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The economics of power are not always what they seem. Here is a brief analysis of the relative economic merits of renewable energy and fuels for electricity production.
The coal industry has been telling us all that renewables are not ready yet. That renewables might be ok in the future and that they are limited. The reality is quite different and the economics are starkly in favour of renewables right now, as the Stern Report clearly identified. The really expensive option is to ignore climate change and keep burning coal and other fossil fuels.
Quite a few of the issues around the economics of power generation could do with some clarification and somewhat independent analysis. We mainly get highly partisan analysis provided by the advocates of some approach and rarely a broad spectrum view of the options available. I have made an attempt to surface some of the big issues that probably should be more widely understood.
The arithmetic is not the important thing because it is not a matter of calculating things to the 4th significant figure to know what needs to be done. It is sufficient to understand the big picture and the overall dimensions and leave the fine calculations to specific choices to do or not do a project.
Hydro-electricity
Clean Coal
At the risk of using a propaganda term we still need to understand the proposal to use coal as the solution to energy needs.
“Clean Coal” refers to two main things. Reducing the dirty emissions from burning coal (S02/Acid, dust and even radioactive materials). Reducing these emissions makes coal less environmentally damaging and was the main focus in the 1980s and 1990s when acid rain became a big problem in Europe. Newer coal powered generation is relatively clean in this sense.
The more recent meaning applied to “Clean Coal” is about the carbon emissions. It might better be described as carbon capture and storage. This ultimately says you expend an additional 30%-50% more energy to bury CO2 as it is emitted form the power station. The concept is simple but there are no working examples at industrial scale. Risks of this approach are largely unknown and the fundamental problem is that you keep burning fossil fuels that are running out anyway.
Hydro electricity is probably the most commonly understood renewable energy source. It has its place but there is a limit on how much of the wild river systems can be dammed and harnessed for electricity. We probably passed the limit well before the Five Gorges Dam.
Worth noting is that hydro-electricity storage is an important part of a total renewable energy package. You often hear people ask the pointed question “But can solar energy provide baseload power requirements?”. Clearly solar energy cannot operate effectively with no sunshine (night and poor weather) but, it CAN generate more than is needed when the sun shines and power pumping stations that efficiently store energy in the form of water to be used in hydro-power stations. In fact, this is a technique used in “baseload” coal stations to use surplus electricity generated overnight for use in peak demand periods.
Hydro power is a very low CO2 emitter in operation but large dams create a large carbon footprint when built. Other environmental damage is usually caused by damming rivers for hydro power that makes new hydro-power sources hard to find.
Wind turbines
Wind power is an enormous untapped resource. A lot of wind power is difficult to harness because it is irregular or out to sea. But, where it can be harnessed, it is a potentially great contributor to total energy production. A quick look around Holland shows that you can readily integrate agriculture, industry and living space with wind power. Denmark, Germany and other countries located in that region of Europe are rapidly increasing their wind generated power in response to global warming. Australia is severely lagging behind that. Globally, 1.5% of electricity is generated by wind power, but this was reported to have grown by a factor of nearly 5 over 6 years, between 2000 and 2006 and this is expected to double again by 2010. A growth rate of 20%+ per annum. Meanwhile Australia is introducing wind generation at less than 5% growth, despite favourable sites. See Crisis? for a discussion of why.
Now, lets think of the numbers here. There will be 160 Gw of electricity generated from the wind in 2010 on average all the time. That means around 2% of the expected demand then. The cost of wind generated power is going down as fossil fuel costs go up and that is before carbon trading kicks in. After that the economics are the proverbial no-brainer.
What is the available capacity of wind energy? It has been calculated at 72 Terra watt in a study at Stanford University.That is somewhat more than 5 times the estimated total electricity demand by the year 2020. The ramp up is obviously an issue but the raw capacity is definitely there.
For 1 Gwh of electricity (we have to multiply by hours to get energy from power output) of electricity is the same as burning about 450 tonnes of coal and producing 370 tonnes of Carbon (in the form of CO2 and CO plus small amounts of other carbon emissions) or about 900 tonnes of CO2 (more mass because of the oxygen molecules). The rest of the coal is waste and pollution like Sulphur and dust. Obviously these figures vary according to the efficiency of the power generation and the kind of coal used but it is a good median of the the current situation.
This means that we are looking at plenty of capacity to use wind and it is already economic to build wind power over coal powered stations. It is not the total solution to all our prolbems BUT, we COULD replace what we do now with just that one technology and not significantly lose any lifestyle or economic development. Wind produces 0.5% of the total CO2 that coal does in the total lifecycle of the generating plant. it is 1% of the CO2 of Gas generation which emits half the carbon of coal fired electricity generation and less pollution.
Electricity demand is shown in this link.
An analysis of Carbon Footprints of fuels is here. Also see … for my analysis of relative efficiencies and impacts of fuels.
Solar Photo-voltaic
Carbon Tax/Credits
Carbon emission trading, taxes and credits are a market mechanism designed to incorporate the social and environmental costs of burning fossil fuels (and other things like clearing forests) into the economic costing models. In the past it was assumed that social and environmental costs were negligible or beneficial. Climate Change and Global Warming have demonstrated the need to a more complete assessment of the economics.
The mechanism of using a Carbon Tax to incorporate carbon impacts into costing models is one of the recommended methods of delivering promises made in the Kyoto Protocol.
Solar photovoltaic generation is what people think of immediately for solar power. It makes sense that you can convert sunlight to electricity and that is immediately usable. Currently, this technology is expensive to produces, costly to install and uses scarce materials to manufacture. It works well and is great for remote powering of electrical equipment. Many new developments aim to bring the cost of this technology down and it is expected to follow Moore’s Law for technology for at least the next 30 years. Large scale generation methods are also in embryonic stages.
The most promising things about this technology is the near certainty that the cost will reduce dramatically and that newer materials will allow integrated building materials to be incorporated into building structures that can generate electricity. Such advances will be highly beneficial in drier and sunnier places such as Canberra where roofing materials can be turned into efficient power generators for more than 300 days of the year.
Right now the CO2 emissions from silicon photovoltaic cells are about 5% of coal powered generation due to the energy intensive manufacturing process. Installation costs are also very high because the panels are delicate and quite small, requiring several to be connected together to produce worthwhile output. Cost per Kwh is between 2-5 times that of coal fired electricity right now.
Solar photovoltaic power generation is not readily scalable to be used as utility power generation. Some research has suggested that PV combined with large scale concentrating mirrors might become economical but this is not in the near future and may require high temperature (superconduction at ~-50 Celsius) superconductors to be viable.
Solar Thermal
Solar thermal is already a technology that can be used to generate large amounts of electricity using steam just like coal fired or gas fired power. Its main limitation is that it is dependent on sunshine and cannot generate at night or heavy overcast days. It is however not short of energy. Each square meter of land receives 1 Kw of power from the sun when it is shining - this varies a bit but 1 Kw is a good average. That means that 1 sq Km can produce 1 Gw of power. a few hundred sq Km of solar generation can therefore produce most of the power needs of most countries.
Of course, there are issues with this. Ramp up time is going to be relatively slow. Most parts of the world do not have that much space to devote to power generation. BUT some DO. Arid regions that currently graze 1 animal per sq Km could easily be converted to power generation without economic loss. Environment considerations exist but not as great as many other issues. Certainly much less of an issue than global warming.
This kind of generation if located a long way from cities will lose efficiency in terms of transmission losses but the clearest advantage is that it can support energy intensive industries such as aluminium production in remoter areas. The essentially free and clean energy once these systems are in operation can greatly help to generate sustainable development in regional areas far from traditional power generation.
Many grid management issues exist and need to be solved, however, it is clear that solar thermal is economic and feasible and can be done now. As part of an overall approach to reducing carbon emissions, it seems a compelling option.
Geothermal
Geothermal power generation is another abundant source of energy. IT is not widely available but where it is available, it is extraordinarily efficient. Iceland is able to generate a quarter of its electricity and a large portion of its heating needs from geothermal (3 quarters is from hydro-power). In Australia, there are some outstanding sites for geothermal power that are yet to be seriously exploited.
The technology is not very new and the power source is nearly inexhaustible. Places like Hawaii and Indonesia may be able to harness this energy to generate highly sustainable industry and good working conditions in the tropics. Such developments could result in significant shifts in economic power.
Wave and tide
Waves and tides form another large untapped resource. The capital cost of building a power station to capture tidal and wave energy is high but the operation and maintenance is low.
Bio Waste
Eureka Tile
After the Great Depression, my father worked on a project to use 50% sawdust mixed into the bricks. They found that the bricks were lighter and did not lose much strength. AND they found that they could greatly reduce the amount of fuel needed to fire the bricks. All up, the cost of these bricks could be half that of normal bricks when transported. After the Depression, people forgot about this experiment because energy was plentiful and cost no issue anymore.
Using waste products for making bio-fuels is a different thing entirely from using food crops to make bio fuel as discussed here.
There are many agricultural and industrial activities that can make use of “waste” by-products to generate a little or a lot of energy. Garbage tips are in fact a major source of a potent greenhouse gas, methane. Capturing methane at a garbage tip is a good way to reduce that contributor to global warming. But! methane is just natural gas - the stuff we buy to cook with and heat water and our homes. A number of garbage management companies are now capturing that methane and using it as a fuel onsite and sometimes on-selling it as bottled gas.
Similar things apply in sewerage works, abattoirs, intensive farming and food processing. Waste products can be used to generate power to operate a processing plant, warm things up or be used elsewhere. Sugar cane producers typically burn cane and other vegetation. New techniques (re-invented from the depression era) make fuel grade alcohol and methane from the waste products instead of burning.
Building it
So, if there are so many options available and they seem so straight forward to implement what is the problem? The usual answers are:
- The technology is inefficient - we need to wait for better technology
- The cost is not competitive with coal, oil and gas
- It takes too long to build
- Solar energy is only produced during the day so it cannot produce baseload power
- There is no skills base to build and manage it (ie the grid is not capable of taking it)
The efficiency issue is moderately true. However, there is no impediment to solar thermal. It is quite efficient already and more efficiency is possible. Given the enormous resource going to “waste” right now, what is the problem? It is not like burning fossil fuels where inefficient processes lose the value. You are getting the sunlight for free. Other technologies like PV will become more competitive when they are more efficient (as with all generation methods)
Electric vehicle charging from solar
If there is so much solar energy out there what else can we do with it?
Perhaps the answer lies in how we run cars in the future. Electric cars are already in use and the biggest issue is how to charge them up. Charging is needed in the middle of the day and overnight for most commuters so this is not too bad for renewables. The more solar generated electricity gets used to charge car batteries the better overall efficient. A change in tariff arrangements is needed but the economics are sound.
It seems to be a better solution to the oil crisis than cutting down rainforest to grow palm oil for cars.
Cost competitiveness is hotly debated, the Garnaut Review in Australia shows quite clearly that the “hidden” costs of burning fossil fuels will be borne by the community and not the polluters. When you add that cost you get a much more favourable cost for renewables. Solar generation becomes much more competitive and wind is already competitive in many parts of the country. As economies of scale build and the grid is adapted to the differing profiles of renewable power generation and more sophisticate control mechanisms are built in then those problems will not be problems anymore. They will, instead become major opportunities to become more efficient.
Carbon tax/credits make the whole renewables pricing structure a complete new equation. In less than 3 years it has gone from uncompetitive to very competitive and that trend will only continue as fossil fuels are depleted and the cost of carbon emissions is fully added in to energy costs.
The baseload power argument is a furphy. IT is a coal power plant term that reflects the limitations of coal fired generation. Coal must keep burning even at night to generate power even when ther is no demand for it. This is why off-peak electricity is cheaper (water heating and industry) to encourage use of electricity at night. Peak generation during daylight hours is in fact beneficial. These days the peak demand comes from airconditioning at exactly the time the sun is shining brightest. Wind generation is variable but happens at any time the peaks tend to be around dawn and dusk which suit the domestic demand for electricity at these times.
In california they are building a 177 Mw solar thermal power station in about 7 months. That will power about 120,000 homes (36 Kwh per day on average). This is not very slow compared to building hydro, coal or nuclear generation that takes many years of construction and infrastructure to transport fuel. Solar and wind fuel comes to you. All you need is a connection to the grid to produce power. That means that the management issue is actually less of a problem overall. Managers can concentrate on electricity rather than other things.
It is not economics that is stopping renewable energy. It is not a lack of sound technology. It is a combination if self interest and denial that prevents rapid implementation of renewable energy sources. Germany and other western European nations are showing the way, now it is up to the USA, Australia, China and India to take the next steps and make renewable energy the mainstream.