With the threat of climate change looming and a shortening time window for action, researchers are scrambling to develop economic alternatives to dirty fossil fuel energy. Whether renewables can replace fossil fuel in time remains to be seen. Carbon-based industries have had two centuries to develop their vast global infrastructure and mature market. It will not be easy to displace that huge investment in existing infrastructure and systems. The IPCC’s fifth assessment report, however has considered the question of economic impact and in their April 13, 2014 press release, found that in a business-as-usual scenarios, consumption grows by 1.6 to 3 percent per year while ambitious mitigation would only reduce this growth by around 0.06 percentage points a year when amortized over a century . The impacts may be even smaller, as underlying estimates do not take into account economic benefits of reduced climate change.
The IEA is the leading energy organization in the world, one which has traditionally supported the fossil fuel industry. Not surprisingly, the IEA’s studies show that renewables constitute a negligible amount of the current total global energy supply. What may be more surprising is the IEA’s projections that even by 2050, fossil fuels will still make up a significant share of the total global energy supply. The IEA is banking on Carbon Capture and Storage (CCS) technology. Clearly both these scenarios cannot co-exist.
To put everything in perspective, the two graphs below show 1) the makeup of the existing global energy supply (notice that renewables barely show up) and 2) a graph showing growth within the renewable sector itself. Notice how small a segment of total energy that renewables make up.
Whatever solution we decide to adopt, one thing is clear, they only solve one part of the problem caused by two centuries of unabated emissions. Even if emissions were stopped today, the planet will continue warming for a long period afterwards. Climate modeling research done at Princeton showed that atmospheric warming can continue for another 0.6 Deg C for four centuries after all emissions have ceased (Frölicher et al. 2013). Global warming to date has already triggered many harmful changes in our ecosystem which must be addressed and human societies have to be made more resilient to deal with impacts already beginning to manifest.
Figure 1: IEA 2012 energy supply history (Source: IEA 2012 Key World Energy Statistics)
Renewable energy Pro’s
- In 2013, renewable energy is the fastest growing power sector
- In 2013, solar is cheaper than electricity from diesel generators – popular in developing nations – thanks largely to cost savings from mass production
- 2013 is a decisive year for concentrating solar power with a number of large hundred megawatt plants ready to go live
- In 2013, renewable energy accounts for 20% of global power generation
- Between 2013 and 2020, a 70 per cent reduction in the cost of solar-generated electricity is possible (Daniel Kammen of the University of California, Berkeley)
- Renewable energy will rise to 25 % global power generation by 2018
- Between 2012 and 2018, renewable energy generation is predicted to increase by 40 per cent, with over a third of this growth occurring in China
- Renewables are on the rise in most regions with only Russia lagging behind (Adam Brown of the IEA in Paris)
- By 2016, the amount of electricity generated worldwide from wind, solar and hydro energy will exceed what is made using natural gas
- By 2016, green power will provide double the electricity of nuclear plants – and outstrip every other electricity source except coal
- Globally, the biggest source of green electricity is hydropower, followed by onshore wind
- Big dams like China’s Three Gorges have given hydropower a bad reputation – displacing human populations, wiping out wildlife and disrupting water flows. As a result, the World Bank stopped funding large-scale projects in the 1990s, but started again in the past decade. There are now well-developed procedures for managing the sustainability of dams. A planned dam on the Congo river, for instance, will not flood any land: the river flows at such high volumes that a reservoir isn’t needed. (Adam Brown of the IEA in Paris)
- To ease the transition to renewable energies – and ensure a reliable electricity supply – new power plants can combine renewables and fossil fuels. For example, biofuels are mixed in with coal in co-firing plants, cutting greenhouse gas emissions.
Renewable Energy Con’s
- Growth in renewables isn’t yet enough to stop dangerous climate change; green power is on the rise, but so is our appetite for energy, so new coal and gas-fired power stations are in the pipeline
- Energy analysts warn that major changes in policy are still needed to avoid tipping over the 2 °C threshold that constitutes dangerous global warming
- Coal, being cheaper than all current forms of energy, is the elephant in the room is coal
- By 2018, coal is projected to still account for 40 % of global electricity generation
- Renewables should catch up with coal shortly after 2035 (see graph). Even so, coal will still generate roughly one-third of our electricity supply. It can be cleaned up to some extent, either by capturing and storing the emissions, or by switching to clean-burning technologies like chemical looping. But these solutions are far from economical.
Observations about IEA Projections
There are a number of interesting observations about these projections:
- renewable projections are quite low compared to what the theoretical capability of renewables are (see Desertec projections for example)
- renewables (light green rectangles at bottom left of the diagram) are projected to still play a minor role in the overall energy mix in 2050
- the specific category of biomass and waste experiences the greatest expansion
- the IEA is counting on significant expansion of the global nuclear fleet
- Oil and coal decrease by about 30% but natural gas increases slightly
- Because there is more dependency on electricity, there is more conversion losses
We should also not expect to see energy levels remain the same between 2009 and 2050. Another 2 billion people are projected to be living on the planet by 2050 and there are expected to be improvements in efficiency as well as carbon mitigation. All these variables will affect the final 2050 energy numbers. We should be comparing the rate of growth instead of absolute numbers. For instance, comparing the rate of energy consumption growth between a sustainable development scenario vs a business-as-usual growth one. We should realistically expect a lower rate of growth rather than a case of zero growth between 2009 and 2050. Zero growth in energy usage would be a remarkable achievement in efficiency and attitude change.
The IEA projections are conservative and renewable energy may surprise us. There is already an intense amount of research in renewable energy and breakthroughs are occurring at an accelerated rate. This low expected fractional contribution of renewables to the projected 2050 global energy mix is also perhaps not so surprising when one considers a parameter called the Energy Returned On Investment (EROI), defined as the ratio of the amount of energy extracted over the amount of energy required to extract it. Fossil fuels, occupy the highest EROI while renewables are usually found in the lower end of the spectrum.
Based on studies of historical economical performance for modern developed nations:
- an EROI of at least 6:1 is required to avoid slipping into recession (dieselnet)
- an EROI that falls below 3:1 will bring about energy starvation (dieselnet)
In 2012, the overall average EROI of the Unite States was 12:1.(dieselnet)
Fossil fuels have very high energy densities. Their EROI was 100:1 when the first oil well was successfully drilled. Since then, EROI has been rapidly decreasing as the easy oil supply is exhausted and the more difficult supplies are exploited. Compare the 100:1 ratio of oil in 1930 vs the less than 10:1 EROI of oil sands.
Figure 3a: EROI with uncertainty band (Source: Sigmaxi)
Figure 3b: EROI chart (Source: Mother Earth News)
Renewables, on the other hand, have very low EROI. For this reason, in spite of all the new stories, renewables are not expected to make a huge difference in our future energy supply.
Hence, in the IEA projections, Fossil Fuels still expected to still provide the majority of our energy supply in 2050. In fact, two countries, China and India, are expected to drive the majority of energy demand well into 2035. Together, these two countries are expected to consume 2/3 to 3/4 of the global energy supply.
The IEA projections also reveal some other surprises. They forecast nuclear to play a major role – to at least double or even treble. The validity of this assumption must be questioned after the Fukushima nuclear accident, causing countries like Germany to ban nuclear.
From the IEA perspective, the significant new source is seen to be biomass and waste, something which is given very little media attention compared to renewables.
The Importance of Carbon Capture from Coal Plants
The principal problem is that carbon pollution is not priced correctly.
And there is no confidence that it’s going to be priced correctly in the
future. When I say “correctly,” I mean that the price of emitting carbon
dioxide should be big enough such that every running coal power station
has carbon capture technology fitted to it. Solving climate change is a
complex topic, but in a single crude brushstroke, here is the solution:
the price of carbon dioxide must be such that people
stop burning coal without capture. Most of the solution is captured in
this one brush-stroke because, in the long term, coal is the big fossil fuel.
(Trying to reduce emissions from oil and gas is of secondary importance
because supplies of both oil and gas are expected to decline over the next
50 years.) – David McKay, Sustainable Energy – Without the Hot Air
Finally, the IEA strategy is relying on Carbon Capture and Storage (CCS) technology. At the 2012 IEA Annual Outlook meeting, IEA Chief Economist Fatih Birol was not hopeful about the lack of progess in Carbon Capture and Storage (CCS) technology. The IEA has based its’ scenarios on CCS providing 19 percent of needed global CO2 emissions reductions by 2050. “We see CCS as very crucial technology, but as crucial as it is we don’t see much happening,” Birol remarked at the Carnegie Endowment for International Peace.
The IEA’s lack of optimism was also shared with the Global CCS Institute who said in October 2012 that the net total of large-scale projects currently under development globally has only increased by one over the last year. “I’m sorry to tell you, but with our numbers, the situation at this moment does not look very bright for CCS even though we need CCS very much,” Birol said. Critics do not believe that CCS is viable and the slow pace of development may reflect the reality of this criticism. If this is true, the next question to ask is “Does the IEA have a plan B in case CCS does not materialize?”.
It is difficult to see how such a model will keep global warming within the safe limits which climate scientists warn about and perhaps the underlying economic growth assumptions must be questioned. As a general plan B or even an integral part of plan A, there should be a serious discussion of a strategic and significant component of degrowth and reduction in developed nation’s average.
Renewable Energy Sectors
Figure 4: Falling PV prices (Source: DOE NREL Solar Market Report)
Figure 5: Falling PV prices (Source: EIA, CIA, World Bank, Bertstein Analysis)
Figure 6: Falling PV prices (Source: EIA)
While there are many sources of renewable energy, the sun is the greatest source of energy on the planet. While the needs of human civilization is measured in the tens of terrawatts, the sun’s energy on the earth is 160 to 170 thousand terrawatts (Argone National Labs 2013). An often cited figure is that more solar energy falls on the surface of the earth in one hour than all humanity presently uses in an hour. So while there are many renewable energy options, solar energy represents by far the most abundant renewable energy source available. Solar energy is seen as the area where the biggest breakthroughs may occur. The IEA itself is projecting that costs for solar may drop 70% by 2020 – a drop that will be below grid parity.
As can be seen in the figures below, solar energy has a potential supply that dwarfs the global demand for energy today and for the foreseeable future. However, a dramatic reduction in the costs of converting sunlight to usable electricity, heat, or fuel must first be achieved before this potential can be realized. The solution depends on an aggressive research program to find new processes and engineering the use of readily available materials that will result in the required price reduction.
The EROI for solar is increasing dramatically and the large research effort in solar technology means that predictions regarding solar energy viability and projections such as the IEA can change overnight with new discoveries. The EIA released a document in 2013 Revolution Now which finds that solar PV is now at a state of grid parity and technology costs will continue to plummet while fossil fuel costs will continue to increase as conventional supplies run out and the industry turns to more expensive unconventional sources.
Unpredictable discoveries such as inexpensive print-at-home solar panels from CSIRO that can dramatically lower costs and alter predictions such as IEA’s overnight
Figure 7: Earth’s energy balance (Source: Argonne National Lab)
Figure 8: Available solar vs projected global energy demand in 2030 (Source: Argonne National Lab)
Figure 9: Usable renewable energy (per annum) vs nonrenewables (Source: Perez & Perez 2009)
Figure 10: Projected global energy demand (Source: Argonne National Lab)
Hence, even though solar PV’s and concentrated solar make up a fraction of the projected IEA future energy supply, nontraditional forms of solar energy are excluded in these projections. The nature of scientific research is that it is nonlinear and unpredictable so many potentially paradigm shifting technologies cannot be included in the projections due to their unknowns. In the field of solar, there are many innovations with tremendous potential which are not included in the IEA projections due to too many unknowns at this time. Without doubt, if they were realized, the IEA projections would quickly become outdated. The reason these innovations can be game changes is that if they can become practically realized, they could cost effectively tap into an enormous and practically unlimited reservoir of energy available from the sun. This energy store dwarfs all fossil fuel stores combined. This is what makes solar energy research so relevant.
The DESERTEC Concept was developed by a network of politicians, scientists and economists from around the Mediterranean, from which arose the DESERTEC Foundation. It demonstrates a way to provide climate protection, energy security and development by generating sustainable power from the sites where renewable sources of energy are at their most abundant.
The Desertec Foundation provides a remarkably different possible energy future than IEA’s. They believe that the amount of renewable energy that can be exploited with current technology can provide all the energy required to power all of human civlization. In particular, the Desertec map below shows how much land area in the Sahara is required to power the entire planet, using EXISTING TECHNOLOGY. This flies directly in the face of energy analysts who claim we need dirty fossil fuel for the next 50 years.
The Desertec Foundation’s calculations are based upon rigorous engineering and scientific analysis. This leads us to question whether the IEA’s claims are set in stone or not. At the very least, it shows that renewables may actually be able to scale up in ways that the IEA say are not possible. This alternate view brings into question whether the IEA’s objectivity. Certainly in a manner as important as AGW, we cannot afford to be biased.
- sufficient supplies of inexpensive, clean electricity for all of human civilization
- global scalability can significantly reduce worldwide emissions of CO2:
- China and India can leapfrog coal and oil, making cuts in CO2 emissions whilst maintaining or increasing their energy supplies
- Saudi Arabia can move directly from being oil-rich to being solar-rich
- The USA can meet all its energy needs from its south western states
- green jobs
- in arid regions, the creation of fresh water by the desalination of sea water using the waste heat from CSP plants
- potential for growing plants for food and other uses in the shaded areas under the solar mirrors (using desalinated sea water), turning nonproductive land into productive agricultural land
- global security
The labs of Daniel Norcera and Nathan Lewis are attempting to create a new generation of solar technology that creates electricity or hydrogen directly from sunlight and water. If hydrogen can be cheaply produced, it can be stored and used in a fuel cell whenever required, hence bypassing the intermittent nature of solar power. These technologies are designed to use very low energy to manufacture and commonly available material and to be recyclable. This all means much higher EROI’s than current generation of solar have/
Other unexpected events that are going against the IEA projections are Germany with a target to go 100% renewable, especially solar.
Daniel Norcera and the Artificial Leaf
Daniel Norcera and the Artificial Leaf
Nathan Lewis and his artificial leaf
The IEA projections ignores the potential of Concentrated Solar Power (CSP), which, according to Desertec’s calculations can alone supply many more times the energy that the world needs.
Figure 12: Concentrated Solar Power potential exclude by IEA projections (Source: Sustainable Energy – Without the Hot Air)
In the figure above, the yellow 600 km by 600 km square in North America, completely filled with concentrating solar power, would provide enough power to give 500 million people the average American’s consumption of 250 kWh/d. This map also shows the square of size 600 km by 600 km in Africa. This is based on an assumed power density of 15 W/m2.. The area of one yellow square is a little bigger than the area of Arizona, and 16 times the
area of New Jersey. Within each big square is a smaller red 145 km by 145 km square showing the area required in the desert – one New Jersey – to supply 30 million people with 250 kWh per day per person. (Source: Sustainable Energy – Without the Hot Air)
The Case of the German Solar Industry
Germany has surprised the rest of the world. It has becoming the leading solar nation on the planet with an installed base of 30 gigawatts of solar capacity by the end of 2012 compared to the United States 6.4 gigawatt. This, in spite of Germany receiving the same amount of solar radiation as Alaska. Any other region in the US has more solar insolation than Germany. So why does Germany have 5 times the capacity as the US? ….policy. The German government has heavily subsidized renewable energy for years through a variety of measures, the most import being feed-in tariffs allowing German citizens to become power producers and sell their power back to the grid if they cannot use it. The governments aggressive policy change to embrace Solar Energy has resulted in a remarkable world record 44% of the global solar capacity as of 2012.
US policy makers and corporations have felt that nobody would pay higher prices for renewable energy and this has hampered the necessary policy changes to make widespread adoption possible. The Germans have proven the US wrong. They have shown that, in fact people are willing to pay higher monetary costs if they perceive the environmental return is greater.
“One of the main drivers of the growth of the German solar industry has been guaranteed electricity prices, which is a good example of how governments can support the industry,” said Dr. Marko Delimar, IEEE Director of EMEA and Professor of Electrical Engineering and Computing at the University of Zagreb. He adds: “This has a reverse effect as well – the photovoltaic producers are not equal participants in the electricity market, therefore work needs to be done for them to be prepared to participate in the market when this favorable treatment ends. This may happen much faster than expected, as in some countries like Spain or Greece, the regulatory photovoltaic support is already being stopped or slowed down.”
The German Solar Energy Success Story
Feed-In Tariffs – The Key to the success of Germany’s Renewable Energy Program
The German parliament adopted the “Renewable Energy Sources Act” on the 29th March of 2000 . This law was spearheaded by the late Hermann Scheer , one of the globes leading proponents of clean energy who developed the underlying concepts during the late 1980s and early 1990s and was able to convert his ideas into tangible policy results.
The law that gave priority to renewable energy sources, guaranteed access to the grid for renewables and included a comprehensive feed-in-tarrif system became known as “Scheers-Law” around the world. Today it has been introduced to some extent by over 60 countries and states around the globe. Scheers-Law has had the most impact commercialization of photovoltaic technology. In the middle of the last decade many companies around the world started to significantly increase their production capacity, driven mostly by demand in Germany as a result of Scheers-Law.
Since 2009 the prices for PV-solar systems have fallen by up to 70% and continue to decline and industry experts claim that photovoltaic & multi-kWh energy storage will become the cheapest source of electricy even in OECD countries by 2020. If this happens, it will lead to a profound restructuring of the entire world economy. In particuliar, fossil energy markets will lose significant market shares. Perhaps the enormous right wing funding of anti-renewable energy policies, principally coming from big oil sources is a reaction to the writing on the wall.
With 24.5 GW of PV-Solar capacity installed on more than 1 million roofs in Germany, the Germans feel they are just getting started. During one particuliarly dark & windy winter month in January 2012, PV-solar produced up to 7 GW or 10% of peak-load demand in Germany. When a deadly cold wave brought the fossil & nuclear dominated energy system of France close to collapse, german PV-solar kept many gas & oil fired powerplants offline, which significantly lowered the spot-prices at the European Energy Exchange.
Speaking at the Intersolar Europe 2012 trade fair in Munich, Germany, an expert panels of IEEE members, representing the world’s largest technical professional association dedicated to advancing technology, yesterday said that collaboration is key to develop the global solar energy marketplace. Solar capacity has more than quadruple between 2007 and 2010, rising from 9.5 gigawatts to 40 gigawatts.
Dr. Karl Weber, IEEE Member and Principal Expert Smart Grid, TUV Sud stated “Countries like Germany, US and China already have very good technical standards in place that support the growth of the solar market. They are also among the countries with the biggest investments to foster a rapid adoption and market penetration both among the business and household sectors. We need to share their experience with the rest of the world, especially with countries whose climate conditions are best suited for solar. Cooperation among all key market players, supported by international standards can definitely push this market to success”
Dr. Juris Kalejs, IEEE Member and CTO, American Capital Energy, emphasized that collaboration as the main ingredient in this recipe for success. ” innovation is a critical component to driving success in any industry but we are already looking at state of the art technologies in the renewable energy markets. We now need to work on preparing all markets to cope with this sophisticated level of innovation through international collaboration and cooperation. The smart grid will be critical to helping solar utilities understand where they need to distribute energy; by sharing best practices and data obtained through modelling, we can drive an efficient solar industry that works for all nations,” stated Dr. Kalejs.
“IEEE members are industry leaders around the world and drive discussion and partnership through our publications, conferences and workshops while leading the way with universally adopted standards that deliver more cost-effective and efficient solar implementation worldwide,” said IEEE President and CEO Gordon Day.
Without the Hot Air – A Down-to-Earth Analysis of how to make the UK Completely Sustainable
Sustainable Energy – Without The Hot Air is a book that helps to clarify many misconceptions about sustainable energy. It was written by David Mckay, Chief Scientific Advisor to the UK Department of Energy and Climate Change, the Regius Professor of Engineering at the University of Cambridge and a distinguished Fellow of the Royal Society. Professor McKay wrote this book in order to clear up confusion around the many options available for sustainable energy so that the UK public could make better decisions with respect to sustainable energy. He has devised a very simple way to do this. First, professor McKay employs a consistent and simple comparison tool throughout the book: a side-by-side red and green columns in which:
- red measures the energy consumed by typical usage of a common unsustainable technology (ie. car)
- green provides a measure of the output of sustainable energy technology
Second, the book employs units of energy measurements already familar to most people through their electricity bills: KWattsHours/day per person. By expressing various renewable technology outputs not as a large plant output figure in the megawatts (which is meaningless to an individual) instead, McKay employs a per-person figure that makes it understandable and relevant to the lay person.
Figure 14: Comparison of a few common energy loads and sources
(Source: Without the Hot Air Synopsis)
On the left:
- driving 50 km per day consumes 40 kWh per day,
- taking an annual long-range ﬂight by jet uses 30 kWh per day (averaged over the year)
On the right:
- covering the windiest 10% of Britain with onshore windfarms would yield 20 kWh per day per person
- covering every south-facing roof with solar water-heating panels would capture 13 kWh per day per person
- wave machines intercepting Atlantic waves over 500 km of coastline would provide 4 kWh per day per person
per person in “cartoon Britain 2008” (left two columns).
The current energy footprint is 125KWh/d. This is then compared to the 2 colums on the right which shows a future consumption plan based upon renewables and efficiency gains, along with a possible breakdown on the far right. In order to decrease fossil fuel usage, this plan requires that electricity supply be increased from 18 to 48 kWh/d per person to compensate.
(Source: Without the Hot Air Synopsis)
Figure 16: Comparison of 5 different possible scenarios to power the UK
(Source: Without the Hot Air Synopsis)
In this third example, five energy plans for Britain are examined. All these supply-side plans assume that demand has been substantially
reduced by efﬁciency savings in heating and transport. All of these plans call for reduction of energy demand by electrifying transport and heating (using heat pumps). Electric vehicles serve a second convenient function – the charging of their batteries is a large electricity demand that is easily turn-off-and-onable, so smart battery-charging would help match supply to demand in a renewable-heavy or nuclear-heavy electricity network.
The electriﬁcation of transport and heating requires a substantial increase in electricity generation. The ﬁve plans supply this required electricity using ﬁve different mixes of the carbon-free options. The mixes represent different political complexions:
- plan G, the Green plan, which excludes both “clean coal” and nuclear power,
- plan N, the NIMBY plan, makes especially heavy use of other countries’ renewables such as the Desertec project (see above),
- plan E, the Economist’s plan focuses on the most economical carbon-free choices: onshore wind farms, nuclear power, and a handful of tidal lagoons.
Figure 17: A map of renewable resources for scenario 6, the Middle Scenario
(Source: Without the Hot Air Synopsis)
This map of Britain shows a sixth plan which features every possible low carbon energy source, and lies roughly in the middle of the ﬁrst ﬁve, so McKay named it plan M (for “middle”) Plan M. A plan that adds up, for Scotland, England, and Wales.
- grey–green squares are wind farms. Each is 100 km2 in size and is shown to scale
- red lines in the sea are wave farms, shown to scale
- light-blue lightning-shaped polygons: solar photovoltaic farms –20 km2 each, shown to scale
- blue sharp-cornered polygons in the sea: tide farms
- blue blobs in the sea (Blackpool and the Wash): tidal lagoons
- light-green land areas: woods and short-rotation coppices (to scale)
- yellow-green areas: biofuel (to scale)
- small blue triangles: waste incineration plants (not to scale)
- big brown diamonds: clean coal power stations, with coﬁring of biomass, and carbon capture and storage (not to scale)
- purple dots: nuclear power stations (not to scale) – 3.3 GW average production at each of 12 sites
- yellow hexagons across the channel: concentrating solar power facilities in remote deserts (to scale, 335 km2 each). The pink wiggly line in France represents new HVDC lines, 2000 km long, conveying 40 GW from remote deserts to the UK
- yellow stars in Scotland: new pumped storage facilities
- red stars: existing pumped storage facilities
- blue dots: solar panels for hot water on all roofs
Space Based Solar Power (SBSP)
Figure 18: NASA Conceptual comparison of 1) laser and 2) microwave power transmission
Figure 23: NASA concept drawing for solar collector
One exotic solar technology that would circumvent the limited capacity of earthbound solar PV’s is Space Based Solar Power (SBSP) . This technology had its inception in 1973 when Peter Glaser was granted U.S. patent number 3,781,647 for his method of transmitting power over long distances (from space to earth) using microwaves from a very large antenna (up to one square kilometer) on the satellite to a much larger one, now known as a rectenna, on the ground. In 1974, NASA signed a contract with Glaser’s company,ADL which led 4 other companies in a study on SBSP.
- There is no air in space, so the collecting surfaces could receive much more intense sunlight, unobstructed by the filtering effects of atmospheric gasses, cloud cover, and other weather events. Consequently, collection in orbit is approximately 144% of the maximum attainable on Earth’s surface.
- A satellite could be illuminated over 99% of the time, and be in Earth’s shadow on only 75 minutes per night at the spring and fall equinoxes. Orbiting satellites can be exposed to a consistently high degree of solar radiation, generally for 24 hours per day, whereas surface panels can collect for 12 hours per day at most.
- Relatively quick redirecting of power directly to areas that need it most. A collecting satellite could possibly direct power on demand to different surface locations based on geographical baseload or peak load power needs.
- Elimination of plant and wildlife interference.
- The large cost of launching a satellite in to space
- Inaccessibility: Maintenance of a earth-based solar panel is relatively simple, but performing maintenance on a solar panel in space incurs the extra cost of transporting a team of astronauts into space.
- The space environment is hostile; panels suffer about 8 times the degradation they would on Earth. System lifetimes on the order of a decade would be expected, which makes it difficult to produce enough power to be economical.
- Space debris are a major hazard to large objects in space, and all large structures such as SBSP systems have been mentioned as potential sources of orbital debris.
- The broadcast frequency of the microwave downlink (if used) would require isolating the SBSP systems away from other satellites. GEO space is already well used and it is considered unlikely the ITU would allow an SPS to be launched.
the system had 3 major components:
- a means of collecting solar power in space, for example via solar concentrators, solar cells or a heat engine
- a means of transmitting power to earth, for example via microwave or laser
- a means of receiving power on earth, for example via a microwave antenna (rectenna)
Two basic methods of conversion have been studied:
- photovoltaic (PV) and solar dynamic (SD). Photovoltaic conversion uses semiconductor cells to directly convert photons into electrical power
- solar dynamic uses mirrors to concentrate light on a boiler. The use of solar dynamic could reduce mass per watt. Most analyses of SBSP have focused on photovoltaic conversion
Wireless power transmission was proposed early on as a means to transfer energy from collection to the Earth’s surface, using either microwave or laser radiation at a variety of frequencies.
The paper does not represent of the official US Army position on biofuels but reflects the concerns among US military experts based upon their experience from the numerous biofuel research projects conducted by various branches of the US Department of Defense. The paper argues that uncultivated biofuel yields are unable to displace any meaningful fraction of US primary energy needs,while increasing yields through cultivation actually consumes more energy than it adds to the biomass.
Kiefer’s argument hinges on EROI and his claim is that when all data sources are taken into account, the EROI of biofuel falls below energy starvation levels:
- food crop-based ethanol and biodiesel have EROI below 3:1,
- hydrotreated and cellulosic crop fuels have EROI of less than 0.7:1
From looking at the EROI charts above, we can see that Oil in the 1930’s had the highest EROI of all, 100:1. That high EROI has long since vanished. Energy sources with the highest EROI have traditionally include hydro power, coal, natural gas, oil and nuclear energy. Among the newer energy sources, reasonably high EROI levels that match or exceed the current US 12:1 average may be possible with solar, wind, geothermal, as well as wood and waste-derived energy. Tar sand fuels are estimated to have EROI of up to about 10:1. Biofuels are at the very bottom.
The low EROI of biofuels is due to high (petroleum) energy consumption in their mono-culture production. US-based corn ethanol has an EROI of ~ 1.25 because the nitrogen fertilizers used are ammonia-based, which is manufactured from natural gas. Hence, the life cycle of corn-ethanol is described as:
- transformation of high quality fossil fuel into an approximately equivalent amount of lower quality gasoline additive,
- releases significant CO2 emissions
- consumes significant quantities of water
Cost of Biofuels
- Energy Sprawl—Soy can produce 70 gallons of biodiesel per acre and corn 500 gallons of ethanol per acre, corresponding to a power density of only 0.069 W/m2 and 0.315 W/m2, respectively. Replacing the 28 exajoules of energy that the US uses every year for transportation with biodiesel would require 3.2 billion acres of soy—one billion more than all US territory including Alaska. Algae biodiesel has the highest potential power density of any biofuel, but its predicted best-case future performance is equivalent to today’s solar panels.
- “Green Grabbing”—Large amounts of cellulosic forest floor debris and cultivated crop residue stalks and leaves that are considered feedstocks for “2nd generation biofuels” are not truly waste that can be harvested for fuel, but are vital parts of the ecosystem that need to be left in place to conserve soil and water. Whatever fraction of biomass is removed from an ecosystem or farmer’s field instead of being left to compost and recycle is a loss that must eventually be replaced or the soil will be depleted. Another form of “green grabbing” are confiscations of land from poor villagers in Latin America, Africa and Asia to grow biofuel crops.
- GHG Emissions—The low EROI of biofuels also indicates high CO2emissions, while the use of nitrogen fertilizers to grow biofuel crops translates to high emissions of N2O—a GHG much more potent than CO2. In addition, very significant CO2 emissions can be released via indirect land use change (ILUC). Indonesia, for instance, became the world’s third CO2 emitter (after China and the United States) due to the burning of forest and peatland while converting jungle into palm plantations that supply the European biofuel demand.
- Competition of Fuel and Food—By putting an upward pressure on food prices, biofuels are becoming a threat to global food security, and thereby to global stability. For example, one of the underlying reasons of the “Arab Spring” uprisings was outrage at increasing food prices.
- Water Demand—Conventional gasoline has a water footprint of 2.3 to 4.4 liters of water per liter of ethanol equivalent energy (L/L). In contrast, global averages for biofuels range from sugar beet ethanol at 1,388 L/L, through corn ethanol (2,570 L/L), soy biodiesel (13,676 L/L) and rapeseed biodiesel (14,201 L/L) to jatropha biodiesel at 19,924 L/L. This level of water demand is not sustainable in a world that is facing water deficit. Countries that already rely on desalination of seawater—from Saudi Arabia to Spain—are spending one liter of ethanol equivalent energy to produce from 126 to 970 liters of water.
Having our Energy Cake and Eating it too
We are in an extremely difficult situation – or so it may seem. From the above analysis, we can see that it will be challenging to try to have our energy cake and eat it too. Can we really supply this amount of energy to 9 billion people and still have a far reduced which brings climate back into balance? Are these two not contrary to each other?
There is much talk about improving efficiencies as a way to lower ecological and carbon footprints but one thing that policy makers continually ignore is Jevon’s Paradox. This states that as technology is made more efficient, rather than decreasing consumption of energy, it actually increases it. The cheaper cost of energy supply has consistently been shown to create even higher energy demand which in the end cancels out any efficiency gains. This effect is also known as the Boomerang Effect.
Underpinning all of the above approaches to solving our energy problem is a BIG tacit assumption – that we must maintain our high energy lifestyle and in fact, extend it to many more people as the population increases. Is this really a valid assumption? We in the industrialized world have become addicted to a high energy lifestyle. We have made a fundamental error, mistaking non-essentials for necessities. And now, we cannot give them up; we cannot give up our “progress addiction”.
Table 2: Energy Densities/square meter of various Renewable Sources in the UK
(Source: David Mackay, Without the Hot Air)
Figure 19: Amount of money spent on Renewables by Different Countries
 IPCC: Greenhouse gas emissions accelerate despite reduction efforts – Many pathways to substantial emissions reductions are available. IPCC press release, April 13, 2014.