The science on climate change is settled, although there are some who still do not recognize or accept the problem. * So far, the planet has warmed .8 degrees celsius as a global average since the start of the industrial revolution. Experts tell us that– to avoid catastrophic consequences– we must keep from warming more than 2C.
The big problem is that we are headed for at least a 4C (7.6 Fahrenheit) rise in global temperature. 4C is alarming. But we could also race right past 4C. The fossil fuel industry tells us that the known reserves of the world contain five times the amount of greenhouse gases required to reach the 2C mark.
Unless we move away from fossil fuel consumption, we will create an instability to our climate systems that will make it much more difficult and expensive to live on this planet. Predictability and stability in our weather patterns is one of the fundamental tenets of our civilization, as important to humanity’s existence as the development of agriculture, organized religion, the rule of law, or a written language.
- Electrical grid transitioned to renewable sources: wind, water, solar. Nuclear power emits no GHG, but has other drawbacks.
- Move society’s energy use to the grid: electric cars, electric trains, fully electric houses and buildings, shipping and transport.
- Build renewable infrastructure in developing countries
- Reduce consumption and waste
There is much to be worked out in the transition to renewable energy sources, but the best thing we can do is implement the technology we presently have while solving the rest of the variables in a clean energy economy.
Both fossil fuels and renewable energy sources have their attributes and their limitations. Fossil fuels are light, fast, cheap, portable, and powerful. FF’s can do things that renewable sources cannot. We have no means, at this point, to get an airplane off the ground using electricity, and even if we could, we have no means of storing enough electrical energy for a flight from one city to another. Cars can run on electricity, and light trucks can run on hybrid systems, but large trucks that haul goods and heavy construction machinery need fossil fuel. Same goes for ships.
Fossil fuels can produce energy on demand. This is perhaps their biggest attribute, and their best advantage over renewables.
Fossil fuels require centralization. This is their second biggest limitation.** Petroleum, coal and natural gas need to be extracted from the ground, usually in a remote area. Petroleum and gas need to be refined, then shipped to a central distribution point. Coal requires little refinement, but large coal plants are preferable because they need large amounts of water to cool their systems. Plants tend to ship their electricity long distances, and 6-8% of electrical power is lost in transmission, making the plant less efficient and adding even more CO2 to our atmosphere.
The big limitation of renewable energy is the problem of intermittence. No solar energy when the doesn’t shine, and no wind power when it’s calm. Hydropower can produce energy on demand by increasing water flow, but this is a slow process. Much of the problem of intermittence can be averted by solving the problem of storage.
All the existing batteries in the world have the capacity to store merely 10 minutes of the world’s electricity needs, according to a report commissioned by Bill Gates.
Battery technology has made good breakthroughs in the past ten years, but the concentration has been on small batteries for devices like phones and pads. Breakthroughs in large, and even medium sized, electrical storage can greatly enhance the performance of renewable energy, especially wind and solar. Tesla, the electric auto company, has made some remarkable advancements in a car batteries; doing things the major auto manufacturers believed were impossible. Hopefully, some of their new technology can translate to renewables. Elon Musk, Tesla’s CEO, plans a $5 billion battery factory to be built in one of four southwestern states, possibly starting construction this year. Musk hopes to drive down the cost of its 60 kilowatt-hour battery pack by 30 percent, to about $10,000. This could make a major impact on the distributed storage industry. Musk also plans to power much of his plant with solar panels and wind turbines.
Without some major technological breakthroughs, it will not be possible (nor would it be a good idea) to eliminate fossil fuels completely. Their use, however, can be greatly reduced. Here is a simple sampling of the renewable energy options presently available.
Wind is the fastest growing renewable energy source, and it has the potential to produce more electricity than any other renewable source. In 2010, according to the World Wind Energy Association, wind power generated 430 TWh or about 2.5% of worldwide electricity usage. Between 2005 and 2010 the average annual growth in new installations was 27.6%. Wind power market penetration — world wide– is expected to reach 3.35% by 2013 and 8% by 2018. The United States pioneered wind farms in the 1980’s, primarily in California, and led the world in capacity into the 1990s. Germany surpassed the U.S. in 1997. China also has a growing wind capacity, and in 2010 they became the world leader.
Wind farms have a number of inconspicuous benefits. A wind farm launched in 2014 in Elgin, NE created 17 good paying jobs. This is a big deal is a town on 645 people. Farms also generate tax revenue in depressed areas, which makes them big supporters of public education.
Another discrete value of renewables is that they use no water.
A typical coal plant with a once-through cooling system consumes 0.36 to 1.1 billion gallons of water. A typical coal plant with a wet-recirculating cooling system withdraws much less water each cycle, but over the course of a year consumes 1.7 to 4.0 billion gallons. A dry-cooled system still consumes water, but much less. When water is drawn into a coal power plant, millions of fish eggs, fish larvae, and juvenile fish travel along with it. In addition, millions of adult fish may become trapped against the intake structures. Many of these fish are injured or die in the process.
A common complaint about wind farms is that birds and bats collide with turbines and die. More birdlife dies by colliding with stationary buildings than moving turbines, and wind power consumes no water during operation or hurts any fish.
Wind power works best as a centralized source because it requires significant and consistent wind to reach productive levels. Wind farms are effective when located in exceptionally windy spots, and away from populated areas where the noise can be a nuisance. A small turbine can produce useful power for a home, if zoning and property size allow one to be mounted high enough off the ground, usually 80 feet and preferably 100 feet in the air.
Solar power is the most applicable to residential housing. A 5 kilowatt array can typically supply half an normal household’s electrical use. Some houses have too much shade from trees or other buildings to make solar effective, however there are now solar gardens which allow consumers to purchase electricity from a source in their neighborhood, even their block.
Solar panels came onto the market in the 70’s, and the ones that have not been damaged are still producing energy. Because of reduction in product cost and rise in energy cost, solar can now compete in some markets on a per dollar basis with fossil fuels. There cost of solar panels has come down 80% in the past ten years. This is a big moment in the solar industry. Marketing of solar is often centered around how it can pay for itself in ten years. But what happens when those ten years expire? Most solar installations have a 25 warranty, and there can be some maintenance costs. Otherwise, after 10 years, solar energy is free— NO COST. Let’s see fossil fuel do that.
Electricity coming from centralized sources loses 6-8% in transmission. With Minnesota’s goal of 25% of its energy from renewable sources by 2025, a loss of 8% is a big swing. Transmission loss from rooftop to basement or garage is minimal, and since there is no carbon emitted in the production, it’s also without significance to Climate Change.
Net metering laws are very important to the solar industry. Net metering allows the grid to be used for storage, and most of a solar house’s energy is produced during the day while most of it is consumed in the evening. Depending on area of the country, solar arrays are less productive in the winter than the summer. Snow cover and low sun angle reduce output. In Minnesota, a rooftop array will typically make most of it annual production during the warm months and feed energy into the grid, then draw that energy back during the cold months.
There are two main types of solar panels, Photovoltaic (PV) and solar thermal. PV creates electricity, and solar thermal produces hot water, which can be used for bathing and washing but also to produce energy. Solar thermal is very effective water warming system, and it’s especially useful in warmer climates where a large portion of household energy use goes to water heating. In Hawaii, solar thermal installation is a code requirement in a new house, and a builder must obtain a variance to avoid installing it (typically due to shade problems).
Biomass has been successful at reducing emissions, but there is some controversy about how much fossil fuel is used to produce it. Like ethanol, as a source of energy it is relatively clean. But its embodied energy (the amount consumed in the creation of the product) can be high, which offsets its value.
In Sweden, the city of Kalmar (population of 60,000) has achieved carbon neutrality by generating all its electricity from biomass, mostly in the form of waste timber and sawdust which they get from surrounding sustainable forests. The third largest city in Sweden, Malmo, has reduced it carbon emission to under 10 percent by combining biomass with wind and solar energy.
Biomass can consist of a number of plant and animal products, including waste from a lumber mill, fast growing plants like switchgrass, and even chicken manure and other livestock waste. The collection and transport of these products usually involves petroleum propelled machines. In Kalmar, all vehicles on the roads are required to run on Biogas (made from waste wood and some chicken manure). However, to balance their needs, the residents use ethanol imported from Brazil, which means it travels by ocean freighter.
Biomass can be burned like coal, which makes its inclusion in a coal fired plant relatively cheap. Converting a coal plant to biomass is also an option.
Geothermal, like wind power and solar, can be both a household power source or centralized. Iceland has a wealth of geothermal activity and derives a lot of its power from Geothermal plants like the one pictured.
In a home, geothermal is optimally installed when the house is built because it involves burying tubes deep in the ground or under a large area of land. Below the frostline, ground temperature is a relatively consistent 58 degrees. Geothermal Heat Pumps move liquid through the buried tubes. The liquid changes temperature as it travels, and this conversion creates energy. Installing a geothermal heat pump is an expensive home investment, but there are state and federal incentive programs. Heat pumps use electricity to move the liquid, but their energy use is minimal compared to a furnace. Supplementing with solar can make the system completely renewable.
Geothermal can be added to an existing home by digging a well for pipes, as long as the machinery involved can access the property.
Hydroelectric is considered one of the forms of hydropower. Because it is well established and a centralized macro source, it is separated here. Dams use descending water to turn turbines that generate electricity. 16% of the world’s electricity is created this way, making it presently the most productive renewable source. The first Hydroelectric generator went online in Niagara Falls in 1881. Presently, Hydroelectric supplies about 6.4% of America’s total electricity.
Large scale hydroelectric can create a number of serious environmental and social problems. By blocking rivers and streams, dams cause habitat destruction, prevention of fish passage, and displacement of local communities. If done right, however, hydropower can have minimal impact on the environment, usually involving a smaller scale generating system. The Low Impact Hydropower Institute (LIHI) has developed a voluntary certification program for new projects. Criteria standards are based on the most recent and stringent mitigation measures recommended by state and federal agencies.
There are a number of experimental hydropower sources being developed today, including using wave power and tidal power to generate electricity. Hydropower can be very useful in solving the inherent problems with wind and solar power– intermittence and storage.
Wave power has been experimented with for over 100 years, and it is creating new interest now. It uses a machine called a Wave Energy Converter. In 2008, the first experimental wave farm was opened in Portugal, at the Aguçadoura Wave Park.
Tidal power is produced through the use of tidal energy generators. Large underwater turbines are placed in areas with high tidal movements. They capture the kinetic motion of the ebbing and surging of ocean. Tidal power has great potential because of the massive size of the oceans.
Hydroelectric generation can also work without dams, in a process known as diversion, or run-of-the-river. Portions of water from fast-flowing rivers can be diverted through a penstock to a turbine set in the river or off to the side. The generating stations at Niagara Falls are an example of diversion hydropower. Another design uses a traditional water wheel on a floating platform to capture the kinetic force of the moving river. Unfortunately, this doesn’t produce much power. The entire Amazon River would produce only 650 MW of power.
Another type of hydropower, though not a true energy source, is pumped storage. In a pumped storage plant, water is moved from a lower reservoir to a higher reservoir during off-peak times, using electricity generated from other types of energy sources (preferably renewable). When the power is needed, it is released back into the lower reservoir through turbines. Some power is lost, but pumped storage systems can be up to 80 percent efficient. There is currently more than 90 GW of pumped storage capacity worldwide, with about one-quarter of that in the United States. Future increases in pumped storage capacity could result from the integration of hydropower and wind power technologies. Researchers believe that hydropower may be able to act as a battery for wind power by storing water during high wind periods.
* Yale Project on Climate Change Communication: At present, only one in ten (12%) Americans understand that 90% or more climate scientists have concluded that human-caused climate change is happening. Recent research has found that this public misunderstanding about the degree of scientific consensus is highly consequential: public perceptions of the scientific consensus appear to influence public beliefs that global warming is happening, human-caused and a serious problem that requires public action and legislative support. – See more at: http://environment.yale.edu/climate-communication/article/how-to-communicate-the-scientific-consensus-on-climate-change/#sthash.wudUBsZn.dpuf
**Fossil Fuels’ biggest limitation is that they are choking the life out of the planet. Details of this are covered in other areas of the website.
Resources for this page include: Union for Concerned Scientists, US Green Building Council, TED talks, teslamotors.com, Powerfully Green (powerfullygreen.com), Jim Logan Architects (jlogan.com), World Wind Energy Association, Rolling Stone magazine, New York Times, Washington Post, US Dept. of Energy, fresh-energy.org, and Wikipedia.