Mar. 2017, p. 4. Asian Development Bank, www.adb.org/sites/default/files/publication/356466/nepal-energy-assessment-road- map.pdf.
Basha, Mehaboob. “Economic Analysis of Retrofitting Existing Gas Turbine Power Plants with Cogeneration Facility.” Wiley-IEEE Press, Oct. 2016. IEEE Xplore, doi.org/10.1109/SEGE.2016.7589535.
Beccali, M. “Assessing the Feasibility of Cogeneration Retrofit and District Heating/Cooling Networks in Small Italian Islands.” 15 Dec. 2017. ScienceDirect, doi.org/10.1016/j.energy.2017.07.011.
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Wackernagel, M. “Ecological Footprint and Appropriated Carrying Capacity.” UBC Open Collections, The University of British Columbia, Oct. 1994, open.library.ubc.ca/cIRcle/collections/ubctheses/831/items/1.0088048.
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Part 3
Chow T. T. “Energy and exergy analysis of photovoltaic–thermal collector with and without glass cover.” Applied Energy, vol. 86, no. 3, Mar. 2009, pp. 310-316. ScienceDirect, doi.org/10.1016/j.apenergy.2008.04.016.
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[1] Cogeneration is not carbon-free, but it has a reduced carbon footprint.